API Reference

Create a challenge to sign message

posthttps://api.circle.com/v1/w3s/user/sign/message

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Generates a challenge for signing a message from a specified user-controlled wallet. This endpoint supports Ethereum-based blockchains (using EIP-191) and Solana (using Ed25519 signatures). Note that Smart Contract Accounts (SCA) are specific to Ethereum and EVM-compatible chains. The difference between Ethereum's EOA and SCA can be found in the account types guide. You can also check the list of Ethereum Dapps that support SCA: https://eip1271.io/.

Header parameters
X-User-Token
string
Required

Unique system generated JWT session token for specific user.

Body parameters
message
string
Required

The user friendly message that needs to be signed. If it is a hex string, encodedByHex needs to be TRUE. The hex string should start with “0x” and have even length.

walletId
string
Required

System-generated unique identifier of the resource.

encodedByHex
boolean

Indicator of whether the input message is encoded by hex. If TRUE, then the message should be a hex string. By default, it is False.

memo
string

The human readable explanation for this sign action. Useful for presenting with extra information.

Response
RequestChoose a language
ResponseChoose an example
1{
2  "data": {
3    "challengeId": "c4d1da72-111e-4d52-bdbf-2e74a2d803d5"
4  }
5}
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