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+# Windows Port Handoff
+
+## What this project is
+
+`iai-personal-memory-engine` (repo at `C:\Users\Daniel Hertz\Documents\GitHub\iai-personal-memory-engine`)
+is a local MCP server that gives Claude Code persistent long-term memory across sessions.
+It captures every conversation, builds a personal model of the user, and injects relevant
+context at session start — automatically. It is Python + Rust (PyO3), with a Node.js MCP wrapper.
+
+It was macOS-only. We are porting it to Windows.
+
+## What has already been done (Step 1 — committed)
+
+**Commit:** `1dc1d64` — "Add platform-agnostic IPC transport layer for Windows porting"
+
+Created `src/iai_mcp/_ipc.py` — a platform-agnostic IPC abstraction module.
+
+- On POSIX: delegates to the existing Unix-domain socket at `~/.iai-mcp/.daemon.sock`
+- On Windows: uses TCP loopback `127.0.0.1:<ephemeral port>`, port stored in `~/.iai-mcp/.daemon.port`
+
+Updated all 9 callsites that previously used raw `asyncio.open_unix_connection` /
+`asyncio.start_unix_server` / `socket.AF_UNIX`:
+- `src/iai_mcp/concurrency.py`
+- `src/iai_mcp/socket_server.py`
+- `src/iai_mcp/cli/__init__.py`
+- `src/iai_mcp/core/__init__.py`
+- `src/iai_mcp/direct_write.py`
+- `src/iai_mcp/daemon/_watchdog.py`
+- `src/iai_mcp/doctor/_lifecycle_checks.py`
+- `src/iai_mcp/doctor/__init__.py`
+- `src/iai_mcp/semantic_recall.py`
+
+## Completion Status
+
+**Steps 1-7: COMPLETED** ✅
+
+- **Step 1** (`1dc1d64`): Platform-agnostic IPC (Unix sockets → TCP loopback on Windows)
+- **Step 2** (`8154b9b`): fcntl file locking → `_filelock.py` shim
+- **Steps 3+4+9** (`c009736`): POSIX signals, resource module, CLI daemon logging
+- **Steps 7+10** (`8ecd257`): uid/geteuid guards, os.fchmod guards, icacls file security
+- **Step 5** (`0e8321c`): Windows Task Scheduler daemon installer (schtasks.exe)
+- **Step 6** (`f4865bf`): PowerShell hook equivalents (.ps1 scripts + hook installer updates)
+- **Step 7 — bench files** (`59839a3`): `resource.getrusage()` → psutil `peak_wset` on Windows;
+  POSIX path unchanged. All four bench files (`memory_footprint.py`,
+  `memorygraph_memory.py`, `consolidation_rss_peak.py`, `embed_warm_cost.py`)
+  now import cleanly on Windows.
+- **Fix** (`13808e1`): `lifecycle_event_log.py` was importing `timedelta` /
+  `timezone` from `iai_mcp._filelock` (regression from the Step 2 rewrite).
+  Moved them back to the `datetime` import. Was broken on ALL platforms, not
+  just Windows — surfaced only when we exercised the full import chain.
+- **Help text** (`019e52f`): `daemon install` / `uninstall` / `start` / `stop` /
+  `logs` argparse help now lists the Windows backend (Task Scheduler / schtasks /
+  `%APPDATA%\\iai-mcp\\logs`) alongside launchd and systemd.
+
+## Verified on Windows in-situ (this session)
+
+Running from `C:\\Users\\Daniel Hertz\\Documents\\GitHub\\iai-personal-memory-engine`
+with system Python 3.14 (no venv, no full project install):
+
+- All 23 files touched by the port: **AST parse clean**.
+- 10/10 ported runtime modules (excluding ones that need numpy/hnswlib at
+  import-time): **import clean** on Windows.
+- `python -m iai_mcp.cli --help`: **lists all subcommands**, no crash.
+- `python -m iai_mcp.cli daemon install --dry-run`: **emits a valid Task
+  Scheduler XML** with the right user, pythonw path, log dir, and LogonTrigger.
+  XML file write uses `encoding="utf-16"` — schtasks-compatible.
+- `python -m iai_mcp.cli capture-hooks status`: **detects all three `.ps1`
+  hook templates** in the source tree, reports the expected
+  `~/.claude/hooks/*.ps1` install paths and "NOT WIRED" status.
+
+Cosmetic only (not blocking): the em-dash in the schtasks XML description
+renders as `�` when printed to a cp1252 console, but the file written to
+disk for `schtasks /Create /XML` is UTF-16 and round-trips fine.
+
+## What remains
+
+**Nothing — the port is COMPLETE and verified end-to-end (see below).**
+
+The full venv E2E run (`pip install -e ".[dev]"` → Rust extension + numpy +
+hnswlib, then `daemon install` / `capture-hooks install` / live daemon start)
+was carried out. It passed, but only after fixing three real runtime bugs that
+the earlier AST-parse and import-only checks could not catch — the port was not
+actually working before that run.
+
+## End-to-end verification (COMPLETE)
+
+Run from the venv (Python 3.12.10) on Windows 11:
+
+- Rust `iai_mcp_native.*.pyd`, numpy, hnswlib: **import clean**.
+- Daemon starts via **all three** paths — direct `python -m iai_mcp.daemon`,
+  detached `pythonw`, and the production **Task Scheduler** task — reporting
+  `ok: True`, state WAKE, with a valid `~/.iai-mcp/.daemon.port` written.
+- State-save survived **20 concurrent `daemon status` readers** with zero tick
+  failures (previously failed within seconds).
+- Hooks wired in `~/.claude/settings.json` (Stop / UserPromptSubmit /
+  SessionStart), all pointing at `.ps1` scripts.
+- `tests/test_cli_daemon.py`: **32 passed, 2 skipped** (was 27 passed,
+  7 failed); 78 passed across all touched modules.
+
+### Bugs found and fixed during the E2E run
+
+1. **`lifecycle_lock._is_pid_alive` used `os.kill(pid, 0)`** — the POSIX
+   liveness idiom. Windows `os.kill` rejects signal 0 with `WinError 87`, so
+   the daemon crashed on startup whenever a stale `.locked` was present (i.e.
+   after every reboot/relaunch). Guarded the probe to POSIX; Windows relies on
+   the psutil refinement that already followed.
+2. **schtasks XML `<WorkingDirectory>` with spaces** — set to `%APPDATA%\iai-mcp\logs`
+   under `C:\Users\<First Last>\...`. The Task Scheduler engine rejects an
+   XML-set working directory containing spaces with `0x8007010B`
+   ("directory name is invalid"), so the task never launched even though the
+   path exists. Removed the element (the daemon never depends on cwd).
+3. **`daemon_state.save_state` `os.replace` reader contention** — on Windows
+   `os.replace` (MoveFileEx) fails with `WinError 5`/`32` (→ `PermissionError`)
+   when a concurrent reader holds the destination open without
+   `FILE_SHARE_DELETE`, which Python's `open()` does not request. Every
+   scheduler tick was failing. Added a short Windows-only retry loop.
+
+Plus: `tests/test_cli_daemon.py` fixtures were POSIX-only (fake daemon used
+`asyncio.start_unix_server`; two stop tests referenced `signal.SIGKILL`).
+Ported the fake daemon to the `_ipc` transport (TCP loopback + port file on
+Windows) and skipped the SIGKILL-escalation tests on Windows.
+
+Commits: `7b13793` (lifecycle_lock), `9ced147` (schtasks WorkingDirectory),
+`1edccb3` (daemon_state replace retry), `5d26920` (test fixtures).
+
+### Bench Files — resource.getrusage() (OPTIONAL — not required for daemon)
+
+Lower priority, affects only benchmarking tools (not runtime code).
+
+`fcntl` is POSIX-only. On Windows, importing any of these files raises `ModuleNotFoundError`.
+
+Files to fix:
+- `src/iai_mcp/capture_queue.py` — uses `fcntl.flock()`
+- `src/iai_mcp/hippo/_db.py` — uses `fcntl.flock()`
+- `src/iai_mcp/lifecycle_event_log.py` — uses `fcntl.flock()`
+- `src/iai_mcp/lifecycle.py` — uses `fcntl.flock()`
+- `src/iai_mcp/lock_protocol.py` — uses `fcntl.flock()`
+- `src/iai_mcp/doctor/_lifecycle_checks.py` — uses `fcntl.flock()`
+
+**Fix:** Create `src/iai_mcp/_filelock.py` that provides a `flock(fd, operation)` shim:
+- On POSIX: delegates to `fcntl.flock(fd, operation)`
+- On Windows: uses `msvcrt.locking()` with appropriate size (use `os.path.getsize` or a large constant like `2**31 - 1`)
+
+Example shim:
+```python
+import platform, os
+if platform.system() == "Windows":
+    import msvcrt
+    LOCK_EX = 1; LOCK_SH = 2; LOCK_UN = 4; LOCK_NB = 8
+    def flock(fd, operation):
+        if isinstance(fd, int):
+            raw = fd
+        else:
+            raw = fd.fileno()
+        if operation & LOCK_UN:
+            try: msvcrt.locking(raw, msvcrt.LK_UNLCK, 2**30)
+            except OSError: pass
+        elif operation & LOCK_EX:
+            mode = msvcrt.LK_NBLCK if (operation & LOCK_NB) else msvcrt.LK_LOCK
+            msvcrt.locking(raw, mode, 2**30)
+        elif operation & LOCK_SH:
+            mode = msvcrt.LK_NBLCK if (operation & LOCK_NB) else msvcrt.LK_LOCK
+            msvcrt.locking(raw, mode, 2**30)
+else:
+    import fcntl as _fcntl
+    LOCK_EX = _fcntl.LOCK_EX; LOCK_SH = _fcntl.LOCK_SH
+    LOCK_UN = _fcntl.LOCK_UN; LOCK_NB = _fcntl.LOCK_NB
+    def flock(fd, operation):
+        _fcntl.flock(fd, operation)
+```
+
+Then in each affected file, replace:
+```python
+import fcntl
+...
+fcntl.flock(fd, fcntl.LOCK_EX)
+```
+with:
+```python
+from iai_mcp._filelock import flock, LOCK_EX, LOCK_SH, LOCK_UN, LOCK_NB
+...
+flock(fd, LOCK_EX)
+```
+
+---
+
+### Step 3 — resource module (CRITICAL — daemon crashes on import)
+
+`resource` is POSIX-only. `src/iai_mcp/daemon/__init__.py` imports it at the top level.
+
+Files to fix:
+- `src/iai_mcp/daemon/__init__.py` — `resource.getrlimit()`, `resource.setrlimit()`
+
+**Fix:** Wrap in a platform guard:
+```python
+import platform as _platform
+if _platform.system() != "Windows":
+    import resource as _resource
+    def _raise_fd_limit():
+        soft, hard = _resource.getrlimit(_resource.RLIMIT_NOFILE)
+        if soft < 4096:
+            _resource.setrlimit(_resource.RLIMIT_NOFILE, (min(4096, hard), hard))
+else:
+    def _raise_fd_limit():
+        pass  # Windows manages FD limits via OS handles
+```
+
+Also fix in bench files (lower priority, bench-only):
+- `bench/memory_footprint.py`, `bench/embed_warm_cost.py`, `bench/consolidation_rss_peak.py`,
+  `bench/memorygraph_memory.py` — use `psutil.Process(os.getpid()).memory_info().rss` instead
+  of `resource.getrusage(resource.RUSAGE_SELF).ru_maxrss`
+
+---
+
+### Step 4 — POSIX signals (CRITICAL — daemon crashes on Windows)
+
+`signal.SIGHUP`, `signal.SIGKILL` do not exist on Windows.
+
+Files to fix:
+- `src/iai_mcp/daemon/__init__.py` — registers SIGHUP handler; calls SIGTERM/SIGKILL
+- `src/iai_mcp/daemon/_watchdog.py` — `os.kill(os.getpid(), signal.SIGKILL)`
+- `src/iai_mcp/cli/_daemon.py` — `os.kill(pid, signal.SIGTERM)` / `SIGKILL`
+- `src/iai_mcp/doctor/__init__.py` — `os.kill(pid, signal.SIGTERM)`
+
+**Fix:**
+```python
+import platform, signal, os
+
+def _terminate_process(pid: int, graceful: bool = True) -> None:
+    if platform.system() == "Windows":
+        os.kill(pid, signal.CTRL_C_EVENT)
+    else:
+        sig = signal.SIGTERM if graceful else signal.SIGKILL
+        os.kill(pid, sig)
+
+# For SIGHUP registration, guard it:
+if hasattr(signal, "SIGHUP"):
+    signal.signal(signal.SIGHUP, _reload_handler)
+```
+
+For `os.kill(os.getpid(), signal.SIGKILL)` (self-termination in watchdog), replace with
+`sys.exit(1)` on Windows.
+
+---
+
+### Step 5 — Daemon installer: Windows Task Scheduler (MAJOR)
+
+`iai-mcp daemon install` only supports launchd (macOS) and systemd (Linux).
+It needs a Windows backend.
+
+File: `src/iai_mcp/cli/_daemon.py`
+
+Add `_is_windows()` guard and implement `cmd_daemon_install_windows()` that:
+1. Uses Python's `subprocess` to call `schtasks.exe` — the built-in Windows Task Scheduler CLI.
+2. Creates a task that runs `pythonw.exe -m iai_mcp.daemon` at login, hidden.
+3. Writes a `WINDOWS_SERVICE_TARGET` path constant analogous to `LAUNCHD_TARGET`.
+
+Example schtasks command:
+```
+schtasks /Create /SC ONLOGON /TN "iai-mcp-daemon" /TR "pythonw.exe -m iai_mcp.daemon" /RL HIGHEST /F
+```
+
+Also implement `cmd_daemon_uninstall_windows()`:
+```
+schtasks /Delete /TN "iai-mcp-daemon" /F
+```
+
+And `cmd_daemon_start_windows()` / `cmd_daemon_stop_windows()`:
+```
+schtasks /Run /TN "iai-mcp-daemon"
+taskkill /F /IM pythonw.exe /FI "WINDOWTITLE eq iai-mcp-daemon"
+```
+
+Wire these into the existing `cmd_daemon_install()` dispatch block alongside the
+`_is_macos()` and `_is_linux()` branches.
+
+---
+
+### Step 6 — Shell hooks: PowerShell equivalents (MAJOR)
+
+Claude Code on Windows does not run `.sh` hook scripts. The three hooks need `.ps1` equivalents.
+
+Hooks are in `src/iai_mcp/_deploy/hooks/`:
+- `iai-mcp-turn-capture.sh` — appends each prompt+response turn to per-session buffer
+- `iai-mcp-session-capture.sh` — at session end, rolls the buffer for the daemon
+- `iai-mcp-session-recall.sh` — at session start, pipes cached memory prefix to stdout
+
+**Fix:** Create `.ps1` versions of each that call the Python CLI equivalents:
+```powershell
+# iai-mcp-turn-capture.ps1
+$python = (Get-Command python).Source
+& $python -m iai_mcp capture-turn @args
+```
+The Python CLI already has `capture-transcript`, `session-start` subcommands —
+the PowerShell hooks just need to call them.
+
+Also update `src/iai_mcp/cli/_capture.py`'s `cmd_capture_hooks_install()` to:
+1. Detect Windows and copy `.ps1` files instead of `.sh` files
+2. Patch `~/.claude/settings.json` hooks to reference `.ps1` paths on Windows
+
+---
+
+### Step 7 — os.getuid / pwd module guards (MODERATE)
+
+`os.getuid()` and the `pwd` module are POSIX-only.
+
+Files to fix:
+- `src/iai_mcp/crypto.py` — `os.geteuid()` at line ~121
+- `src/iai_mcp/cli/_crypto.py` — `st.st_uid == os.geteuid()` at line ~39
+- `src/iai_mcp/hippo/__init__.py` — `pwd.getpwuid(os.getuid()).pw_dir` at line ~54
+
+**Fix:**
+```python
+# For ownership checks:
+if hasattr(os, "geteuid") and st.st_uid != os.geteuid():
+    raise PermissionError(...)
+
+# For home directory (hippo/__init__.py):
+# Replace pwd.getpwuid(os.getuid()).pw_dir with:
+home = str(Path.home())
+```
+
+---
+
+### Step 8 — Rust build: disable macOS-only features (MODERATE)
+
+`rust/iai_mcp_embed_core/Cargo.toml` has `accelerate` and `metal` features
+(Apple Accelerate framework and Apple Metal GPU). These fail to compile on Windows.
+
+**Fix:** In `pyproject.toml` (the setuptools-rust build config), add platform-conditional
+feature flags. Find the `[[tool.setuptools-rust.ext-modules]]` section and add:
+
+```toml
+[[tool.setuptools-rust.ext-modules]]
+target = "iai_mcp_native"
+path = "rust/iai_mcp_native/Cargo.toml"
+binding = "PyO3"
+features = ["extension-module"]
+args = ["--no-default-features"]
+```
+
+This already disables default features. Verify `accelerate` and `metal` are not in the
+default feature set of `Cargo.toml`. If they are, add a `[target.'cfg(target_os = "macos")'.dependencies]`
+section in `Cargo.toml` to gate them.
+
+---
+
+### Step 9 — Log paths and temp dirs (MINOR)
+
+`src/iai_mcp/cli/_daemon.py` uses `~/Library/Logs/` for daemon logs (macOS-specific).
+
+**Fix:** Add `_get_daemon_log_path()`:
+```python
+import platform
+def _get_daemon_log_path() -> Path:
+    if platform.system() == "Darwin":
+        return Path.home() / "Library" / "Logs" / "iai-mcp-daemon.stderr.log"
+    elif platform.system() == "Windows":
+        return Path(os.environ.get("APPDATA", Path.home())) / "iai-mcp" / "logs" / "daemon.log"
+    else:
+        return Path.home() / ".local" / "share" / "iai-mcp" / "logs" / "daemon.log"
+```
+
+---
+
+### Step 10 — chmod security for crypto key (MINOR)
+
+`src/iai_mcp/crypto.py` calls `os.chmod(key_file, 0o600)` to restrict the encryption key.
+On Windows, `chmod` is a no-op for access control. Use `icacls.exe` instead:
+
+```python
+import platform, subprocess
+def _secure_key_file(path: Path) -> None:
+    if platform.system() == "Windows":
+        user = os.environ.get("USERNAME", "")
+        subprocess.run(
+            ["icacls", str(path), "/inheritance:d", "/grant:r", f"{user}:F"],
+            check=False, capture_output=True,
+        )
+    else:
+        path.chmod(0o600)
+```
+
+---
+
+## Next Steps (for the next session)
+
+The core daemon + hook infrastructure is now Windows-ready, and bench files
+no longer crash on Windows import. Remaining work:
+
+1. **Manual testing on Windows:** Verify the port works by:
+   ```powershell
+   cd "C:\Users\Daniel Hertz\Documents\GitHub\iai-personal-memory-engine"
+   python -m venv .venv
+   .venv\Scripts\activate
+   pip install -e ".[dev]"
+   python -m iai_mcp daemon install --dry-run  # Check schtasks XML renders
+   python -m iai_mcp capture-hooks install --dry-run  # Check hook paths
+   ```
+
+2. **Update CLAUDE.md:** Add Windows-specific setup notes to the project's CLAUDE.md (if it exists) or create one with:
+   - Running `iai-mcp daemon install` on Windows (uses Task Scheduler)
+   - Running `iai-mcp capture-hooks install` on Windows (uses PowerShell hooks)
+   - Expected log locations (`%APPDATA%\iai-mcp\logs\`)
+
+## Verification Checklist
+
+All verified on Windows 11 / Python 3.12.10:
+- [x] Daemon imports without crashing on Windows
+- [x] Daemon actually starts and serves (direct, `pythonw`, and Task Scheduler)
+- [x] `iai-mcp daemon install` creates a Task Scheduler entry that launches
+- [x] `iai-mcp capture-hooks install` creates PowerShell hooks and registers in settings.json
+- [x] Hook commands reference `.ps1` files (not `.sh`) on Windows in settings.json
+- [x] State persists across scheduler ticks under concurrent reader load
+- [ ] Logs go to `%APPDATA%\iai-mcp\logs\` (Windows) not `~/.local/share` (Linux)
+      — log dir created; `pythonw` discards stdio so the daemon writes no file
+      there in normal operation (not blocking)
+- [ ] Crypto key file created with appropriate icacls permissions
+      — code path ported (Step 10), not exercised in this E2E run
+
+## Key Design Decisions
+
+1. **Platform detection:** Uses `platform.system()` checks (`== "Windows"`, `== "Darwin"`, `== "Linux"`) throughout
+2. **File locking:** `_filelock.py` shim normalizes `msvcrt.locking()` (Windows) to `fcntl.flock()` interface (POSIX)
+3. **Daemon management:** Task Scheduler on Windows, launchd on macOS, systemd on Linux
+4. **Hooks:** Python calls wrapped in shell scripts (.sh on POSIX) or PowerShell scripts (.ps1 on Windows)
+5. **No cross-platform abstractions:** Branching logic is explicit per-platform to avoid accidental breakage
+
+After Step 5 (daemon installer):
+```powershell
+iai-mcp daemon install
+iai-mcp daemon status
+```
+
+After Step 6 (hooks):
+```powershell
+iai-mcp capture-hooks install
+iai-mcp capture-hooks status
+```
+
+Full E2E after all steps:
+```powershell
+iai-mcp doctor
+```
+
+## Notes
+
+- The user is on Windows 11 Pro, Python 3.12, Node 18+, has Rust toolchain
+- GitHub user: `danielhertz1999-bit`, repo fork is under their account
+- The upstream repo is `CodeAbra/iai-personal-memory-engine`
+- All changes should be committed to the local `main` branch; a PR to upstream can be opened later
+- Keep each step as a separate commit for clean history
+- The `setproctitle` module (used in `daemon/__init__.py`) may need a try/except fallback
+  on Windows if it fails to compile — wrap: `try: from setproctitle import setproctitle\nexcept ImportError: setproctitle = lambda x: None`
diff --git a/bench/consolidation_rss_peak.py b/bench/consolidation_rss_peak.py
index 5984da7..151d6db 100644
--- a/bench/consolidation_rss_peak.py
+++ b/bench/consolidation_rss_peak.py
@@ -4,7 +4,6 @@
 import gc
 import json
 import os
-import resource
 import shutil
 import sys
 import tempfile
@@ -38,6 +37,14 @@ def _cur_rss_bytes() -> int:
 
 
 def _ru_maxrss_bytes() -> int:
+    if sys.platform == "win32":
+        try:
+            import psutil
+            mi = psutil.Process().memory_info()
+            return int(getattr(mi, "peak_wset", mi.rss))
+        except Exception:
+            return 0
+    import resource
     r = resource.getrusage(resource.RUSAGE_SELF).ru_maxrss
     if sys.platform == "darwin":
         return int(r)
diff --git a/bench/embed_warm_cost.py b/bench/embed_warm_cost.py
index ce2f086..f5fef0b 100644
--- a/bench/embed_warm_cost.py
+++ b/bench/embed_warm_cost.py
@@ -58,23 +58,42 @@
 """
 
 _PAYLOAD_RSS = r"""
-import sys, resource
+import sys
 sys.path.insert(0, {src_path!r})
+import platform as _plat
+_system = _plat.system()
+if _system == "Windows":
+    import psutil as _psutil
+    def _peak_raw():
+        mi = _psutil.Process().memory_info()
+        return int(getattr(mi, "peak_wset", mi.rss))
+    def _to_mb(raw):
+        return raw / 1048576
+    _unit_is_bytes = True
+else:
+    import resource as _resource
+    def _peak_raw():
+        return _resource.getrusage(_resource.RUSAGE_SELF).ru_maxrss
+    if _system == "Darwin":
+        def _to_mb(raw):
+            return raw / 1048576
+        _unit_is_bytes = True
+    else:
+        def _to_mb(raw):
+            return raw / 1024
+        _unit_is_bytes = False
 from iai_mcp.embed import Embedder
 e = Embedder()
-rss_post_construct_raw = resource.getrusage(resource.RUSAGE_SELF).ru_maxrss
+rss_post_construct_raw = _peak_raw()
 text = {text!r}
 _ = e.embed(text)
-rss_post_encode_raw = resource.getrusage(resource.RUSAGE_SELF).ru_maxrss
-import platform as _plat
-is_mac = (_plat.system() == "Darwin")
-def to_mb(raw):
-    return raw / 1048576 if is_mac else raw / 1024
-print(f"rss_post_construct_mb={{to_mb(rss_post_construct_raw):.1f}}")
-print(f"rss_post_encode_mb={{to_mb(rss_post_encode_raw):.1f}}")
+rss_post_encode_raw = _peak_raw()
+print(f"rss_post_construct_mb={{_to_mb(rss_post_construct_raw):.1f}}")
+print(f"rss_post_encode_mb={{_to_mb(rss_post_encode_raw):.1f}}")
 print(f"rss_post_construct_raw={{rss_post_construct_raw}}")
 print(f"rss_post_encode_raw={{rss_post_encode_raw}}")
-print(f"unit_is_bytes={{is_mac}}")
+print(f"unit_is_bytes={{_unit_is_bytes}}")
+print(f"rss_platform={{_system}}")
 """
 
 
@@ -210,10 +229,17 @@ def measure_rss(src_path: str, text: str) -> dict:
     rss_post_construct_mb = float(kv["rss_post_construct_mb"])
     rss_post_encode_mb = float(kv["rss_post_encode_mb"])
     unit_is_bytes = kv["unit_is_bytes"] == "True"
+    rss_platform = kv.get("rss_platform", "")
+    if rss_platform == "Windows":
+        unit_label = "bytes (Windows peak_wset)"
+    elif rss_platform == "Darwin" or (unit_is_bytes and not rss_platform):
+        unit_label = "bytes (macOS)"
+    else:
+        unit_label = "KB (Linux)"
     print(
         f"  RSS post-construct={rss_post_construct_mb:.1f}MB  "
         f"post-first-encode={rss_post_encode_mb:.1f}MB  "
-        f"unit={'bytes (macOS)' if unit_is_bytes else 'KB (Linux)'}"
+        f"unit={unit_label}"
     )
     return {
         "rss_post_construct_mb": rss_post_construct_mb,
@@ -221,6 +247,7 @@ def measure_rss(src_path: str, text: str) -> dict:
         "rss_post_construct_raw": int(kv["rss_post_construct_raw"]),
         "rss_post_encode_raw": int(kv["rss_post_encode_raw"]),
         "unit_is_bytes_macos": unit_is_bytes,
+        "rss_platform": rss_platform,
     }
 
 
diff --git a/bench/memory_footprint.py b/bench/memory_footprint.py
index ea879df..504ff3a 100644
--- a/bench/memory_footprint.py
+++ b/bench/memory_footprint.py
@@ -4,7 +4,6 @@
 import gc
 import json
 import os
-import resource
 import sys
 import tempfile
 import time
@@ -42,6 +41,11 @@ def _threshold_mb_for_n(n: int) -> float:
 
 
 def _rss_mb() -> float:
+    if sys.platform == "win32":
+        import psutil
+        mi = psutil.Process().memory_info()
+        return float(getattr(mi, "peak_wset", mi.rss)) / 1024.0 / 1024.0
+    import resource
     r = resource.getrusage(resource.RUSAGE_SELF).ru_maxrss
     if sys.platform == "darwin":
         return float(r) / 1024.0 / 1024.0
diff --git a/bench/memorygraph_memory.py b/bench/memorygraph_memory.py
index 06291be..e8f9c46 100644
--- a/bench/memorygraph_memory.py
+++ b/bench/memorygraph_memory.py
@@ -2,7 +2,6 @@
 
 import argparse
 import gc
-import resource
 import sys
 from pathlib import Path
 from uuid import uuid4
@@ -14,6 +13,11 @@
 
 
 def rss_mb() -> float:
+    if sys.platform == "win32":
+        import psutil
+        mi = psutil.Process().memory_info()
+        return float(getattr(mi, "peak_wset", mi.rss)) / (1024 * 1024)
+    import resource
     ru = resource.getrusage(resource.RUSAGE_SELF).ru_maxrss
     if sys.platform == "darwin":
         return ru / (1024 * 1024)
diff --git a/mcp-wrapper/package-lock.json b/mcp-wrapper/package-lock.json
index 776a840..c45beb4 100644
--- a/mcp-wrapper/package-lock.json
+++ b/mcp-wrapper/package-lock.json
@@ -7,6 +7,7 @@
     "": {
       "name": "iai-mcp-wrapper",
       "version": "1.0.0",
+      "license": "MIT",
       "dependencies": {
         "@modelcontextprotocol/sdk": "^1.0.0",
         "zod": "^3.23.0"
diff --git a/mcp-wrapper/src/bridge.ts b/mcp-wrapper/src/bridge.ts
index 8d6f907..07db282 100644
--- a/mcp-wrapper/src/bridge.ts
+++ b/mcp-wrapper/src/bridge.ts
@@ -1,13 +1,13 @@
 
 import * as crypto from "node:crypto";
 import * as net from "node:net";
-import * as os from "node:os";
-import * as path from "node:path";
+import {
+  type ConnectTarget,
+  createDaemonConnection,
+  daemonUnreachableHint,
+  getDaemonConnectTarget,
+} from "./ipc.js";
 
-function getDaemonSocketPath(): string {
-  return process.env.IAI_DAEMON_SOCKET_PATH
-    ?? path.join(os.homedir(), ".iai-mcp", ".daemon.sock");
-}
 const SOCKET_CONNECT_TIMEOUT_MS = 5000;
 const ERR_DAEMON_UNREACHABLE = -32002;
 
@@ -69,29 +69,30 @@ export class PythonCoreBridge {
   private async _doStart(): Promise<void> {
     this.reconnectAttempted = false;
 
+    const target = getDaemonConnectTarget();
+    if (target === null) {
+      throw new DaemonUnreachableError(daemonUnreachableHint());
+    }
+
     let sock: net.Socket;
     try {
       sock = await this.connectWithTimeout(
-        getDaemonSocketPath(),
+        target,
         SOCKET_CONNECT_TIMEOUT_MS,
       );
     } catch (e) {
-      throw new DaemonUnreachableError(
-        "iai-mcp daemon not running. "
-        + "Run: launchctl load -w ~/Library/LaunchAgents/com.iai-mcp.daemon.plist "
-        + "or run scripts/install.sh"
-      );
+      throw new DaemonUnreachableError(daemonUnreachableHint());
     }
     this.sock = sock;
     this.attachSocketHandlers();
   }
 
   private connectWithTimeout(
-    socketPath: string,
+    target: ConnectTarget,
     timeoutMs: number,
   ): Promise<net.Socket> {
     return new Promise((resolve, reject) => {
-      const sock = net.createConnection(socketPath);
+      const sock = createDaemonConnection(target);
       // Keep a pending/abandoned connect attempt from pinning the event loop
       // (e.g. an in-flight reconnect after socket death). A live connected
       // socket re-refs below so real RPC still holds the process open.
@@ -193,8 +194,12 @@ export class PythonCoreBridge {
         if (testDelayMs > 0) {
           await new Promise<void>((r) => setTimeout(r, testDelayMs));
         }
+        const target = getDaemonConnectTarget();
+        if (target === null) {
+          return;
+        }
         this.sock = await this.connectWithTimeout(
-          getDaemonSocketPath(),
+          target,
           SOCKET_CONNECT_TIMEOUT_MS,
         );
         this.attachSocketHandlers();
@@ -254,13 +259,6 @@ export class PythonCoreBridge {
 }
 
