Gemini CLI

npx shibbo init gemini

What it writes

• Rules: GEMINI.md. Gemini CLI doesn't read AGENTS.md unless you add it to context.fileName in settings.
• MCP and hooks: both in .gemini/settings.json:

{
  "mcpServers": { "shibbo": { "command": "npx", "args": ["shibbo", "mcp"] } },
  "hooks": {
    "AfterTool": [
      { "matcher": "write_file|replace",
        "hooks": [{ "name": "shibbo-check", "type": "command", "command": "npx shibbo hook post-edit --for gemini", "timeout": 30000 }] }
    ],
    "AfterAgent": [
      { "hooks": [{ "name": "shibbo-reply", "type": "command", "command": "npx shibbo hook stop --for gemini", "timeout": 30000 }] }
    ]
  }
}

How feedback reaches the agent

After write_file or replace, shibbo answers with hookSpecificOutput.additionalContext, which Gemini appends to the tool result. When the agent finishes, shibbo checks prompt_response and, for heavy slop, answers {"decision": "deny", "reason": ...}, which asks for a retry with that reason. It skips the check when stop_hook_active is set.

Note

For unpaid-tier and Google One users, Google replaced Gemini CLI with Antigravity CLI on 18 June 2026. The setup above applies to Gemini CLI.

Sources: GEMINI.md, MCP, hooks reference.