> For the complete documentation index, see [llms.txt](https://docs.tinyman.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.tinyman.org/v1-integration/transactions/optin.md).

# OptIn

### Transaction:

1. App Call - OptIn to the Validator App
   * signed by Pooler/Swapper

```
{
  "txn": {
    "type": "appl",
    "snd": "{POOOLER/SWAPPER_ADDRESS}",
    "apid": {VALIDATOR_APP_ID},
    "apan": 1, // OnComplete: OptIn
    "apaa": []
    ...
  },
}
```

### Validator App State Changes

**Global State**

None

**User Account Local State**

None