Relaycode is a developer tool for building and submitting extrinsics (transactions) on Polkadot, Kusama, and other Substrate chains. It's funded by the Web3 Foundation.
W3F Grant
The grant application was merged in October 2024. Milestone 2 was delivered in February 2026.
Technical Approach
Instead of using the legacy @polkadot/api, Relaycode is built on Dedot — a modern Substrate interaction library. The UI features 24+ specialized input component types for various extrinsic parameters, with a dual-pane interface showing human-readable inputs alongside SCALE-encoded hex.
Ecosystem Context
Relaycode supports Polkadot, Kusama, and Westend chains with built-in wallet integration for signing transactions. It integrates with the Wisesama API for chain metadata.