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.

1. Sub-solvers find orders in the CoW orderbook and compute routes.
2. Sub-solvers sign and submit proposals to BYOS.
3. BYOS validates each proposal in the background.
4. When the CoW driver calls /solve, BYOS returns its best proposal per order.
5. The driver settles the solution on-chain through a per-sub-solver Trampoline contract.
6. 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.

Deployment

Step-by-step guide to deploy a new BYOS instance. Covers the contract deployment order, service configuration, and verification.

Operational runbook

Admin dashboard reference, log lines by worker, Slack notification events, uptime monitoring, and a monitoring checklist for operators.

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.

Active deployments

Chain-specific addresses, endpoints, and parameters for each active BYOS deployment.

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.