 
-export function sessionOpenSocketPath(): string {
-  const env = process.env.IAI_DAEMON_SOCKET_PATH;
-  if (env) return env;
-  return path.join(os.homedir(), ".iai-mcp", ".daemon.sock");
-}
-
-
 export function newSessionId(): string {
   return crypto.randomUUID();
 }
@@ -275,8 +273,12 @@ export function emitSessionOpen(sessionId: string): Promise<void> {
       resolve();
     };
     try {
-      const socketPath = sessionOpenSocketPath();
-      const sock = net.createConnection(socketPath, () => {
+      const target = getDaemonConnectTarget();
+      if (target === null) {
+        finish();
+        return;
+      }
+      const sock = createDaemonConnection(target, () => {
         const msg =
           JSON.stringify({
             type: "session_open",
diff --git a/mcp-wrapper/src/ipc.ts b/mcp-wrapper/src/ipc.ts
new file mode 100644
index 0000000..b361983
--- /dev/null
+++ b/mcp-wrapper/src/ipc.ts
@@ -0,0 +1,97 @@
+
+/**
+ * Platform-agnostic IPC transport, mirroring the Python `iai_mcp._ipc` module.
+ *
+ *   POSIX:   Unix-domain socket  ->  ~/.iai-mcp/.daemon.sock
+ *   Windows: TCP loopback         ->  127.0.0.1:<port>, port read from
+ *                                     ~/.iai-mcp/.daemon.port
+ *
+ * The base dir is ~/.iai-mcp (os.homedir()) to match `_ipc._BASE_DIR`, which
+ * uses Path.home() regardless of IAI_MCP_STORE.
+ */
+import * as fs from "node:fs";
+import * as net from "node:net";
+import * as os from "node:os";
+import * as path from "node:path";
+
+export const IS_WINDOWS = process.platform === "win32";
+
+export type ConnectTarget = string | { host: string; port: number };
+
+function daemonBaseDir(): string {
+  return path.join(os.homedir(), ".iai-mcp");
+}
+
+export function daemonSocketPath(): string {
+  return path.join(daemonBaseDir(), ".daemon.sock");
+}
+
+export function daemonPortFile(): string {
+  return path.join(daemonBaseDir(), ".daemon.port");
+}
+
+export function readDaemonPort(): number | null {
+  try {
+    const txt = fs.readFileSync(daemonPortFile(), "utf-8").trim();
+    const port = Number.parseInt(txt, 10);
+    return Number.isFinite(port) && port > 0 ? port : null;
+  } catch {
+    return null;
+  }
+}
+
+/**
+ * Resolve the daemon IPC endpoint.
+ *   POSIX   -> Unix-domain socket path (string)
+ *   Windows -> { host: "127.0.0.1", port } from the port file
+ * Returns null when the endpoint cannot be determined (on Windows: port file
+ * absent => daemon not running). IAI_DAEMON_SOCKET_PATH overrides on POSIX.
+ */
+export function getDaemonConnectTarget(): ConnectTarget | null {
+  const env = process.env.IAI_DAEMON_SOCKET_PATH;
+  if (env) return env;
+  if (IS_WINDOWS) {
+    const port = readDaemonPort();
+    return port === null ? null : { host: "127.0.0.1", port };
+  }
+  return daemonSocketPath();
+}
+
+export function daemonUnreachableHint(): string {
+  if (IS_WINDOWS) {
+    return (
+      "iai-mcp daemon not running. "
+      + 'Start it with: schtasks /Run /TN "iai-mcp-daemon" '
+      + "(or: iai-mcp daemon install)."
+    );
+  }
+  if (process.platform === "darwin") {
+    return (
+      "iai-mcp daemon not running. "
+      + "Run: launchctl load -w ~/Library/LaunchAgents/com.iai-mcp.daemon.plist "
+      + "or run scripts/install.sh"
+    );
+  }
+  return (
+    "iai-mcp daemon not running. "
+    + "Run: systemctl --user start iai-mcp-daemon or run scripts/install.sh"
+  );
+}
+
+/**
+ * Open a net.Socket to the daemon for either transport. Accepts the union
+ * target returned by getDaemonConnectTarget so callers stay platform-agnostic.
+ */
+export function createDaemonConnection(
+  target: ConnectTarget,
+  connectListener?: () => void,
+): net.Socket {
+  if (typeof target === "string") {
+    return connectListener
+      ? net.createConnection(target, connectListener)
+      : net.createConnection(target);
+  }
+  return connectListener
+    ? net.createConnection(target.port, target.host, connectListener)
+    : net.createConnection(target.port, target.host);
+}
diff --git a/mcp-wrapper/src/lifecycle.ts b/mcp-wrapper/src/lifecycle.ts
index 2dff96f..9b07444 100644
--- a/mcp-wrapper/src/lifecycle.ts
+++ b/mcp-wrapper/src/lifecycle.ts
@@ -5,9 +5,17 @@ import { mkdir, rename, unlink, writeFile } from "node:fs/promises";
 import { homedir } from "node:os";
 import { dirname, join } from "node:path";
 import { promisify } from "node:util";
+import {
+  type ConnectTarget,
+  createDaemonConnection,
+  getDaemonConnectTarget,
+  IS_WINDOWS,
+} from "./ipc.js";
 
 const execFileAsync = promisify(execFile);
 
+const SCHTASKS_TASK_NAME = "iai-mcp-daemon";
+
 
 export const HEARTBEAT_REFRESH_INTERVAL_MS = 30_000;
 
@@ -95,7 +103,10 @@ export class WrapperLifecycle {
     if (alive) {
       return;
     }
-    if (this.platform === "darwin") {
+    // macOS: launchctl kickstart. Windows: schtasks /Run the daemon task.
+    // Both are best-effort; fall through to the wake-signal sentinel on
+    // failure or on Linux (where systemd/scripts own daemon startup).
+    if (this.platform === "darwin" || this.platform === "win32") {
       try {
         await this.spawnKickstart();
         return;
@@ -170,7 +181,12 @@ function isoNow(): string {
 
 function defaultSocketReachable(socketPath: string): () => Promise<boolean> {
   return async () => {
-    const { createConnection } = await import("node:net");
+    // POSIX: probe the (possibly injected) Unix socket path. Windows: probe
+    // the TCP loopback endpoint from the daemon port file.
+    const target: ConnectTarget | null = IS_WINDOWS
+      ? getDaemonConnectTarget()
+      : socketPath;
+    if (target === null) return false;
     return await new Promise<boolean>((resolve) => {
       let settled = false;
       const settle = (v: boolean): void => {
@@ -182,7 +198,7 @@ function defaultSocketReachable(socketPath: string): () => Promise<boolean> {
         }
         resolve(v);
       };
-      const socket = createConnection({ path: socketPath });
+      const socket = createDaemonConnection(target);
       socket.setTimeout(1_000);
       socket.once("connect", () => settle(true));
       socket.once("error", () => settle(false));
@@ -192,6 +208,13 @@ function defaultSocketReachable(socketPath: string): () => Promise<boolean> {
 }
 
 function defaultSpawnKickstart(): () => Promise<void> {
+  if (IS_WINDOWS) {
+    return async () => {
+      await execFileAsync("schtasks", ["/Run", "/TN", SCHTASKS_TASK_NAME], {
+        timeout: KICKSTART_TIMEOUT_MS,
+      });
+    };
+  }
   return async () => {
     const uid = typeof process.getuid === "function" ? process.getuid() : 0;
     const args = ["kickstart", "-k", `gui/${uid}/${LAUNCHD_LABEL}`];
diff --git a/pyproject.toml b/pyproject.toml
index 684c975..579ba91 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -72,6 +72,7 @@ iai_mcp = [
     "_deploy/launchd/*.plist",
     "_deploy/systemd/*.service",
     "_deploy/hooks/*.sh",
+    "_deploy/hooks/*.ps1",
     "_wrapper/*.js",
 ]
 
diff --git a/src/iai_mcp/__main__.py b/src/iai_mcp/__main__.py
new file mode 100644
index 0000000..a6d7fbc
--- /dev/null
+++ b/src/iai_mcp/__main__.py
@@ -0,0 +1,18 @@
+"""Package entry point so ``python -m iai_mcp`` works.
+
+The Windows PowerShell hooks (``_deploy/hooks/*.ps1``) invoke the CLI as
+``python -m iai_mcp <subcommand>`` rather than via the ``iai-mcp`` console
+script (which may not be on PATH inside a hook subprocess). That form requires
+this module; without it Python raises "No module named iai_mcp.__main__" and
+every hook silently no-ops. Delegates to the same entry point as the
+``iai-mcp`` console script and ``python -m iai_mcp.cli``.
+"""
+
+from __future__ import annotations
+
+import sys
+
+from iai_mcp.cli import main
+
+if __name__ == "__main__":
+    sys.exit(main())
diff --git a/src/iai_mcp/_deploy/hooks/iai-mcp-session-capture.ps1 b/src/iai_mcp/_deploy/hooks/iai-mcp-session-capture.ps1
new file mode 100644
index 0000000..9910b52
--- /dev/null
+++ b/src/iai_mcp/_deploy/hooks/iai-mcp-session-capture.ps1
@@ -0,0 +1,146 @@
+# IAI-MCP Stop hook — ambient WRITE-side capture (Windows).
+#
+# PowerShell equivalent of iai-mcp-session-capture.sh.
+# Fires when a Claude Code session ends. Calls `iai-mcp capture-transcript
+# --no-spawn` to batch-capture the session transcript.
+# Fail-safe: always exits 0.
+
+$ErrorActionPreference = 'SilentlyContinue'
+
+try {
+    $inputText = [Console]::In.ReadToEnd()
+} catch {
+    $inputText = ''
+}
+
+$session_id = ''
+$transcript_path = ''
+$cwd = ''
+try {
+    $obj = $inputText | ConvertFrom-Json
+    $session_id = if ($obj.session_id) { $obj.session_id } else { '' }
+    $transcript_path = if ($obj.transcript_path) { $obj.transcript_path } else { '' }
+    $cwd = if ($obj.cwd) { $obj.cwd } else { '' }
+} catch {}
+
+# Fallback: locate transcript if the hook payload didn't include its path.
+if (-not $transcript_path -and $session_id) {
+    $projectsDir = Join-Path $env:USERPROFILE '.claude\projects'
+    if (Test-Path $projectsDir) {
+        Get-ChildItem -Path $projectsDir -Directory | ForEach-Object {
+            $candidate = Join-Path $_.FullName "$session_id.jsonl"
+            if ((Test-Path $candidate) -and -not $transcript_path) {
+                $transcript_path = $candidate
+            }
+        }
+    }
+}
+
+$logDir = Join-Path $env:USERPROFILE '.iai-mcp\logs'
+if (-not (Test-Path $logDir)) { New-Item -ItemType Directory -Path $logDir -Force | Out-Null }
+$logDate = (Get-Date).ToUniversalTime().ToString('yyyy-MM-dd')
+$logFile = Join-Path $logDir "capture-$logDate.log"
+$ts = (Get-Date).ToUniversalTime().ToString('yyyy-MM-ddTHH:mm:ssZ')
+
+Add-Content -Path $logFile -Value "---" -ErrorAction SilentlyContinue
+Add-Content -Path $logFile -Value "$ts session=$session_id cwd=$cwd transcript=$transcript_path" -ErrorAction SilentlyContinue
+
+if (-not $transcript_path -or -not (Test-Path $transcript_path)) {
+    Add-Content -Path $logFile -Value "$ts skipped: no transcript found" -ErrorAction SilentlyContinue
+    exit 0
+}
+
+# Rename the active-writer marker so the drain can see it.
+if ($session_id) {
+    $liveFile = Join-Path $env:USERPROFILE ".iai-mcp\.deferred-captures\$session_id.live.jsonl"
+    if (Test-Path $liveFile) {
+        $epoch = [int][double]::Parse((Get-Date -UFormat '%s'))
+        $newName = "$session_id.live-$epoch.jsonl"
+        $destDir = Split-Path $liveFile -Parent
+        Move-Item -Path $liveFile -Destination (Join-Path $destDir $newName) -Force -ErrorAction SilentlyContinue
+    }
+    $offsetState = Join-Path $env:USERPROFILE ".iai-mcp\.capture-state\$session_id.offset"
+    if (Test-Path $offsetState) { Remove-Item -Path $offsetState -Force -ErrorAction SilentlyContinue }
+}
+
+# Find the iai-mcp CLI
+$iai_cli = $null
+
+# 1. Environment variable override
+if ($env:IAI_MCP_SESSION_CAPTURE_CLI -and (Test-Path $env:IAI_MCP_SESSION_CAPTURE_CLI)) {
+    $iai_cli = $env:IAI_MCP_SESSION_CAPTURE_CLI
+}
+
+# 2. Cached CLI path
+if (-not $iai_cli) {
+    $cliCache = Join-Path $env:USERPROFILE '.iai-mcp\.cli-path'
+    if (Test-Path $cliCache) {
+        $cached = (Get-Content $cliCache -ErrorAction SilentlyContinue).Trim()
+        if ($cached -and (Test-Path $cached)) { $iai_cli = $cached }
+    }
+}
+
+# 3. PATH lookup
+if (-not $iai_cli) {
+    try {
+        $resolved = (Get-Command iai-mcp -ErrorAction Stop).Source
+        if ($resolved) {
+            $iai_cli = $resolved
+            Set-Content -Path (Join-Path $env:USERPROFILE '.iai-mcp\.cli-path') -Value $iai_cli -ErrorAction SilentlyContinue
+        }
+    } catch {}
+}
+
+# 4. Common Windows install locations
+if (-not $iai_cli) {
+    $candidates = @(
+        (Join-Path $env:USERPROFILE '.local\bin\iai-mcp.exe'),
+        (Join-Path $env:USERPROFILE 'IAI-MCP\.venv\Scripts\iai-mcp.exe'),
+        (Join-Path $env:LOCALAPPDATA 'Programs\Python\Scripts\iai-mcp.exe')
+    )
+    foreach ($c in $candidates) {
+        if (Test-Path $c) {
+            $iai_cli = $c
+            Set-Content -Path (Join-Path $env:USERPROFILE '.iai-mcp\.cli-path') -Value $iai_cli -ErrorAction SilentlyContinue
+            break
+        }
+    }
+}
+
+# 5. Fall back to python -m iai_mcp
+if (-not $iai_cli) {
+    $pyExe = $null
+    try { $pyExe = (Get-Command python -ErrorAction Stop).Source } catch {}
+    if ($pyExe) {
+        $iai_cli = "__python__"
+    }
+}
+
+if (-not $iai_cli) {
+    Add-Content -Path $logFile -Value "$ts skipped: iai-mcp CLI not found" -ErrorAction SilentlyContinue
+    exit 0
+}
+
+# Run capture with a 30s timeout
+try {
+    if ($iai_cli -eq "__python__") {
+        $pyExe = (Get-Command python -ErrorAction Stop).Source
+        $proc = Start-Process -FilePath $pyExe `
+            -ArgumentList '-m', 'iai_mcp', 'capture-transcript', '--no-spawn', '--session-id', $session_id, '--max-turns', '100000', $transcript_path `
+            -NoNewWindow -PassThru -RedirectStandardOutput (Join-Path $logDir 'capture-stdout.tmp') -RedirectStandardError (Join-Path $logDir 'capture-stderr.tmp')
+    } else {
+        $proc = Start-Process -FilePath $iai_cli `
+            -ArgumentList 'capture-transcript', '--no-spawn', '--session-id', $session_id, '--max-turns', '100000', $transcript_path `
+            -NoNewWindow -PassThru -RedirectStandardOutput (Join-Path $logDir 'capture-stdout.tmp') -RedirectStandardError (Join-Path $logDir 'capture-stderr.tmp')
+    }
+    $exited = $proc.WaitForExit(30000)
+    if (-not $exited) {
+        try { $proc.Kill() } catch {}
+    }
+    $rc = if ($exited) { $proc.ExitCode } else { 124 }
+} catch {
+    $rc = 1
+}
+
+Add-Content -Path $logFile -Value "$ts rc=$rc" -ErrorAction SilentlyContinue
+exit 0
diff --git a/src/iai_mcp/_deploy/hooks/iai-mcp-session-recall.ps1 b/src/iai_mcp/_deploy/hooks/iai-mcp-session-recall.ps1
new file mode 100644
index 0000000..8de2379
--- /dev/null
+++ b/src/iai_mcp/_deploy/hooks/iai-mcp-session-recall.ps1
@@ -0,0 +1,143 @@
+# IAI-MCP SessionStart hook — recall injection (Windows).
+#
+# PowerShell equivalent of iai-mcp-session-recall.sh.
+# Fires on Claude Code session start. Prints the cached session prefix
+# to stdout for Claude Code to inject as additionalContext.
+# Fail-safe: always exits 0 with empty stdout on any error.
+
+$ErrorActionPreference = 'SilentlyContinue'
+
+try {
+    $inputText = [Console]::In.ReadToEnd()
+} catch {
+    $inputText = ''
+}
+
+$session_id = ''
+$source_evt = ''
+try {
+    $obj = $inputText | ConvertFrom-Json
+    $session_id = if ($obj.session_id) { $obj.session_id } else { '' }
+    $source_evt = if ($obj.source) { $obj.source } else { '' }
+} catch {}
+
+$logDir = Join-Path $env:USERPROFILE '.iai-mcp\logs'
+if (-not (Test-Path $logDir)) { New-Item -ItemType Directory -Path $logDir -Force | Out-Null }
+$logDate = (Get-Date).ToUniversalTime().ToString('yyyy-MM-dd')
+$logFile = Join-Path $logDir "recall-$logDate.log"
+$ts = (Get-Date).ToUniversalTime().ToString('yyyy-MM-ddTHH:mm:ssZ')
+
+Add-Content -Path $logFile -Value "---" -ErrorAction SilentlyContinue
+Add-Content -Path $logFile -Value "$ts session=$session_id source=$source_evt" -ErrorAction SilentlyContinue
+
+# Try the precache file first
+$cachePath = Join-Path $env:USERPROFILE '.iai-mcp\.session-start-payload.cached.md'
+if ((Test-Path $cachePath) -and (Get-Item $cachePath).Length -gt 0) {
+    try {
+        $cacheOut = Get-Content $cachePath -Raw -ErrorAction Stop
+        if ($cacheOut.Length -gt 10000) { $cacheOut = $cacheOut.Substring(0, 10000) }
+        if ($cacheOut) {
+            [Console]::Out.Write($cacheOut)
+            $cacheAge = [int]((Get-Date) - (Get-Item $cachePath).LastWriteTime).TotalSeconds
+            Add-Content -Path $logFile -Value "$ts cache-hit age=${cacheAge}s bytes=$($cacheOut.Length)" -ErrorAction SilentlyContinue
+            exit 0
+        }
+    } catch {}
+    Add-Content -Path $logFile -Value "$ts cache-miss empty" -ErrorAction SilentlyContinue
+} else {
+    Add-Content -Path $logFile -Value "$ts cache-miss absent" -ErrorAction SilentlyContinue
+}
+
+# Find the iai-mcp CLI
+$iai_cli = $null
+
+if ($env:IAI_MCP_SESSION_RECALL_CLI -and (Test-Path $env:IAI_MCP_SESSION_RECALL_CLI)) {
+    $iai_cli = $env:IAI_MCP_SESSION_RECALL_CLI
+}
+
+if (-not $iai_cli) {
+    $cliCache = Join-Path $env:USERPROFILE '.iai-mcp\.cli-path'
+    if (Test-Path $cliCache) {
+        $cached = (Get-Content $cliCache -ErrorAction SilentlyContinue).Trim()
+        if ($cached -and (Test-Path $cached)) { $iai_cli = $cached }
+    }
+}
+
+if (-not $iai_cli) {
+    try {
+        $resolved = (Get-Command iai-mcp -ErrorAction Stop).Source
+        if ($resolved) {
+            $iai_cli = $resolved
+            Set-Content -Path (Join-Path $env:USERPROFILE '.iai-mcp\.cli-path') -Value $iai_cli -ErrorAction SilentlyContinue
+        }
+    } catch {}
+}
+
+if (-not $iai_cli) {
+    $candidates = @(
+        (Join-Path $env:USERPROFILE '.local\bin\iai-mcp.exe'),
+        (Join-Path $env:USERPROFILE 'IAI-MCP\.venv\Scripts\iai-mcp.exe'),
+        (Join-Path $env:LOCALAPPDATA 'Programs\Python\Scripts\iai-mcp.exe')
+    )
+    foreach ($c in $candidates) {
+        if (Test-Path $c) {
+            $iai_cli = $c
+            Set-Content -Path (Join-Path $env:USERPROFILE '.iai-mcp\.cli-path') -Value $iai_cli -ErrorAction SilentlyContinue
+            break
+        }
+    }
+}
+
+$usePythonModule = $false
+if (-not $iai_cli) {
+    try {
+        $pyExe = (Get-Command python -ErrorAction Stop).Source
+        $usePythonModule = $true
+    } catch {}
+}
+
+if (-not $iai_cli -and -not $usePythonModule) {
+    Add-Content -Path $logFile -Value "$ts skipped: iai-mcp CLI not found" -ErrorAction SilentlyContinue
+    exit 0
+}
+
+# Run session-start with a 10s timeout
+$hookTimeout = if ($env:IAI_MCP_RECALL_HOOK_TIMEOUT) { [int]$env:IAI_MCP_RECALL_HOOK_TIMEOUT } else { 10 }
+$outTmp = Join-Path $logDir 'recall-stdout.tmp'
+
+try {
+    if ($usePythonModule) {
+        $pyExe = (Get-Command python -ErrorAction Stop).Source
+        $proc = Start-Process -FilePath $pyExe `
+            -ArgumentList '-m', 'iai_mcp', 'session-start', '--session-id', $session_id `
+            -NoNewWindow -PassThru -RedirectStandardOutput $outTmp -RedirectStandardError (Join-Path $logDir 'recall-stderr.tmp')
+    } else {
+        $proc = Start-Process -FilePath $iai_cli `
+            -ArgumentList 'session-start', '--session-id', $session_id `
+            -NoNewWindow -PassThru -RedirectStandardOutput $outTmp -RedirectStandardError (Join-Path $logDir 'recall-stderr.tmp')
+    }
+    $exited = $proc.WaitForExit($hookTimeout * 1000)
+    if (-not $exited) {
+        try { $proc.Kill() } catch {}
+        $rc = 124
+    } else {
+        $rc = $proc.ExitCode
+    }
+} catch {
+    $rc = 1
+}
+
+if ($rc -eq 0 -and (Test-Path $outTmp)) {
+    $out = Get-Content $outTmp -Raw -ErrorAction SilentlyContinue
+    if ($out) {
+        [Console]::Out.Write($out)
+    }
+    $outLen = if ($out) { $out.Length } else { 0 }
+} else {
+    $outLen = 0
+}
+
+Remove-Item -Path $outTmp -Force -ErrorAction SilentlyContinue
+
+Add-Content -Path $logFile -Value "$ts rc=$rc bytes=$outLen" -ErrorAction SilentlyContinue
+exit 0
diff --git a/src/iai_mcp/_deploy/hooks/iai-mcp-turn-capture.ps1 b/src/iai_mcp/_deploy/hooks/iai-mcp-turn-capture.ps1
new file mode 100644
index 0000000..a830aa5
--- /dev/null
+++ b/src/iai_mcp/_deploy/hooks/iai-mcp-turn-capture.ps1
@@ -0,0 +1,65 @@
+# IAI-MCP UserPromptSubmit hook — per-turn ambient capture (Windows).
+#
+# PowerShell equivalent of iai-mcp-turn-capture.sh.
+# Reads stdin JSON, extracts session_id + transcript_path, runs inline
+# Python for low-latency capture. Fail-safe: always exits 0.
+
+$ErrorActionPreference = 'SilentlyContinue'
+
+try {
+    $inputText = [Console]::In.ReadToEnd()
+} catch {
+    $inputText = ''
+}
+
+$session_id = ''
+$transcript_path = ''
+try {
+    $obj = $inputText | ConvertFrom-Json
+    $session_id = if ($obj.session_id) { $obj.session_id } else { '' }
+    $transcript_path = if ($obj.transcript_path) { $obj.transcript_path } else { '' }
+} catch {}
+
+$logDir = Join-Path $env:USERPROFILE '.iai-mcp\logs'
+if (-not (Test-Path $logDir)) { New-Item -ItemType Directory -Path $logDir -Force | Out-Null }
+$logDate = (Get-Date).ToUniversalTime().ToString('yyyy-MM-dd')
+$logFile = Join-Path $logDir "turn-capture-$logDate.log"
+$ts = (Get-Date).ToUniversalTime().ToString('yyyy-MM-ddTHH:mm:ssZ')
+
+if (-not $session_id -or -not $transcript_path) {
+    Add-Content -Path $logFile -Value "$ts skipped: missing session_id or transcript_path" -ErrorAction SilentlyContinue
+    exit 0
+}
+
+# Find python
+$pyExe = $null
+try { $pyExe = (Get-Command python -ErrorAction Stop).Source } catch {}
+if (-not $pyExe) {
+    try { $pyExe = (Get-Command python3 -ErrorAction Stop).Source } catch {}
+}
+if (-not $pyExe) {
+    # Check common venv location
+    $venvPy = Join-Path $env:USERPROFILE '.iai-mcp\.venv\Scripts\python.exe'
+    if (Test-Path $venvPy) { $pyExe = $venvPy }
+}
+if (-not $pyExe) {
+    Add-Content -Path $logFile -Value "$ts skipped: python not found" -ErrorAction SilentlyContinue
+    exit 0
+}
+
+# Run the Python CLI for turn capture with a 5s timeout
+try {
+    $proc = Start-Process -FilePath $pyExe `
+        -ArgumentList '-m', 'iai_mcp', 'capture-turn-deferred', '--session-id', $session_id, '--transcript-path', $transcript_path `
+        -NoNewWindow -PassThru -RedirectStandardError (Join-Path $logDir 'turn-capture-stderr.tmp')
+    $exited = $proc.WaitForExit(5000)
+    if (-not $exited) {
+        try { $proc.Kill() } catch {}
+    }
+    $rc = if ($exited) { $proc.ExitCode } else { 124 }
+} catch {
+    $rc = 1
+}
+
+Add-Content -Path $logFile -Value "$ts session=$session_id rc=$rc" -ErrorAction SilentlyContinue
+exit 0
diff --git a/src/iai_mcp/_filelock.py b/src/iai_mcp/_filelock.py
new file mode 100644
index 0000000..db1d11a
--- /dev/null
+++ b/src/iai_mcp/_filelock.py
@@ -0,0 +1,100 @@
+"""Platform-agnostic file locking shim.
+
+On POSIX: thin wrapper around fcntl.flock.
+On Windows: msvcrt.locking with errno normalisation so callers checking
+errno.EWOULDBLOCK / errno.EAGAIN on non-blocking failures work unchanged.
+The file offset is saved/restored around each call (msvcrt locks relative to
+the file position; fcntl.flock does not move it) and the blocking path polls
+so it waits indefinitely like POSIX rather than giving up after msvcrt's ~10 s.
+
+Known divergence — shared locks are not truly shared on Windows.
+``msvcrt.locking`` only offers exclusive byte-range locks, so LOCK_SH is
+serviced as an exclusive lock: a second concurrent reader blocks where POSIX
+would let both in. This is a throughput limitation, not a correctness one, and
+it is deliberately NOT fixed with Win32 ``LockFileEx`` (which does support
+shared locks) because callers in ``hippo/_db.py`` rely on fcntl.flock's atomic
+lock *conversion* — downgrading EXCLUSIVE->SHARED and escalating SHARED->
+EXCLUSIVE in place on the same fd. ``LockFileEx`` has no atomic conversion
+(you must Unlock then re-Lock, racing other waiters), so swapping it in would
+trade a throughput limit for a correctness hazard on the conversion paths.
+A faithful port would need those call sites reworked to a conversion-free
+protocol first.
+"""
+from __future__ import annotations
+
+import os
+import platform
+
+if platform.system() == "Windows":
+    import errno as _errno
+    import msvcrt as _msvcrt
+    import time as _time
+
+    LOCK_SH = 1
+    LOCK_EX = 2
+    LOCK_NB = 4
+    LOCK_UN = 8
+
+    _LOCK_BYTES = 2**30
+    # Poll interval when emulating POSIX's block-until-acquired behaviour.
+    _BLOCK_POLL_SECONDS = 0.05
+
+    def flock(fd: int, operation: int) -> None:
+        if not isinstance(fd, int):
+            fd = fd.fileno()
+        # msvcrt.locking locks bytes starting from the current file position, so
+        # we must seek to 0 to lock a consistent byte range across callers.
+        # fcntl.flock leaves the file offset untouched, however, so save the
+        # caller's offset and restore it afterwards to match POSIX semantics.
+        try:
+            saved_offset: int | None = os.lseek(fd, 0, os.SEEK_CUR)
+        except OSError:
+            saved_offset = None
+        os.lseek(fd, 0, os.SEEK_SET)
+        try:
+            if operation & LOCK_UN:
+                try:
+                    _msvcrt.locking(fd, _msvcrt.LK_UNLCK, _LOCK_BYTES)
+                except OSError:
+                    pass
+            elif operation & (LOCK_EX | LOCK_SH):
+                if operation & LOCK_NB:
+                    try:
+                        _msvcrt.locking(fd, _msvcrt.LK_NBLCK, _LOCK_BYTES)
+                    except OSError:
+                        raise OSError(
+                            _errno.EWOULDBLOCK, "resource temporarily unavailable"
+                        )
+                else:
+                    # POSIX flock blocks until the lock is acquired, but msvcrt
+                    # has no infinite-block mode (LK_LOCK gives up after ~10 s
+                    # and raises). Poll LK_NBLCK so a blocking acquire matches
+                    # POSIX semantics instead of spuriously failing under long
+                    # contention (e.g. while the consolidator holds the lock).
+                    while True:
+                        try:
+                            _msvcrt.locking(fd, _msvcrt.LK_NBLCK, _LOCK_BYTES)
+                            break
+                        except OSError:
+                            os.lseek(fd, 0, os.SEEK_SET)
+                            _time.sleep(_BLOCK_POLL_SECONDS)
+        finally:
+            if saved_offset is not None:
+                try:
+                    os.lseek(fd, saved_offset, os.SEEK_SET)
+                except OSError:
+                    pass
+
+else:
+    import fcntl as _fcntl
+
+    LOCK_SH = _fcntl.LOCK_SH
+    LOCK_EX = _fcntl.LOCK_EX
+    LOCK_NB = _fcntl.LOCK_NB
+    LOCK_UN = _fcntl.LOCK_UN
+
+    def flock(fd: int, operation: int) -> None:
+        _fcntl.flock(fd, operation)
+
+
+__all__ = ["flock", "LOCK_EX", "LOCK_NB", "LOCK_SH", "LOCK_UN"]
diff --git a/src/iai_mcp/_ipc.py b/src/iai_mcp/_ipc.py
new file mode 100644
index 0000000..48e7cd2
--- /dev/null
+++ b/src/iai_mcp/_ipc.py
@@ -0,0 +1,352 @@
+"""
+Platform-agnostic IPC transport layer.
+
+POSIX:   Unix-domain socket  →  ~/.iai-mcp/.daemon.sock
+         Access control is provided by the socket file's filesystem permissions.
+
+Windows: TCP loopback         →  127.0.0.1:<ephemeral port>
+         Port is persisted in ~/.iai-mcp/.daemon.port.
+         Because loopback TCP is reachable by any local process, an
+         auth-token handshake is layered on top: the daemon generates a
+         32-byte random hex token on start, writes it to
+         ~/.iai-mcp/.daemon.token (ACL-restricted to the current user via
+         icacls), and requires every client to send that token as the
+         first line of each connection.  Connections that send the wrong
+         token are closed immediately without processing any requests.
+"""
+from __future__ import annotations
+
+import asyncio
+import inspect
+import os
+import platform
+import secrets
+import socket
+import subprocess
+from pathlib import Path
+from typing import Any
+
+IS_WINDOWS: bool = platform.system() == "Windows"
+
+_BASE_DIR: Path = Path.home() / ".iai-mcp"
+SOCKET_PATH: Path = _BASE_DIR / ".daemon.sock"  # POSIX only — kept for compatibility
+PORT_FILE: Path = _BASE_DIR / ".daemon.port"     # Windows only
+TOKEN_FILE: Path = _BASE_DIR / ".daemon.token"   # Windows only — auth secret
+
+_TOKEN_BYTES = 32  # 256-bit random token → 64 hex chars on the wire
+
+
+# ---------------------------------------------------------------------------
+# Port file helpers (Windows only)
+# ---------------------------------------------------------------------------
+
+def _port_file_path() -> Path:
+    """Resolve the Windows port-file location at call time.
+
+    Mirrors the POSIX ``IAI_DAEMON_SOCKET_PATH`` override (see ``ipc_address``)
+    so a daemon bound to a non-default endpoint — a custom ``IAI_MCP_STORE``,
+    or an isolated test harness — persists its port *alongside* that socket
+    path (``<socket-path>.port``) instead of always clobbering the shared
+    ``~/.iai-mcp/.daemon.port``. Without this, every Windows daemon (and every
+    test) raced for one global port file. Resolved dynamically, not as a module
+    constant, because tests set the env var after import.
+    """
+    env = os.environ.get("IAI_DAEMON_SOCKET_PATH")
+    if env:
+        return Path(f"{env}.port")
+    return PORT_FILE
+
+
+def _read_port() -> int | None:
+    try:
+        return int(_port_file_path().read_text(encoding="utf-8").strip())
+    except (FileNotFoundError, ValueError, OSError):
+        return None
+
+
+def _write_port(port: int) -> None:
+    path = _port_file_path()
+    path.parent.mkdir(parents=True, exist_ok=True)
+    path.write_text(str(port), encoding="utf-8")
+
+
+def _remove_port_file() -> None:
+    try:
+        _port_file_path().unlink()
+    except (FileNotFoundError, OSError):
+        pass
+
+
+# ---------------------------------------------------------------------------
+# Token file helpers (Windows only)
+# ---------------------------------------------------------------------------
+
+def _restrict_token_file(path: Path) -> None:
+    """Restrict token file to current user only via icacls (Windows equivalent of chmod 0o600)."""
+    username = os.environ.get("USERNAME", "")
+    if username:
+        subprocess.run(
+            ["icacls", str(path), "/inheritance:d", "/grant:r", f"{username}:F"],
+            check=False,
+            capture_output=True,
+        )
+
+
+def _token_file_path() -> Path:
+    """Resolve the Windows auth-token file at call time, mirroring
+    ``_port_file_path`` so the token is per-endpoint (an isolated test harness
+    or a custom ``IAI_MCP_STORE``) rather than a single shared
+    ``~/.iai-mcp/.daemon.token`` that every daemon and test would clobber."""
+    env = os.environ.get("IAI_DAEMON_SOCKET_PATH")
+    if env:
+        return Path(f"{env}.token")
+    return TOKEN_FILE
+
+
+def _generate_token() -> str:
+    """Generate a fresh 32-byte random token and persist it to the token file."""
+    token = secrets.token_hex(_TOKEN_BYTES)
+    path = _token_file_path()
+    path.parent.mkdir(parents=True, exist_ok=True)
+    path.write_text(token, encoding="utf-8")
+    _restrict_token_file(path)
+    return token
+
+
+def _read_token() -> str | None:
+    try:
+        return _token_file_path().read_text(encoding="utf-8").strip()
+    except (FileNotFoundError, OSError):
+        return None
+
+
+def _remove_token_file() -> None:
+    try:
+        _token_file_path().unlink()
+    except (FileNotFoundError, OSError):
+        pass
+
+
+# ---------------------------------------------------------------------------
+# Auth-wrapping helpers (Windows only)
+# ---------------------------------------------------------------------------
+
+def _make_authenticated_handler(handler: Any, token: str) -> Any:
+    """
+    Wrap *handler* so that the first line received on each connection must be
+    the auth token.  If it matches, the connection proceeds normally.
+    If it doesn't, the connection is closed immediately.
+    """
+    async def _auth_handler(
+        reader: asyncio.StreamReader,
+        writer: asyncio.StreamWriter,
+    ) -> None:
+        try:
+            line = await asyncio.wait_for(reader.readline(), timeout=5.0)
+        except (asyncio.TimeoutError, OSError):
+            writer.close()
+            return
+        received = line.decode("utf-8", errors="replace").strip()
+        if not secrets.compare_digest(received, token):
+            writer.close()
+            return
+        await handler(reader, writer)
+
+    return _auth_handler
+
+
+async def _send_token_async(writer: asyncio.StreamWriter) -> None:
+    """Send the auth token as the first line on a Windows client connection."""
+    token = _read_token()
+    if token is None:
+        raise FileNotFoundError(
+            f"Daemon auth token not found: {_token_file_path()} missing."
+        )
+    writer.write((token + "\n").encode("utf-8"))
+    await writer.drain()
+
+
+def _send_token_sync(sock: socket.socket) -> None:
+    """Send the auth token as the first line on a synchronous Windows client socket."""
+    token = _read_token()
+    if token is None:
+        raise FileNotFoundError(
+            f"Daemon auth token not found: {_token_file_path()} missing."
+        )
+    sock.sendall((token + "\n").encode("utf-8"))
+
+
+# ---------------------------------------------------------------------------
+# Public helpers
+# ---------------------------------------------------------------------------
+
+def ipc_address() -> str | tuple[str, int]:
+    """
+    Return the current IPC endpoint.
+    POSIX: Unix socket path string.
+    Windows: ("127.0.0.1", port) tuple.
+    """
+    if not IS_WINDOWS:
+        env = os.environ.get("IAI_DAEMON_SOCKET_PATH")
+        return env if env else str(SOCKET_PATH)
+    port = _read_port()
+    if port is None:
+        raise FileNotFoundError(
+            "Daemon not running: ~/.iai-mcp/.daemon.port not found."
+        )
+    return ("127.0.0.1", port)
+
+
+async def open_ipc_connection(
+    addr: str | tuple[str, int] | None = None,
+    *,
+    timeout: float | None = None,
+) -> tuple[asyncio.StreamReader, asyncio.StreamWriter]:
+    """
+    Open a client connection to the daemon.
+
+    On POSIX wraps asyncio.open_unix_connection; on Windows wraps
+    asyncio.open_connection over TCP loopback and performs the auth-token
+    handshake before returning.
+
+    The *addr* parameter is ignored on Windows (always uses port file).
+    """
+    coro: Any
+    if IS_WINDOWS:
+        port = _read_port()
+        if port is None:
+            raise FileNotFoundError(
+                f"Daemon not running: {_port_file_path()} not found."
+            )
+        coro = asyncio.open_connection("127.0.0.1", port)
+    else:
+        if addr is None:
+            env = os.environ.get("IAI_DAEMON_SOCKET_PATH")
+            addr = env if env else str(SOCKET_PATH)
+        coro = asyncio.open_unix_connection(str(addr))
+
+    if timeout is not None:
+        reader, writer = await asyncio.wait_for(coro, timeout=timeout)
+    else:
+        reader, writer = await coro
+
+    if IS_WINDOWS:
+        await _send_token_async(writer)
+
+    return reader, writer
+
+
+async def start_ipc_server(
+    handler: Any,
+    addr: str | Path | None = None,
+) -> tuple[asyncio.AbstractServer, str | tuple[str, int], bool]:
+    """
+    Start the daemon server.
+
+    Returns ``(server, actual_addr, needs_manual_cleanup)`` where:
+    - *actual_addr* is the socket path (POSIX) or ("127.0.0.1", port) (Windows).
+    - *needs_manual_cleanup* is True if the caller must call ``shutdown_ipc``
+      in its finally block (i.e. asyncio will NOT clean up automatically).
+
+    On Windows a fresh auth token is generated and written to TOKEN_FILE, and
+    the port is written to PORT_FILE immediately after bind.
+    """
+    if IS_WINDOWS:
+        token = _generate_token()
+        authenticated_handler = _make_authenticated_handler(handler, token)
+        server = await asyncio.start_server(authenticated_handler, "127.0.0.1", 0)
+        port: int = server.sockets[0].getsockname()[1]
+        _write_port(port)
+        return server, ("127.0.0.1", port), True
+
+    # POSIX: try to use asyncio's built-in cleanup_socket (Python 3.12+)
+    if addr is None:
+        env = os.environ.get("IAI_DAEMON_SOCKET_PATH")
+        path_str = env if env else str(SOCKET_PATH)
+    else:
+        path_str = str(addr)
+
+    sig = inspect.signature(asyncio.start_unix_server)
+    supports_cleanup = "cleanup_socket" in sig.parameters
+    kwargs: dict[str, Any] = {"cleanup_socket": True} if supports_cleanup else {}
+
+    server = await asyncio.start_unix_server(handler, path=path_str, **kwargs)
+    return server, path_str, not supports_cleanup
+
+
+def cleanup_ipc_address(addr: str | Path | None = None) -> None:
+    """
+    Remove a stale socket file before binding (POSIX only). No-op on Windows.
+    """
+    if IS_WINDOWS:
+        return
+    if addr is None:
+        env = os.environ.get("IAI_DAEMON_SOCKET_PATH")
+        path = Path(env) if env else SOCKET_PATH
+    else:
+        path = Path(addr)
+    try:
+        path.unlink()
+    except FileNotFoundError:
+        pass
+    except OSError:
+        try:
+            path.unlink()
+        except OSError:
+            pass
+
+
+def shutdown_ipc(addr: str | tuple[str, int] | None = None) -> None:
+    """
+    Clean up after daemon shutdown.
+    POSIX: unlink the socket file (idempotent).
+    Windows: remove the port file and the token file.
+    """
+    if IS_WINDOWS:
+        _remove_port_file()
+        _remove_token_file()
+        return
+    if addr is None or isinstance(addr, tuple):
+        env = os.environ.get("IAI_DAEMON_SOCKET_PATH")
+        path = Path(env) if env else SOCKET_PATH
+    else:
+        path = Path(addr)
+    try:
+        path.unlink()
+    except (FileNotFoundError, OSError):
+        pass
+
+
+def make_sync_ipc_socket() -> tuple[socket.socket, str | tuple[str, int]]:
+    """
+    Create a synchronous (blocking) client socket and the address to connect to.
+
+    Returns ``(sock, addr)`` where *addr* is a string path (POSIX) or
+    ``("127.0.0.1", port)`` tuple (Windows).  Caller is responsible for
+    ``settimeout``, ``connect``, and ``close``.
+
+    On Windows the caller must also call ``send_sync_auth_token(sock)`` after
+    ``connect()`` and before sending any application messages.
+    """
+    if IS_WINDOWS:
+        port = _read_port()
+        if port is None:
+            raise FileNotFoundError(
+                "Daemon not running: ~/.iai-mcp/.daemon.port not found."
+            )
+        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        return s, ("127.0.0.1", port)
+
+    env = os.environ.get("IAI_DAEMON_SOCKET_PATH")
+    path = env if env else str(SOCKET_PATH)
+    s = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
+    return s, path
+
+
+def send_sync_auth_token(sock: socket.socket) -> None:
+    """
+    Send the Windows auth token on a synchronous socket immediately after connect().
+    No-op on POSIX.
+    """
+    if IS_WINDOWS:
+        _send_token_sync(sock)
diff --git a/src/iai_mcp/backup.py b/src/iai_mcp/backup.py
index 40f2301..d425a67 100644
--- a/src/iai_mcp/backup.py
+++ b/src/iai_mcp/backup.py
@@ -29,7 +29,7 @@ def export_jsonl(output: Path | None = None) -> Path:
 
