What is BYOS
BYOS (Bring Your Own Solver) is a bonded CoW Protocol solver. It lets external routers — called sub-solvers — submit routes to CoW auctions. Sub-solvers do not need a bonding pool, a DAO vote, or KYC. They deposit collateral into an escrow and sign EIP-712 proposals.
From the protocol side, BYOS is one ordinary solver. The sub-solver relationship is internal.
- Sub-solvers find orders in the CoW orderbook and compute routes.
- Sub-solvers sign and submit proposals to BYOS.
- BYOS validates each proposal in the background.
- When the CoW driver calls
/solve, BYOS returns its best proposal per order. - The driver settles the solution on-chain through a per-sub-solver Trampoline contract.
- If the settlement reverts, BYOS debits the sub-solver's escrow.
Interested in becoming a Sub-solver?
Check the Sub-solver integration guide. Step-by-step instructions to go from zero to a settled proposal.
Documentation map
Design document
The normative specification. It defines the order flow, the proposal schema, the penalty schedule, the scoring model, and the gas cut. All other documents refer to it. If a document and the design document disagree, the design document is correct.
Contracts reference
Interface tables for Escrow, Trampoline, and TrampolineFactory: function signatures, events, errors, roles, and transfer restrictions. Use this page to look up a specific function or event. The design document explains why each contract works the way it does.
Service architecture
The off-chain service: two-listener model, proposal ingestion, the /solve handler, background workers (validation, penalties, retention), the state machine, persistence, and the scoring and gas cut formulas. Use this page to understand how the service processes proposals.
Sub-solver integration guide
Step-by-step instructions to go from zero to a settled proposal. Covers escrow deposit, proposal construction, signature, submission, and what happens after settlement. Start here if you want to integrate as a sub-solver.
Glossary
Definitions for all domain terms. Every implementation repo uses this vocabulary.
SLO targets
Latency targets for /solve, GET /proposals, and the validation loop.
Trampoline / settlement isolation
Proof that a sub-solver's route cannot reach GPv2Settlement funds.
CoW protocol reference
Background material on the CoW mechanisms BYOS depends on:
- Fee collection — how CoW collects and distributes fees.
- Solver slashing policy — the penalty framework BYOS mirrors for sub-solvers.
- Solver auctions — how the CoW auction and scoring work.
- Solver CIPs — the CIPs that govern solver competition rules.