Introduction

Fairseq is the Rust SDK for temporal ordering proofs: cryptographic evidence that a set of transactions was sequenced fairly (FIFO) and anchored to verifiable time.

Standard zkVMs prove what was computed. Fairseq proves when.

What you get

• Prover + verifier primitives for temporal ordering proofs
• Hosted + self-hosted workflows (the hosted proving service is introduced in later prompts)
• Developer-first integration: the product spec targets time-to-first-proof under 10 minutes

Who it's for

Fairseq is designed for:

• L2 sequencer operators who need to prove fair ordering to users, integrators, and regulators
• DEX protocol teams who want provable fairness guarantees around matching and execution ordering
• DeFi aggregators that need verifiable ordering for "best execution" claims

Core idea (high-level)

Fairseq binds ordering to verifiable time using VDF-backed anchoring (the Lighthouse Network). At a protocol level, you collect transactions, commit to their order, and produce a proof that the published order matches the arrival-time constraints.