     records = store.all_records()
     count = 0
-    with open(output, "w") as f:
+    with open(output, "w", encoding="utf-8") as f:
         for rec in records:
             entry = {
                 "id": str(rec.id),
diff --git a/src/iai_mcp/capture.py b/src/iai_mcp/capture.py
index 9c54ae6..e2eeae4 100644
--- a/src/iai_mcp/capture.py
+++ b/src/iai_mcp/capture.py
@@ -94,6 +94,16 @@ def is_drain_in_progress() -> bool:
 
 
 def _pid_is_alive(pid: int) -> bool:
+    # NOT os.kill(pid, 0): on Windows signal 0 is CTRL_C_EVENT (it would try to
+    # signal the process group), not a liveness probe — so the stale-PID
+    # crash-recovery rescan never reclaims abandoned .processing-<pid> files.
+    # psutil.pid_exists is correct and cross-platform (psutil is a hard dep).
+    try:
+        import psutil
+
+        return psutil.pid_exists(pid)
+    except Exception:
+        pass
     try:
         os.kill(pid, 0)
     except ProcessLookupError:
@@ -113,11 +123,13 @@ def _strip_processing_marker(
         return path, True
     new_path = path.with_name(new_name)
     try:
-        path.rename(new_path)
+        # replace (not rename): rename raises on Windows if the dest exists;
+        # POSIX rename already replaces, so behaviour is unchanged there.
+        path.replace(new_path)
     except OSError as e:
         if log_path is not None:
             try:
-                with log_path.open("a") as logf:
+                with log_path.open("a", encoding="utf-8") as logf:
                     logf.write(
                         f"{datetime.now(timezone.utc).isoformat()} "
                         f"strip-marker-failed {path.name}: {type(e).__name__}\n"
@@ -163,7 +175,7 @@ def _quarantine_file(
     except Exception as exc:  # noqa: BLE001 -- fail-safe boundary
         log.debug("quarantine_event_write_failed: %s", exc)
         try:
-            with log_path.open("a") as logf:
+            with log_path.open("a", encoding="utf-8") as logf:
                 logf.write(
                     f"{datetime.now(timezone.utc).isoformat()} "
                     f"quarantined-event-skipped {target.name}\n"
@@ -172,7 +184,7 @@ def _quarantine_file(
             log.debug("quarantine_event_log_fallback_failed: %s", exc2)
 
     try:
-        with log_path.open("a") as logf:
+        with log_path.open("a", encoding="utf-8") as logf:
             logf.write(
                 f"{datetime.now(timezone.utc).isoformat()} "
                 f"quarantined {target.name}: crash_loop attempts={attempts}\n"
@@ -211,7 +223,7 @@ def _advance_failed_path(
     if next_attempt > FAILED_MAX_ATTEMPTS:
         new_name = f"{base}.permanent-failed-{ts_str}.jsonl"
         failed_path = fpath.with_name(new_name)
-        fpath.rename(failed_path)
+        fpath.replace(failed_path)
         try:
             from iai_mcp.events import write_event
 
@@ -229,7 +241,7 @@ def _advance_failed_path(
         except Exception as exc:  # noqa: BLE001 -- fail-safe boundary
             log.debug("permanent_capture_failure_event_failed: %s", exc)
             try:
-                with log_path.open("a") as logf:
+                with log_path.open("a", encoding="utf-8") as logf:
                     logf.write(
                         f"{datetime.now(timezone.utc).isoformat()} "
                         f"permanent_capture_failure-event-skipped {new_name}\n"
@@ -239,7 +251,7 @@ def _advance_failed_path(
         return failed_path
     new_name = f"{base}.failed-{ts_str}-attempt-{next_attempt}.jsonl"
     failed_path = fpath.with_name(new_name)
-    fpath.rename(failed_path)
+    fpath.replace(failed_path)
     return failed_path
 
 
@@ -481,7 +493,7 @@ def capture_transcript(
 
     counts = {"inserted": 0, "reinforced": 0, "skipped": 0, "errors": 0}
     seen = 0
-    with path.open() as fh:
+    with path.open(encoding="utf-8") as fh:
         for line in fh:
             if seen >= max_turns:
                 break
@@ -587,7 +599,7 @@ def write_deferred_event(
     deferred_dir.mkdir(parents=True, exist_ok=True)
     path = deferred_dir / f"{session_id}.live.jsonl"
     need_header = (not path.exists()) or path.stat().st_size == 0
-    with path.open("a") as fh:
+    with path.open("a", encoding="utf-8") as fh:
         if need_header:
             header = {
                 "version": 1,
@@ -716,7 +728,7 @@ def write_deferred_captures(
     final_name = f"{session_id}-{int(time.time())}-{os.getpid()}.jsonl"
     out_path = deferred_dir / final_name
     tmp_path = deferred_dir / f"{final_name}.tmp"
-    with tmp_path.open("w") as fh:
+    with tmp_path.open("w", encoding="utf-8") as fh:
         header = {
             "version": 1,
             "deferred_at": datetime.now(timezone.utc).isoformat(),
@@ -727,7 +739,7 @@ def write_deferred_captures(
         path = Path(transcript_path).expanduser()
         if path.exists():
             seen = 0
-            with path.open() as src:
+            with path.open(encoding="utf-8") as src:
                 for line in src:
                     if seen >= max_turns:
                         break
@@ -833,7 +845,7 @@ def _drain_deferred_captures_impl(store: MemoryStore) -> dict[str, int]:
                 ".jsonl", f".crash-{next_n}.jsonl"
             )
             try:
-                fpath.rename(fpath.with_name(new_name))
+                fpath.replace(fpath.with_name(new_name))
             except Exception as exc:  # noqa: BLE001
                 log.debug("crash_rename_failed %s: %s", fpath.name, exc)
 
@@ -867,12 +879,12 @@ def _drain_deferred_captures_impl(store: MemoryStore) -> dict[str, int]:
             fpath.stem + f".processing-{os.getpid()}.jsonl"
         )
         try:
-            fpath.rename(claim_path)
+            fpath.replace(claim_path)
         except FileNotFoundError:
             continue
         except OSError as e:
             try:
-                with log_path.open("a") as logf:
+                with log_path.open("a", encoding="utf-8") as logf:
                     logf.write(
                         f"{datetime.now(timezone.utc).isoformat()} "
                         f"claim-failed {fpath.name}: {type(e).__name__}\n"
@@ -885,14 +897,14 @@ def _drain_deferred_captures_impl(store: MemoryStore) -> dict[str, int]:
         file_had_insert_failure = False
         file_first_error: str | None = None
         try:
-            with work_path.open() as fh:
+            with work_path.open(encoding="utf-8") as fh:
                 lines = [ln.rstrip("\n") for ln in fh if ln.strip()]
             if not lines:
                 work_path.unlink()
                 continue
             header = json.loads(lines[0])
             if header.get("version", 0) > 1:
-                with log_path.open("a") as logf:
+                with log_path.open("a", encoding="utf-8") as logf:
                     logf.write(
                         f"{datetime.now(timezone.utc).isoformat()} skip "
                         f"{work_path.name}: version={header.get('version')}\n"
@@ -913,7 +925,7 @@ def _drain_deferred_captures_impl(store: MemoryStore) -> dict[str, int]:
                         break
                     partial_path = work_path.with_suffix(".partial.jsonl")
                     tmp_path = work_path.with_suffix(".partial.tmp")
-                    with tmp_path.open("w") as ph:
+                    with tmp_path.open("w", encoding="utf-8") as ph:
                         ph.write(lines[0] + "\n")
                         for r in remainder:
                             ph.write(r + "\n")
@@ -972,7 +984,7 @@ def _drain_deferred_captures_impl(store: MemoryStore) -> dict[str, int]:
                 )
                 if not _strip_ok:
                     try:
-                        with log_path.open("a") as logf:
+                        with log_path.open("a", encoding="utf-8") as logf:
                             logf.write(
                                 f"{datetime.now(timezone.utc).isoformat()} "
                                 f"insert-failed-skip {work_path.name}: "
@@ -988,7 +1000,7 @@ def _drain_deferred_captures_impl(store: MemoryStore) -> dict[str, int]:
                     first_error=file_first_error or "unknown",
                     log_path=log_path,
                 )
-                with log_path.open("a") as logf:
+                with log_path.open("a", encoding="utf-8") as logf:
                     logf.write(
                         f"{datetime.now(timezone.utc).isoformat()} insert-failed "
                         f"{work_path.name}: first_error={file_first_error}\n"
@@ -1004,7 +1016,7 @@ def _drain_deferred_captures_impl(store: MemoryStore) -> dict[str, int]:
                 )
                 if not _strip_ok:
                     try:
-                        with log_path.open("a") as logf:
+                        with log_path.open("a", encoding="utf-8") as logf:
                             logf.write(
                                 f"{datetime.now(timezone.utc).isoformat()} "
                                 f"exception-skip {work_path.name}: "
@@ -1020,7 +1032,7 @@ def _drain_deferred_captures_impl(store: MemoryStore) -> dict[str, int]:
                     first_error=file_first_error or repr(e),
                     log_path=log_path,
                 )
-                with log_path.open("a") as logf:
+                with log_path.open("a", encoding="utf-8") as logf:
                     logf.write(
                         f"{datetime.now(timezone.utc).isoformat()} failed "
                         f"{work_path.name}: {type(e).__name__}: {e}\n"
@@ -1043,7 +1055,7 @@ def _drain_deferred_captures_impl(store: MemoryStore) -> dict[str, int]:
 
 def _count_lines(fpath: Path) -> int:
     try:
-        with fpath.open() as fh:
+        with fpath.open(encoding="utf-8") as fh:
             return sum(1 for ln in fh if ln.strip())
     except OSError:
         return 0
@@ -1108,7 +1120,7 @@ def drain_permanent_failed_files(
         file_dropped = 0
 
         try:
-            with fpath.open() as fh:
+            with fpath.open(encoding="utf-8") as fh:
                 lines = [ln.rstrip("\n") for ln in fh if ln.strip()]
 
             if not lines:
@@ -1247,7 +1259,7 @@ def _drain_active_live_captures_impl(
         if not _LIVE_ACTIVE_RE.search(fpath.name):
             continue
         try:
-            with fpath.open() as fh:
+            with fpath.open(encoding="utf-8") as fh:
                 raw_lines = fh.readlines()
         except OSError:
             continue
@@ -1273,7 +1285,7 @@ def _drain_active_live_captures_impl(
         prev_offset: int = 0
         try:
             if offset_path.exists():
-                prev_offset = int(offset_path.read_text().strip() or "0")
+                prev_offset = int(offset_path.read_text(encoding="utf-8").strip() or "0")
         except (ValueError, OSError):
             prev_offset = 0
 
@@ -1321,7 +1333,7 @@ def _drain_active_live_captures_impl(
         state_dir.mkdir(parents=True, exist_ok=True)
         tmp_offset = offset_path.with_suffix(".drain-offset.tmp")
         try:
-            tmp_offset.write_text(str(new_offset))
+            tmp_offset.write_text(str(new_offset), encoding="utf-8")
             os.replace(tmp_offset, offset_path)
         except OSError as exc:
             log.warning("drain_active_offset_write_failed: %s", exc)
diff --git a/src/iai_mcp/capture_queue.py b/src/iai_mcp/capture_queue.py
index 3c601af..b157f7f 100644
--- a/src/iai_mcp/capture_queue.py
+++ b/src/iai_mcp/capture_queue.py
@@ -1,11 +1,12 @@
 from __future__ import annotations
 
 import errno
-import fcntl
 import json
 import os
 import secrets
 import threading
+
+from iai_mcp._filelock import LOCK_EX, LOCK_NB, LOCK_UN, flock
 import time
 from collections.abc import Callable
 from datetime import datetime, timezone
@@ -184,7 +185,7 @@ def ingest_pending(self, handler: Callable[[dict], None]) -> int:
 
             try:
                 try:
-                    fcntl.flock(lock_fd, fcntl.LOCK_EX | fcntl.LOCK_NB)
+                    flock(lock_fd, LOCK_EX | LOCK_NB)
                 except OSError as exc:
                     if exc.errno in (errno.EWOULDBLOCK, errno.EAGAIN):
                         continue
@@ -211,7 +212,7 @@ def ingest_pending(self, handler: Callable[[dict], None]) -> int:
                 ingested += 1
             finally:
                 try:
-                    fcntl.flock(lock_fd, fcntl.LOCK_UN)
+                    flock(lock_fd, LOCK_UN)
                 except OSError:
                     pass
                 os.close(lock_fd)
@@ -300,12 +301,12 @@ def _audit_drop(
             return
         try:
             try:
-                fcntl.flock(fd, fcntl.LOCK_EX)
+                flock(fd, LOCK_EX)
                 os.write(fd, line.encode("utf-8"))
                 os.fsync(fd)
             finally:
                 try:
-                    fcntl.flock(fd, fcntl.LOCK_UN)
+                    flock(fd, LOCK_UN)
                 except OSError:
                     pass
         finally:
diff --git a/src/iai_mcp/claude_cli.py b/src/iai_mcp/claude_cli.py
index db8b63f..81c0b75 100644
--- a/src/iai_mcp/claude_cli.py
+++ b/src/iai_mcp/claude_cli.py
@@ -70,7 +70,7 @@ def _read_keychain_credentials() -> dict | None:
 def verify_credentials_subscription() -> dict:
     if CREDENTIALS_PATH.exists():
         try:
-            data = json.loads(CREDENTIALS_PATH.read_text())
+            data = json.loads(CREDENTIALS_PATH.read_text(encoding="utf-8"))
         except (OSError, json.JSONDecodeError) as exc:
             return {"ok": False, "reason": "credentials_unreadable", "error": str(exc)}
     else:
diff --git a/src/iai_mcp/cli/__init__.py b/src/iai_mcp/cli/__init__.py
index da6501d..e8d0e53 100644
--- a/src/iai_mcp/cli/__init__.py
+++ b/src/iai_mcp/cli/__init__.py
@@ -23,6 +23,7 @@
 
 DAEMON_LABEL: str = "com.iai-mcp.daemon"
 SERVICE_NAME: str = "iai-mcp-daemon.service"
+SCHTASKS_TASK_NAME: str = "iai-mcp-daemon"
 
 CONSENT_BANNER: str = """\
 ==============================================================================
@@ -56,6 +57,10 @@ def _is_linux() -> bool:
     return platform.system() == "Linux"
 
 
+def _is_windows() -> bool:
+    return platform.system() == "Windows"
+
+
 def _ensure_crypto_key_present():
     if os.environ.get("IAI_MCP_CRYPTO_PASSPHRASE"):
         return None
@@ -72,15 +77,17 @@ def _ensure_crypto_key_present():
 
 
 def _try_short_timeout_connect(timeout_ms: int = 250) -> bool:
-    import socket as _socket
-
-    sock_path = os.environ.get("IAI_DAEMON_SOCKET_PATH") or str(SOCKET_PATH)
-    s = _socket.socket(_socket.AF_UNIX, _socket.SOCK_STREAM)
+    from iai_mcp._ipc import make_sync_ipc_socket, send_sync_auth_token
+    try:
+        s, addr = make_sync_ipc_socket()
+    except (FileNotFoundError, OSError):
+        return False
     s.settimeout(timeout_ms / 1000.0)
     try:
-        s.connect(sock_path)
+        s.connect(addr)
+        send_sync_auth_token(s)
         return True
-    except (FileNotFoundError, ConnectionRefusedError, OSError, _socket.timeout):
+    except (FileNotFoundError, ConnectionRefusedError, OSError):
         return False
     finally:
         try:
@@ -99,18 +106,14 @@ def _send_jsonrpc_request(
     read_timeout: float = 30.0,
 ) -> dict | None:
     import asyncio
+    from iai_mcp._ipc import open_ipc_connection
     from iai_mcp.cli._capture import _is_custom_store as _isc
     if not os.environ.get("IAI_DAEMON_SOCKET_PATH") and _isc():
         return None
 
-    sock_path = os.environ.get("IAI_DAEMON_SOCKET_PATH") or str(SOCKET_PATH)
-
     async def _runner() -> dict | None:
         try:
-            reader, writer = await asyncio.wait_for(
-                asyncio.open_unix_connection(sock_path),
-                timeout=connect_timeout,
-            )
+            reader, writer = await open_ipc_connection(timeout=connect_timeout)
         except (FileNotFoundError, ConnectionRefusedError, OSError, asyncio.TimeoutError):
             return None
         try:
@@ -142,17 +145,12 @@ async def _runner() -> dict | None:
 
 def _send_socket_request(req: dict, *, timeout: float = 30.0) -> dict | None:
     import asyncio
+    from iai_mcp._ipc import open_ipc_connection
 
     async def _runner() -> dict | None:
-        _sock = os.environ.get("IAI_DAEMON_SOCKET_PATH") or str(SOCKET_PATH)
         try:
-            reader, writer = await asyncio.wait_for(
-                asyncio.open_unix_connection(_sock),
-                timeout=5.0,
-            )
-        except (FileNotFoundError, ConnectionRefusedError):
-            return None
-        except OSError:
+            reader, writer = await open_ipc_connection(timeout=5.0)
+        except (FileNotFoundError, ConnectionRefusedError, OSError):
             return None
         try:
             writer.write((json.dumps(req) + "\n").encode("utf-8"))
@@ -324,6 +322,7 @@ def _maintenance_compact_metrics(
     _launchd_template,
     _render_launchd_plist,
     _render_systemd_unit,
+    _render_schtasks_xml,
     _prompt_consent,
     _record_consent_receipt,
     _remove_state_files,
@@ -658,14 +657,17 @@ def _build_parser() -> argparse.ArgumentParser:
     di = daemon_sub.add_parser(
         "install",
         help=(
-            "install launchd plist (macOS) / systemd user unit (Linux); "
-            "first-run consent banner unless --yes"
+            "install launchd plist (macOS) / systemd user unit (Linux) / "
+            "Task Scheduler job (Windows); first-run consent banner unless --yes"
         ),
     )
     di.add_argument(
         "--dry-run",
         action="store_true",
-        help="print plist/unit contents without writing or invoking launchctl/systemctl",
+        help=(
+            "print service definition (plist / unit / schtasks XML) without "
+            "writing or invoking launchctl/systemctl/schtasks"
+        ),
     )
     di.add_argument(
         "--yes", "-y",
@@ -676,17 +678,19 @@ def _build_parser() -> argparse.ArgumentParser:
 
     du = daemon_sub.add_parser(
         "uninstall",
-        help="C4 clean uninstall: remove plist/unit + 3 state files",
+        help="C4 clean uninstall: remove plist/unit/scheduled task + 3 state files",
     )
     du.add_argument("--yes", "-y", action="store_true")
     du.set_defaults(func=cmd_daemon_uninstall)
 
     daemon_sub.add_parser(
-        "start", help="launchctl kickstart / systemctl --user start",
+        "start",
+        help="launchctl kickstart / systemctl --user start / schtasks /Run",
     ).set_defaults(func=cmd_daemon_start)
 
     daemon_sub.add_parser(
-        "stop", help="launchctl kill SIGTERM / systemctl --user stop",
+        "stop",
+        help="launchctl kill SIGTERM / systemctl --user stop / schtasks /End",
     ).set_defaults(func=cmd_daemon_stop)
 
     daemon_sub.add_parser(
@@ -699,7 +703,10 @@ def _build_parser() -> argparse.ArgumentParser:
 
     dlogs = daemon_sub.add_parser(
         "logs",
-        help="tail daemon log file (macOS Library/Logs) or journalctl (Linux)",
+        help=(
+            "tail daemon log file (macOS Library/Logs, "
+            "Linux journalctl, Windows %%APPDATA%%\\iai-mcp\\logs)"
+        ),
     )
     dlogs.add_argument("-f", "--follow", action="store_true")
     dlogs.add_argument("-n", "--lines", type=int, default=50)
@@ -1046,7 +1053,23 @@ def _cmd_doctor_lazy(args: argparse.Namespace) -> int:
     return parser
 
 
+def _force_utf8_streams() -> None:
+    """Recalled memory is arbitrary UTF-8 (emoji, CJK, smart quotes, em-dashes).
+    The session-recall hook reads this CLI's stdout, but on Windows — and under
+    a POSIX C/POSIX locale — stdout/stderr default to a non-UTF-8 codepage, so
+    writing recalled memory would raise UnicodeEncodeError and the hook would
+    silently produce no context. Force UTF-8 on the std streams."""
+    for _stream in (sys.stdout, sys.stderr):
+        _reconfigure = getattr(_stream, "reconfigure", None)
+        if _reconfigure is not None:
+            try:
+                _reconfigure(encoding="utf-8")
+            except (ValueError, OSError):
+                pass
+
+
 def main(argv: list[str] | None = None) -> int:
+    _force_utf8_streams()
     parser = _build_parser()
     args = parser.parse_args(argv)
     return args.func(args)
diff --git a/src/iai_mcp/cli/_capture.py b/src/iai_mcp/cli/_capture.py
index 37f23d7..f65f3cb 100644
--- a/src/iai_mcp/cli/_capture.py
+++ b/src/iai_mcp/cli/_capture.py
@@ -90,7 +90,7 @@ def read_live_fingerprint(session_id: str) -> int | None:
     try:
         if not p.exists():
             return None
-        raw = p.read_text().strip()
+        raw = p.read_text(encoding="utf-8").strip()
         if not raw:
             return None
         return int(raw)
@@ -102,7 +102,7 @@ def write_live_fingerprint(session_id: str, total_size: int) -> None:
     d = Path.home() / ".iai-mcp" / ".capture-state"
     d.mkdir(parents=True, exist_ok=True)
     tmp = d / f"{session_id}.live-fingerprint.tmp"
-    tmp.write_text(str(total_size))
+    tmp.write_text(str(total_size), encoding="utf-8")
     os.replace(tmp, d / f"{session_id}.live-fingerprint")
 
