When someone sends a DM to the bot and isn't on the allowlist — whether it's a new user or an existing user on a new channel — nanobot automatically replies with a **pairing code** (like `ABCD-EFGH`) that expires in 10 minutes. To grant them access:
```text
/pairing approve ABCD-EFGH
```
To see who's waiting, use `/pairing`. To remove someone later, use `/pairing revoke <user_id>` — you can find user IDs in the `/pairing list` output.
See [Configuration: Pairing](./configuration.md#pairing) for the full setup guide.
Use `/model` to inspect the current runtime model:
```text
/model
```
The response shows the current model, the current preset, and the available preset names. `default` is always available and represents the model settings from `agents.defaults.*`.
To switch presets for future turns:
```text
/model fast
/model deep
/model default
```
Preset names come from the top-level `modelPresets` config. Switching is runtime-only: it does not rewrite `config.json`, and an in-progress turn keeps using the model it started with. See [Configuration: Model presets](./configuration.md#model-presets) for setup details.
The gateway wakes up every 30 minutes and checks `HEARTBEAT.md` in your workspace (`~/.nanobot/workspace/HEARTBEAT.md`). If the file has tasks under `## Active Tasks`, the agent executes them and delivers results to your most recently active chat channel. If there are no active tasks, the heartbeat is skipped silently.
The agent can also manage this file itself — ask it to "add a periodic task" and it will update `HEARTBEAT.md` for you. Completed tasks should be deleted from the file, not moved to another section.
> **Note:** The gateway must be running (`nanobot gateway`) and you must have chatted with the bot at least once so it knows which channel to deliver to.
