Payroute
x402 payment rail on Mantle
2026Smart contracts & SDKSolidityTypeScriptFoundryMantle
- v1.0.1
- TypeScript SDK shipped
- Sole author
- escrow contracts
Payroute is an x402 payment rail on Mantle. I was the sole author of the escrow contracts and shipped a TypeScript SDK (v1.0.1) so other teams could integrate without writing raw contract calls.
The problem
Micropayments need a way to hold funds until a service is delivered, then release them without a trusted intermediary. The rail also has to be easy for client applications to adopt — a correct contract is not enough if integration takes a week.
What I built
- Escrow contracts with explicit states for funded, delivered, released, and refunded payments.
- Foundry tests covering the happy path plus replay, double-release, and unauthorised-release cases.
- A TypeScript SDK that wraps contract reads, writes, and event decoding behind a small typed API, published as v1.0.1.
What I learned
The SDK was the product. Once integration was reduced to a few typed calls, teams could evaluate the rail in an afternoon instead of reading the contracts line by line.