 
@@ -142,7 +142,7 @@ def read_watermark(session_id: str) -> str | None:
     try:
         if not p.exists():
             return None
-        return p.read_text().strip() or None
+        return p.read_text(encoding="utf-8").strip() or None
     except OSError:
         return None
 
@@ -151,7 +151,7 @@ def write_watermark(session_id: str, ts: str) -> None:
     d = Path.home() / ".iai-mcp" / ".capture-state"
     d.mkdir(parents=True, exist_ok=True)
     tmp = d / f"{session_id}.watermark.tmp"
-    tmp.write_text(_utc_iso(ts))
+    tmp.write_text(_utc_iso(ts), encoding="utf-8")
     os.replace(tmp, d / f"{session_id}.watermark")
 
 
@@ -276,11 +276,11 @@ def cmd_capture_turn_deferred(args: argparse.Namespace) -> int:
         prev_offset = 0
         if offset_path.exists():
             try:
-                prev_offset = int(offset_path.read_text().strip() or "0")
+                prev_offset = int(offset_path.read_text(encoding="utf-8").strip() or "0")
             except ValueError:
                 prev_offset = 0
 
-        with transcript.open() as fh:
+        with transcript.open(encoding="utf-8") as fh:
             all_lines = fh.readlines()
         total = len(all_lines)
 
@@ -310,7 +310,7 @@ def cmd_capture_turn_deferred(args: argparse.Namespace) -> int:
 
         new_offset = prev_offset + consumed
         tmp_path = offset_path.parent / (offset_path.name + ".tmp")
-        tmp_path.write_text(str(new_offset))
+        tmp_path.write_text(str(new_offset), encoding="utf-8")
         os.replace(tmp_path, offset_path)
         return 0
     except Exception as e:
@@ -323,15 +323,17 @@ def cmd_capture_turn_deferred(args: argparse.Namespace) -> int:
 
 
 def _capture_hook_paths() -> tuple:
-    src = _res.files("iai_mcp") / "_deploy" / "hooks" / "iai-mcp-session-capture.sh"
-    dst = Path.home() / ".claude" / "hooks" / "iai-mcp-session-capture.sh"
+    ext = _hook_ext()
+    src = _res.files("iai_mcp") / "_deploy" / "hooks" / f"iai-mcp-session-capture{ext}"
+    dst = Path.home() / ".claude" / "hooks" / f"iai-mcp-session-capture{ext}"
     settings = Path.home() / ".claude" / "settings.json"
     return src, dst, settings
 
 
 def _turn_hook_paths() -> tuple:
-    src = _res.files("iai_mcp") / "_deploy" / "hooks" / "iai-mcp-turn-capture.sh"
-    dst = Path.home() / ".claude" / "hooks" / "iai-mcp-turn-capture.sh"
+    ext = _hook_ext()
+    src = _res.files("iai_mcp") / "_deploy" / "hooks" / f"iai-mcp-turn-capture{ext}"
+    dst = Path.home() / ".claude" / "hooks" / f"iai-mcp-turn-capture{ext}"
     return src, dst
 
 
@@ -387,6 +389,38 @@ def _build_iai_mcp_server_entry() -> dict:
     }
 
 
+def _iai_entry_or_placeholder(config_label: str, *, include_type: bool) -> dict:
+    """Build the MCP server entry, or a placeholder (with a stderr warning)
+    when the wrapper isn't built yet, so ``capture-hooks install`` doesn't
+    crash mid-run after it has already written the hooks. ``include_type``
+    controls the stdio ``type`` field that Claude Code expects but Claude
+    Desktop omits."""
+    from iai_mcp import cli as _cli
+
+    try:
+        entry = _build_iai_mcp_server_entry()
+    except FileNotFoundError as exc:
+        print(
+            f"WARN: MCP wrapper not found — {config_label} entry written with "
+            f"placeholder args. Build it first: cd mcp-wrapper && npm run build. "
+            f"({exc})",
+            file=_cli.sys.stderr,
+        )
+        entry = {
+            "command": "node",
+            "args": ["<run: cd mcp-wrapper && npm run build>"],
+            "env": {
+                "IAI_MCP_PYTHON": _cli.sys.executable,
+                "IAI_MCP_STORE": str(Path.home() / ".iai-mcp"),
+                "TRANSFORMERS_VERBOSITY": "error",
+                "TOKENIZERS_PARALLELISM": "false",
+            },
+        }
+    if include_type:
+        entry.setdefault("type", "stdio")
+    return entry
+
+
 def _patch_claude_desktop_config(action: str) -> str:
     from iai_mcp import cli as _cli
     import json as _json
@@ -399,12 +433,13 @@ def _patch_claude_desktop_config(action: str) -> str:
         if action == "uninstall":
             return f"Claude Desktop: {cfg_path} absent — skipped"
         cfg_path.parent.mkdir(parents=True, exist_ok=True)
-        data = {"mcpServers": {"iai-mcp": _build_iai_mcp_server_entry()}}
-        cfg_path.write_text(_json.dumps(data, indent=2))
+        entry = _iai_entry_or_placeholder("Claude Desktop", include_type=False)
+        data = {"mcpServers": {"iai-mcp": entry}}
+        cfg_path.write_text(_json.dumps(data, indent=2), encoding="utf-8")
         return f"Claude Desktop: created {cfg_path} with iai-mcp registered"
 
     try:
-        data = _json.loads(cfg_path.read_text())
+        data = _json.loads(cfg_path.read_text(encoding="utf-8"))
     except (OSError, ValueError) as e:
         return f"Claude Desktop: {cfg_path} unreadable ({type(e).__name__}) — skipped"
 
@@ -413,20 +448,19 @@ def _patch_claude_desktop_config(action: str) -> str:
     if action == "uninstall":
         if "iai-mcp" in servers:
             servers.pop("iai-mcp", None)
-            cfg_path.write_text(_json.dumps(data, indent=2))
+            cfg_path.write_text(_json.dumps(data, indent=2), encoding="utf-8")
             return f"Claude Desktop: removed iai-mcp from {cfg_path}"
         return f"Claude Desktop: iai-mcp not in config — no change"
 
-    new_entry = _build_iai_mcp_server_entry()
+    new_entry = _iai_entry_or_placeholder("Claude Desktop", include_type=False)
     if servers.get("iai-mcp") == new_entry:
         return f"Claude Desktop: {cfg_path} already has iai-mcp — no change"
     servers["iai-mcp"] = new_entry
-    cfg_path.write_text(_json.dumps(data, indent=2))
+    cfg_path.write_text(_json.dumps(data, indent=2), encoding="utf-8")
     return f"Claude Desktop: patched {cfg_path} (iai-mcp registered)"
 
 
 def _patch_claude_code_config(action: str) -> str:
-    from iai_mcp import cli as _cli
     import json as _json
 
     cfg_path = Path.home() / ".claude.json"
@@ -435,46 +469,25 @@ def _patch_claude_code_config(action: str) -> str:
         if not cfg_path.exists():
             return "Claude Code: ~/.claude.json absent — skipped"
         try:
-            data = _json.loads(cfg_path.read_text())
+            data = _json.loads(cfg_path.read_text(encoding="utf-8"))
         except (OSError, ValueError) as e:
             return f"Claude Code: ~/.claude.json unreadable ({type(e).__name__}) — skipped"
         servers = data.get("mcpServers", {})
         if "iai-mcp" in servers:
             servers.pop("iai-mcp")
             data["mcpServers"] = servers
-            cfg_path.write_text(_json.dumps(data, indent=2))
+            cfg_path.write_text(_json.dumps(data, indent=2), encoding="utf-8")
             return "Claude Code: removed iai-mcp from ~/.claude.json"
         return "Claude Code: iai-mcp not in ~/.claude.json — no change"
 
-    try:
-        entry = _build_iai_mcp_server_entry()
-    except FileNotFoundError as exc:
-        entry = {
-            "type": "stdio",
-            "command": "node",
-            "args": ["<run: cd mcp-wrapper && npm run build>"],
-            "env": {
-                "IAI_MCP_PYTHON": _cli.sys.executable,
-                "IAI_MCP_STORE": str(Path.home() / ".iai-mcp"),
-                "TRANSFORMERS_VERBOSITY": "error",
-                "TOKENIZERS_PARALLELISM": "false",
-            },
-        }
-        print(
-            f"WARN: MCP wrapper not found — ~/.claude.json entry written with "
-            f"placeholder args. Build it first: cd mcp-wrapper && npm run build. "
-            f"({exc})",
-            file=_cli.sys.stderr,
-        )
-    else:
-        entry.setdefault("type", "stdio")
+    entry = _iai_entry_or_placeholder("~/.claude.json", include_type=True)
 
     if not cfg_path.exists():
-        cfg_path.write_text(_json.dumps({"mcpServers": {"iai-mcp": entry}}, indent=2))
+        cfg_path.write_text(_json.dumps({"mcpServers": {"iai-mcp": entry}}, indent=2), encoding="utf-8")
         return "Claude Code: created ~/.claude.json with iai-mcp registered"
 
     try:
-        data = _json.loads(cfg_path.read_text())
+        data = _json.loads(cfg_path.read_text(encoding="utf-8"))
     except (OSError, ValueError) as e:
         return f"Claude Code: ~/.claude.json unreadable ({type(e).__name__}) — skipped"
 
@@ -482,18 +495,25 @@ def _patch_claude_code_config(action: str) -> str:
     if servers.get("iai-mcp") == entry:
         return "Claude Code: ~/.claude.json already has iai-mcp — no change"
     servers["iai-mcp"] = entry
-    cfg_path.write_text(_json.dumps(data, indent=2))
+    cfg_path.write_text(_json.dumps(data, indent=2), encoding="utf-8")
     return "Claude Code: patched ~/.claude.json (iai-mcp registered)"
 
 
-_CAPTURE_HOOK_MARKER = "iai-mcp-session-capture.sh"
-_TURN_HOOK_MARKER = "iai-mcp-turn-capture.sh"
-_SESSION_RECALL_HOOK_MARKER = "iai-mcp-session-recall.sh"
+import platform as _platform
+
+_CAPTURE_HOOK_MARKER = "iai-mcp-session-capture"
+_TURN_HOOK_MARKER = "iai-mcp-turn-capture"
+_SESSION_RECALL_HOOK_MARKER = "iai-mcp-session-recall"
+
+
+def _hook_ext() -> str:
+    return ".ps1" if _platform.system() == "Windows" else ".sh"
 
 
 def _session_recall_hook_paths() -> tuple:
-    src = _res.files("iai_mcp") / "_deploy" / "hooks" / "iai-mcp-session-recall.sh"
-    dst = Path.home() / ".claude" / "hooks" / "iai-mcp-session-recall.sh"
+    ext = _hook_ext()
+    src = _res.files("iai_mcp") / "_deploy" / "hooks" / f"iai-mcp-session-recall{ext}"
+    dst = Path.home() / ".claude" / "hooks" / f"iai-mcp-session-recall{ext}"
     settings = Path.home() / ".claude" / "settings.json"
     return src, dst, settings
 
@@ -503,7 +523,7 @@ def _load_settings(path):
     if not path.exists():
         return {}
     try:
-        return _json.loads(path.read_text())
+        return _json.loads(path.read_text(encoding="utf-8"))
     except (OSError, ValueError):
         return {}
 
@@ -525,12 +545,14 @@ def cmd_capture_hooks_install(args: argparse.Namespace) -> int:
 
     dst.parent.mkdir(parents=True, exist_ok=True)
     dst.write_bytes(src.read_bytes())
-    dst.chmod(dst.stat().st_mode | stat.S_IXUSR | stat.S_IXGRP)
+    if hasattr(os, "chmod") and _platform.system() != "Windows":
+        dst.chmod(dst.stat().st_mode | stat.S_IXUSR | stat.S_IXGRP)
     print(f"installed: {dst}")
 
     turn_dst.parent.mkdir(parents=True, exist_ok=True)
     turn_dst.write_bytes(turn_src.read_bytes())
-    turn_dst.chmod(turn_dst.stat().st_mode | stat.S_IXUSR | stat.S_IXGRP)
+    if hasattr(os, "chmod") and _platform.system() != "Windows":
+        turn_dst.chmod(turn_dst.stat().st_mode | stat.S_IXUSR | stat.S_IXGRP)
     print(f"installed: {turn_dst}")
 
     settings.parent.mkdir(parents=True, exist_ok=True)
@@ -539,8 +561,12 @@ def cmd_capture_hooks_install(args: argparse.Namespace) -> int:
     stop_list = data["hooks"].setdefault("Stop", [])
     submit_list = data["hooks"].setdefault("UserPromptSubmit", [])
 
-    hook_cmd = f"bash {dst}"
-    turn_cmd = f"bash {turn_dst}"
+    if _platform.system() == "Windows":
+        hook_cmd = f"powershell -ExecutionPolicy Bypass -File \"{dst}\""
+        turn_cmd = f"powershell -ExecutionPolicy Bypass -File \"{turn_dst}\""
+    else:
+        hook_cmd = f"bash {dst}"
+        turn_cmd = f"bash {turn_dst}"
 
     already_stop = any(
         any(_CAPTURE_HOOK_MARKER in (h.get("command") or "")
@@ -568,11 +594,15 @@ def cmd_capture_hooks_install(args: argparse.Namespace) -> int:
     if src_recall.exists():
         dst_recall.parent.mkdir(parents=True, exist_ok=True)
         dst_recall.write_bytes(src_recall.read_bytes())
-        dst_recall.chmod(dst_recall.stat().st_mode | stat.S_IXUSR | stat.S_IXGRP)
+        if hasattr(os, "chmod") and _platform.system() != "Windows":
+            dst_recall.chmod(dst_recall.stat().st_mode | stat.S_IXUSR | stat.S_IXGRP)
         print(f"installed: {dst_recall}")
 
         ss_list = data["hooks"].setdefault("SessionStart", [])
-        recall_cmd = f"bash {dst_recall}"
+        if _platform.system() == "Windows":
+            recall_cmd = f"powershell -ExecutionPolicy Bypass -File \"{dst_recall}\""
+        else:
+            recall_cmd = f"bash {dst_recall}"
         already_recall = any(
             any(_SESSION_RECALL_HOOK_MARKER in (h.get("command") or "")
                 for h in (entry.get("hooks") or []))
@@ -589,7 +619,7 @@ def cmd_capture_hooks_install(args: argparse.Namespace) -> int:
     else:
         print(f"WARN: recall hook template missing in package data: {src_recall}")
 
-    settings.write_text(_json.dumps(data, indent=2))
+    settings.write_text(_json.dumps(data, indent=2), encoding="utf-8")
 
     code_msg = _patch_claude_code_config("install")
     print(code_msg)
@@ -648,7 +678,7 @@ def cmd_capture_hooks_uninstall(args: argparse.Namespace) -> int:
                 changed = True
                 print(f"patched: {settings} ({key} entry removed)")
         if changed:
-            settings.write_text(_json.dumps(data, indent=2))
+            settings.write_text(_json.dumps(data, indent=2), encoding="utf-8")
         else:
             print(f"(no hook entry to remove) {settings}")
 
@@ -664,7 +694,7 @@ def cmd_capture_hooks_uninstall(args: argparse.Namespace) -> int:
                 data["hooks"]["SessionStart"] = kept_ss
             else:
                 data["hooks"].pop("SessionStart", None)
-            settings.write_text(_json.dumps(data, indent=2))
+            settings.write_text(_json.dumps(data, indent=2), encoding="utf-8")
             print(f"patched: {settings} (SessionStart entry removed)")
         else:
             print(f"(no SessionStart entry to remove) {settings}")
@@ -724,7 +754,7 @@ def cmd_capture_hooks_status(args: argparse.Namespace) -> int:
         desktop_wired = False
     else:
         try:
-            d = _json.loads(desktop_cfg.read_text())
+            d = _json.loads(desktop_cfg.read_text(encoding="utf-8"))
             desktop_wired = "iai-mcp" in d.get("mcpServers", {})
             desktop_line = f"Claude Desktop: {desktop_cfg}  {'WIRED' if desktop_wired else 'NOT WIRED'}"
         except (OSError, ValueError):
diff --git a/src/iai_mcp/cli/_crypto.py b/src/iai_mcp/cli/_crypto.py
index 3a41997..a6a32bb 100644
--- a/src/iai_mcp/cli/_crypto.py
+++ b/src/iai_mcp/cli/_crypto.py
@@ -35,8 +35,10 @@ def cmd_crypto_status(args: argparse.Namespace) -> int:
         length = st.st_size
         status["mode"] = mode_octal
         status["mode_secure"] = (st.st_mode & 0o077 == 0)
-        status["uid"] = st.st_uid
-        status["uid_matches_process"] = (st.st_uid == _os.geteuid())
+        status["uid"] = getattr(st, "st_uid", -1)
+        status["uid_matches_process"] = (
+            hasattr(_os, "geteuid") and st.st_uid == _os.geteuid()
+        )
         status["length_bytes"] = length
         status["length_valid"] = (length == KEY_BYTES)
         status["passphrase_fallback_set"] = bool(
diff --git a/src/iai_mcp/cli/_daemon.py b/src/iai_mcp/cli/_daemon.py
index 609eca5..98b8b58 100644
--- a/src/iai_mcp/cli/_daemon.py
+++ b/src/iai_mcp/cli/_daemon.py
@@ -63,7 +63,7 @@ def _launchd_template():
 
 def _render_launchd_plist() -> str:
     from iai_mcp import cli as _cli
-    text = _launchd_template().read_text()
+    text = _launchd_template().read_text(encoding="utf-8")
     username = os.environ.get("USER") or Path.home().name
     text = text.replace("/usr/local/bin/python3", _cli.sys.executable)
     text = text.replace("{USERNAME}", username)
@@ -73,11 +73,64 @@ def _render_launchd_plist() -> str:
 def _render_systemd_unit() -> str:
     from iai_mcp import cli as _cli
     tmpl = _res.files("iai_mcp") / "_deploy" / "systemd" / "iai-mcp-daemon.service"
-    text = tmpl.read_text()
+    text = tmpl.read_text(encoding="utf-8")
     text = text.replace("/usr/bin/python3", _cli.sys.executable)
     return text
 
 
+def _find_pythonw() -> str:
+    exe = Path(sys.executable)
+    pythonw = exe.parent / "pythonw.exe"
+    if pythonw.exists():
+        return str(pythonw)
+    return sys.executable
+
+
+def _render_schtasks_xml() -> str:
+    pythonw = _find_pythonw()
+    username = os.environ.get("USERNAME", "")
+    # No <WorkingDirectory>: the Task Scheduler engine rejects a working
+    # directory set via XML when the path contains spaces (e.g. the default
+    # %APPDATA% under "C:\\Users\\First Last\\..."), failing the launch with
+    # 0x8007010B "The directory name is invalid" — even though the path exists
+    # and CreateProcess accepts it fine outside the scheduler. The daemon never
+    # depends on cwd (all state lives under ~/.iai-mcp via absolute paths), so
+    # we omit it and let the task default to %windir%\\system32.
+    return f"""\
+<?xml version="1.0" encoding="UTF-16"?>
+<Task version="1.2" xmlns="http://schemas.microsoft.com/windows/2004/02/mit/task">
+  <RegistrationInfo>
+    <Description>iai-mcp sleep daemon — background memory consolidation for Claude Code</Description>
+  </RegistrationInfo>
+  <Triggers>
+    <LogonTrigger>
+      <Enabled>true</Enabled>
+      <UserId>{username}</UserId>
+    </LogonTrigger>
+  </Triggers>
+  <Principals>
+    <Principal id="Author">
+      <UserId>{username}</UserId>
+      <LogonType>InteractiveToken</LogonType>
+      <RunLevel>LeastPrivilege</RunLevel>
+    </Principal>
+  </Principals>
+  <Settings>
+    <MultipleInstancesPolicy>IgnoreNew</MultipleInstancesPolicy>
+    <DisallowStartIfOnBatteries>false</DisallowStartIfOnBatteries>
+    <StopIfGoingOnBatteries>false</StopIfGoingOnBatteries>
+    <ExecutionTimeLimit>PT0S</ExecutionTimeLimit>
+    <Hidden>true</Hidden>
+  </Settings>
+  <Actions>
+    <Exec>
+      <Command>{pythonw}</Command>
+      <Arguments>-m iai_mcp.daemon</Arguments>
+    </Exec>
+  </Actions>
+</Task>"""
+
+
 def _prompt_consent(stream_out=None) -> bool:
     from iai_mcp import cli as _cli
     if stream_out is None:
@@ -106,7 +159,7 @@ def _record_consent_receipt() -> None:
     safe_ts = ts.replace(":", "").replace("-", "").replace(".", "")
     receipt = state_dir / f".consent-{safe_ts}.json"
     try:
-        receipt.write_text(json.dumps(payload, indent=2))
+        receipt.write_text(json.dumps(payload, indent=2), encoding="utf-8")
         os.chmod(receipt, 0o600)
     except OSError as exc:
         print(f"warning: could not write consent receipt: {exc}", file=sys.stderr)
@@ -140,25 +193,71 @@ def cmd_daemon_install(args: argparse.Namespace) -> int:
     elif _cli._is_linux():
         content = _render_systemd_unit()
         target = _cli.SYSTEMD_TARGET
+    elif _cli._is_windows():
+        content = _render_schtasks_xml()
+        target = None
     else:
         print(f"Unsupported OS: {platform.system()}", file=sys.stderr)
         return 1
 
     if dry_run:
-        print(f"# Would install to: {target}")
+        if target is not None:
+            print(f"# Would install to: {target}")
+        else:
+            print(f"# Would create scheduled task: {_cli.SCHTASKS_TASK_NAME}")
         print(content)
         return 0
 
+    _cli._ensure_crypto_key_present()
+
+    if _cli._is_windows():
+        import subprocess as _sp
+        import tempfile as _tmpmod
+
+        log_dir = Path(os.environ.get("APPDATA", str(Path.home()))) / "iai-mcp" / "logs"
+        log_dir.mkdir(parents=True, exist_ok=True)
+
+        fd, xml_path = _tmpmod.mkstemp(suffix=".xml", prefix="iai-mcp-task-")
+        try:
+            with os.fdopen(fd, "w", encoding="utf-16") as f:
+                f.write(content)
+            result = _sp.run(
+                [
+                    "schtasks", "/Create",
+                    "/TN", _cli.SCHTASKS_TASK_NAME,
+                    "/XML", xml_path,
+                    "/F",
+                ],
+                check=False, capture_output=True, text=True,
+            )
+            if result.returncode != 0:
+                print(
+                    f"schtasks /Create failed ({result.returncode}): "
+                    f"{result.stderr.strip()}",
+                    file=sys.stderr,
+                )
+                return 1
+        finally:
+            try:
+                os.unlink(xml_path)
+            except OSError:
+                pass
+
+        _sp.run(
+            ["schtasks", "/Run", "/TN", _cli.SCHTASKS_TASK_NAME],
+            check=False, capture_output=True,
+        )
+        print(f"Installed scheduled task: {_cli.SCHTASKS_TASK_NAME}")
+        return 0
+
     target.parent.mkdir(parents=True, exist_ok=True)
-    target.write_text(content)
+    target.write_text(content, encoding="utf-8")
     try:
         os.chmod(target, 0o644)
     except OSError:
         pass
 
-    _cli._ensure_crypto_key_present()
-
-    uid = os.getuid()
+    uid = os.getuid() if hasattr(os, "getuid") else 0
     if _cli._is_macos():
         _cli.subprocess.run(
             ["launchctl", "bootout", f"gui/{uid}", str(target)],
@@ -228,7 +327,7 @@ def cmd_daemon_uninstall(args: argparse.Namespace) -> int:
             print("Uninstall cancelled.", file=sys.stderr)
             return 1
 
-    uid = os.getuid()
+    uid = os.getuid() if hasattr(os, "getuid") else 0
     if _cli._is_macos():
         if _cli.LAUNCHD_TARGET.exists():
             _cli.subprocess.run(
@@ -253,6 +352,16 @@ def cmd_daemon_uninstall(args: argparse.Namespace) -> int:
                 ["systemctl", "--user", "daemon-reload"],
                 check=False, capture_output=True,
             )
+    elif _cli._is_windows():
+        import subprocess as _sp
+        _sp.run(
+            ["schtasks", "/End", "/TN", _cli.SCHTASKS_TASK_NAME],
+            check=False, capture_output=True,
+        )
+        _sp.run(
+            ["schtasks", "/Delete", "/TN", _cli.SCHTASKS_TASK_NAME, "/F"],
+            check=False, capture_output=True,
+        )
 
     _remove_state_files()
     print("Daemon uninstalled. State files removed.")
@@ -261,7 +370,7 @@ def cmd_daemon_uninstall(args: argparse.Namespace) -> int:
 
 def cmd_daemon_start(args: argparse.Namespace) -> int:
     from iai_mcp import cli as _cli
-    uid = os.getuid()
+    uid = os.getuid() if hasattr(os, "getuid") else 0
     if _cli._is_macos():
         target = _cli.LAUNCHD_TARGET
         _cli.subprocess.run(
@@ -282,6 +391,12 @@ def cmd_daemon_start(args: argparse.Namespace) -> int:
             ["systemctl", "--user", "start", _cli.SERVICE_NAME],
             check=False,
         )
+    elif _cli._is_windows():
+        import subprocess as _sp
+        _sp.run(
+            ["schtasks", "/Run", "/TN", _cli.SCHTASKS_TASK_NAME],
+            check=False, capture_output=True,
+        )
     else:
         print(f"Unsupported OS: {platform.system()}", file=sys.stderr)
         return 1
@@ -302,7 +417,7 @@ def cmd_daemon_stop(args: argparse.Namespace) -> int:
     except (OSError, ValueError, RuntimeError) as exc:
         logger.debug("sentinel write failed (non-blocking): %s", exc)
 
-    uid = os.getuid()
+    uid = os.getuid() if hasattr(os, "getuid") else 0
     if _cli._is_macos():
         from iai_mcp.lifecycle_lock import LifecycleLock, _is_pid_alive
 
@@ -318,8 +433,9 @@ def cmd_daemon_stop(args: argparse.Namespace) -> int:
             return 0
 
         if _is_pid_alive(pid):
+            _term_sig = getattr(_signal, "SIGTERM", _signal.SIGINT)
             try:
-                os.kill(pid, _signal.SIGTERM)
+                os.kill(pid, _term_sig)
             except (ProcessLookupError, PermissionError) as exc:
                 logger.debug("SIGTERM to daemon pid=%d failed: %s", pid, exc)
                 return 0
@@ -332,8 +448,9 @@ def cmd_daemon_stop(args: argparse.Namespace) -> int:
                 _time.sleep(interval)
 
             if _is_pid_alive(pid):
+                _kill_sig = getattr(_signal, "SIGKILL", _term_sig)
                 try:
-                    os.kill(pid, _signal.SIGKILL)
+                    os.kill(pid, _kill_sig)
                 except (ProcessLookupError, PermissionError) as exc:
                     logger.debug("SIGKILL to daemon pid=%d failed: %s", pid, exc)
         return 0
@@ -342,6 +459,36 @@ def cmd_daemon_stop(args: argparse.Namespace) -> int:
             ["systemctl", "--user", "stop", _cli.SERVICE_NAME],
             check=False,
         )
+    elif _cli._is_windows():
+        import subprocess as _sp
+        from iai_mcp.lifecycle_lock import LifecycleLock, _is_pid_alive
+
+        _sp.run(
+            ["schtasks", "/End", "/TN", _cli.SCHTASKS_TASK_NAME],
+            check=False, capture_output=True,
+        )
+
+        payload = LifecycleLock().read()
+        pid = payload["pid"] if payload else None
+        if pid is not None and _is_pid_alive(pid):
+            try:
+                os.kill(pid, _signal.SIGINT)
+            except (ProcessLookupError, PermissionError) as exc:
+                logger.debug("SIGINT to daemon pid=%d failed: %s", pid, exc)
+                return 0
+
+            deadline = _time.monotonic() + _stop_escalation_bound()
+            interval = _stop_poll_interval()
+            while _time.monotonic() < deadline:
+                if not _is_pid_alive(pid):
+                    return 0
+                _time.sleep(interval)
+
+            if _is_pid_alive(pid):
+                _sp.run(
+                    ["taskkill", "/F", "/PID", str(pid)],
+                    check=False, capture_output=True,
+                )
     else:
         print(f"Unsupported OS: {platform.system()}", file=sys.stderr)
         return 1
@@ -437,12 +584,20 @@ def cmd_daemon_status(args: argparse.Namespace) -> int:
     return 0
 
 
+def _get_daemon_log_path() -> Path:
+    if platform.system() == "Darwin":
+        return Path.home() / "Library" / "Logs" / "iai-mcp-daemon.stderr.log"
+    if platform.system() == "Windows":
+        return Path(os.environ.get("APPDATA", str(Path.home()))) / "iai-mcp" / "logs" / "daemon.log"
+    return Path.home() / ".local" / "share" / "iai-mcp" / "logs" / "daemon.log"
+
+
 def cmd_daemon_logs(args: argparse.Namespace) -> int:
     from iai_mcp import cli as _cli
     follow = bool(getattr(args, "follow", False))
     lines = int(getattr(args, "lines", 50))
     if _cli._is_macos():
-        path = Path.home() / "Library" / "Logs" / "iai-mcp-daemon.stderr.log"
+        path = _get_daemon_log_path()
         argv = ["tail"]
         if follow:
             argv.append("-f")
@@ -453,6 +608,15 @@ def cmd_daemon_logs(args: argparse.Namespace) -> int:
         if follow:
             argv.append("-f")
         _cli.subprocess.run(argv, check=False)
+    elif platform.system() == "Windows":
+        path = _get_daemon_log_path()
+        if not path.exists():
+            print(f"No log file at {path}", file=sys.stderr)
+            return 1
+        with open(path, "r", encoding="utf-8", errors="replace") as f:
+            all_lines = f.readlines()
+        for line in all_lines[-lines:]:
+            print(line, end="")
     else:
         print(f"Unsupported OS: {platform.system()}", file=sys.stderr)
         return 1
diff --git a/src/iai_mcp/cli/_maintenance.py b/src/iai_mcp/cli/_maintenance.py
index 228956f..d177c66 100644
--- a/src/iai_mcp/cli/_maintenance.py
+++ b/src/iai_mcp/cli/_maintenance.py
@@ -63,7 +63,7 @@ def _maintenance_compact_preflight_daemon_alive() -> str | None:
     if not _cli.STATE_PATH.exists():
         return None
     try:
-        state = _json.loads(_cli.STATE_PATH.read_text())
+        state = _json.loads(_cli.STATE_PATH.read_text(encoding="utf-8"))
     except (OSError, ValueError):
         return None
     pid = state.get("daemon_pid")
@@ -181,7 +181,7 @@ def _maintenance_compact_apply(
         }
         try:
             failed_path.parent.mkdir(parents=True, exist_ok=True)
-            failed_path.write_text(_json.dumps(failed_payload, indent=2))
+            failed_path.write_text(_json.dumps(failed_payload, indent=2), encoding="utf-8")
         except OSError:
             pass
         print(
@@ -206,7 +206,7 @@ def _maintenance_compact_apply(
     }
     try:
         audit_path.parent.mkdir(parents=True, exist_ok=True)
-        audit_path.write_text(_json.dumps(payload, indent=2))
+        audit_path.write_text(_json.dumps(payload, indent=2), encoding="utf-8")
     except OSError as exc:
         print(
             f"warning: could not write audit file {audit_path}: {exc}",
diff --git a/src/iai_mcp/concurrency.py b/src/iai_mcp/concurrency.py
index cf74987..f8a80e4 100644
--- a/src/iai_mcp/concurrency.py
+++ b/src/iai_mcp/concurrency.py
@@ -13,15 +13,8 @@
 
 
 def cleanup_stale_socket(path: Path = SOCKET_PATH) -> None:
-    try:
-        path.unlink()
-    except FileNotFoundError:
-        pass
-    except OSError:
-        try:
-            path.unlink()
-        except OSError:
-            pass
+    from iai_mcp._ipc import cleanup_ipc_address
+    cleanup_ipc_address(path)
 
 
 def _validate_socket_message(req: dict) -> tuple[bool, str | None]:
@@ -238,19 +231,11 @@ async def serve_control_socket(
     dispatcher: Callable[[dict], Awaitable[dict]] | None = None,
     socket_path: Path = SOCKET_PATH,
 ) -> None:
-    cleanup_stale_socket(socket_path)
-    socket_path.parent.mkdir(parents=True, exist_ok=True)
+    from iai_mcp._ipc import IS_WINDOWS, cleanup_ipc_address, start_ipc_server, shutdown_ipc
 
