Sign Message

Sign arbitrary messages with HSM/MPC keys.

Endpoint

POST /sign

Description

Signs arbitrary messages using HSM/MPC keys. Supports both raw messages and EIP-712 structured data.

Request Body

{
  "messages": [
    "hello world",
    "hello web3"
  ],
  "format": "rsv",
  "hashed": false,
  "signer": {
    "clientId": "your-fireblocks-client-id",
    "versionId": "1"
  },
  "eip712": {
    "address": "0x...",
    "chainId": "137"
  }
}

Response

[
  {
    "address": "0xdb074b3c323a7ad418ebbe66bad231f43f680563",
    "publicKey": "049113caedb5d570dc9a47974f819b9d2c88ffcf622c1f3c756be7955d9f16eae28d8f00ec4fa359c311ae4c25b58d2b1d872d6e4c37600494416d856615fb7e4b",
    "signatures": [
      {
        "r": "...",
        "s": "...",
        "v": 27
      }
    ],
    "errors": null
  }
]

Response Fields

address (string): The public address of the signer
publicKey (string): The public key of the signer
signatures (array): Array of signature objects with r, s, v values
errors (array, nullable): Array of error messages if signing failed

Example Request

curl -X POST https://api.msa.omnes.tech/sign \
  -H "Content-Type: application/json" \
  -d '{
    "messages": [
      "hello world",
      "hello web3"
    ],
    "format": "rsv",
    "hashed": false,
    "signer": {
      "clientId": "your-fireblocks-client-id",
      "versionId": "1"
    }
  }'

const response = await fetch('https://api.msa.omnes.tech/sign', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    messages: ['hello world', 'hello web3'],
    format: 'rsv',
    hashed: false,
    signer: {
      clientId: 'your-fireblocks-client-id',
      versionId: '1',
    },
  }),
});

const result = await response.json();
console.log('Signer address:', result[0].address);
console.log('Signatures:', result[0].signatures);

import requests

url = "https://api.msa.omnes.tech/sign"
payload = {
    "messages": [
        "hello world",
        "hello web3"
    ],
    "format": "rsv",
    "hashed": False,
    "signer": {
        "clientId": "your-fireblocks-client-id",
        "versionId": "1"
    }
}

response = requests.post(url, json=payload)
result = response.json()
print(f"Signer address: {result[0]['address']}")
print(f"Signatures: {result[0]['signatures']}")

Use Cases

Message authentication: Sign messages for authentication purposes
EIP-712 signing: Sign structured data for dApps
Batch signing: Sign multiple messages in a single request
HSM/MPC signing: Use enterprise-grade signing infrastructure

Best Practices

Use EIP-712 for structured data: Use EIP-712 format for better UX and security
Handle errors: Check for errors in the response array
Verify signatures: Always verify signatures on-chain or off-chain
Protect credentials: Never expose HSM/MPC credentials

Transact Signer - Execute transactions with HSM/MPC

💡 Tip: Use EIP-712 format for signing structured data. This provides better UX and security compared to raw message signing.

Sign Message

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