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POST
/
v1
/
w3s
/
developer
/
sign
/
message
Sign message
curl --request POST \
  --url https://api.circle.com/v1/w3s/developer/sign/message \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "message": "I agree with this transfer",
  "entitySecretCiphertext": "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",
  "walletId": "c4d1da72-111e-4d52-bdbf-2e74a2d803d5",
  "encodedByHex": false,
  "memo": "Transfer USDC to Sam",
  "blockchain": "MATIC-AMOY",
  "walletAddress": "0xca9142d0b9804ef5e239d3bc1c7aa0d1c74e7350"
}
'
{
  "data": {
    "signature": "3W6r38STvZuBSmk2bbbct132SjEsYSARo3CJi3JQvNUaFoYu..."
  }
}

Authorizations

​
Authorization
string
header
required

Circle's API Keys are formatted in the following structure "PREFIX:ID:SECRET". All three parts are requred to make a successful request.

Headers

​
X-Request-Id
string

Developer-provided parameter used to identify this request. Useful when communicating with Circle Support. A unique identifier, which can be helpful for identifying a request when communicating with Circle support.

Example:

"2adba88e-9d63-44bc-b975-9b6ae3440dde"

Body

application/json

Schema for the request payload to sign a message.

​
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.

Example:

"I agree with this transfer"

​
entitySecretCiphertext
string<byte>
required

A base64 string expression of the entity secret ciphertext. The entity secret should be encrypted by the entity public key. Circle mandates that the entity secret ciphertext is unique for each API request.

Example:

"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"

​
walletId
string<uuid>

System-generated unique identifier of the resource.

Example:

"c4d1da72-111e-4d52-bdbf-2e74a2d803d5"

​
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.

Example:

false

​
memo
string

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

Example:

"Transfer USDC to Sam"

​
blockchain
enum<string>

The blockchain network that the resource is to be created on or is currently on.

Available options:
ETH,
ETH-SEPOLIA,
AVAX,
AVAX-FUJI,
MATIC,
MATIC-AMOY,
SOL,
SOL-DEVNET,
ARB,
ARB-SEPOLIA,
NEAR,
NEAR-TESTNET,
EVM,
EVM-TESTNET,
UNI,
UNI-SEPOLIA,
BASE,
BASE-SEPOLIA,
OP,
OP-SEPOLIA,
APTOS,
APTOS-TESTNET,
ARC-TESTNET,
MONAD,
MONAD-TESTNET
Example:

"MATIC-AMOY"

​
walletAddress
string

Blockchain generated unique identifier, associated with wallet (account), smart contract or other blockchain objects.

Example:

"0xca9142d0b9804ef5e239d3bc1c7aa0d1c74e7350"

Response

Successfully signed a message.

​
data
object
required