Codex Chat Viewer

A local-first desktop Codex CLI log viewer for OpenAI Codex CLI rollout-*.jsonl session logs.

Review, search, filter, and export local Codex CLI session logs without reading raw JSONL files.

Codex Chat Viewer opens local Codex CLI JSONL logs, usually stored as rollout-*.jsonl, and turns Codex session logs into readable, filterable transcript views that you can also export to Markdown.

Why?

Codex CLI is useful, but its local JSONL session logs are not easy to review as-is.

This project makes those logs easier to review by separating human prompts, Codex responses, tool calls, tool results, task context, and session metadata in a readable local UI.

It works as a companion viewer for Codex CLI sessions, making local session logs easier to inspect, review, document, and revisit after the work is done.

Important Note About Codex Rollout Logs

Codex Chat Viewer reads local Codex CLI JSONL session logs. These are typically named rollout-*.jsonl.

These files are treated as an observed local session format, not as an official stable public export format.

The parser is based on rollout structures currently seen in local Codex CLI logs, and those structures may change in future Codex CLI versions. The file picker accepts *.jsonl files, but the viewer is designed around these observed rollout log shapes.

If OpenAI later provides a stable official session export format, this project may add support for it as a separate input adapter.

What It Does

Codex Chat Viewer is for developers who want a local desktop viewer for Codex CLI sessions without reading raw JSONL logs directly.

The app currently focuses on:

• opening local Codex JSONL rollout logs (rollout-*.jsonl)
• switching between Terminal, Markdown, DM, and Messenger viewing styles
• rendering readable conversation blocks
• showing who or what produced each block
• collapsing and expanding conversation blocks inline
• filtering noisy sections such as tool calls, tool results, or metadata
• searching within the currently rendered session transcript
• exporting the transcript based on the current filter icon state to Markdown
• keeping everything local

Features

Implemented

• Kotlin/JVM Gradle application
• Swing-based desktop app
• Local-first desktop workflow
• JSONL file picker with *.jsonl filter
• Safe Codex sessions directory detection:
  • CODEX_HOME/sessions
  • ~/.codex/sessions
  • user home fallback
• Last selected directory remembered during the current app session
• Selected file metadata display
• Conservative Codex session ID detection
• codex resume <session-id> display when a session ID is detected
• Copy Resume Command button
• Minimal JSONL parsing for Codex rollout logs
• Speaker/source labels:
  • [SYSTEM]
  • [CONTEXT]
  • [TASK]
  • [YOU]
  • [CODEX]
  • [TOOL CALL]
  • [TOOL RESULT]
• Duplicate suppression for known duplicate rollout event shapes
• AGENTS.md / project instruction context separated from direct user prompts
• Task prompt document content separated as [TASK] when safely identifiable
• UTF-8 file reading
• Unicode-friendly viewer rendering
• Terminal-style dark viewer
• Markdown Style document preview rendering with section cards, note blocks, and technical callouts
• DM Style component-based direct message rendering with right-aligned [YOU], left-aligned [CODEX], and centered metadata cards
• Messenger Style component-based conversation rendering with right-aligned [YOU], left-aligned [CODEX], and centered metadata cards
• Styled label colors for faster scanning
• Soft-wrapped main viewer without horizontal scrolling
• Inline collapse / expand for transcript blocks
• Theme-driven toggle markers for block headers
• Compact icon filter toggles:
  • YOU
  • CODEX
  • CALL
  • RESULT
  • META
• Cached parsed entries with filter-based re-rendering
• In-view transcript search with Ctrl+F
• Case-insensitive match highlighting for the currently rendered transcript
• Previous / next match navigation:
  • Enter for next
  • Shift+Enter for previous
  • wraps around from the last result back to the first
• Search state resets when opening a new JSONL file
• Search highlights are recalculated after filter changes
• Search highlights do not affect Markdown export
• Collapse / expand state is local to the currently rendered transcript view
• Footer stats:
  • parsed candidates
  • visible entries
  • ignored lines
  • malformed lines
• Markdown export based on the current filter icon state
• Markdown export avoids raw JSONL and hidden filtered entries
• Markdown export includes safe metadata:
  • source file name
  • source file path
  • session ID if detected
• Markdown transcript body is stored inside a fenced text block
• UTF-8 Markdown file writing
• Safe Markdown export filename handling:
  • suggests a non-conflicting default file name when possible
  • asks before overwriting an existing file
• Opens Windows File Explorer with the exported Markdown file selected after export
• Portable Windows zip build task

