Relayer
Also known as: Transaction Broadcaster, MetaTx Forwarder, Bridge Node
An off-chain actor or service that submits transactions on behalf of users in systems like rollups, bridges, and meta-transactions.
A relayer is a node, service, or intermediary that submits transactions to the blockchain on behalf of users, often covering gas fees or aggregating off-chain data. Relayers are critical components in rollups, cross-chain bridges, and meta-transaction systems, enabling trust-minimized communication between protocols and improving user experience. In meta-transactions, users sign data off-chain, and relayers broadcast it. In rollups, relayers bundle and post rollup blocks to Layer 1. Examples include Flashbots, Gelato, and Connext. They play key roles in Web3 composability, scalability, and UX.