# Gemini CLI

> Get notified when Gemini CLI finishes a response or needs tool permission. Gemini CLI hooks (AfterAgent, Notification) that send to Slack, Telegram, or SMS.

Source: https://docs.alphorn.dev/ai-agents/gemini-cli/

Gemini CLI runs commands on agent events through [hooks](https://geminicli.com/docs/hooks/). Two events matter for notifications:

- **`AfterAgent`** - the agent finished a response.
- **`Notification`** - Gemini CLI needs your attention, for example to approve a tool (`notification_type` is `ToolPermission`).

## 1. Create the hook script

```bash title="~/.gemini/hooks/alphorn-notify.sh"
#!/usr/bin/env bash
# Forwards Gemini CLI AfterAgent and Notification hook events to Alphorn.
jq -c '{
  title: ("Gemini CLI - " + (.cwd | split("/") | last)),
  message: (if .hook_event_name == "Notification"
            then (.message // "Needs your attention")
            else (.prompt_response // "Finished") end),
  priority: (if .hook_event_name == "Notification" then 4 else 2 end),
  tags: ["ai-agent", "gemini-cli",
         (if .hook_event_name == "Notification" then "permission" else "completed" end)]
}' | curl -fsS --max-time 5 -X POST https://app.alphorn.dev/n/V1StGXR8_Z5jdHi6B-myT \
  -H "Authorization: Bearer $ALPHORN_API_KEY" \
  -H "Content-Type: application/json" \
  -d @- > /dev/null
exit 0
```

```bash
chmod +x ~/.gemini/hooks/alphorn-notify.sh
```

The script prints nothing and exits `0`. Gemini CLI parses the output of a successful hook as JSON, and exit code `2` blocks.

## 2. Register the hooks

```json title="~/.gemini/settings.json"
{
  "hooks": {
    "AfterAgent": [
      {
        "matcher": "*",
        "hooks": [
          { "name": "alphorn-done", "type": "command", "command": "~/.gemini/hooks/alphorn-notify.sh", "timeout": 10000 }
        ]
      }
    ],
    "Notification": [
      {
        "matcher": "*",
        "hooks": [
          { "name": "alphorn-input", "type": "command", "command": "~/.gemini/hooks/alphorn-notify.sh", "timeout": 10000 }
        ]
      }
    ]
  }
}
```

`timeout` is in **milliseconds** in Gemini CLI. Use `.gemini/settings.json` in a project to enable the hooks only there. `ALPHORN_API_KEY` must be set in the environment Gemini CLI runs in. In some older Gemini CLI versions hooks had to be enabled in `settings.json` first, so if they never fire, update Gemini CLI or check its hooks docs for your version.

## Event fields

| Event | Useful fields |
|---|---|
| All | `session_id`, `cwd`, `hook_event_name`, `timestamp` |
| `AfterAgent` | `prompt`, `prompt_response` (the agent's final text) |
| `Notification` | `notification_type`, `message`, `details` |

See [AI Agent Notifications](/ai-agents) for routing conventions and an `AGENTS.md` snippet that lets the agent send notifications on its own.