Debugging Hyperliquid Signature Errors: Msgpack, EIP-712 and Signer Recovery

A systematic way to diagnose Hyperliquid signatures that recover the wrong address or fail only for particular actions.

Identify the signing scheme first

L1 actions and user-signed actions do not use one interchangeable payload. Select the scheme from the action type before constructing typed data or hashing msgpack.

Canonicalize before hashing

Field order, numeric representation, trailing zeroes and address casing can change the encoded payload. Create one canonical serializer and prohibit strategies from constructing signing objects ad hoc.

Log safe intermediate evidence

Record action type, canonical JSON, msgpack hash, typed-data domain and recovered address. Never log private keys or raw secrets. Compare these artifacts with a known-good official SDK fixture.

Do not trust local recovery alone

Recovering the expected signer locally only proves the signature matches the locally constructed digest. If the server reconstructs a different payload, it can recover another address. Compare every domain and action field.

Test every action family

Order, cancel, transfer, vault and agent-management actions have different shapes and authority expectations. Keep golden vectors for each supported action in CI.

Fix the integration properly

Use the official signing guidance and SDK as reference. TierZero can audit Hyperliquid bot integrations and signer isolation through code review.

Production checklist

Before launch, define ownership, test fixtures, failure states, alerts and a rollback procedure. For a scoped engineering review, use the TierZero project form.