> For the complete documentation index, see [llms.txt](https://docs.bitcoinos.build/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.bitcoinos.build/technical-documentation/grail-pro-charms-zkbtc/technical-overview/grail-pro/grail-pro-institutional-integration/backend-api-integration.md).

# Backend API Integration

Authentication: Obtain a JWT token via a secure login service to identify the user.  The token is used to identify the user to the back-end.

Key APIs:

#### Transaction API Requests

POST /api/v1/peg-in\
Request body: 

{\
&#x20; "wallet\_address": "\<user\_wallet\_address>",\
&#x20; "amount": "\<amount>",\
&#x20; "recovery\_key": "\<recovery\_key>",\
&#x20; "transaction\_type": "peg-in"\
}

**Response body:**

{\
&#x20; "status": "success",\
&#x20; "taproot\_address": "\<taproot\_address>"\
}

#### Cosigner State API Request

GET /api/v1/cosigners/state

**Response:**

{\
&#x20; "cosigners": \[\
&#x20;   {\
&#x20;     "public\_key": "\<public\_key>",\
&#x20;     "attestation": "\<attestation\_document>"\
&#x20;   }\
&#x20; ],\
&#x20; "aggregation\_strategy": "\<strategy\_description>"\
}

<br>


---

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