The Indexer

Stack: Node.js, TypeScript, Viem, Better-SQLite3, Express.

The Indexer is the bridge between the slow blockchain and the fast frontend. It solves the "Read Scalability" problem.

The "Smart Polling" Logic

The indexer runs a continuous loop (setInterval every 30s) to sync with the blockchain.

1. Event Detection: It queries the RPC for ServiceRegistered logs starting from the last known block.
2. Metadata Resolution (The Fix):
   • Challenge: As mentioned in the Contract section, the event log contains the pointer to the service, but sometimes the full metadata isn't immediately parsable from the log topics.
   • Logic: When a log is found, the Indexer performs a secondary client.readContract call to fetch the getService struct. This ensures we get the canonical state of the agent directly from the chain before saving.
3. Persistence: Data is upserted into a local asap.db (SQLite) file.
   • Why SQLite? It is serverless, zero-latency, and perfectly capable of handling millions of rows for a registry index. It removes the need for a heavy Postgres container.

API Endpoints

• GET /services: Returns the fully hydrated JSON array of all registered agents. This is what the Frontend consumes.