Fix bridge server crash with newer FastMCP versions

[SteffenPL]

Summary

• NapariBridgeServer.__init__ crashes with AttributeError: 'FastMCP' object has no attribute '_tool_manager' on newer versions of FastMCP
• Uses the public remove_tool() API instead, with a fallback to the old _tool_manager._tools.pop() for backward compatibility
• If both methods fail, silently passes (the tools may simply not exist)

🤖 Generated with Claude Code

Summary by CodeRabbit

• Refactor
  • Made lifecycle tool removal during startup more robust: now uses the public removal mechanism with safe fallbacks and quieter error handling to reduce initialization disruptions and noisy logs.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: 0891d2d8-572b-459c-b70e-a9ad8b1ad0cf

📥 Commits

Reviewing files that changed from the base of the PR and between 1a70065 and d2693c6.

📒 Files selected for processing (1)

• src/napari_mcp/bridge_server.py

🚧 Files skipped from review as they are similar to previous changes (1)

• src/napari_mcp/bridge_server.py

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📝 Walkthrough

Walkthrough

The NapariBridgeServer.__init__ lifecycle tool removal for close_viewer and init_viewer now first calls the public self.server.remove_tool(name). If that method is missing it falls back to self.server._tool_manager._tools.pop(name, None). If remove_tool exists but raises, the exception is caught and debug-logged instead of propagating.

Changes

Cohort / File(s)	Summary
Tool Removal Robustness src/napari_mcp/bridge_server.py	Replace direct internal deletion with a preferred call to self.server.remove_tool(name); fall back to _tool_manager._tools.pop(name, None) when remove_tool is absent; catch-and-debug-log any other exceptions from remove_tool instead of letting them surface.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~8 minutes

Poem

🐰 I tried the door that’s meant to be,
A gentle knock, a public key.
If locks refuse or answers stray,
I slip a window, hop away.
Debugging carrots pave the way. 🥕✨

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The pull request title clearly and concisely describes the main change: fixing a bridge server crash with newer FastMCP versions, which directly matches the core issue and solution in the changeset.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

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[coderabbitai]

🧹 Nitpick comments (1)

src/napari_mcp/bridge_server.py (1)

122-128: Narrow exception handling and consider adding debug logging.

The fallback logic is reasonable for backward compatibility, but can be improved:

1. (AttributeError, Exception) is redundant—Exception already covers AttributeError. The second catch on line 124 should catch only AttributeError since the _tool_manager._tools.pop() call won't raise exceptions with the default None.
2. Catching broad Exception in the first try-except (line 123) could mask unexpected errors. Since remove_tool() is now a stable API in FastMCP v2.3.4+, consider catching only AttributeError (for older versions) or letting other exceptions propagate to aid troubleshooting.
3. Silent failure provides no feedback if removal fails unexpectedly. Adding a debug log when both approaches fail would help with future troubleshooting.

♻️ Optional: Improved exception handling with logging

+        import logging
+        logger = logging.getLogger(__name__)
+
         # Remove lifecycle tools that should not be available in bridge mode
         for name in ("close_viewer", "init_viewer"):
             try:
                 self.server.remove_tool(name)
-            except (AttributeError, Exception):
+            except AttributeError:
+                # remove_tool() not available in FastMCP < v2.3.4
                 try:
                     self.server._tool_manager._tools.pop(name, None)
-                except (AttributeError, Exception):
-                    pass
+                except AttributeError:
+                    logger.debug("Could not remove tool %r using any method", name)
+            except Exception as e:
+                logger.debug("remove_tool(%r) failed unexpectedly: %s", name, e)

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In `@src/napari_mcp/bridge_server.py` around lines 122 - 128, Replace the broad
exception handling around tool removal so only AttributeError is caught for
backward-compatibility: attempt self.server.remove_tool(name) and except
AttributeError try the fallback self.server._tool_manager._tools.pop(name,
None); if that also raises AttributeError or returns None/logically indicates
failure, emit a debug log (via self.logger or module logger) describing the tool
name and failure; do not catch Exception globally so other errors from
remove_tool propagate for visibility.

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Nitpick comments:
In `@src/napari_mcp/bridge_server.py`:
- Around line 122-128: Replace the broad exception handling around tool removal
so only AttributeError is caught for backward-compatibility: attempt
self.server.remove_tool(name) and except AttributeError try the fallback
self.server._tool_manager._tools.pop(name, None); if that also raises
AttributeError or returns None/logically indicates failure, emit a debug log
(via self.logger or module logger) describing the tool name and failure; do not
catch Exception globally so other errors from remove_tool propagate for
visibility.

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ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: 8560aa5b-f1a6-46d3-9d7e-e6a3eb97111d

📥 Commits

Reviewing files that changed from the base of the PR and between 44b90a7 and 1a70065.

📒 Files selected for processing (1)

• src/napari_mcp/bridge_server.py

[SteffenPL]

CodeRabbit feedback is integrated, ready for review.