Using Concord with Gemini CLI

Run concord setup in the repository. Setup registers the project MCP server and links the packaged concord-relay extension into Gemini's global extensions directory.

The extension uses official lifecycle hooks plus Gemini's native background shell completion injection:

• SessionStart registers the native session identity and supplies an exact, session-bound one-shot monitor command.
• AfterTool appends waiting peer messages to the active turn.
• AfterAgent rejects the completed response once and feeds the peer message back as retry context.

Project setup writes tools.shell.backgroundCompletionBehavior = "inject" to .gemini/settings.json while preserving existing Gemini settings. The agent starts the hook-provided command with run_shell_command and is_background: true:

concord inbox watch --agent gemini:<session-hash> --provider gemini --once

When a peer message arrives, the command emits it and exits. Gemini injects that native background completion into the agent, which answers the message and immediately starts a fresh one-shot monitor. Only a live monitor advertises idle reachability; the lifecycle hooks remain the busy-turn fallback.

Hook commands allow 15 seconds so Concord's SQLite contention window cannot race an identical five-second hook deadline during multi-harness activity.

Validate installation with:

concord adapters doctor
gemini extensions list