Planned

• Live service support for active Codex sessions:
  • detect updates from the currently opened JSONL session file and append newly parsed entries to the current transcript
  • or provide a separate live file mode so live parsing can stay independent from the static viewer flow

Markdown Export

The Markdown export feature saves the transcript based on the current filter icon state.

If a message type is hidden in the viewer, it is not included in the exported Markdown file. Collapsed blocks are exported with their full content.

Search highlights and the current search query do not affect the exported Markdown output.

The exported file keeps the terminal-style transcript format instead of turning the conversation into a polished article-style Markdown document.

Example shape:

# Codex Chat Viewer Export

Source file: rollout-xxxx.jsonl  
Path: C:\Users\user\.codex\sessions\...\rollout-xxxx.jsonl  
Session ID: xxxx

```text
[YOU]
...

[CODEX]
...

[TOOL CALL]
...

[TOOL RESULT]
...
```

When exporting, the app suggests a Markdown filename based on the selected JSONL file. If a matching .md file already exists, the app suggests a non-conflicting filename such as name (1).md. If you explicitly select an existing file, the app asks before overwriting it.

After a successful export, Windows File Explorer opens with the exported .md file selected.

Search

Codex Chat Viewer includes in-view search for the text currently rendered in the main transcript area.

• Press Ctrl+F to open the search bar.
• Press Ctrl+F again or Esc to close it.
• Type to highlight matching text in the currently visible transcript.
• Press Enter to move to the next match.
• Press Shift+Enter to move to the previous match.
• Search is case-insensitive by default.

Search works on the currently rendered transcript, not on hidden filtered entries. If a section is hidden by the filter toggles, it is not searched until it is visible again.

Screenshots

Requirements

• JDK 21 or later
• Windows is the primary development target
• Gradle Wrapper included

The project uses the included Gradle Wrapper, so you do not need to install Gradle manually after cloning.

Run

Windows

gradlew.bat run

Manual Windows Release Zip

The portable Windows release artifact is built locally and uploaded manually to GitHub Releases.

Build the local release artifact with:

gradlew.bat packageWindowsReleaseZip

The generated files are written under the build output directory:

app/build/release/windows/app-image/
app/build/release/windows/codex-chat-viewer-windows-x64.zip

The zip is intended for manual upload to GitHub Releases after a local check. The expected user flow is:

• build codex-chat-viewer-windows-x64.zip locally
• extract the zip
• run Codex Chat Viewer.exe
• verify the app opens without a separate Java install
• upload the zip to GitHub Releases manually

jpackage is required for the release build because the release zip bundles a Java runtime. If jpackage is not already on PATH, point the build to a full JDK by setting JPACKAGE_HOME or JPACKAGE_EXECUTABLE.

The source-code zip from GitHub's green Code button is not the same as the portable release zip. End users should download the release asset instead of the source archive.

Development Notes

Codex Chat Viewer reads local Codex CLI session logs from paths such as:

~/.codex/sessions

or:

%CODEX_HOME%/sessions

The app does not upload logs anywhere.

Codex rollout logs may contain prompts, code, file paths, shell commands, command outputs, tool calls, and private project information. Treat local session files carefully.

Exported Markdown files may also contain private session content. Review them before sharing.

Privacy

This is a local-first utility.

• No network behavior is required for viewing logs.
• Real Codex session logs should not be committed.
• Private local samples should remain ignored.
• Exported files may contain private session content, so review them before sharing.

Release

Codex Chat Viewer is distributed as a portable Windows zip through GitHub Releases.

Download zip
Extract folder
Run Codex Chat Viewer.exe

License

MIT License