THthirdweb
Wallets

Sign Message

Signs an arbitrary message using the specified wallet. This endpoint supports both text and hexadecimal message formats. The signing is performed using thirdweb Engine with smart wallet support for gasless transactions.

Authentication: This endpoint requires project authentication and wallet authentication. For backend usage, use x-secret-key header. For frontend usage, use x-client-id + Authorization: Bearer <jwt> headers.

post/v1/wallets/sign-message

Request

  • Base URL
    https://api.thirdweb.com
  • Auth
    HTTP bearer and API key in header x-client-id

Request body

fromstring required

The wallet address or ENS name that will sign the message.

chainIdinteger required

The blockchain network identifier where the signing will occur. Common values include: 1 (Ethereum), 137 (Polygon), 56 (BSC).

messagestring required

The message to be signed. Can be plain text or hexadecimal format (starting with 0x). The format is automatically detected.

Example request

{
  "from": "0x1234567890123456789012345678901234567890",
  "chainId": 1,
  "message": "Hello, world!"
}

Response

Message signed successfully. Returns the cryptographic signature that can be used for verification.

Changes

No recorded changes to this operation across all 5 revisions of this API.