-    _supports_cleanup_socket = False
-    try:
-        import inspect as _inspect
-        import asyncio as _asyncio_mod
-        _loop_sig = _inspect.signature(
-            _asyncio_mod.get_event_loop_policy().new_event_loop().create_unix_server
-        )
-        _supports_cleanup_socket = "cleanup_socket" in _loop_sig.parameters
-    except (TypeError, ValueError, AttributeError):
-        _supports_cleanup_socket = False
+    cleanup_ipc_address(socket_path)
+    if not IS_WINDOWS:
+        socket_path.parent.mkdir(parents=True, exist_ok=True)
 
     async def handle(reader: asyncio.StreamReader, writer: asyncio.StreamWriter) -> None:
         try:
@@ -280,23 +265,16 @@ async def handle(reader: asyncio.StreamReader, writer: asyncio.StreamWriter) ->
             except (OSError, ConnectionError):  # noqa: BLE001 -- cleanup is best-effort
                 pass
 
-    _server_kwargs = {"cleanup_socket": True} if _supports_cleanup_socket else {}
-    server = await asyncio.start_unix_server(
-        handle, path=str(socket_path), **_server_kwargs,
-    )
-    try:
-        os.chmod(str(socket_path), 0o600)
-    except OSError:
-        pass
+    server, actual_addr, needs_cleanup = await start_ipc_server(handle, socket_path)
+    if not IS_WINDOWS:
+        try:
+            os.chmod(str(socket_path), 0o600)
+        except OSError:
+            pass
 
     try:
         async with server:
             await shutdown.wait()
     finally:
-        if not _supports_cleanup_socket:
-            try:
-                socket_path.unlink()
-            except FileNotFoundError:
-                pass
-            except OSError:
-                pass
+        if needs_cleanup:
+            shutdown_ipc(actual_addr)
diff --git a/src/iai_mcp/core/__init__.py b/src/iai_mcp/core/__init__.py
index efeb543..60c1998 100644
--- a/src/iai_mcp/core/__init__.py
+++ b/src/iai_mcp/core/__init__.py
@@ -958,9 +958,10 @@ async def _send_to_daemon(
     timeout: float = 30.0,
     socket_path=None,
 ) -> dict:
+    from iai_mcp._ipc import open_ipc_connection
     path_used = socket_path if socket_path is not None else SOCKET_PATH
     try:
-        reader, writer = await asyncio.open_unix_connection(str(path_used))
+        reader, writer = await open_ipc_connection(str(path_used))
     except (FileNotFoundError, ConnectionRefusedError) as exc:
         return {"ok": False, "reason": "daemon_not_running", "error": str(exc)}
 
diff --git a/src/iai_mcp/core/_identity.py b/src/iai_mcp/core/_identity.py
index c71d51f..6ae1515 100644
--- a/src/iai_mcp/core/_identity.py
+++ b/src/iai_mcp/core/_identity.py
@@ -27,7 +27,7 @@ def _load_l0_identity_seed() -> str:
     )
     if os.path.isfile(config_path):
         try:
-            with open(config_path) as f:
+            with open(config_path, encoding="utf-8") as f:
                 cfg = json.load(f)
             identity = cfg.get("identity", {})
             parts = []
diff --git a/src/iai_mcp/crypto.py b/src/iai_mcp/crypto.py
index b82f76b..00dc5a4 100644
--- a/src/iai_mcp/crypto.py
+++ b/src/iai_mcp/crypto.py
@@ -12,12 +12,28 @@
 from cryptography.hazmat.primitives.kdf.pbkdf2 import PBKDF2HMAC
 
 
+import platform as _platform
+import subprocess as _subprocess
+
 CIPHERTEXT_PREFIX: str = "iai:enc:v1:"
 NONCE_BYTES: int = 12
 KEY_BYTES: int = 32
 PBKDF2_ITERATIONS: int = 600_000
 SERVICE_NAME_DEFAULT: str = "iai-mcp"
 
+
+def _secure_key_file(path: Path) -> None:
+    """Restrict file permissions to owner-only. On POSIX uses chmod; on Windows uses icacls."""
+    if _platform.system() == "Windows":
+        user = os.environ.get("USERNAME", "")
+        if user:
+            _subprocess.run(
+                ["icacls", str(path), "/inheritance:d", "/grant:r", f"{user}:F"],
+                check=False, capture_output=True,
+            )
+    else:
+        path.chmod(0o600)
+
 _DEFAULT_STORE_ROOT: Path = Path.home() / ".iai-mcp"
 _KEY_FILE_NAME: str = ".crypto.key"
 
@@ -112,13 +128,13 @@ def _try_file_get(self) -> Optional[bytes]:
         if not path.exists():
             return None
         st = os.stat(path)
-        if st.st_mode & 0o077 != 0:
+        if hasattr(os, "geteuid") and st.st_mode & 0o077 != 0:
             raise CryptoKeyError(
                 f"crypto key file at {path} has insecure mode "
                 f"0o{st.st_mode & 0o777:03o}; expected 0o600 "
                 f"(run: chmod 0o600 {path})"
             )
-        if st.st_uid != os.geteuid():
+        if hasattr(os, "geteuid") and st.st_uid != os.geteuid():
             raise CryptoKeyError(
                 f"crypto key file at {path} is owned by uid={st.st_uid}; "
                 f"current process runs as uid={os.geteuid()} (refusing to read)"
@@ -144,12 +160,18 @@ def _try_file_set(self, key: bytes) -> None:
         tmp = final.parent / f"{final.name}.tmp.{os.getpid()}"
         fd = os.open(str(tmp), os.O_CREAT | os.O_EXCL | os.O_WRONLY, 0o600)
         try:
-            os.fchmod(fd, 0o600)
+            if hasattr(os, "fchmod"):
+                os.fchmod(fd, 0o600)
             os.write(fd, key)
             os.fsync(fd)
         finally:
             os.close(fd)
-        os.rename(str(tmp), str(final))
+        if not hasattr(os, "fchmod"):
+            _secure_key_file(tmp)
+        # os.replace (not os.rename): on Windows rename raises if the
+        # destination exists, which it always does during key rotation. POSIX
+        # rename already replaces, so this is behaviour-preserving there.
+        os.replace(str(tmp), str(final))
 
 
     def get_or_create(self) -> bytes:
diff --git a/src/iai_mcp/daemon/__init__.py b/src/iai_mcp/daemon/__init__.py
index 027c2b1..bd27805 100644
--- a/src/iai_mcp/daemon/__init__.py
+++ b/src/iai_mcp/daemon/__init__.py
@@ -6,7 +6,7 @@
 import json
 import logging
 import os
-import resource
+import platform as _platform
 import signal
 import sys
 import threading
@@ -116,6 +116,10 @@ def _hippo_health_check_on_boot(store) -> dict[str, int | str]:
 
 
 def _raise_fd_limit() -> None:
+    if _platform.system() == "Windows":
+        return
+    import resource as _resource
+
     try:
         floor = int(
             os.environ.get("IAI_MCP_DAEMON_NOFILE_FLOOR", _DAEMON_NOFILE_FLOOR_DEFAULT)
@@ -124,18 +128,18 @@ def _raise_fd_limit() -> None:
         floor = _DAEMON_NOFILE_FLOOR_DEFAULT
 
     try:
-        soft, hard = resource.getrlimit(resource.RLIMIT_NOFILE)
+        soft, hard = _resource.getrlimit(_resource.RLIMIT_NOFILE)
     except (OSError, ValueError):
         return
 
-    effective_hard = hard if hard != resource.RLIM_INFINITY else floor
+    effective_hard = hard if hard != _resource.RLIM_INFINITY else floor
 
     target = min(max(soft, floor), effective_hard)
     if target <= soft:
         return
 
     try:
-        resource.setrlimit(resource.RLIMIT_NOFILE, (target, hard))
+        _resource.setrlimit(_resource.RLIMIT_NOFILE, (target, hard))
         log.debug("daemon_fd_limit_raised soft=%d->%d hard=%d", soft, target, hard)
     except (OSError, ValueError) as exc:
         log.debug("daemon_fd_limit_raise failed (non-fatal): %s", exc)
@@ -750,10 +754,35 @@ def _set_process_title(title: str = "iai lilli (iai_mcp.daemon)") -> None:
         pass
 
 
+def _auto_set_embed_offline() -> None:
+    """Set IAI_MCP_EMBED_OFFLINE if the bge-small-en-v1.5 model is already cached locally.
+
+    The Rust hf-hub client uses a different TLS stack than Python and may fail to reach
+    huggingface.co in restricted network environments (e.g., containers with custom CA
+    certificates). When the model files are already present in the HF cache, setting this
+    env var tells the Rust embedder to skip the network entirely.
+    """
+    if os.environ.get("IAI_MCP_EMBED_OFFLINE"):
+        return
+    import pathlib
+
+    revision = "5c38ec7c405ec4b44b94cc5a9bb96e735b38267a"
+    hf_home = os.environ.get("HF_HOME") or os.environ.get("HUGGINGFACE_HUB_CACHE")
+    if hf_home:
+        cache_base = pathlib.Path(hf_home)
+    else:
+        cache_base = pathlib.Path.home() / ".cache" / "huggingface" / "hub"
+    snap = cache_base / "models--BAAI--bge-small-en-v1.5" / "snapshots" / revision
+    if (snap / "model.safetensors").exists() and (snap / "tokenizer.json").exists():
+        os.environ["IAI_MCP_EMBED_OFFLINE"] = "1"
+        log.debug("bge-small-en-v1.5 found in HF cache — setting IAI_MCP_EMBED_OFFLINE=1")
+
+
 async def main() -> int:
     _set_process_title()
     _require_native()
     _raise_fd_limit()
+    _auto_set_embed_offline()
 
     store = await _open_exclusive_store_with_backoff(
         lambda: MemoryStore(
@@ -1000,10 +1029,15 @@ def _capture_handler(record: dict) -> None:
 
         shutdown = asyncio.Event()
         loop = asyncio.get_running_loop()
-        for sig in (signal.SIGTERM, signal.SIGINT, signal.SIGHUP):
+        _shutdown_sigs = [signal.SIGINT]
+        if hasattr(signal, "SIGTERM"):
+            _shutdown_sigs.append(signal.SIGTERM)
+        if hasattr(signal, "SIGHUP"):
+            _shutdown_sigs.append(signal.SIGHUP)
+        for sig in _shutdown_sigs:
             try:
                 loop.add_signal_handler(sig, shutdown.set)
-            except (NotImplementedError, RuntimeError):
+            except (NotImplementedError, RuntimeError, ValueError):
                 pass
 
         try:
diff --git a/src/iai_mcp/daemon/_watchdog.py b/src/iai_mcp/daemon/_watchdog.py
index b40409f..b96e3f9 100644
--- a/src/iai_mcp/daemon/_watchdog.py
+++ b/src/iai_mcp/daemon/_watchdog.py
@@ -416,7 +416,10 @@ def _self_kill(reason: str, kind: str) -> None:
         _write_breadcrumb(line)
     except Exception:  # noqa: BLE001 -- breadcrumb is best-effort ONLY
         pass
-    os.kill(os.getpid(), signal.SIGKILL)
+    if hasattr(signal, "SIGKILL"):
+        os.kill(os.getpid(), signal.SIGKILL)
+    else:
+        sys.exit(1)
 
 
 def _capture_blackbox(
@@ -630,10 +633,9 @@ def _check_crisis_mode_expiry(
 
 
 async def _probe_status_roundtrip(sock_path: str, read_timeout: float) -> bool:
+    from iai_mcp._ipc import open_ipc_connection
     try:
-        reader, writer = await asyncio.wait_for(
-            asyncio.open_unix_connection(sock_path), timeout=5.0
-        )
+        reader, writer = await open_ipc_connection(sock_path, timeout=5.0)
     except (FileNotFoundError, ConnectionRefusedError, OSError):
         return False
     except asyncio.TimeoutError:
diff --git a/src/iai_mcp/daemon_state.py b/src/iai_mcp/daemon_state.py
index ac6e2eb..019254b 100644
--- a/src/iai_mcp/daemon_state.py
+++ b/src/iai_mcp/daemon_state.py
@@ -2,12 +2,42 @@
 
 import json
 import os
+import platform
 import tempfile
+import time
 from datetime import datetime, timedelta, timezone
 from pathlib import Path
 
 STATE_PATH: Path = Path.home() / ".iai-mcp" / ".daemon-state.json"
 
+_IS_WINDOWS: bool = platform.system() == "Windows"
+
+
+def _atomic_replace(src: str, dst: Path) -> None:
+    """os.replace, with a brief retry loop on Windows.
+
+    On Windows os.replace maps to MoveFileEx, which fails with
+    PermissionError (WinError 5/ACCESS_DENIED or 32/SHARING_VIOLATION) when
+    another process momentarily holds the destination open. Python's open()
+    on Windows does not request FILE_SHARE_DELETE, so any concurrent reader
+    (`daemon status`, the MCP server, a hook reading first-turn state) can
+    transiently block the replace. The handle is held only briefly, so a few
+    short retries resolve it. POSIX rename is atomic and never sees this, so
+    the path there is unchanged (single attempt, errors propagate).
+    """
+    if not _IS_WINDOWS:
+        os.replace(src, dst)
+        return
+    attempts = 10
+    for i in range(attempts):
+        try:
+            os.replace(src, dst)
+            return
+        except PermissionError:
+            if i == attempts - 1:
+                raise
+            time.sleep(0.05)
+
 DIGEST_SHOW_THRESHOLD_HOURS: int = 18
 
 FIRST_TURN_TTL_HOURS: int = 24
@@ -18,7 +48,7 @@ def load_state() -> dict:
     if not STATE_PATH.exists():
         return {}
     try:
-        return json.loads(STATE_PATH.read_text())
+        return json.loads(STATE_PATH.read_text(encoding="utf-8"))
     except (OSError, json.JSONDecodeError):
         return {}
 
@@ -36,7 +66,7 @@ def save_state(state: dict) -> None:
             f.flush()
             os.fsync(f.fileno())
         os.chmod(tmp, 0o600)
-        os.replace(tmp, STATE_PATH)
+        _atomic_replace(tmp, STATE_PATH)
     except (OSError, TypeError, ValueError):
         try:
             os.unlink(tmp)
diff --git a/src/iai_mcp/direct_write.py b/src/iai_mcp/direct_write.py
index 4a67d9a..b3dfc35 100644
--- a/src/iai_mcp/direct_write.py
+++ b/src/iai_mcp/direct_write.py
@@ -116,19 +116,18 @@ def _find_record_by_tag_direct(db: Any, tag: str) -> str | None:
 
 
 def _try_get_embedding_fast(text: str, cue: str) -> list[float] | None:
-    socket_path = os.environ.get("IAI_DAEMON_SOCKET_PATH")
-    if socket_path:
-        try:
-            import socket as _socket
-            s = _socket.socket(_socket.AF_UNIX, _socket.SOCK_STREAM)
-            s.settimeout(0.1)
-            s.connect(socket_path)
-            s.close()
-        except (OSError, ConnectionRefusedError, FileNotFoundError):
-            return None
-    else:
+    from iai_mcp._ipc import IS_WINDOWS, make_sync_ipc_socket, send_sync_auth_token
+    # On POSIX only proceed when IAI_DAEMON_SOCKET_PATH is explicitly set
+    if not IS_WINDOWS and not os.environ.get("IAI_DAEMON_SOCKET_PATH"):
+        return None
+    try:
+        s, addr = make_sync_ipc_socket()
+        s.settimeout(0.1)
+        s.connect(addr)
+        send_sync_auth_token(s)
+        s.close()
+    except (OSError, ConnectionRefusedError, FileNotFoundError):
         return None
-
     return None
 
 
@@ -194,7 +193,7 @@ def _write_sidecar(root: Path, record_id: str, embedding: list[float], db: Any)
 
     try:
         npy_tmp.write_bytes(blob)
-        json_tmp.write_text(json.dumps({"uuid": record_id, "vec_label": vec_label}))
+        json_tmp.write_text(json.dumps({"uuid": record_id, "vec_label": vec_label}), encoding="utf-8")
         os.replace(npy_tmp, npy_final)
         os.replace(json_tmp, json_final)
     except OSError as exc:
diff --git a/src/iai_mcp/doctor/__init__.py b/src/iai_mcp/doctor/__init__.py
index a33196f..97e7bf3 100644
--- a/src/iai_mcp/doctor/__init__.py
+++ b/src/iai_mcp/doctor/__init__.py
@@ -56,11 +56,9 @@ def _resolve_socket_path() -> Path:
 
 
 async def _socket_status_probe(socket_path: Path, timeout: float) -> dict | None:
+    from iai_mcp._ipc import open_ipc_connection
     try:
-        reader, writer = await asyncio.wait_for(
-            asyncio.open_unix_connection(path=str(socket_path)),
-            timeout=timeout,
-        )
+        reader, writer = await open_ipc_connection(str(socket_path), timeout=timeout)
     except (FileNotFoundError, ConnectionRefusedError, asyncio.TimeoutError, OSError):
         return None
     try:
@@ -307,7 +305,8 @@ def _kill_orphan_cores() -> tuple[bool, str, int]:
             if "iai_mcp.core" not in cl:
                 continue
             pid = p.info["pid"]
-            os.kill(pid, signal.SIGTERM)
+            _term = getattr(signal, "SIGTERM", signal.SIGINT)
+            os.kill(pid, _term)
             killed.append(pid)
         except (psutil.NoSuchProcess, psutil.AccessDenied):
             continue
diff --git a/src/iai_mcp/doctor/_lifecycle_checks.py b/src/iai_mcp/doctor/_lifecycle_checks.py
index 0a589f4..7a1c46e 100644
--- a/src/iai_mcp/doctor/_lifecycle_checks.py
+++ b/src/iai_mcp/doctor/_lifecycle_checks.py
@@ -113,11 +113,9 @@ def check_a_daemon_alive() -> CheckResult:
 
 
 async def _socket_connect_probe(socket_path: Path, timeout: float) -> str | None:
+    from iai_mcp._ipc import open_ipc_connection
     try:
-        reader, writer = await asyncio.wait_for(
-            asyncio.open_unix_connection(path=str(socket_path)),
-            timeout=timeout,
-        )
+        reader, writer = await open_ipc_connection(str(socket_path), timeout=timeout)
     except FileNotFoundError:
         return "FileNotFoundError"
     except ConnectionRefusedError:
@@ -136,11 +134,16 @@ async def _socket_connect_probe(socket_path: Path, timeout: float) -> str | None
 
 def check_b_socket_fresh() -> CheckResult:
     socket_path = _resolve_socket_path()
-    if not socket_path.exists():
+    # Windows binds TCP loopback and records the port in a sidecar file — there
+    # is no AF_UNIX socket file — so check whichever endpoint actually exists
+    # for this platform. (The connect probe below is already cross-platform.)
+    from iai_mcp._ipc import IS_WINDOWS, _port_file_path
+    endpoint = _port_file_path() if IS_WINDOWS else socket_path
+    if not endpoint.exists():
         return CheckResult(
             "(b) socket file fresh",
             False,
-            f"{socket_path} does not exist",
+            f"{endpoint} does not exist",
         )
 
     t0 = time.monotonic()
@@ -169,7 +172,8 @@ def check_b_socket_fresh() -> CheckResult:
 
 def check_c_lock_healthy() -> CheckResult:
     import errno as _errno
-    import fcntl as _fcntl
+    from iai_mcp._filelock import LOCK_NB, LOCK_SH, LOCK_UN
+    from iai_mcp._filelock import flock as _flock
 
     lock_path = _resolve_hippo_db_path().parent / ".lock"
     if not lock_path.exists():
@@ -180,10 +184,12 @@ def check_c_lock_healthy() -> CheckResult:
         )
     fd = None
     try:
-        fd = os.open(str(lock_path), os.O_RDONLY)
+        # O_RDWR required on Windows (msvcrt.locking needs write access);
+        # harmless on POSIX since flock ignores open mode.
+        fd = os.open(str(lock_path), os.O_RDWR)
         try:
-            _fcntl.flock(fd, _fcntl.LOCK_SH | _fcntl.LOCK_NB)
-            _fcntl.flock(fd, _fcntl.LOCK_UN)
+            _flock(fd, LOCK_SH | LOCK_NB)
+            _flock(fd, LOCK_UN)
             return CheckResult(
                 "(c) lock file healthy",
                 True,
@@ -197,7 +203,7 @@ def check_c_lock_healthy() -> CheckResult:
                     f"{lock_path} held (consolidating or recall active — normal)",
                 )
             raise
-    except Exception as e:  # noqa: BLE001 — fcntl/OSError/permission all FAIL
+    except Exception as e:  # noqa: BLE001 — flock/OSError/permission all FAIL
         logger.debug("check_c: store-lock probe failed: %s", e)
         return CheckResult(
             "(c) lock file healthy",
diff --git a/src/iai_mcp/fsm_reconcile.py b/src/iai_mcp/fsm_reconcile.py
index c148d1a..802a8e5 100644
--- a/src/iai_mcp/fsm_reconcile.py
+++ b/src/iai_mcp/fsm_reconcile.py
@@ -17,7 +17,7 @@ def _read_canonical(path: Path) -> str | None:
     if not path.exists():
         return None
     try:
-        raw = json.loads(path.read_text())
+        raw = json.loads(path.read_text(encoding="utf-8"))
     except (OSError, json.JSONDecodeError):
         return None
     if not isinstance(raw, dict):
@@ -30,7 +30,7 @@ def _read_legacy(path: Path) -> str | None:
     if not path.exists():
         return None
     try:
-        raw = json.loads(path.read_text())
+        raw = json.loads(path.read_text(encoding="utf-8"))
     except (OSError, json.JSONDecodeError):
         return None
     if not isinstance(raw, dict):
@@ -55,7 +55,7 @@ def _auto_correct_legacy(legacy_path: Path, canonical_state: str) -> bool:
     try:
         raw: dict = {}
         if legacy_path.exists():
-            raw = json.loads(legacy_path.read_text())
+            raw = json.loads(legacy_path.read_text(encoding="utf-8"))
             if not isinstance(raw, dict):
                 raw = {}
     except (OSError, json.JSONDecodeError):
diff --git a/src/iai_mcp/hippo/__init__.py b/src/iai_mcp/hippo/__init__.py
index 280cab4..482a5f3 100644
--- a/src/iai_mcp/hippo/__init__.py
+++ b/src/iai_mcp/hippo/__init__.py
@@ -3,7 +3,6 @@
 import contextlib
 import enum
 import errno
-import fcntl
 import logging
 import os
 import re
diff --git a/src/iai_mcp/hippo/_db.py b/src/iai_mcp/hippo/_db.py
index 70b51a7..a47b3db 100644
--- a/src/iai_mcp/hippo/_db.py
+++ b/src/iai_mcp/hippo/_db.py
@@ -4,7 +4,6 @@
 
 import contextlib
 import errno
-import fcntl
 import logging
 import os
 import re
@@ -20,6 +19,7 @@
 import numpy as np
 import pyarrow as pa
 
+from iai_mcp._filelock import LOCK_EX, LOCK_NB, LOCK_SH, LOCK_UN, flock
 from iai_mcp.crypto import (
     decrypt_field,
     encrypt_field,
@@ -190,7 +190,7 @@ def _acquire_exclusive_lock(self) -> None:
                 )
                 os.chmod(str(self._lock_path), 0o600)
                 try:
-                    fcntl.flock(base_fd, fcntl.LOCK_EX | fcntl.LOCK_NB)
+                    flock(base_fd, LOCK_EX | LOCK_NB)
                 except OSError as exc:
                     os.close(base_fd)
                     if exc.errno in (errno.EAGAIN, errno.EWOULDBLOCK):
@@ -250,7 +250,7 @@ def _acquire_shared_lock(
                 continue
 
             try:
-                fcntl.flock(base_fd, fcntl.LOCK_SH | fcntl.LOCK_NB)
+                flock(base_fd, LOCK_SH | LOCK_NB)
             except OSError as exc:
                 if exc.errno in (errno.EAGAIN, errno.EWOULDBLOCK):
                     if time.monotonic() >= deadline:
@@ -261,7 +261,7 @@ def _acquire_shared_lock(
                 raise
 
             if _intent_path.exists():
-                fcntl.flock(base_fd, fcntl.LOCK_UN)
+                flock(base_fd, LOCK_UN)
                 if time.monotonic() >= deadline:
                     break
                 time.sleep(_SHARED_RETRY_SLEEP_S)
@@ -277,7 +277,7 @@ def _acquire_shared_lock(
         with _PROCESS_LOCKS_GUARD:
             held_sh = _PROCESS_LOCKS_SHARED.get(self._lock_key)
             if held_sh is not None:
-                fcntl.flock(base_fd, fcntl.LOCK_UN)
+                flock(base_fd, LOCK_UN)
                 os.close(base_fd)
                 base_fd2, refcount2 = held_sh
                 self._lock_fd = os.dup(base_fd2)
@@ -303,7 +303,7 @@ def downgrade_to_shared(self) -> None:
                 return
             base_fd, refcount = held
             try:
-                fcntl.flock(base_fd, fcntl.LOCK_SH)
+                flock(base_fd, LOCK_SH)
             except OSError:
                 return
             del _PROCESS_LOCKS[self._lock_key]
@@ -344,7 +344,7 @@ def escalate_to_exclusive(self, intent_budget_ms: int = 4000) -> None:
         acquired = False
         while time.monotonic() < deadline:
             try:
-                fcntl.flock(base_fd, fcntl.LOCK_EX | fcntl.LOCK_NB)
+                flock(base_fd, LOCK_EX | LOCK_NB)
                 acquired = True
                 break
             except OSError as exc:
@@ -672,7 +672,7 @@ def ingest_pending_embeddings(self) -> int:
                     _log.warning("ingest_pending_embeddings: malformed .npy %s, skipping", npy_path)
                     continue
                 vec = list(_struct.unpack(f"<{n_floats}f", vec_bytes))
-                meta = _json.loads(json_path.read_text())
+                meta = _json.loads(json_path.read_text(encoding="utf-8"))
                 vec_label = int(meta["vec_label"])
             except Exception as exc:  # noqa: BLE001
                 _log.warning("ingest_pending_embeddings: failed to load %s: %s", npy_path, exc)
@@ -1031,7 +1031,7 @@ def close(self) -> None:
                     base_fd, refcount = held
                     if refcount <= 1:
                         try:
-                            fcntl.flock(base_fd, fcntl.LOCK_UN)
+                            flock(base_fd, LOCK_UN)
                         except Exception:  # noqa: BLE001
                             pass
                         try:
diff --git a/src/iai_mcp/lifecycle.py b/src/iai_mcp/lifecycle.py
index a55d68b..29a5e47 100644
--- a/src/iai_mcp/lifecycle.py
+++ b/src/iai_mcp/lifecycle.py
@@ -2,7 +2,6 @@
 
 import asyncio
 import errno
-import fcntl
 import os
 from contextlib import contextmanager
 from datetime import datetime, timezone
@@ -10,6 +9,7 @@
 from pathlib import Path
 from typing import Any, Iterator
 
+from iai_mcp._filelock import LOCK_EX, LOCK_NB, LOCK_UN, flock
 from iai_mcp.lifecycle_event_log import LifecycleEventLog
 from iai_mcp.lifecycle_state import (
     LIFECYCLE_STATE_PATH,
@@ -92,7 +92,7 @@ def _lifecycle_lock(lock_path: Path) -> Iterator[int]:
     fd = os.open(str(lock_path), os.O_RDWR | os.O_CREAT, 0o600)
     try:
         try:
-            fcntl.flock(fd, fcntl.LOCK_EX | fcntl.LOCK_NB)
+            flock(fd, LOCK_EX | LOCK_NB)
         except OSError as exc:
             if exc.errno in (errno.EAGAIN, errno.EWOULDBLOCK):
                 raise LifecycleStateLocked(
@@ -103,7 +103,7 @@ def _lifecycle_lock(lock_path: Path) -> Iterator[int]:
             yield fd
         finally:
             try:
-                fcntl.flock(fd, fcntl.LOCK_UN)
+                flock(fd, LOCK_UN)
             except OSError:
                 pass
     finally:
diff --git a/src/iai_mcp/lifecycle_event_log.py b/src/iai_mcp/lifecycle_event_log.py
index 1ee02fd..2c9b1ee 100644
--- a/src/iai_mcp/lifecycle_event_log.py
+++ b/src/iai_mcp/lifecycle_event_log.py
@@ -1,12 +1,13 @@
 from __future__ import annotations
 
 import errno
-import fcntl
 import gzip
 import json
 import os
 import shutil
 from datetime import datetime, timedelta, timezone
+
+from iai_mcp._filelock import LOCK_EX, LOCK_UN, flock
 from pathlib import Path
 from typing import Any
 
@@ -73,12 +74,12 @@ def append(self, event: dict[str, Any], now: datetime | None = None) -> None:
             0o600,
         )
         try:
-            fcntl.flock(fd, fcntl.LOCK_EX)
+            flock(fd, LOCK_EX)
             try:
                 os.write(fd, line.encode("utf-8"))
                 os.fsync(fd)
             finally:
-                fcntl.flock(fd, fcntl.LOCK_UN)
+                flock(fd, LOCK_UN)
         finally:
             os.close(fd)
 
@@ -127,7 +128,7 @@ def read_all(self, date_str: str | None = None) -> list[dict[str, Any]]:
         if not target.exists():
             return []
         out: list[dict[str, Any]] = []
-        with target.open("r") as f:
+        with target.open("r", encoding="utf-8") as f:
             for line in f:
                 line = line.strip()
                 if not line:
diff --git a/src/iai_mcp/lifecycle_lock.py b/src/iai_mcp/lifecycle_lock.py
index 699d2ba..03d5fbe 100644
--- a/src/iai_mcp/lifecycle_lock.py
+++ b/src/iai_mcp/lifecycle_lock.py
@@ -3,6 +3,7 @@
 import json
 import logging
 import os
+import platform
 import socket
 import tempfile
 from datetime import datetime, timezone
@@ -50,12 +51,17 @@ def _is_pid_alive(pid: int) -> bool:
     if pid <= 0:
         return False
 
-    try:
-        os.kill(pid, 0)
-    except ProcessLookupError:
-        return False
-    except PermissionError:
-        return True
+    # os.kill(pid, 0) is the POSIX liveness idiom, but on Windows os.kill
+    # rejects signal 0 with OSError [WinError 87] (invalid parameter). Skip
+    # the probe there and rely on the psutil refinement below, which both
+    # confirms the pid exists and that it is actually an iai_mcp.daemon.
+    if platform.system() != "Windows":
+        try:
+            os.kill(pid, 0)
+        except ProcessLookupError:
+            return False
+        except PermissionError:
+            return True
 
     try:
         import psutil
diff --git a/src/iai_mcp/lifecycle_state.py b/src/iai_mcp/lifecycle_state.py
index 1abecd3..a47a61e 100644
--- a/src/iai_mcp/lifecycle_state.py
+++ b/src/iai_mcp/lifecycle_state.py
@@ -137,7 +137,7 @@ def load_state(path: Path | None = None) -> LifecycleStateRecord:
     if not target.exists():
         return default_state()
     try:
-        raw = json.loads(target.read_text())
+        raw = json.loads(target.read_text(encoding="utf-8"))
     except (OSError, json.JSONDecodeError):
         return default_state()
     try:
diff --git a/src/iai_mcp/lock_protocol.py b/src/iai_mcp/lock_protocol.py
index b105406..535eab4 100644
--- a/src/iai_mcp/lock_protocol.py
+++ b/src/iai_mcp/lock_protocol.py
@@ -1,11 +1,12 @@
 from __future__ import annotations
 
 import errno
-import fcntl
 import logging
 import os
 from pathlib import Path
 
+from iai_mcp._filelock import LOCK_NB, LOCK_SH, flock
+
 logger = logging.getLogger(__name__)
 
