aster-api-auth-v3

To sign Aster Futures API v3 requests, generate an EIP-712 typed data signature using the domain AsterSignTransaction with chainId 1666. You encode an ASCII-sorted key=value parameter string, sign it with your ECDSA private key, and attach the resulting hex signature to your query string or form-encoded body.

Aster Futures API authentication fails when nonces are not monotonically generated in microseconds or when clock skew exceeds the recvWindow. Querying server time before signing requests helps prevent ±5s rejection windows and ensures your EIP-712 signature is accepted without timing errors.

When signing Aster Futures TRADE and USER_DATA requests, you must include user, signer, and a microsecond nonce in your parameter string. Parameters must be ASCII-sorted into key=value pairs before EIP-712 encoding to ensure deterministic, verifiable ECDSA signatures for the AsterSignTransaction domain.

Yes, EIP-712 request signing applies to MARKET_DATA and USER_STREAM endpoints, as well as TRADE and USER_DATA calls. The signing mechanism produces hex ECDSA signatures suitable for attaching to query strings or POST and DELETE form-encoded bodies across all these Aster Futures API v3 endpoint types.

You should store user, signer, and private keys in environment variables for secure Aster Futures request signing. This prevents hardcoding sensitive ECDSA private key material in your client or middleware components while generating the required EIP-712 signatures.

The correct EIP-712 domain structure for Aster Futures API off-chain request signing uses the domain name AsterSignTransaction, version 1, chainId 1666, and a verifyingContract set to zeros. This structure encodes the Message type for authenticating your ECDSA signed requests.