> ## Documentation Index
> Fetch the complete documentation index at: https://docs.blockradar.co/llms.txt
> Use this file to discover all available pages before exploring further.

# Signing API

> Sign messages and typed data from any Blockradar wallet.

The Signing API lets you sign arbitrary messages and EIP-712 typed data from a Blockradar wallet or child address. This is used for authentication flows, permit-style approvals, and off-chain agreement signing.

## What you can do

* Sign a plain message from a master wallet or child address
* Sign EIP-712 structured typed data for standards-compliant workflows

## Endpoints

| Method | Endpoint                                                    | Description                             |
| ------ | ----------------------------------------------------------- | --------------------------------------- |
| `POST` | `/wallets/{walletId}/sign/message`                          | Sign a message (master wallet)          |
| `POST` | `/wallets/{walletId}/sign/typed-data`                       | Sign EIP-712 typed data (master wallet) |
| `POST` | `/wallets/{walletId}/addresses/{addressId}/sign/message`    | Sign a message (child address)          |
| `POST` | `/wallets/{walletId}/addresses/{addressId}/sign/typed-data` | Sign EIP-712 typed data (child address) |

<Card title="Full API Reference" icon="book" href="/en/api-reference/signing/master-wallet-sign-message">
  View all signing endpoints in the API Reference tab.
</Card>