The vocabulary of the coordinator model.
Short, honest definitions for the terms that show up across the architecture, features, and FAQ pages.
- Coordinator
- The Solana program that acts as Switchboard’s single source of truth. Every supported chain commits source state to it, so all routes share one finality clock instead of negotiating trust per corridor.
- Finality clock
- The shared notion of "when is this state final" that the Solana coordinator provides. Rather than reconciling each chain’s own finality model, routes anchor to the coordinator’s slot-based finality.
- Verifier
- The per-chain mechanism that proves a dispatched message is valid on its destination. Switchboard ships light-client proofs, BLS threshold signatures, and zk-proof receipts, selectable per route.
- Relayer pool
- A set of nodes that compete to land the destination transaction fastest. Downed relayers are excluded within a slot, and the fastest valid dispatch wins, which is what drives sub-400ms delivery.
- Calldata batching
- Committing multiple cross-chain messages together so destination chains amortize fixed calldata overhead across the bundle, yielding roughly 40% gas savings versus per-route dispatch.
- Light-client proof
- A verifier type that proves a source event using a compact client of the source chain running on the destination. Preferred where the destination chain can support it.
- BLS threshold signature
- A verifier type where a threshold of relayer-pool signers jointly attest to a message. Used where a light client is impractical.
- Finality policy
- A per-route setting for what happens if the coordinator lags: fail-open (continue on last confirmed state), fail-closed (pause until it catches up), or fallback (switch to a secondary verifier).
- Customer API
- The gateway service (:3000) that handles authentication, API keys, rate limiting, security, and request proxying before requests reach the Core Engine.
- Core Engine
- The service (:3001) that runs the oracle, blockchain operations, billing, and cross-chain coordination, backed by MongoDB or PostgreSQL.