 
@@ -55,7 +56,7 @@ def acquire_client_shared_nb(fd: int, lock_path: Path) -> bool:
         return False
 
     try:
-        fcntl.flock(fd, fcntl.LOCK_SH | fcntl.LOCK_NB)
+        flock(fd, LOCK_SH | LOCK_NB)
         return True
     except OSError as exc:
         if exc.errno in (errno.EAGAIN, errno.EWOULDBLOCK):
diff --git a/src/iai_mcp/memory_bank.py b/src/iai_mcp/memory_bank.py
index e1889c2..b703560 100644
--- a/src/iai_mcp/memory_bank.py
+++ b/src/iai_mcp/memory_bank.py
@@ -225,7 +225,8 @@ def append_recent_record(
             0o600,
         )
         try:
-            os.fchmod(fd, 0o600)
+            if hasattr(os, "fchmod"):
+                os.fchmod(fd, 0o600)
             os.write(fd, line)
             os.fsync(fd)
         finally:
diff --git a/src/iai_mcp/migrate/_reembed.py b/src/iai_mcp/migrate/_reembed.py
index c25fb17..66ff9bf 100644
--- a/src/iai_mcp/migrate/_reembed.py
+++ b/src/iai_mcp/migrate/_reembed.py
@@ -74,7 +74,7 @@ def _progress_read(store: MemoryStore) -> dict:
     if not path.exists():
         return {}
     try:
-        return json.loads(path.read_text())
+        return json.loads(path.read_text(encoding="utf-8"))
     except (OSError, json.JSONDecodeError, ValueError):
         return {}
 
diff --git a/src/iai_mcp/provenance_buffer.py b/src/iai_mcp/provenance_buffer.py
index 1d5bc3c..7d0d4ff 100644
--- a/src/iai_mcp/provenance_buffer.py
+++ b/src/iai_mcp/provenance_buffer.py
@@ -33,7 +33,7 @@ def defer_provenance(
             "cue": cue,
             "session_id": session_id,
         }))
-    with open(path, "a") as f:
+    with open(path, "a", encoding="utf-8") as f:
         f.write("\n".join(lines) + "\n")
 
 
@@ -42,7 +42,7 @@ def flush_deferred_provenance(store: MemoryStore) -> int:
     if not path.exists():
         return 0
     try:
-        with open(path) as f:
+        with open(path, encoding="utf-8") as f:
             raw_lines = f.read().strip().splitlines()
     except OSError:
         return 0
@@ -72,7 +72,7 @@ def flush_deferred_provenance(store: MemoryStore) -> int:
             return 0
 
     try:
-        path.write_text("")
+        path.write_text("", encoding="utf-8")
     except OSError:
         pass
     return len(pairs)
diff --git a/src/iai_mcp/provenance_queue.py b/src/iai_mcp/provenance_queue.py
index a8c076c..d59fadb 100644
--- a/src/iai_mcp/provenance_queue.py
+++ b/src/iai_mcp/provenance_queue.py
@@ -124,7 +124,7 @@ def _spill_to_disk(self, pairs: list) -> None:
             with tmp_path.open("w", encoding="utf-8") as fh:
                 for rid, entry in pairs:
                     fh.write(json.dumps({"id": str(rid), "entry": entry}) + "\n")
-            tmp_path.rename(fpath)
+            tmp_path.replace(fpath)
         except (OSError, TypeError, ValueError) as exc:
             logger.warning("provenance_queue_spill_failed", extra={"err": str(exc)[:200], "n_pairs": len(pairs)})
             try:
@@ -164,7 +164,7 @@ def _drain_overflow_dir(self) -> int:
                 logger.warning("provenance_queue_spill_drain_failed", extra={"err": str(exc)[:200]})
                 try:
                     failed = fpath.with_suffix(f".failed-{int(time.time())}.jsonl")
-                    fpath.rename(failed)
+                    fpath.replace(failed)
                     sys.stderr.write(
                         '{"event":"provenance_queue_spill_drain_failed","error":'
                         + _json_str(str(exc)) + '}\n'
diff --git a/src/iai_mcp/runtime_graph_cache.py b/src/iai_mcp/runtime_graph_cache.py
index add150a..b5029e0 100644
--- a/src/iai_mcp/runtime_graph_cache.py
+++ b/src/iai_mcp/runtime_graph_cache.py
@@ -3,6 +3,7 @@
 import json
 import logging
 import os
+import platform
 import sys
 import threading
 from datetime import datetime, timezone
@@ -113,6 +114,16 @@ def _get_persistent_graph():
 _WORKER_TIMEOUT_MAX_S: float = 3600.0
 _first_spawn_seen: bool = False
 
+# Windows `multiprocessing` spawn is broken for the RGC worker: the spawn child
+# launches under the venv's *base* interpreter (`sys._base_executable`, e.g.
+# `...\Python312\pythonw.exe`) rather than the venv interpreter, re-imports the
+# heavy `iai_mcp.daemon` module, and hangs well past the watchdog timeout —
+# killing it took the parent daemon down with it. `ctx.set_executable(...)` does
+# not override the base-interpreter selection (verified empirically). On Windows
+# we therefore run the worker in an in-process daemon thread (`_ThreadWorkerHandle`)
+# instead of spawning; POSIX keeps the spawned subprocess unchanged.
+_IS_WINDOWS: bool = platform.system() == "Windows"
+
 
 class WorkerCrashedError(RuntimeError):
     """Child worker exited with a non-zero exit code."""
@@ -157,6 +168,69 @@ def _terminate_worker(process) -> None:
         pass
 
 
+class _ThreadWorkerHandle:
+    """In-process stand-in for a spawned worker `Process`, used on Windows.
+
+    Runs `_worker_entry` in a daemon thread of the current process and exposes
+    the subset of the `multiprocessing.Process` API the rebuild path touches
+    (`start`, `is_alive`, `join`, `exitcode`, `terminate`, `kill`), so the
+    surrounding spawn/drain logic is reused verbatim. See the `_IS_WINDOWS`
+    note above for why spawn cannot be used here.
+
+    Trade-off: the worker no longer runs in a separate address space, so the
+    fat per-rebuild allocations live in the daemon heap until they fall out of
+    scope and are GC'd, rather than being reclaimed by process exit. The
+    rebuild is a periodic sleep-time operation, not a hot path, so this is an
+    acceptable cost for correctness. The AES-key isolation the subprocess gave
+    is moot in-process anyway; the worker module still never imports the
+    storage/crypto surface, so no key is reachable through it.
+    """
+
+    def __init__(self, target, conn) -> None:
+        self._target = target
+        self._conn = conn
+        self._exitcode: int | None = None
+        self._thread = threading.Thread(target=self._run, daemon=True)
+
+    def _run(self) -> None:
+        try:
+            self._target(self._conn)
+            self._exitcode = 0
+        except SystemExit as exc:
+            # The worker calls sys.exit(1) on its error path; map that to a
+            # non-zero exitcode so the parent's crash check fires as it would
+            # for a subprocess.
+            self._exitcode = exc.code if isinstance(exc.code, int) else 1
+        except BaseException:  # noqa: BLE001 -- mirror a non-zero subprocess exit
+            self._exitcode = 1
+
+    def start(self) -> None:
+        self._thread.start()
+
+    def is_alive(self) -> bool:
+        return self._thread.is_alive()
+
+    def join(self, timeout: float | None = None) -> None:
+        self._thread.join(timeout)
+
+    @property
+    def exitcode(self) -> int | None:
+        # Mirror Process.exitcode: None while the worker is still running.
+        if self._thread.is_alive():
+            return None
+        return self._exitcode
+
+    def terminate(self) -> None:
+        # A Python thread cannot be force-killed. On the normal path the worker
+        # unwinds when the parent closes its pipe end (EOFError); on a genuine
+        # compute hang the daemon thread is left to finish in the background
+        # (daemon=True, so it never blocks interpreter shutdown).
+        pass
+
+    def kill(self) -> None:
+        pass
+
+
 def _drain_worker_result(parent_conn, timeout: float) -> dict:
     """Drain the chunked compact result envelope into a parent-side dict.
 
@@ -953,20 +1027,27 @@ def _rebuild_and_save_rgc(store: Any, *, force: bool = False) -> dict:
         except Exception:  # noqa: BLE001
             est_node_count = 0
 
-        # Spawn the worker. Spawn-context (not fork) so the child re-imports
-        # cleanly on macOS and Linux; the child closes its end after start so
-        # the parent does not hold a half-of-pipe alive on crash detection.
+        # Start the worker. On POSIX we spawn a subprocess (spawn-context, not
+        # fork, so the child re-imports cleanly on macOS and Linux) and close
+        # the parent's copy of the child end so we don't hold half a pipe alive
+        # on crash detection. On Windows spawn is broken for this worker (see
+        # `_IS_WINDOWS`), so we run it in an in-process daemon thread and keep
+        # child_conn open — the in-process worker owns that same Connection.
         first_spawn_flag = not _first_spawn_seen
         timeout_s = _resolve_timeout(est_node_count)
         ctx = multiprocessing.get_context("spawn")
         parent_conn, child_conn = ctx.Pipe(duplex=True)
-        process = ctx.Process(
-            target=_worker_entry_indirection,
-            args=(child_conn,),
-            daemon=True,
-        )
-        process.start()
-        child_conn.close()
+        if _IS_WINDOWS:
+            process = _ThreadWorkerHandle(_worker_entry_indirection, child_conn)
+            process.start()
+        else:
+            process = ctx.Process(
+                target=_worker_entry_indirection,
+                args=(child_conn,),
+                daemon=True,
+            )
+            process.start()
+            child_conn.close()
 
         db_path = store.db._hippo_dir / "brain.sqlite3"
         ro_conn = None
diff --git a/src/iai_mcp/semantic_recall.py b/src/iai_mcp/semantic_recall.py
index b6bda69..8278e2b 100644
--- a/src/iai_mcp/semantic_recall.py
+++ b/src/iai_mcp/semantic_recall.py
@@ -66,17 +66,12 @@ def _send_embed_cue_rpc(cue: str, timeout_ms: int) -> "list[float] | None":
     import asyncio
     import json
 
-    from iai_mcp.concurrency import SOCKET_PATH
-
-    sock_path = os.environ.get("IAI_DAEMON_SOCKET_PATH") or str(SOCKET_PATH)
+    from iai_mcp._ipc import open_ipc_connection
     connect_timeout = timeout_ms / 1000.0
 
     async def _runner() -> "list[float] | None":
         try:
-            reader, writer = await asyncio.wait_for(
-                asyncio.open_unix_connection(sock_path),
-                timeout=connect_timeout,
-            )
+            reader, writer = await open_ipc_connection(timeout=connect_timeout)
         except (FileNotFoundError, ConnectionRefusedError, OSError, asyncio.TimeoutError):
             return None
         try:
diff --git a/src/iai_mcp/sleep_wal.py b/src/iai_mcp/sleep_wal.py
index 3b51619..0394bac 100644
--- a/src/iai_mcp/sleep_wal.py
+++ b/src/iai_mcp/sleep_wal.py
@@ -97,7 +97,7 @@ def pending_entries(self) -> list[WALEntry]:
             return []
         entries: dict[str, WALEntry] = {}
         try:
-            with open(self.path) as f:
+            with open(self.path, encoding="utf-8") as f:
                 for line in f:
                     line = line.strip()
                     if not line:
@@ -119,7 +119,7 @@ def cleanup(self, max_age_hours: int = 168) -> int:
         kept: list[str] = []
         removed = 0
         try:
-            with open(self.path) as f:
+            with open(self.path, encoding="utf-8") as f:
                 for line in f:
                     line = line.strip()
                     if not line:
@@ -134,7 +134,7 @@ def cleanup(self, max_age_hours: int = 168) -> int:
                         continue
                     kept.append(line)
             if removed > 0:
-                self.path.write_text("\n".join(kept) + "\n" if kept else "")
+                self.path.write_text("\n".join(kept) + "\n" if kept else "", encoding="utf-8")
         except OSError:
             pass
         return removed
@@ -142,7 +142,7 @@ def cleanup(self, max_age_hours: int = 168) -> int:
     def _append(self, entry: WALEntry) -> None:
         try:
             self.path.parent.mkdir(parents=True, exist_ok=True)
-            with open(self.path, "a") as f:
+            with open(self.path, "a", encoding="utf-8") as f:
                 f.write(json.dumps(entry.to_dict()) + "\n")
         except OSError as exc:
             logger.warning("WAL write failed: %s", exc)
diff --git a/src/iai_mcp/socket_server.py b/src/iai_mcp/socket_server.py
index 2d21108..22dace7 100644
--- a/src/iai_mcp/socket_server.py
+++ b/src/iai_mcp/socket_server.py
@@ -10,6 +10,7 @@
 from pathlib import Path
 from typing import Any
 
+from iai_mcp._ipc import IS_WINDOWS, cleanup_ipc_address, open_ipc_connection, shutdown_ipc, start_ipc_server
 from iai_mcp.concurrency import SOCKET_PATH, cleanup_stale_socket
 from iai_mcp.core import UnknownMethodError
 
@@ -205,30 +206,32 @@ async def handle(
 
 
     async def serve(self, socket_path: Path | None = None) -> None:
+        if IS_WINDOWS:
+            # Windows: TCP server on loopback; socket_path is unused
+            server, actual_addr, needs_cleanup = await start_ipc_server(self.handle)
+            try:
+                async with server:
+                    await self.shutdown_event.wait()
+                    server.close()
+                    await server.wait_closed()
+            finally:
+                if needs_cleanup:
+                    shutdown_ipc(actual_addr)
+            return
+
         if socket_path is None:
             env_path = os.environ.get("IAI_DAEMON_SOCKET_PATH")
             socket_path = Path(env_path) if env_path else SOCKET_PATH
 
-        sig = inspect.signature(asyncio.start_unix_server)
-        supports_cleanup_socket = "cleanup_socket" in sig.parameters
-
         inherited = _inherit_activated_socket()
         if inherited is not None:
-            server = await asyncio.start_unix_server(
-                self.handle,
-                sock=inherited,
-            )
+            server = await asyncio.start_unix_server(self.handle, sock=inherited)
+            needs_cleanup = False
+            actual_addr: Any = str(socket_path)
         else:
-            cleanup_stale_socket(socket_path)
+            cleanup_ipc_address(socket_path)
             socket_path.parent.mkdir(parents=True, exist_ok=True)
-            server_kwargs: dict[str, Any] = (
-                {"cleanup_socket": True} if supports_cleanup_socket else {}
-            )
-            server = await asyncio.start_unix_server(
-                self.handle,
-                path=str(socket_path),
-                **server_kwargs,
-            )
+            server, actual_addr, needs_cleanup = await start_ipc_server(self.handle, socket_path)
             try:
                 os.chmod(str(socket_path), 0o600)
             except OSError:
@@ -240,8 +243,5 @@ async def serve(self, socket_path: Path | None = None) -> None:
                 server.close()
                 await server.wait_closed()
         finally:
-            if inherited is None and not supports_cleanup_socket:
-                try:
-                    socket_path.unlink()
-                except (FileNotFoundError, OSError):
-                    pass
+            if inherited is None and needs_cleanup:
+                shutdown_ipc(actual_addr)
diff --git a/src/iai_mcp/tz.py b/src/iai_mcp/tz.py
index 027199b..6106921 100644
--- a/src/iai_mcp/tz.py
+++ b/src/iai_mcp/tz.py
@@ -33,7 +33,7 @@ def _seed_config(cfg_path: Path, tz_key: str) -> None:
     existing: dict = {}
     if cfg_path.exists():
         try:
-            with open(cfg_path) as f:
+            with open(cfg_path, encoding="utf-8") as f:
                 existing = json.load(f)
             if not isinstance(existing, dict):
                 existing = {}
@@ -44,7 +44,7 @@ def _seed_config(cfg_path: Path, tz_key: str) -> None:
         existing["user"] = {}
     existing["user"]["timezone"] = tz_key
     tmp = cfg_path.with_suffix(".tmp")
-    with open(tmp, "w") as f:
+    with open(tmp, "w", encoding="utf-8") as f:
         json.dump(existing, f, indent=2)
     os.replace(tmp, cfg_path)
 
@@ -53,7 +53,7 @@ def load_user_tz() -> ZoneInfo:
     cfg_path = _config_path()
     if cfg_path.exists():
         try:
-            with open(cfg_path) as f:
+            with open(cfg_path, encoding="utf-8") as f:
                 cfg = json.load(f)
         except (json.JSONDecodeError, OSError):
             cfg = None
diff --git a/src/iai_mcp/user_model.py b/src/iai_mcp/user_model.py
index 4480f4f..743e157 100644
--- a/src/iai_mcp/user_model.py
+++ b/src/iai_mcp/user_model.py
@@ -41,7 +41,7 @@ def load() -> UserModel:
     if not path.exists():
         return default()
     try:
-        data = json.loads(path.read_text())
+        data = json.loads(path.read_text(encoding="utf-8"))
     except (OSError, json.JSONDecodeError):
         return default()
 
diff --git a/tests/_socket_test_helpers.py b/tests/_socket_test_helpers.py
new file mode 100644
index 0000000..5b166f1
--- /dev/null
+++ b/tests/_socket_test_helpers.py
@@ -0,0 +1,87 @@
+"""Cross-platform fake-daemon socket binding for tests.
+
+Production code reaches the daemon via ``iai_mcp._ipc``: on POSIX a unix-domain
+socket at ``IAI_DAEMON_SOCKET_PATH``; on Windows TCP loopback with the port
+persisted to ``"<IAI_DAEMON_SOCKET_PATH>.port"``. Tests that stand up a *raw*
+fake daemon socket (to simulate stalls, fast replies, dead endpoints, etc.)
+must bind the matching transport so the production client actually connects to
+them. This helper hides the per-platform binding; callers keep their own
+accept/recv/reply logic unchanged.
+"""
+from __future__ import annotations
+
+import os
+import secrets
+import socket
+from pathlib import Path
+
+from iai_mcp._ipc import IS_WINDOWS
+
+
+def write_fake_daemon_token(sock_path) -> None:
+    """Write an auth token alongside a fake daemon socket so the production
+    client's mandatory Windows handshake (see ``_ipc._send_token_async``) finds
+    one. The raw fake servers don't validate it, so any value works. No-op on
+    POSIX, where access control is the unix-socket file permissions."""
+    if IS_WINDOWS:
+        Path(f"{sock_path}.token").write_text(secrets.token_hex(16), encoding="utf-8")
+
+
+def send_daemon_token(sock: socket.socket, sock_path) -> None:
+    """Send the auth token as the first line on a *raw* client socket, matching
+    the daemon's Windows handshake. Reads ``<sock_path>.token`` (written by the
+    daemon or by ``write_fake_daemon_token``). No-op on POSIX."""
+    if IS_WINDOWS:
+        token = Path(f"{sock_path}.token").read_text(encoding="utf-8").strip()
+        sock.sendall((token + "\n").encode("utf-8"))
+
+
+def bind_fake_daemon_socket(sock_path) -> socket.socket:
+    """Return a bound, listening socket that an ``_ipc`` client configured with
+    ``IAI_DAEMON_SOCKET_PATH=sock_path`` will connect to.
+
+    POSIX: ``AF_UNIX`` bound at ``sock_path``. Windows: ``AF_INET`` on
+    ``127.0.0.1:<ephemeral>`` with the chosen port written to
+    ``"<sock_path>.port"`` (matching ``_ipc._port_file_path``). Caller owns the
+    returned socket (``accept``/``recv``/``close``).
+    """
+    if IS_WINDOWS:
+        srv = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        srv.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+        srv.bind(("127.0.0.1", 0))
+        port = srv.getsockname()[1]
+        Path(f"{sock_path}.port").write_text(str(port), encoding="utf-8")
+        write_fake_daemon_token(sock_path)
+    else:
+        try:
+            os.unlink(sock_path)
+        except FileNotFoundError:
+            pass
+        srv = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
+        srv.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+        srv.bind(str(sock_path))
+    srv.listen(5)
+    return srv
+
+
+def daemon_endpoint_ready_path(sock_path) -> Path:
+    """Path that exists once a daemon bound at ``sock_path`` is reachable: the
+    unix socket file on POSIX, the ``<sock_path>.port`` file on Windows."""
+    return Path(f"{sock_path}.port") if IS_WINDOWS else Path(sock_path)
+
+
+def daemon_endpoint(sock_path):
+    """Connect target for a daemon bound at ``sock_path``: the unix socket path
+    (POSIX) or ``("127.0.0.1", port)`` read from ``<sock_path>.port`` (Windows).
+    Raises ``FileNotFoundError`` if the Windows port file is absent."""
+    if IS_WINDOWS:
+        port = int(Path(f"{sock_path}.port").read_text(encoding="utf-8").strip())
+        return ("127.0.0.1", port)
+    return str(sock_path)
+
+
+def new_daemon_client_socket() -> socket.socket:
+    """A raw client socket of the right family for the current platform
+    (``AF_INET`` on Windows, ``AF_UNIX`` on POSIX)."""
+    family = socket.AF_INET if IS_WINDOWS else socket.AF_UNIX
+    return socket.socket(family, socket.SOCK_STREAM)
diff --git a/tests/test_bridge_socket_first.py b/tests/test_bridge_socket_first.py
index 66113dc..7a563b8 100644
--- a/tests/test_bridge_socket_first.py
+++ b/tests/test_bridge_socket_first.py
@@ -176,7 +176,7 @@ def _wait_for_daemon_socket(sock_path: Path, timeout_sec: float = 30.0) -> bool:
 def test_start_throws_DaemonUnreachableError_when_socket_missing(
     built_wrapper, tmp_path
 ):
-    sock_dir = Path(f"/tmp/iai-7.1-noconn-{os.getpid()}-{id(tmp_path)}")
+    sock_dir = tmp_path / "sock"
     sock_dir.mkdir(parents=True, exist_ok=True)
     sock_path = sock_dir / "d.sock"
     store_dir = sock_dir / "store"
@@ -294,7 +294,7 @@ def test_start_throws_DaemonUnreachableError_when_socket_missing(
 
 
 def test_start_succeeds_with_warm_daemon_no_extra_spawn(built_wrapper, tmp_path):
-    sock_dir = Path(f"/tmp/iai-7.1-warm-{os.getpid()}-{id(tmp_path)}")
+    sock_dir = tmp_path / "sock"
     sock_dir.mkdir(parents=True, exist_ok=True)
     sock_path = sock_dir / "d.sock"
     store_dir = sock_dir / "store"
diff --git a/tests/test_capture.py b/tests/test_capture.py
index 933110b..223b1c6 100644
--- a/tests/test_capture.py
+++ b/tests/test_capture.py
@@ -5,6 +5,8 @@
 """
 from __future__ import annotations
 
+import tempfile
+
 import json
 import platform
 import uuid
@@ -124,7 +126,7 @@ def test_deferred_capture_beyond_200(iai_home, tmp_path):
     out_path = write_deferred_captures(
         session_id=SESSION_ID,
         transcript_path=transcript,
-        cwd="/tmp/test",
+        cwd=str(Path(tempfile.gettempdir()) / "test"),
     )
 
     assert out_path.exists(), f"Deferred capture file not created at {out_path}"
diff --git a/tests/test_capture_queue.py b/tests/test_capture_queue.py
index 94875e3..134f913 100644
--- a/tests/test_capture_queue.py
+++ b/tests/test_capture_queue.py
@@ -1,8 +1,9 @@
 from __future__ import annotations
 
 import errno
-import fcntl
 import json
+from iai_mcp._filelock import LOCK_EX, LOCK_NB, LOCK_SH, LOCK_UN
+from iai_mcp._filelock import flock as _flock
 import os
 import threading
 import time
@@ -171,7 +172,7 @@ def test_idempotent_ingest_lock_skipped(tmp_path):
     lock_a = tmp_path / f"pending-{ulid_a}.lock"
     fd = os.open(str(lock_a), os.O_WRONLY | os.O_CREAT, 0o600)
     try:
-        fcntl.flock(fd, fcntl.LOCK_EX | fcntl.LOCK_NB)
+        _flock(fd, LOCK_EX | LOCK_NB)
 
         seen: list[str] = []
 
@@ -186,7 +187,7 @@ def handler(record: dict) -> None:
         assert not (tmp_path / f"pending-{ulid_c}.json").exists()
     finally:
         try:
-            fcntl.flock(fd, fcntl.LOCK_UN)
+            _flock(fd, LOCK_UN)
         except OSError:
             pass
         os.close(fd)
diff --git a/tests/test_capture_source_uuid_idem.py b/tests/test_capture_source_uuid_idem.py
index 328559e..f7bd137 100644
--- a/tests/test_capture_source_uuid_idem.py
+++ b/tests/test_capture_source_uuid_idem.py
@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+import tempfile
+
 import json
 import platform
 from datetime import datetime, timezone
@@ -240,7 +242,7 @@ def test_drain_deferred_deduplicates_already_inserted_uuid(iai_home):
         "version": 1,
         "deferred_at": "2026-05-31T18:00:00.000Z",
         "session_id": SESSION,
-        "cwd": "/tmp/test",
+        "cwd": str(Path(tempfile.gettempdir()) / "test"),
     }
     event = {
         "text": TEXT,
diff --git a/tests/test_capture_transcript_no_spawn.py b/tests/test_capture_transcript_no_spawn.py
index 85e822a..9c9541a 100644
--- a/tests/test_capture_transcript_no_spawn.py
+++ b/tests/test_capture_transcript_no_spawn.py
@@ -37,7 +37,7 @@ def _count_iai_mcp_processes() -> dict[str, int]:
 
 
 def _isolated_env(tmp_path: Path) -> tuple[dict[str, str], Path]:
-    sock_dir = Path(f"/tmp/iai-no-spawn-{os.getpid()}-{id(tmp_path)}")
+    sock_dir = tmp_path / "sock"
     sock_dir.mkdir(parents=True, exist_ok=True)
     sock_path = sock_dir / "d.sock"
 
diff --git a/tests/test_capture_transcript_no_spawn_defer.py b/tests/test_capture_transcript_no_spawn_defer.py
index 302d954..4d0e520 100644
--- a/tests/test_capture_transcript_no_spawn_defer.py
+++ b/tests/test_capture_transcript_no_spawn_defer.py
@@ -20,7 +20,7 @@
 
 
 def _isolated_env(tmp_path: Path) -> tuple[dict[str, str], Path, Path]:
-    sock_dir = Path(f"/tmp/iai-no-spawn-defer-{os.getpid()}-{id(tmp_path)}")
+    sock_dir = tmp_path / "sock"
     sock_dir.mkdir(parents=True, exist_ok=True)
     sock_path = sock_dir / "d.sock"
 
diff --git a/tests/test_cli_crypto.py b/tests/test_cli_crypto.py
index e79cfa5..9dc0a37 100644
--- a/tests/test_cli_crypto.py
+++ b/tests/test_cli_crypto.py
@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+import sys
+
 import json
 import os
 import secrets
@@ -30,7 +32,8 @@ def test_cli_crypto_status_shows_file_backend(tmp_path, monkeypatch, capsys):
     assert "default" in out
     assert "file" in out_lower, f"status must report backend=file; got:\n{out}"
     assert ".crypto.key" in out, f"status must include the file path; got:\n{out}"
-    assert "600" in out, f"status must expose mode 0o600; got:\n{out}"
+    if sys.platform != "win32":
+        assert "600" in out, f"status must expose mode 0o600; got:\n{out}"
     assert "keyring" not in out_lower, (
         f"status must NOT mention keyring (backend retired in 07.10); got:\n{out}"
     )
@@ -89,7 +92,8 @@ def test_cli_crypto_rotate_regenerates_key(tmp_path, monkeypatch, capsys):
     assert len(new_key_bytes) == 32
     assert new_key_bytes != key_a, "rotate must write a fresh key to the file"
     mode = stat.S_IMODE(os.stat(key_path).st_mode)
-    assert mode == 0o600, f"rotated key file must be 0o600, got 0o{mode:03o}"
+    if sys.platform != "win32":
+        assert mode == 0o600, f"rotated key file must be 0o600, got 0o{mode:03o}"
 
     store2 = MemoryStore()
     post_ct = store2.db.open_table(RECORDS_TABLE).to_pandas()[
@@ -260,7 +264,8 @@ def test_cli_crypto_init_creates_fresh_file(tmp_path, monkeypatch, capsys):
     assert key_path.exists()
     assert key_path.stat().st_size == 32
     mode = stat.S_IMODE(os.stat(key_path).st_mode)
-    assert mode == 0o600, f"init key file must be 0o600, got 0o{mode:03o}"
+    if sys.platform != "win32":
+        assert mode == 0o600, f"init key file must be 0o600, got 0o{mode:03o}"
     assert ".crypto.key" in out
     raw = key_path.read_bytes()
     for i in range(0, 32, 4):
diff --git a/tests/test_cli_daemon.py b/tests/test_cli_daemon.py
index 8140bb1..3342b9b 100644
--- a/tests/test_cli_daemon.py
+++ b/tests/test_cli_daemon.py
@@ -5,6 +5,7 @@
 import json
 import os
 import platform
+import signal
 import sys
 import tempfile
 import threading
@@ -14,6 +15,7 @@
 
 import pytest
 
+from iai_mcp import _ipc
 from iai_mcp import cli as cli_mod
 
 
@@ -60,10 +62,20 @@ async def _handle(reader, writer):
                         pass
 
             async def _serve():
-                self.path.parent.mkdir(parents=True, exist_ok=True)
-                self._server = await asyncio.start_unix_server(
-                    _handle, path=str(self.path),
-                )
+                # Mirror the production IPC transport (_ipc): Unix-domain
+                # socket on POSIX, TCP loopback + port file on Windows
+                # (asyncio.start_unix_server does not exist on Windows).
+                if _ipc.IS_WINDOWS:
+                    self._server = await asyncio.start_server(
+                        _handle, "127.0.0.1", 0,
+                    )
+                    port = self._server.sockets[0].getsockname()[1]
+                    _ipc._write_port(port)
+                else:
+                    self.path.parent.mkdir(parents=True, exist_ok=True)
+                    self._server = await asyncio.start_unix_server(
+                        _handle, path=str(self.path),
+                    )
                 self._ready.set()
                 async with self._server:
                     await self._server.serve_forever()
@@ -96,13 +108,20 @@ async def _shutdown():
         loop.call_soon_threadsafe(loop.stop)
         if self._thread is not None:
             self._thread.join(timeout=5.0)
+        if _ipc.IS_WINDOWS:
+            _ipc._remove_port_file()
 
 
 @pytest.fixture
-def short_socket(tmp_path: Path) -> Path:
+def short_socket(tmp_path: Path, monkeypatch: pytest.MonkeyPatch) -> Path:
     candidate = tmp_path / "d.sock"
     if len(str(candidate)) > 100:
         candidate = Path(tempfile.mkdtemp(prefix="iai-clitest-")) / "d.sock"
+    # On Windows the IPC layer rendezvous via a TCP port file, not the socket
+    # path. Redirect _ipc.PORT_FILE into the temp dir so the fake daemon and
+    # the CLI client (both reference this module global) find each other,
+    # without reading or clobbering a real daemon's ~/.iai-mcp/.daemon.port.
+    monkeypatch.setattr(_ipc, "PORT_FILE", candidate.parent / ".daemon.port")
     return candidate
 
 
@@ -715,6 +734,10 @@ def test_stop_bootout_precedes_sigterm(monkeypatch: pytest.MonkeyPatch) -> None:
     assert ("kill", 4242, sig.SIGTERM) in calls
 
 
+@pytest.mark.skipif(
+    not hasattr(signal, "SIGKILL"),
+    reason="SIGKILL escalation is POSIX-only; Windows os.kill has no SIGKILL",
+)
 def test_stop_escalates_to_sigkill_when_pid_survives(
     monkeypatch: pytest.MonkeyPatch,
 ) -> None:
@@ -740,6 +763,10 @@ def test_stop_escalates_to_sigkill_when_pid_survives(
     assert ("kill", 5151, sig.SIGTERM) in calls
 
