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, the agent executes them and delivers results to your most recently active chat channel.
**Setup:** edit `~/.nanobot/workspace/HEARTBEAT.md` (created automatically by `nanobot onboard`):
```markdown
## Periodic Tasks
- [ ] Check weather forecast and send a summary
- [ ] Scan inbox for urgent emails
```
The agent can also manage this file itself — ask it to "add a periodic task" and it will update `HEARTBEAT.md` for you.
> **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.
