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Gemini CLI

Gemini support mirrors the Claude Code shape, split across two scripts. The briefing hook is shipped. Serialize can run too: the upstream transcript_path stub (gemini-cli#14715) was fixed in gemini-cli v0.21.0 (2025-12-16), so a real path reaches the SessionEnd hook on that version and later. What daimon serialize does with a Gemini transcript once it has a real path is unverified by this project, see the Verify section below.

What each script does​

  • daimon-gemini-session-start.py — SessionStart hook. Shells out to daimon brief and injects the result via Gemini's {"hookSpecificOutput": {"additionalContext": ...}} envelope. Gemini requires pure-JSON stdout ("Silence is Mandatory") — unlike the Claude Code hook, nothing is ever printed raw; operator-facing diagnostics ride {"systemMessage": ...} instead. SessionStart is advisory-only: exit 0 always, startup is never blocked.
  • daimon-gemini-session-end.py — SessionEnd hook. Mirrors the Claude Code SessionEnd hook: spawns daimon serialize <transcript_path> detached when transcript_path is non-empty, and logs a graceful skip when it is not. On gemini-cli v0.21.0 and later (the fix for gemini-cli#14715), transcript_path carries a real path, so the hook spawns serialize. On earlier versions the field still arrives empty and the hook still skips.

Install (manual, from a clone)​

gemini-hooks.py is the lifecycle manager (same shape as codex-hooks.py):

python3 hook/gemini-hooks.py install   [--dry-run]
python3 hook/gemini-hooks.py uninstall [--dry-run]
python3 hook/gemini-hooks.py status

Install copies both scripts (plus _daimon_hook_lib.py) to ~/.gemini/hooks/ and registers them in ~/.gemini/settings.json (user layer). Requires the daimon CLI on PATH (uv tool install 'daimon-briefing[pretty]').

MCP​

hook/gemini-hooks.py install also registers the read-only MCP server in ~/.gemini/settings.json's mcpServers.daimon, alongside its two hooks, and removes it on uninstall. Gemini has no per-prompt recall hook (SessionStart-only, see above), so the recall hint has nowhere to render here yet.

Teach the agent the protocol​

daimon skill install gemini      # managed block in ~/.gemini/GEMINI.md

On the shared GEMINI.md file, daimon only ever touches its own marker block — daimon skill uninstall gemini removes exactly that block. Re-run install after upgrading daimon to refresh the content.

Verify​

daimon status

On gemini-cli v0.21.0 or later, daimon status should show a fresh checkpoint for the project after a session ends. Whether a Gemini transcript actually parses into a checkpoint is unverified by this project: daimon serialize has purpose-built parsing for Codex, Windsurf and Kimi, plus a generic fallback, and nobody on the project has run a real Gemini session through it since the upstream fix shipped. If daimon status shows no fresh checkpoint, or a serialize error, a parsing gap is the likely cause, and a report naming your gemini-cli version is welcome.

On gemini-cli before v0.21.0, expect capture to show as skipped rather than written. Briefing injection on SessionStart works independently of capture either way.