Solana Transaction Indexer

A real-time Solana blockchain transaction indexer built in Rust. It connects to Solana mainnet via WebSocket, parses and stores transactions in PostgreSQL, and serves a REST API, WebSocket feed, and Prometheus metrics endpoint.

Architecture

Solana mainnet (WebSocket)
        |
        v
  Ingestion layer     <- logsSubscribe, auto-reconnect with exponential backoff
        | tokio::mpsc
        v
  Parser              <- extracts signature, slot, programs, token transfers
        |
        +--> PostgreSQL   <- batch inserts, ON CONFLICT DO NOTHING
        |
        +--> broadcast::channel -> WebSocket clients (live feed)

  axum HTTP server    <- REST API + WebSocket endpoint + Prometheus metrics

Stack

• Rust + Tokio
• sqlx
• axum
• Prometheus

Quick Start

sudo service postgresql start
createdb solana_indexer

export DATABASE_URL=postgres://postgres:postgres@localhost:5432/solana_indexer
sqlx migrate run

cargo run

API Endpoints

Method	Endpoint	Description
GET	/health	Health check + indexed count
GET	/metrics	Prometheus metrics
GET	/api/stats	Transaction + transfer counts
GET	/api/transactions?limit=20	Recent transactions
GET	/api/transactions/:signature	Single transaction
GET	/api/transactions/program/:program_id	By program
GET	/api/token-transfers/:mint	Token transfers by mint
WS	/ws	Live transaction stream

Testing

export DATABASE_URL=postgres://postgres:postgres@localhost:5432/solana_indexer
cargo test

Example Queries

curl "http://localhost:3000/api/transactions/program/JUP6LkbZbjS1jKKwapdHNy74zcZ3tLUZoi5QNyVTaV4?limit=10"
curl "http://localhost:3000/api/token-transfers/EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v?limit=10"
websocat ws://localhost:3000/ws
curl http://localhost:3000/metrics