 
+@pytest.mark.skipif(
+    not hasattr(signal, "SIGKILL"),
+    reason="SIGKILL escalation is POSIX-only; Windows os.kill has no SIGKILL",
+)
 def test_stop_no_sigkill_when_pid_dies_during_wait(
     monkeypatch: pytest.MonkeyPatch,
 ) -> None:
diff --git a/tests/test_cli_ensure_crypto_key_present.py b/tests/test_cli_ensure_crypto_key_present.py
index 73ad5c5..fd6c686 100644
--- a/tests/test_cli_ensure_crypto_key_present.py
+++ b/tests/test_cli_ensure_crypto_key_present.py
@@ -2,6 +2,7 @@
 
 import os
 import stat
+import sys
 
 import pytest
 
@@ -21,7 +22,8 @@ def test_ensure_crypto_key_generates_on_fresh_install(tmp_path, monkeypatch):
     assert path is not None
     assert path.exists()
     assert path.stat().st_size == 32
-    assert stat.S_IMODE(path.stat().st_mode) == 0o600
+    if sys.platform != "win32":
+        assert stat.S_IMODE(path.stat().st_mode) == 0o600
 
 
 def test_ensure_crypto_key_idempotent_when_file_exists(tmp_path, monkeypatch):
diff --git a/tests/test_concurrency.py b/tests/test_concurrency.py
index 885b877..4a3ce08 100644
--- a/tests/test_concurrency.py
+++ b/tests/test_concurrency.py
@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+import sys
+
 import asyncio
 import json
 import os
@@ -7,14 +9,24 @@
 
 import pytest
 
+from iai_mcp._ipc import IS_WINDOWS, open_ipc_connection
+
+
+def _endpoint_ready_path(sock_path: Path) -> Path:
+    """Path that exists once the control socket has bound: the unix socket on
+    POSIX, the TCP port file (``<sock_path>.port``) on Windows."""
+    return Path(f"{sock_path}.port") if IS_WINDOWS else sock_path
+
 
 @pytest.fixture
 def socket_path(tmp_path, monkeypatch):
     from iai_mcp import concurrency
-    sock_dir = Path(f"/tmp/iai-{os.getpid()}-{id(tmp_path)}")
+    sock_dir = tmp_path / "sock"
     sock_dir.mkdir(parents=True, exist_ok=True)
     sock_path = sock_dir / "d.sock"
     monkeypatch.setattr(concurrency, "SOCKET_PATH", sock_path)
+    # Per-test endpoint isolation honored by start_ipc_server/open_ipc_connection.
+    monkeypatch.setenv("IAI_DAEMON_SOCKET_PATH", str(sock_path))
     try:
         yield sock_path
     finally:
@@ -40,13 +52,14 @@ async def runner():
             serve_control_socket(store=None, state=state, shutdown=shutdown,
                                  socket_path=socket_path)
         )
+        ready_path = _endpoint_ready_path(socket_path)
         for _ in range(100):
-            if socket_path.exists():
+            if ready_path.exists():
                 break
             await asyncio.sleep(0.02)
-        assert socket_path.exists(), "socket never bound"
+        assert ready_path.exists(), "socket never bound"
 
-        reader, writer = await asyncio.open_unix_connection(path=str(socket_path))
+        reader, writer = await open_ipc_connection()
         writer.write(b'{"type":"status"}\n')
         await writer.drain()
         line = await reader.readline()
@@ -90,15 +103,16 @@ async def runner():
                 dispatcher=custom_dispatcher, socket_path=socket_path,
             )
         )
+        ready_path = _endpoint_ready_path(socket_path)
         for _ in range(100):
-            if socket_path.exists():
+            if ready_path.exists():
                 break
             await asyncio.sleep(0.02)
-        assert socket_path.exists()
+        assert ready_path.exists()
 
         responses = []
         for req in requests:
-            r, w = await asyncio.open_unix_connection(path=str(socket_path))
+            r, w = await open_ipc_connection()
             w.write((json.dumps(req) + "\n").encode())
             await w.drain()
             line = await r.readline()
@@ -120,6 +134,9 @@ async def runner():
         assert resp == {"ok": True, "seen": req["type"]}
 
 
+@pytest.mark.skipif(
+    IS_WINDOWS, reason="stale unix-socket-file cleanup is POSIX-only (Windows uses a TCP port file)"
+)
 def test_stale_socket_cleanup(socket_path):
     from iai_mcp.concurrency import serve_control_socket
 
@@ -155,6 +172,9 @@ async def runner():
     assert resp.get("ok") is True
 
 
+@pytest.mark.skipif(
+    IS_WINDOWS, reason="0o600 unix-socket-file mode is POSIX-only (Windows uses a TCP port file)"
+)
 def test_socket_permissions_user_only(socket_path):
     from iai_mcp.concurrency import serve_control_socket
 
@@ -174,4 +194,5 @@ async def runner():
         return sock_mode
 
     sock_mode = asyncio.run(runner())
-    assert sock_mode == 0o600, f"socket mode is {oct(sock_mode)}, expected 0o600"
+    if sys.platform != "win32":
+        assert sock_mode == 0o600, f"socket mode is {oct(sock_mode)}, expected 0o600"
diff --git a/tests/test_concurrency_session_open.py b/tests/test_concurrency_session_open.py
index 9a7cfab..3cf23b1 100644
--- a/tests/test_concurrency_session_open.py
+++ b/tests/test_concurrency_session_open.py
@@ -19,10 +19,13 @@
 
 
 @pytest.fixture
-def tmp_socket(tmp_path: Path) -> Path:
+def tmp_socket(tmp_path: Path, monkeypatch: pytest.MonkeyPatch) -> Path:
     candidate = tmp_path / "d.sock"
     if len(str(candidate)) > 100:
         candidate = Path(tempfile.mkdtemp(prefix="iai-sock-")) / "d.sock"
+    # Per-test endpoint isolation: serve_control_socket + open_ipc_connection
+    # resolve through this (unix socket on POSIX, TCP "<path>.port" on Windows).
+    monkeypatch.setenv("IAI_DAEMON_SOCKET_PATH", str(candidate))
     return candidate
 
 
@@ -256,7 +259,9 @@ def stop(self) -> None:
 
 
 async def _send(path: Path, msg: dict, *, timeout: float = 5.0) -> dict:
-    reader, writer = await asyncio.open_unix_connection(str(path))
+    from iai_mcp._ipc import open_ipc_connection
+
+    reader, writer = await open_ipc_connection(timeout=timeout)
     try:
         writer.write((json.dumps(msg) + "\n").encode("utf-8"))
         await writer.drain()
diff --git a/tests/test_concurrent_wrapper_spawn.py b/tests/test_concurrent_wrapper_spawn.py
index 215d08e..5ef09e8 100644
--- a/tests/test_concurrent_wrapper_spawn.py
+++ b/tests/test_concurrent_wrapper_spawn.py
@@ -37,7 +37,7 @@ def test_launchagent(tmp_path):
     if os.environ.get("IAI_MCP_SKIP_LAUNCHCTL_TESTS") == "1":
         pytest.skip("IAI_MCP_SKIP_LAUNCHCTL_TESTS=1")
 
-    sock_dir = Path(f"/tmp/iai-cspawn-{os.getpid()}-{id(tmp_path) & 0xFFFFFF:x}")
+    sock_dir = tmp_path / "sock"
     sock_dir.mkdir(parents=True, exist_ok=True)
     sock_path = sock_dir / "d.sock"
     if sock_path.exists():
diff --git a/tests/test_core_bedtime_inject.py b/tests/test_core_bedtime_inject.py
index 956e6f7..92b3516 100644
--- a/tests/test_core_bedtime_inject.py
+++ b/tests/test_core_bedtime_inject.py
@@ -12,6 +12,7 @@
 import pytest
 
 from iai_mcp import core
+from iai_mcp._ipc import start_ipc_server
 
 
 class _ThreadedFakeDaemon:
@@ -46,7 +47,7 @@ async def _handle(reader: asyncio.StreamReader, writer: asyncio.StreamWriter) ->
 
             async def _serve() -> None:
                 self.path.parent.mkdir(parents=True, exist_ok=True)
-                self._server = await asyncio.start_unix_server(_handle, path=str(self.path))
+                self._server, _addr, _cleanup = await start_ipc_server(_handle)
                 self._ready.set()
                 async with self._server:
                     await self._server.serve_forever()
@@ -83,10 +84,13 @@ async def _shutdown() -> None:
 
 
 @pytest.fixture
-def tmp_socket(tmp_path: Path) -> Path:
+def tmp_socket(tmp_path: Path, monkeypatch: pytest.MonkeyPatch) -> Path:
     candidate = tmp_path / "d.sock"
     if len(str(candidate)) > 100:
         candidate = Path(tempfile.mkdtemp(prefix="iai-sock-")) / "d.sock"
+    # Per-test endpoint isolation: start_ipc_server + open_ipc_connection resolve
+    # through this (unix socket on POSIX, TCP "<path>.port" on Windows).
+    monkeypatch.setenv("IAI_DAEMON_SOCKET_PATH", str(candidate))
     return candidate
 
 
@@ -115,7 +119,8 @@ async def _handle(reader: asyncio.StreamReader, writer: asyncio.StreamWriter) ->
                 pass
 
     sock.parent.mkdir(parents=True, exist_ok=True)
-    return await asyncio.start_unix_server(_handle, path=str(sock))
+    server, _addr, _cleanup = await start_ipc_server(_handle)
+    return server
 
 
 def test_consent_false_short_circuits_no_socket_touch(
@@ -124,10 +129,12 @@ def test_consent_false_short_circuits_no_socket_touch(
 
     async def _explode(*args, **kwargs):
         raise AssertionError(
-            "C2 violation: asyncio.open_unix_connection reached with consent=False"
+            "C2 violation: daemon connection reached with consent=False"
         )
 
-    monkeypatch.setattr(asyncio, "open_unix_connection", _explode)
+    # Patch the actual connection entry point core uses (cross-platform), not
+    # the POSIX-only asyncio.open_unix_connection.
+    monkeypatch.setattr("iai_mcp._ipc.open_ipc_connection", _explode)
 
     result = asyncio.run(
         core.handle_initiate_sleep_mode({"consent": False, "reason": "not ready"})
diff --git a/tests/test_crypto_file_backend.py b/tests/test_crypto_file_backend.py
index 4272f53..91f2b97 100644
--- a/tests/test_crypto_file_backend.py
+++ b/tests/test_crypto_file_backend.py
@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+import sys
+
 import os
 import secrets
 import stat
@@ -103,7 +105,8 @@ def test_try_file_set_writes_atomic_with_0o600(tmp_path: Path) -> None:
     assert key_path.exists()
     assert key_path.read_bytes() == payload
     mode = stat.S_IMODE(os.stat(key_path).st_mode)
-    assert mode == 0o600
+    if sys.platform != "win32":
+        assert mode == 0o600
 
     leftover_tmps = list(tmp_path.glob(".crypto.key.tmp.*"))
     assert leftover_tmps == [], f"leaked tmp files: {leftover_tmps}"
@@ -174,7 +177,8 @@ def fake_delete(service: str, username: str) -> None:
     key_path = tmp_path / ".crypto.key"
     assert key_path.exists()
     mode = stat.S_IMODE(os.stat(key_path).st_mode)
-    assert mode == 0o600
+    if sys.platform != "win32":
+        assert mode == 0o600
     assert key_path.read_bytes() == keyring_key, (
         "file contents must equal the round-tripped keyring key bytes"
     )
diff --git a/tests/test_daemon.py b/tests/test_daemon.py
index 05a628c..268375a 100644
--- a/tests/test_daemon.py
+++ b/tests/test_daemon.py
@@ -23,7 +23,7 @@ def _short_socket_paths(tmp_path, monkeypatch):
     import os
     from iai_mcp import concurrency
     lock_path = tmp_path / ".lock"
-    sock_dir = Path(f"/tmp/iai-daemon-{os.getpid()}-{id(tmp_path)}")
+    sock_dir = tmp_path / "sock"
     sock_dir.mkdir(parents=True, exist_ok=True)
     sock_path = sock_dir / "d.sock"
     monkeypatch.setattr(concurrency, "SOCKET_PATH", sock_path)
diff --git a/tests/test_daemon_crash_loop_immunity.py b/tests/test_daemon_crash_loop_immunity.py
index 85b7b0d..96154f1 100644
--- a/tests/test_daemon_crash_loop_immunity.py
+++ b/tests/test_daemon_crash_loop_immunity.py
@@ -12,10 +12,17 @@
 
 import pytest
 
+from _socket_test_helpers import (
+    daemon_endpoint,
+    daemon_endpoint_ready_path,
+    new_daemon_client_socket,
+)
+
 
 @pytest.fixture
 def iai_home(tmp_path, monkeypatch):
     monkeypatch.setenv("HOME", str(tmp_path))
+    monkeypatch.setenv("USERPROFILE", str(tmp_path))  # Path.home() reads USERPROFILE on Windows
     monkeypatch.setenv("PYTHON_KEYRING_BACKEND", "keyring.backends.fail.Keyring")
     monkeypatch.setenv("IAI_MCP_CRYPTO_PASSPHRASE", "test-crash-loop-passphrase")
     monkeypatch.setenv("IAI_MCP_STORE", str(tmp_path / ".iai-mcp" / "hippo"))
@@ -217,6 +224,7 @@ def _stub(*_args: Any, **_kwargs: Any) -> dict:
 
 def test_socket_binds_before_drain_completes(tmp_path, monkeypatch, request):
     monkeypatch.setenv("HOME", str(tmp_path))
+    monkeypatch.setenv("USERPROFILE", str(tmp_path))  # Path.home() reads USERPROFILE on Windows
     monkeypatch.setenv("PYTHON_KEYRING_BACKEND", "keyring.backends.fail.Keyring")
     monkeypatch.setenv("IAI_MCP_CRYPTO_PASSPHRASE", "test-bind-first-passphrase")
     monkeypatch.setenv("IAI_MCP_STORE", str(tmp_path / ".iai-mcp" / "hippo"))
@@ -225,7 +233,7 @@ def test_socket_binds_before_drain_completes(tmp_path, monkeypatch, request):
 
     keyring.core._keyring_backend = None
 
-    tmp_socket = Path(f"/tmp/iai-test-{os.getpid()}-{int(time.time()*1000)}.sock")
+    tmp_socket = tmp_path / f"iai-test-{os.getpid()}.sock"
     monkeypatch.setenv("IAI_DAEMON_SOCKET_PATH", str(tmp_socket))
 
     def _cleanup_socket():
@@ -270,11 +278,11 @@ async def _scenario() -> bool:
                     if exc is not None:
                         raise exc
                     return False
-                if tmp_socket.exists():
+                if daemon_endpoint_ready_path(tmp_socket).exists():
                     try:
-                        s = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
+                        s = new_daemon_client_socket()
                         s.settimeout(1.0)
-                        await asyncio.to_thread(s.connect, str(tmp_socket))
+                        await asyncio.to_thread(s.connect, daemon_endpoint(tmp_socket))
                         s.close()
                         snapshot["bound_at"] = time.monotonic()
                         snapshot["drain_started"] = drain_state["started"]
@@ -313,6 +321,7 @@ async def _scenario() -> bool:
 
 def test_atomic_claim_logs_generic_oserror(tmp_path, monkeypatch):
     monkeypatch.setenv("HOME", str(tmp_path))
+    monkeypatch.setenv("USERPROFILE", str(tmp_path))  # Path.home() reads USERPROFILE on Windows
     monkeypatch.setenv("PYTHON_KEYRING_BACKEND", "keyring.backends.fail.Keyring")
     monkeypatch.setenv("IAI_MCP_CRYPTO_PASSPHRASE", "p6-1-fix-a-test-passphrase")
     monkeypatch.setenv("IAI_MCP_STORE", str(tmp_path / ".iai-mcp" / "hippo"))
@@ -330,14 +339,16 @@ def test_atomic_claim_logs_generic_oserror(tmp_path, monkeypatch):
 
     import pathlib as _pathlib
 
-    real_rename = _pathlib.Path.rename
+    real_replace = _pathlib.Path.replace
 
     def boom(self, target):
         if ".processing-" in str(target) and self == fpath:
             raise PermissionError("simulated EACCES on atomic claim")
-        return real_rename(self, target)
+        return real_replace(self, target)
 
-    monkeypatch.setattr(_pathlib.Path, "rename", boom)
+    # The atomic claim uses Path.replace (os.replace) — not rename — so the
+    # claim survives a pre-existing dest on Windows. Patch what the code calls.
+    monkeypatch.setattr(_pathlib.Path, "replace", boom)
 
     from iai_mcp.capture import drain_deferred_captures
     from iai_mcp.store import MemoryStore
@@ -387,7 +398,8 @@ def test_strip_processing_marker_returns_false_on_rename_failure(
     def boom(self, target):
         raise PermissionError("simulated")
 
-    monkeypatch.setattr(_pathlib.Path, "rename", boom)
+    # _strip_processing_marker uses Path.replace (os.replace), not rename.
+    monkeypatch.setattr(_pathlib.Path, "replace", boom)
 
     new_path, ok = _strip_processing_marker(src, log_path=log_path)
     assert ok is False, "strip MUST report failure"
diff --git a/tests/test_daemon_dispatcher.py b/tests/test_daemon_dispatcher.py
index e1c3dd3..d30c7ba 100644
--- a/tests/test_daemon_dispatcher.py
+++ b/tests/test_daemon_dispatcher.py
@@ -8,18 +8,29 @@
 
 import pytest
 
+from iai_mcp._ipc import IS_WINDOWS, open_ipc_connection
+
+
+def _endpoint_ready_path(sock_path: Path) -> Path:
+    """Path that exists once the control socket has bound: the unix socket on
+    POSIX, the TCP port file (``<sock_path>.port``) on Windows."""
+    return Path(f"{sock_path}.port") if IS_WINDOWS else sock_path
+
 
 @pytest.fixture
 def short_socket_paths(tmp_path, monkeypatch):
     from iai_mcp import concurrency, daemon_state
 
-    sock_dir = Path(f"/tmp/iai-disp-{os.getpid()}-{id(tmp_path)}")
+    sock_dir = tmp_path / "sock"
     sock_dir.mkdir(parents=True, exist_ok=True)
     sock_path = sock_dir / "d.sock"
     state_path = tmp_path / ".daemon-state.json"
 
     monkeypatch.setattr(concurrency, "SOCKET_PATH", sock_path)
     monkeypatch.setattr(daemon_state, "STATE_PATH", state_path)
+    # Per-test endpoint isolation (unix socket on POSIX; TCP port file on
+    # Windows) via the env var start_ipc_server/open_ipc_connection honor.
+    monkeypatch.setenv("IAI_DAEMON_SOCKET_PATH", str(sock_path))
 
     try:
         yield None, sock_path, state_path
@@ -36,10 +47,7 @@ def short_socket_paths(tmp_path, monkeypatch):
 
 
 async def _send_ndjson(sock_path: Path, message: dict, *, timeout: float = 5.0) -> dict:
-    reader, writer = await asyncio.wait_for(
-        asyncio.open_unix_connection(path=str(sock_path)),
-        timeout=timeout,
-    )
+    reader, writer = await open_ipc_connection(timeout=timeout)
     try:
         writer.write((json.dumps(message) + "\n").encode("utf-8"))
         await writer.drain()
@@ -67,11 +75,12 @@ async def _with_real_dispatcher(sock_path: Path, state: dict, coro_fn):
             socket_path=sock_path,
         ),
     )
+    ready_path = _endpoint_ready_path(sock_path)
     for _ in range(250):
-        if sock_path.exists():
+        if ready_path.exists():
             break
         await asyncio.sleep(0.01)
-    if not sock_path.exists():
+    if not ready_path.exists():
         shutdown.set()
         await asyncio.wait_for(server_task, timeout=5)
         raise AssertionError("socket never bound")
diff --git a/tests/test_daemon_fdlimit_and_fsm.py b/tests/test_daemon_fdlimit_and_fsm.py
index 14106d9..9da88d9 100644
--- a/tests/test_daemon_fdlimit_and_fsm.py
+++ b/tests/test_daemon_fdlimit_and_fsm.py
@@ -1,8 +1,10 @@
 from __future__ import annotations
 
 import json
-import resource
 import sys
+
+if sys.platform != "win32":
+    import resource
 from pathlib import Path
 from unittest.mock import MagicMock, patch
 
@@ -13,6 +15,7 @@
 from iai_mcp.s2_coordinator import S2Coordinator
 
 
+@pytest.mark.skipif(sys.platform == "win32", reason="resource module not available on Windows")
 class TestRaiseFdLimitClampsToHard:
 
     def test_raises_low_soft_to_floor(self):
diff --git a/tests/test_daemon_state.py b/tests/test_daemon_state.py
index f2f6cf3..d052b16 100644
--- a/tests/test_daemon_state.py
+++ b/tests/test_daemon_state.py
@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+import sys
+
 import json
 import os
 from datetime import datetime, timedelta, timezone
@@ -30,7 +32,8 @@ def test_save_and_load_roundtrip_with_0600_mode(isolated_state_path):
 
     assert isolated_state_path.exists()
     mode = isolated_state_path.stat().st_mode & 0o777
-    assert mode == 0o600, f"expected 0o600, got {oct(mode)}"
+    if sys.platform != "win32":
+        assert mode == 0o600, f"expected 0o600, got {oct(mode)}"
 
     loaded = load_state()
     assert loaded == state
diff --git a/tests/test_daemon_watchdog.py b/tests/test_daemon_watchdog.py
index 74bed32..ef973a9 100644
--- a/tests/test_daemon_watchdog.py
+++ b/tests/test_daemon_watchdog.py
@@ -10,6 +10,15 @@
 import pytest
 
 from iai_mcp import daemon
+from _socket_test_helpers import bind_fake_daemon_socket
+
+# The watchdog's self-kill path uses signal.SIGKILL, which doesn't exist on
+# Windows (the production code guards it with hasattr). These tests assert that
+# POSIX self-kill behavior, so they only apply where SIGKILL exists.
+_REQUIRES_SIGKILL = pytest.mark.skipif(
+    not hasattr(signal, "SIGKILL"),
+    reason="watchdog SIGKILL self-kill is POSIX-only (guarded off on Windows)",
+)
 
 HARD_CAP = 2_684_354_560
 FLOOR = 1_610_612_736
@@ -234,6 +243,7 @@ def _read_breadcrumb(log_path):
     return log_path.read_text(encoding="utf-8")
 
 
+@_REQUIRES_SIGKILL
 def test_thread_wedge_after_n_consecutive_kills(watchdog_env):
     store = object()
     consec = 0
@@ -280,6 +290,7 @@ def test_thread_healthy_busy_not_killed(watchdog_env):
     assert consec == 0
 
 
+@_REQUIRES_SIGKILL
 def test_thread_warn_plus_big_memory_kill(watchdog_env):
     store = object()
     consec = 0
@@ -408,6 +419,7 @@ def _fake_write_event(store, kind, data, **kw):
         pass
 
 
+@_REQUIRES_SIGKILL
 def test_self_kill_is_unconditional_when_breadcrumb_fails_wedge(
     tmp_path, monkeypatch
 ):
@@ -439,6 +451,7 @@ def test_self_kill_is_unconditional_when_breadcrumb_fails_wedge(
     assert kill_calls == [(os.getpid(), signal.SIGKILL)]
 
 
+@_REQUIRES_SIGKILL
 def test_self_kill_is_unconditional_when_breadcrumb_fails_memory(
     tmp_path, monkeypatch
 ):
@@ -470,6 +483,7 @@ def test_self_kill_is_unconditional_when_breadcrumb_fails_memory(
     assert kill_calls == [(os.getpid(), signal.SIGKILL)]
 
 
+@_REQUIRES_SIGKILL
 def test_self_kill_direct_breadcrumb_failure_still_kills(tmp_path, monkeypatch):
 
     def _raise(_line):
@@ -484,16 +498,17 @@ def _raise(_line):
     assert kill_calls == [(os.getpid(), signal.SIGKILL)]
 
 
-def test_probe_returns_false_when_no_socket(tmp_path):
+def test_probe_returns_false_when_no_socket(tmp_path, monkeypatch):
     sock_path = str(tmp_path / "absent.sock")
+    # Isolate the endpoint so the probe can't reach a real daemon on this box.
+    monkeypatch.setenv("IAI_DAEMON_SOCKET_PATH", sock_path)
     assert asyncio.run(daemon._probe_status_roundtrip(sock_path, 0.2)) is False
 
 
-def test_probe_returns_false_on_connect_but_no_reply(tmp_path, short_socket):
+def test_probe_returns_false_on_connect_but_no_reply(tmp_path, short_socket, monkeypatch):
     sock_path = str(short_socket)
-    srv = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
-    srv.bind(sock_path)
-    srv.listen(1)
+    monkeypatch.setenv("IAI_DAEMON_SOCKET_PATH", sock_path)
+    srv = bind_fake_daemon_socket(sock_path)
     accepted: list = []
 
     def _accept_and_hang():
@@ -517,11 +532,10 @@ def _accept_and_hang():
         srv.close()
 
 
-def test_probe_returns_true_on_full_roundtrip(tmp_path, short_socket):
+def test_probe_returns_true_on_full_roundtrip(tmp_path, short_socket, monkeypatch):
     sock_path = str(short_socket)
-    srv = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
-    srv.bind(sock_path)
-    srv.listen(1)
+    monkeypatch.setenv("IAI_DAEMON_SOCKET_PATH", sock_path)
+    srv = bind_fake_daemon_socket(sock_path)
     held: list = []
 
     def _accept_and_reply():
diff --git a/tests/test_doctor_apply_recovery.py b/tests/test_doctor_apply_recovery.py
index 7d39319..7a04d56 100644
--- a/tests/test_doctor_apply_recovery.py
+++ b/tests/test_doctor_apply_recovery.py
@@ -23,7 +23,7 @@ def isolated_daemon_paths(tmp_path, monkeypatch):
     store_dir = iai_dir / "store"
     store_dir.mkdir(parents=True, exist_ok=True)
 
-    sock_dir = Path(f"/tmp/iai-rec-{os.getpid()}-{id(tmp_path)}")
+    sock_dir = tmp_path / "sock"
     sock_dir.mkdir(parents=True, exist_ok=True)
     sock_path = sock_dir / "d.sock"
 
diff --git a/tests/test_doctor_checklist.py b/tests/test_doctor_checklist.py
index 870b3db..8e2641a 100644
--- a/tests/test_doctor_checklist.py
+++ b/tests/test_doctor_checklist.py
@@ -10,11 +10,14 @@
 
 import pytest
 
+from iai_mcp._ipc import IS_WINDOWS
+from _socket_test_helpers import bind_fake_daemon_socket
+
 
 @pytest.fixture
 def short_socket_paths(tmp_path, monkeypatch):
     lock_path = tmp_path / ".lock"
-    sock_dir = Path(f"/tmp/iai-doc-{os.getpid()}-{id(tmp_path)}")
+    sock_dir = tmp_path / "sock"
     sock_dir.mkdir(parents=True, exist_ok=True)
     sock_path = sock_dir / "d.sock"
     state_path = tmp_path / ".daemon-state.json"
@@ -222,9 +225,7 @@ def test_check_b_passes_against_silent_listening_socket(short_socket_paths):
     if sock_path.exists():
         sock_path.unlink()
 
-    server = _socket.socket(_socket.AF_UNIX, _socket.SOCK_STREAM)
-    server.bind(str(sock_path))
-    server.listen(8)
+    server = bind_fake_daemon_socket(sock_path)
     stop = threading.Event()
     accepted: list = []
 
@@ -269,6 +270,10 @@ def _accept_loop():
         th.join(timeout=1.0)
 
 
+@pytest.mark.skipif(
+    IS_WINDOWS,
+    reason="regular-file-where-a-socket-should-be is an AF_UNIX concept; Windows uses a TCP port file",
+)
 def test_check_b_fails_when_socket_is_regular_file(short_socket_paths):
     _, sock_path, _ = short_socket_paths
     if sock_path.exists():
diff --git a/tests/test_doctor_lock_probe.py b/tests/test_doctor_lock_probe.py
index 18452d7..46dab73 100644
--- a/tests/test_doctor_lock_probe.py
+++ b/tests/test_doctor_lock_probe.py
@@ -1,8 +1,8 @@
 from __future__ import annotations
 
-import fcntl
-
 import pytest
+from iai_mcp._filelock import LOCK_EX, LOCK_NB, LOCK_UN
+from iai_mcp._filelock import flock as _flock
 
 from iai_mcp.doctor import check_c_lock_healthy
 
@@ -46,14 +46,14 @@ def test_held_lock_is_healthy(tmp_store):
     try:
         with open(lock_path, "r") as held:
             held_fd = held.fileno()
-            fcntl.flock(held_fd, fcntl.LOCK_EX | fcntl.LOCK_NB)
+            _flock(held_fd, LOCK_EX | LOCK_NB)
 
             result = check_c_lock_healthy()
 
             assert result.passed is True
             assert result.name == "(c) lock file healthy"
             assert "held" in result.detail
-            fcntl.flock(held_fd, fcntl.LOCK_UN)
+            _flock(held_fd, LOCK_UN)
     finally:
         pass
 
diff --git a/tests/test_drain_active_live_e2e.py b/tests/test_drain_active_live_e2e.py
index ebfba36..6e28232 100644
--- a/tests/test_drain_active_live_e2e.py
+++ b/tests/test_drain_active_live_e2e.py
@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+import tempfile
+
 import json
 import platform
 from pathlib import Path
@@ -41,7 +43,7 @@ def _write_live_file(
         "version": 1,
         "deferred_at": "2026-05-31T04:45:00.000000+00:00",
         "session_id": session_id,
-        "cwd": "/tmp/test",
+        "cwd": str(Path(tempfile.gettempdir()) / "test"),
     }
     lines = [json.dumps(header, ensure_ascii=False)]
     for ev in events:
diff --git a/tests/test_drain_deferred_captures.py b/tests/test_drain_deferred_captures.py
index 4a0d401..037376f 100644
--- a/tests/test_drain_deferred_captures.py
+++ b/tests/test_drain_deferred_captures.py
@@ -373,7 +373,7 @@ def test_daemon_main_drain_does_not_crash_on_bad_file(tmp_path, monkeypatch):
     )
     assert bad.exists()
 
-    sock_dir = Path(f"/tmp/iai-drn-{os.getpid()}-{id(tmp_path)}")
+    sock_dir = tmp_path / "sock"
     sock_dir.mkdir(parents=True, exist_ok=True)
     sock_path = sock_dir / "d.sock"
 
diff --git a/tests/test_episodic_verbatim_dedup.py b/tests/test_episodic_verbatim_dedup.py
index d0e7d06..ba34417 100644
--- a/tests/test_episodic_verbatim_dedup.py
+++ b/tests/test_episodic_verbatim_dedup.py
@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+import tempfile
+
 import json
 import platform
 from datetime import datetime, timezone
@@ -55,7 +57,7 @@ def _write_live_file(
         "version": 1,
         "deferred_at": "2026-05-30T10:00:00.000000+00:00",
         "session_id": session_id,
-        "cwd": "/tmp/test",
+        "cwd": str(Path(tempfile.gettempdir()) / "test"),
     }
     lines = [json.dumps(header, ensure_ascii=False)]
     for ev in events:
diff --git a/tests/test_hippo_skeleton.py b/tests/test_hippo_skeleton.py
index 224eb08..454c1bc 100644
--- a/tests/test_hippo_skeleton.py
+++ b/tests/test_hippo_skeleton.py
@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+import sys
+
 import stat
 from datetime import datetime, timezone
 from pathlib import Path
@@ -220,7 +222,8 @@ def test_lock_file_created_on_open(tmp_path: Path) -> None:
     with HippoDB(tmp_path):
         assert lock_path.exists()
         mode = stat.S_IMODE(lock_path.stat().st_mode)
-        assert mode == 0o600, f"Expected 0o600, got {oct(mode)}"
+        if sys.platform != "win32":
+            assert mode == 0o600, f"Expected 0o600, got {oct(mode)}"
 
 
 def test_second_open_same_process_succeeds(tmp_path: Path) -> None:
diff --git a/tests/test_iai_recall_fail_fast.py b/tests/test_iai_recall_fail_fast.py
index b1bd3bf..ae94645 100644
--- a/tests/test_iai_recall_fail_fast.py
+++ b/tests/test_iai_recall_fail_fast.py
@@ -12,6 +12,7 @@
 
 sys.path.insert(0, str(Path(__file__).parent))
 from test_store import _make
+from _socket_test_helpers import bind_fake_daemon_socket
 
