CRYPTO

Sign Transactions

Sign and verify messages on Fast

Human Flow

Message challenge, sign output, and signature verification.

state: idle

Sign

Signature format on Fast: hex string. Fast signatures are returned as raw hex strings; verify against a Fast bech32m address.

Sign Output

No signature yet. Run sign to capture `signature` and signer `address`.

Verify

Verification can be run independently with chain/message/signature/address.

Agent Flow

SDK sign/verify calls with chain-specific signature format notes.

Sign

SDK method
CALLmoney.sign
- Signature format on Fast: hex string.
# SDK method (no HTTP endpoint)
# Use JavaScript snippet instead.
Example success response
{
  "signature": "...",
  "address": "fast1...",
  "chain": "fast",
  "network": "testnet"
}
Example failure responses
Failure
{
  "code": "CHAIN_NOT_CONFIGURED",
  "message": "Chain \"fast\" is not configured for testnet."
}
Recovery: Run setup first: await money.setup({ chain: "fast", network: "testnet" })
Failure
{
  "code": "INVALID_PARAMS",
  "message": "Missing required param: message"
}
Recovery: Provide a non-empty message.

Verify

SDK method
CALLmoney.verifySign
- Verification can run independently from sign if you provide all fields.
# SDK method (no HTTP endpoint)
# Use JavaScript snippet instead.
Example success response
{
  "valid": true,
  "address": "fast1...",
  "chain": "fast",
  "network": "testnet"
}
Example failure responses
Failure
{
  "valid": false,
  "note": "Signature verification failed. The signature does not match the provided address and message."
}
Recovery: Ensure chain, message, signature, and address all match the original sign payload.