Sign Endpoint

Endpoint

POST /agent/sign

The sign endpoint lets you create cryptographic signatures with your agent’s wallet. It supports three signing types, each suited to a different use case.

1. personal_sign — Plain Text Messages

Use case: Prove wallet ownership, sign a message for off-chain verification.

curl -X POST https://api.bankr.bot/agent/sign \
  -H "X-API-Key: bk_YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "type": "personal_sign",
    "message": "Hello from my agent!"
  }'

{ "signature": "0x..." }

2. eth_signTypedData_v4 — EIP-712 Typed Data

Use case: Sign permits, gasless approvals, order book entries, and any structured data that follows the EIP-712 standard.

curl -X POST https://api.bankr.bot/agent/sign \
  -H "X-API-Key: bk_YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "type": "eth_signTypedData_v4",
    "typedData": {
      "domain": { "name": "MyProtocol", "version": "1", "chainId": 8453 },
      "types": { "Message": [{ "name": "content", "type": "string" }] },
      "primaryType": "Message",
      "message": { "content": "Authorize action" }
    }
  }'

{ "signature": "0x..." }

3. eth_signTransaction — Sign Without Broadcasting

Use case: Pre-sign transactions for later submission, multi-sig workflows, or offline signing.

curl -X POST https://api.bankr.bot/agent/sign \
  -H "X-API-Key: bk_YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "type": "eth_signTransaction",
    "transaction": {
      "to": "0xRecipientAddress",
      "value": "0x0",
      "data": "0x...",
      "chainId": 8453
    }
  }'

{ "signedTransaction": "0x..." }