 
 FAIL_FAST_CEILING_S = 3.5
@@ -44,15 +45,7 @@ def _unix_socket_server_stall(sock_path: str, stall_seconds: float = 60.0) -> th
     ready = threading.Event()
 
     def _server():
-        try:
-            os.unlink(sock_path)
-        except FileNotFoundError:
-            pass
-
-        srv = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
-        srv.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
-        srv.bind(sock_path)
-        srv.listen(5)
+        srv = bind_fake_daemon_socket(sock_path)
         ready.set()
         srv.settimeout(120.0)
         try:
@@ -78,15 +71,7 @@ def _unix_socket_server_fast(sock_path: str, hits: list[dict]) -> threading.Even
     ready = threading.Event()
 
     def _server():
-        try:
-            os.unlink(sock_path)
-        except FileNotFoundError:
-            pass
-
-        srv = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
-        srv.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
-        srv.bind(sock_path)
-        srv.listen(5)
+        srv = bind_fake_daemon_socket(sock_path)
         ready.set()
         srv.settimeout(10.0)
         try:
diff --git a/tests/test_immediate_recall_live.py b/tests/test_immediate_recall_live.py
index a16d077..850cbb0 100644
--- a/tests/test_immediate_recall_live.py
+++ b/tests/test_immediate_recall_live.py
@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+import tempfile
+
 import hashlib
 import json
 import os
@@ -29,7 +31,7 @@ def _write_live_file(
         "version": version,
         "deferred_at": datetime.now(timezone.utc).isoformat(),
         "session_id": session_id,
-        "cwd": "/tmp/test",
+        "cwd": str(Path(tempfile.gettempdir()) / "test"),
     }
     lines = [json.dumps(header, ensure_ascii=False)]
     for ev in events:
diff --git a/tests/test_lat05_asleep_skip.py b/tests/test_lat05_asleep_skip.py
index aa9813d..ea2f885 100644
--- a/tests/test_lat05_asleep_skip.py
+++ b/tests/test_lat05_asleep_skip.py
@@ -15,6 +15,7 @@
 
 sys.path.insert(0, str(Path(__file__).parent))
 from test_store import _make
+from _socket_test_helpers import bind_fake_daemon_socket
 
 
 SLEEP_SKIP_CEILING_S = 1.5
@@ -56,15 +57,7 @@ def _start_stall_server(sock_path: str, stall_seconds: float = 60.0) -> threadin
     ready = threading.Event()
 
     def _server():
-        try:
-            os.unlink(sock_path)
-        except FileNotFoundError:
-            pass
-
-        srv = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
-        srv.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
-        srv.bind(sock_path)
-        srv.listen(5)
+        srv = bind_fake_daemon_socket(sock_path)
         ready.set()
         srv.settimeout(120.0)
         try:
diff --git a/tests/test_lifecycle_event_log.py b/tests/test_lifecycle_event_log.py
index 63c37b8..e64e3e9 100644
--- a/tests/test_lifecycle_event_log.py
+++ b/tests/test_lifecycle_event_log.py
@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+import sys
+
 import gzip
 import json
 import multiprocessing as mp
@@ -84,7 +86,8 @@ def test_log_file_chmod_user_only(tmp_path):
     log = LifecycleEventLog(log_dir=tmp_path)
     log.append({"event": "wrapper_event", "kind": "heartbeat_refresh"})
     mode = os.stat(log.current_file()).st_mode & 0o777
-    assert mode == 0o600
+    if sys.platform != "win32":
+        assert mode == 0o600
 
 
 def test_rotation_writes_to_per_date_file(tmp_path):
diff --git a/tests/test_lifecycle_lock.py b/tests/test_lifecycle_lock.py
index 010f38d..f3b6d31 100644
--- a/tests/test_lifecycle_lock.py
+++ b/tests/test_lifecycle_lock.py
@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+import sys
+
 import json
 import os
 from pathlib import Path
@@ -223,4 +225,5 @@ def test_acquire_writes_mode_0600(tmp_path: Path) -> None:
     lock.acquire()
 
     mode = lock_path.stat().st_mode & 0o777
-    assert mode == 0o600, f"expected mode 0o600, got 0o{mode:o}"
+    if sys.platform != "win32":
+        assert mode == 0o600, f"expected mode 0o600, got 0o{mode:o}"
diff --git a/tests/test_lifecycle_state.py b/tests/test_lifecycle_state.py
index 69fdd04..2410d51 100644
--- a/tests/test_lifecycle_state.py
+++ b/tests/test_lifecycle_state.py
@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+import sys
+
 import json
 import os
 from datetime import datetime, timezone
@@ -123,7 +125,8 @@ def test_save_state_chmod_user_only(tmp_path):
     target = tmp_path / "lifecycle_state.json"
     save_state(default_state(), target)
     mode = os.stat(target).st_mode & 0o777
-    assert mode == 0o600
+    if sys.platform != "win32":
+        assert mode == 0o600
 
 
 def test_save_state_rejects_invalid_record(tmp_path):
diff --git a/tests/test_live_e2e_gate.py b/tests/test_live_e2e_gate.py
index 98aef7a..ad8b2b4 100644
--- a/tests/test_live_e2e_gate.py
+++ b/tests/test_live_e2e_gate.py
@@ -1,8 +1,9 @@
 from __future__ import annotations
 
 import errno
-import fcntl
 import json
+from iai_mcp._filelock import LOCK_NB, LOCK_SH, LOCK_UN
+from iai_mcp._filelock import flock as _flock
 import os
 import shutil
 import subprocess
@@ -245,8 +246,8 @@ def _ex_held(store_dir: Path) -> bool:
     probe_fd = -1
     try:
         probe_fd = os.open(str(lock_path), os.O_RDWR)
-        fcntl.flock(probe_fd, fcntl.LOCK_SH | fcntl.LOCK_NB)
-        fcntl.flock(probe_fd, fcntl.LOCK_UN)
+        _flock(probe_fd, LOCK_SH | LOCK_NB)
+        _flock(probe_fd, LOCK_UN)
         return False
     except OSError as exc:
         if exc.errno in (errno.EAGAIN, errno.EWOULDBLOCK):
diff --git a/tests/test_lock_starvation.py b/tests/test_lock_starvation.py
index 2eb8cc9..e39670e 100644
--- a/tests/test_lock_starvation.py
+++ b/tests/test_lock_starvation.py
@@ -1,7 +1,8 @@
 from __future__ import annotations
 
-import fcntl
 import os
+from iai_mcp._filelock import LOCK_EX, LOCK_NB, LOCK_SH, LOCK_UN
+from iai_mcp._filelock import flock as _flock
 import tempfile
 import threading
 import time
@@ -33,7 +34,7 @@ def _reader_loop() -> None:
                 acquired = acquire_client_shared_nb(fd, lock_path)
                 if acquired:
                     time.sleep(0.001)
-                    fcntl.flock(fd, fcntl.LOCK_UN)
+                    _flock(fd, LOCK_UN)
                 else:
                     time.sleep(0.001)
         except Exception as exc:
@@ -54,13 +55,13 @@ def _reader_loop() -> None:
         deadline = time.monotonic() + 4.0
         while time.monotonic() < deadline:
             try:
-                fcntl.flock(fd_ex, fcntl.LOCK_EX | fcntl.LOCK_NB)
+                _flock(fd_ex, LOCK_EX | LOCK_NB)
                 acquired = True
                 break
             except OSError:
                 time.sleep(0.01)
         if acquired:
-            fcntl.flock(fd_ex, fcntl.LOCK_UN)
+            _flock(fd_ex, LOCK_UN)
         os.close(fd_ex)
     finally:
         clear_consolidation_intent(lock_path)
@@ -121,10 +122,10 @@ def test_recency_read_during_busy_meets_slo(hermetic_store: Path) -> None:
     def _hold_exclusive() -> None:
         fd = os.open(str(lock_path), os.O_RDWR)
         try:
-            fcntl.flock(fd, fcntl.LOCK_EX)
+            _flock(fd, LOCK_EX)
             ready.set()
             done.wait(timeout=3.0)
-            fcntl.flock(fd, fcntl.LOCK_UN)
+            _flock(fd, LOCK_UN)
         finally:
             os.close(fd)
 
@@ -178,11 +179,11 @@ def _churn_client() -> None:
                 acquired = acquire_client_shared_nb(fd, lock_path)
                 if acquired:
                     if check_consolidation_intent(lock_path):
-                        fcntl.flock(fd, fcntl.LOCK_UN)
+                        _flock(fd, LOCK_UN)
                         post_acquire_recheck_count += 1
                     else:
                         time.sleep(0.0005)
-                        fcntl.flock(fd, fcntl.LOCK_UN)
+                        _flock(fd, LOCK_UN)
                 else:
                     time.sleep(0.001)
         except Exception as exc:
@@ -202,15 +203,15 @@ def _prober_client() -> None:
             _intent_set.wait(timeout=2.0)
 
             try:
-                fcntl.flock(fd, fcntl.LOCK_SH | fcntl.LOCK_NB)
+                _flock(fd, LOCK_SH | LOCK_NB)
             except OSError:
                 return
 
             if check_consolidation_intent(lock_path):
-                fcntl.flock(fd, fcntl.LOCK_UN)
+                _flock(fd, LOCK_UN)
                 post_acquire_recheck_count += 1
             else:
-                fcntl.flock(fd, fcntl.LOCK_UN)
+                _flock(fd, LOCK_UN)
         finally:
             os.close(fd)
 
@@ -233,13 +234,13 @@ def _prober_client() -> None:
         deadline = time.monotonic() + 4.0
         while time.monotonic() < deadline:
             try:
-                fcntl.flock(fd_ex, fcntl.LOCK_EX | fcntl.LOCK_NB)
+                _flock(fd_ex, LOCK_EX | LOCK_NB)
                 acquired = True
                 break
             except OSError:
                 time.sleep(0.005)
         if acquired:
-            fcntl.flock(fd_ex, fcntl.LOCK_UN)
+            _flock(fd_ex, LOCK_UN)
         os.close(fd_ex)
     finally:
         clear_consolidation_intent(lock_path)
@@ -272,10 +273,10 @@ def test_client_lock_wait_bounded_below_slo(hermetic_store: Path) -> None:
     def _hold_ex() -> None:
         fd = os.open(str(lock_path), os.O_RDWR)
         try:
-            fcntl.flock(fd, fcntl.LOCK_EX)
+            _flock(fd, LOCK_EX)
             ready.set()
             done.wait(timeout=0.6)
-            fcntl.flock(fd, fcntl.LOCK_UN)
+            _flock(fd, LOCK_UN)
         finally:
             os.close(fd)
 
@@ -297,7 +298,7 @@ def _hold_ex() -> None:
             time.sleep(0.01)
         elapsed = time.monotonic() - t0
         if acquired:
-            fcntl.flock(fd_sh, fcntl.LOCK_UN)
+            _flock(fd_sh, LOCK_UN)
     finally:
         os.close(fd_sh)
         t.join(timeout=2.0)
diff --git a/tests/test_mcp_tools.py b/tests/test_mcp_tools.py
index 1e411c9..9d3a694 100644
--- a/tests/test_mcp_tools.py
+++ b/tests/test_mcp_tools.py
@@ -33,7 +33,7 @@ def built_wrapper() -> Path:
 
 @pytest.fixture(scope="module")
 def daemon_sock() -> "Path":
-    sock_dir = Path(f"/tmp/iai-mcp-tools-{os.getpid()}")
+    sock_dir = tmp_path / "sock"
     sock_dir.mkdir(parents=True, exist_ok=True)
     sock_path = sock_dir / "d.sock"
     store_dir = sock_dir / "store"
diff --git a/tests/test_memory_bank_processed.py b/tests/test_memory_bank_processed.py
index a26fb18..6d53f7c 100644
--- a/tests/test_memory_bank_processed.py
+++ b/tests/test_memory_bank_processed.py
@@ -5,6 +5,7 @@
 import logging
 import os
 import stat
+import sys
 from dataclasses import dataclass
 from datetime import datetime, timezone
 from pathlib import Path
@@ -125,7 +126,8 @@ def test_processed_salience_top_n_written_at_rem_completion(
     assert target.exists(), f"expected file at {target}"
 
     file_mode = oct(stat.S_IMODE(os.stat(target).st_mode))
-    assert file_mode == "0o600", f"file mode {file_mode} != 0o600"
+    if sys.platform != "win32":
+        assert file_mode == "0o600", f"file mode {file_mode} != 0o600"
 
     lines = _read_jsonl(target)
     expected_count = min(m_records, 4)
diff --git a/tests/test_memory_bank_recent.py b/tests/test_memory_bank_recent.py
index aed08b4..deeb119 100644
--- a/tests/test_memory_bank_recent.py
+++ b/tests/test_memory_bank_recent.py
@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+import sys
+
 import base64
 import json
 import os
@@ -110,7 +112,8 @@ def test_recent_append_creates_dated_window_file(iai_home):
 
     file_mode = stat.S_IMODE(os.stat(target).st_mode)
     parent_mode = stat.S_IMODE(os.stat(target.parent).st_mode)
-    assert file_mode == 0o600, f"file mode = 0o{file_mode:o}, expected 0o600"
+    if sys.platform != "win32":
+        assert file_mode == 0o600, f"file mode = 0o{file_mode:o}, expected 0o600"
     assert parent_mode == 0o700, f"parent mode = 0o{parent_mode:o}, expected 0o700"
 
     body = target.read_text(encoding="utf-8")
diff --git a/tests/test_session_payload_latency.py b/tests/test_session_payload_latency.py
index b1e281c..38bbca9 100644
--- a/tests/test_session_payload_latency.py
+++ b/tests/test_session_payload_latency.py
@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+import tempfile
+
 import json
 import time
 from datetime import datetime, timezone, timedelta
@@ -20,7 +22,7 @@ def _make_large_live_file(deferred_dir: Path, session_id: str, n_events: int = 5
         "version": 1,
         "deferred_at": datetime.now(timezone.utc).isoformat(),
         "session_id": session_id,
-        "cwd": "/tmp/latency-test",
+        "cwd": str(Path(tempfile.gettempdir()) / "latency-test"),
     }
     lines = [json.dumps(header, ensure_ascii=False)]
     base = datetime(2026, 5, 31, 8, 0, 0, tzinfo=timezone.utc)
diff --git a/tests/test_session_recall_precache.py b/tests/test_session_recall_precache.py
index 0d5d3b1..e0e9aad 100644
--- a/tests/test_session_recall_precache.py
+++ b/tests/test_session_recall_precache.py
@@ -157,10 +157,11 @@ def test_cache_file_mode_is_owner_only(tmp_path, monkeypatch):
     daemon_mod._write_session_start_cache(store, cache_path=cache_path)
 
     assert cache_path.exists(), "cache file was not created"
-    assert oct(stat.S_IMODE(cache_path.stat().st_mode)) == "0o600", (
-        f"cache file mode is not 0o600; got "
-        f"{oct(stat.S_IMODE(cache_path.stat().st_mode))}"
-    )
+    if sys.platform != "win32":
+        assert oct(stat.S_IMODE(cache_path.stat().st_mode)) == "0o600", (
+            f"cache file mode is not 0o600; got "
+            f"{oct(stat.S_IMODE(cache_path.stat().st_mode))}"
+        )
 
 def test_precache_does_not_compress_payload(tmp_path, monkeypatch):
     from iai_mcp import daemon as daemon_mod
diff --git a/tests/test_socket_activity_tracking.py b/tests/test_socket_activity_tracking.py
index 9bde5d3..f6d22f5 100644
--- a/tests/test_socket_activity_tracking.py
+++ b/tests/test_socket_activity_tracking.py
@@ -20,18 +20,29 @@
 
 import pytest
 
+from iai_mcp._ipc import IS_WINDOWS, open_ipc_connection
+
+
+def _endpoint_ready_path(sock_path: Path) -> Path:
+    """Path that exists once SocketServer has bound: the unix socket on POSIX,
+    the TCP port file (``<sock_path>.port``) on Windows."""
+    return Path(f"{sock_path}.port") if IS_WINDOWS else sock_path
+
 
 @pytest.fixture
 def short_socket_paths(tmp_path, monkeypatch):
     from iai_mcp import concurrency, daemon_state
 
-    sock_dir = Path(f"/tmp/iai-srvact-{os.getpid()}-{id(tmp_path)}")
+    sock_dir = tmp_path / "sock"
     sock_dir.mkdir(parents=True, exist_ok=True)
     sock_path = sock_dir / "d.sock"
     state_path = tmp_path / ".daemon-state.json"
 
     monkeypatch.setattr(concurrency, "SOCKET_PATH", sock_path)
     monkeypatch.setattr(daemon_state, "STATE_PATH", state_path)
+    # Per-test endpoint isolation (unix socket on POSIX; TCP port file on
+    # Windows) via the env var both serve() and open_ipc_connection() honor.
+    monkeypatch.setenv("IAI_DAEMON_SOCKET_PATH", str(sock_path))
     store_root = tmp_path / "store_root"
     store_root.mkdir(parents=True, exist_ok=True)
     monkeypatch.setenv("IAI_MCP_STORE", str(store_root))
@@ -51,9 +62,7 @@ def short_socket_paths(tmp_path, monkeypatch):
 
 
 async def _send_line(sock_path: Path, payload: dict, *, timeout: float = 10.0) -> dict:
-    reader, writer = await asyncio.wait_for(
-        asyncio.open_unix_connection(path=str(sock_path)), timeout=timeout,
-    )
+    reader, writer = await open_ipc_connection(timeout=timeout)
     try:
         writer.write((json.dumps(payload) + "\n").encode("utf-8"))
         await writer.drain()
@@ -73,12 +82,13 @@ async def _serve(sock_path: Path, store, coro_fn):
     from iai_mcp.socket_server import SocketServer
 
     srv = SocketServer(store, idle_secs=99999)
-    server_task = asyncio.create_task(srv.serve(socket_path=sock_path))
+    server_task = asyncio.create_task(srv.serve())
+    ready_path = _endpoint_ready_path(sock_path)
     for _ in range(250):
-        if sock_path.exists():
+        if ready_path.exists():
             break
         await asyncio.sleep(0.01)
-    if not sock_path.exists():
+    if not ready_path.exists():
         srv.shutdown_event.set()
         raise AssertionError("socket never bound")
     try:
diff --git a/tests/test_socket_disconnect_reconnect.py b/tests/test_socket_disconnect_reconnect.py
index d1555f6..48d13c5 100644
--- a/tests/test_socket_disconnect_reconnect.py
+++ b/tests/test_socket_disconnect_reconnect.py
@@ -11,6 +11,19 @@
 
 import pytest
 
+from iai_mcp._ipc import IS_WINDOWS
+
+# Heavy end-to-end integration test: builds the Node mcp-wrapper via npm and
+# drives it against an embedded AF_UNIX fake daemon, exercising the full
+# stdio<->unix-socket bridge and reconnect path. Both the npm subprocess
+# invocation and the AF_UNIX bridge are POSIX-stack-specific; a Windows port
+# needs the Node wrapper to speak TCP loopback (separate effort). The Windows
+# socket dispatch/reconnect behavior is covered by the ported _ipc unit tests.
+pytestmark = pytest.mark.skipif(
+    IS_WINDOWS,
+    reason="AF_UNIX + npm + Node-wrapper bridge integration; Windows path covered by _ipc unit tests",
+)
+
 REPO = Path(__file__).resolve().parent.parent
 WRAPPER = REPO / "mcp-wrapper"
 
@@ -160,7 +173,7 @@ def _drop_fake_daemon_conn(proc: subprocess.Popen) -> None:
 
 @pytest.fixture
 def fake_daemon():
-    sock_dir = Path(f"/tmp/iai-mcp-disconnect-{os.getpid()}")
+    sock_dir = tmp_path / "sock"
     sock_dir.mkdir(parents=True, exist_ok=True)
     sock_path = sock_dir / "d.sock"
 
diff --git a/tests/test_socket_fail_loud.py b/tests/test_socket_fail_loud.py
index d3aad26..860f07b 100644
--- a/tests/test_socket_fail_loud.py
+++ b/tests/test_socket_fail_loud.py
@@ -13,10 +13,17 @@
 import psutil
 import pytest
 
+from _socket_test_helpers import (
+    daemon_endpoint,
+    daemon_endpoint_ready_path,
+    new_daemon_client_socket,
+    send_daemon_token,
+)
+
 @pytest.fixture
 def short_socket_paths(tmp_path):
     lock_path = tmp_path / ".lock"
-    sock_dir = Path(f"/tmp/iai-fl-{os.getpid()}-{id(tmp_path)}")
+    sock_dir = tmp_path / "sock"
     sock_dir.mkdir(parents=True, exist_ok=True)
     sock_path = sock_dir / "d.sock"
     state_path = tmp_path / ".daemon-state.json"
@@ -63,9 +70,10 @@ def _spawn_daemon_for_test(sock_path: Path, store_root: Path) -> subprocess.Pope
     )
 
 def _wait_for_socket(sock_path: Path, timeout_sec: float = 30.0) -> bool:
+    ready = daemon_endpoint_ready_path(sock_path)
     deadline = time.monotonic() + timeout_sec
     while time.monotonic() < deadline:
-        if sock_path.exists():
+        if ready.exists():
             return True
         time.sleep(0.1)
     return False
@@ -93,7 +101,7 @@ def test_kill_daemon_midcall_no_orphan_core_spawn(short_socket_paths, tmp_path):
             f"(baseline={baseline}, before={before}) — singleton invariant violated"
         )
 
-        proc.send_signal(signal.SIGKILL)
+        proc.kill()
         proc.wait(timeout=5)
 
         time.sleep(0.5)
@@ -106,11 +114,11 @@ def test_kill_daemon_midcall_no_orphan_core_spawn(short_socket_paths, tmp_path):
             "— invariant: the daemon must never spawn a second core."
         )
 
-        s = sk.socket(sk.AF_UNIX, sk.SOCK_STREAM)
+        s = new_daemon_client_socket()
         s.settimeout(0.5)
         err_kind = None
         try:
-            s.connect(str(sock_path))
+            s.connect(daemon_endpoint(sock_path))
             err_kind = "no_error"
         except (ConnectionRefusedError, FileNotFoundError, OSError) as e:
             err_kind = type(e).__name__
@@ -120,11 +128,11 @@ def test_kill_daemon_midcall_no_orphan_core_spawn(short_socket_paths, tmp_path):
             except OSError:
                 pass
         assert err_kind in (
-            "ConnectionRefusedError", "FileNotFoundError", "OSError",
+            "ConnectionRefusedError", "FileNotFoundError", "OSError", "TimeoutError",
         ), f"unexpected post-kill connect outcome: {err_kind}"
     finally:
         if proc.poll() is None:
-            proc.send_signal(signal.SIGKILL)
+            proc.kill()
             try:
                 proc.wait(timeout=5)
             except subprocess.TimeoutExpired:
@@ -146,9 +154,10 @@ def test_kill_daemon_during_active_connection(short_socket_paths, tmp_path):
             "daemon never bound socket within 30s"
         )
 
-        s = sk.socket(sk.AF_UNIX, sk.SOCK_STREAM)
+        s = new_daemon_client_socket()
         s.settimeout(15)
-        s.connect(str(sock_path))
+        s.connect(daemon_endpoint(sock_path))
+        send_daemon_token(s, sock_path)  # Windows handshake; no-op on POSIX
         msg = (json.dumps({"type": "status"}) + "\n").encode("utf-8")
         s.sendall(msg)
 
@@ -162,7 +171,7 @@ def test_kill_daemon_during_active_connection(short_socket_paths, tmp_path):
         decoded = json.loads(first_response.decode("utf-8"))
         assert decoded.get("ok") is True, decoded
 
-        proc.send_signal(signal.SIGKILL)
+        proc.kill()
         proc.wait(timeout=5)
 
         s.settimeout(2.0)
@@ -183,11 +192,11 @@ def test_kill_daemon_during_active_connection(short_socket_paths, tmp_path):
             "wrapper-side daemon_unreachable translation would silently hang"
         )
 
-        s2 = sk.socket(sk.AF_UNIX, sk.SOCK_STREAM)
+        s2 = new_daemon_client_socket()
         s2.settimeout(0.5)
         err_kind = None
         try:
-            s2.connect(str(sock_path))
+            s2.connect(daemon_endpoint(sock_path))
             err_kind = "no_error"
         except (ConnectionRefusedError, FileNotFoundError, OSError) as e:
             err_kind = type(e).__name__
@@ -197,11 +206,11 @@ def test_kill_daemon_during_active_connection(short_socket_paths, tmp_path):
             except OSError:
                 pass
         assert err_kind in (
-            "ConnectionRefusedError", "FileNotFoundError", "OSError",
+            "ConnectionRefusedError", "FileNotFoundError", "OSError", "TimeoutError",
         ), f"unexpected post-kill connect outcome: {err_kind}"
     finally:
         if proc.poll() is None:
-            proc.send_signal(signal.SIGKILL)
+            proc.kill()
             try:
                 proc.wait(timeout=5)
             except subprocess.TimeoutExpired:
diff --git a/tests/test_socket_first_store_hermeticity.py b/tests/test_socket_first_store_hermeticity.py
index 8e4d79c..655fe5f 100644
--- a/tests/test_socket_first_store_hermeticity.py
+++ b/tests/test_socket_first_store_hermeticity.py
@@ -9,8 +9,19 @@
 
 import pytest
 
+from iai_mcp._ipc import IS_WINDOWS
 from iai_mcp.cli import _send_jsonrpc_request
 
+# This module asserts *which unix-socket path* the client routes to by spying on
+# asyncio.open_unix_connection — a POSIX-only mechanism (Windows routes over TCP
+# loopback via a port file, and open_unix_connection doesn't exist there). The
+# equivalent Windows endpoint routing/isolation is covered by the _ipc
+# port-file tests and the IAI_DAEMON_SOCKET_PATH isolation in PR #6.
+pytestmark = pytest.mark.skipif(
+    IS_WINDOWS,
+    reason="POSIX unix-socket-path routing hermeticity; Windows routes via TCP port file (covered elsewhere)",
+)
+
 def _capture_stdout(fn) -> tuple[str, int]:
     buf = io.StringIO()
     with redirect_stdout(buf):
diff --git a/tests/test_socket_inherit_launchd_fd.py b/tests/test_socket_inherit_launchd_fd.py
index 98096f3..cbe3ac1 100644
--- a/tests/test_socket_inherit_launchd_fd.py
+++ b/tests/test_socket_inherit_launchd_fd.py
@@ -48,7 +48,7 @@ def _bind_to_fd_3(sock_path: Path) -> Iterator[socket.socket]:
             pass
 
 def _short_sock_path(suffix: str) -> Path:
-    sock_dir = Path(f"/tmp/iai-launchd-{os.getpid()}-{suffix}")
+    sock_dir = tmp_path / "sock"
     sock_dir.mkdir(parents=True, exist_ok=True)
     return sock_dir / "d.sock"
 
diff --git a/tests/test_socket_server_dispatch.py b/tests/test_socket_server_dispatch.py
index ac84fd6..1af226d 100644
--- a/tests/test_socket_server_dispatch.py
+++ b/tests/test_socket_server_dispatch.py
@@ -8,17 +8,32 @@
 
 import pytest
 
+from iai_mcp._ipc import IS_WINDOWS, open_ipc_connection
+
+
+def _endpoint_ready_path(sock_path: Path) -> Path:
+    """Path that exists once the SocketServer has bound its endpoint.
+    POSIX: the unix socket file. Windows: the TCP port file written alongside
+    it (``<sock_path>.port``, see iai_mcp._ipc._port_file_path)."""
+    return Path(f"{sock_path}.port") if IS_WINDOWS else sock_path
+
+
 @pytest.fixture
 def short_socket_paths(tmp_path, monkeypatch):
     from iai_mcp import concurrency, daemon_state
 
-    sock_dir = Path(f"/tmp/iai-srvdisp-{os.getpid()}-{id(tmp_path)}")
+    sock_dir = tmp_path / "sock"
     sock_dir.mkdir(parents=True, exist_ok=True)
     sock_path = sock_dir / "d.sock"
     state_path = tmp_path / ".daemon-state.json"
 
     monkeypatch.setattr(concurrency, "SOCKET_PATH", sock_path)
     monkeypatch.setattr(daemon_state, "STATE_PATH", state_path)
+    # Isolate the IPC endpoint per-test. POSIX uses this as the unix socket
+    # path; Windows persists the ephemeral TCP port to "<sock_path>.port".
+    # Both SocketServer.serve() and open_ipc_connection() resolve through it,
+    # so concurrent tests never collide on the shared default endpoint.
+    monkeypatch.setenv("IAI_DAEMON_SOCKET_PATH", str(sock_path))
     store_root = tmp_path / "store_root"
     store_root.mkdir(parents=True, exist_ok=True)
     monkeypatch.setenv("IAI_MCP_STORE", str(store_root))
@@ -44,10 +59,7 @@ async def _send_jsonrpc(
     *,
     timeout: float = 10.0,
 ) -> dict:
-    reader, writer = await asyncio.wait_for(
-        asyncio.open_unix_connection(path=str(sock_path)),
-        timeout=timeout,
-    )
+    reader, writer = await open_ipc_connection(timeout=timeout)
     try:
         envelope: dict = {"jsonrpc": "2.0", "id": req_id, "method": method}
         if params is not None:
@@ -66,10 +78,7 @@ async def _send_jsonrpc(
     return json.loads(line.decode("utf-8"))
 
 async def _send_raw(sock_path: Path, raw_bytes: bytes, *, timeout: float = 5.0) -> dict:
-    reader, writer = await asyncio.wait_for(
-        asyncio.open_unix_connection(path=str(sock_path)),
-        timeout=timeout,
-    )
+    reader, writer = await open_ipc_connection(timeout=timeout)
     try:
         writer.write(raw_bytes)
         await writer.drain()
@@ -88,13 +97,16 @@ async def _with_socket_server(sock_path: Path, store, coro_fn):
     from iai_mcp.socket_server import SocketServer
 
     srv = SocketServer(store, idle_secs=99999)
-    server_task = asyncio.create_task(srv.serve(socket_path=sock_path))
+    # No socket_path: serve() resolves the endpoint from IAI_DAEMON_SOCKET_PATH
+    # (set by the fixture) — a unix socket on POSIX, TCP loopback on Windows.
+    server_task = asyncio.create_task(srv.serve())
 
+    ready_path = _endpoint_ready_path(sock_path)
     for _ in range(250):
-        if sock_path.exists():
+        if ready_path.exists():
             break
         await asyncio.sleep(0.01)
-    if not sock_path.exists():
+    if not ready_path.exists():
         srv.shutdown_event.set()
         try:
             await asyncio.wait_for(server_task, timeout=5)
diff --git a/tests/test_socket_subagent_reuse.py b/tests/test_socket_subagent_reuse.py
index 19009cf..8a0cb88 100644
--- a/tests/test_socket_subagent_reuse.py
+++ b/tests/test_socket_subagent_reuse.py
@@ -155,7 +155,7 @@ def _spawn_daemon_in_background(
     )
 
 def test_subagent_spawns_zero_new_processes(built_wrapper, tmp_path):
-    sock_dir = Path(f"/tmp/iai-subagent-{os.getpid()}-{id(tmp_path)}")
+    sock_dir = tmp_path / "sock"
     sock_dir.mkdir(parents=True, exist_ok=True)
     sock_path = sock_dir / "d.sock"
     store_dir = sock_dir / "store"
diff --git a/tests/test_user_model.py b/tests/test_user_model.py
index 56cc5b0..c5c45b7 100644
--- a/tests/test_user_model.py
+++ b/tests/test_user_model.py
@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+import sys
+
 import os
 import stat
 import uuid
@@ -139,7 +141,8 @@ def test_R1_persistence_roundtrip_chmod_default(
     assert target.exists(), "save() must materialise the file at tmp path"
 
     mode = stat.S_IMODE(os.stat(target).st_mode)
-    assert mode == 0o600, f"file mode must be 0o600, got {oct(mode)}"
+    if sys.platform != "win32":
+        assert mode == 0o600, f"file mode must be 0o600, got {oct(mode)}"
 
     loaded = load()
     assert loaded.top_recent_topics == [