Lens — Unified Stellar Price API

Aggregates price data from Stellar's Classic Order Book (SDEX) and AMM Liquidity Pools into a single, unified API.

What Horizon doesn't do: Horizon's /trade_aggregations only covers SDEX. AMM pool prices (derived from reserve ratios) are not aggregated anywhere. Lens fills this gap.

Endpoints

REST

Method	Path	Description
GET	`/price/:assetA/:assetB`	Current VWAP, 24h volume, best route
GET	`/price/:assetA/:assetB/route?amount=1000`	Best execution route for a given amount
GET	`/price/:assetA/:assetB/history?window=1h`	OHLCV history (`1m`, `5m`, `1h`, `24h`)
GET	`/pools`	Active AMM pools being watched
GET	`/pairs`	Watched trading pairs
GET	`/status`	Indexer health

GraphQL

Available at /graphql with GraphiQL IDE at /graphiql.

query {
  getPrice(assetA: "XLM", assetB: "USDC") {
    price
    bestRoute
    vwap1h
    volume24h
    priceChange24h
  }
  getBestRoute(assetA: "XLM", assetB: "USDC", amount: 500) {
    route
    sdexPrice
    ammPrice
    estimatedOutput
    slippagePct
    recommendation
  }
}

Quick Start

# 1. Start PostgreSQL + Redis
docker-compose up -d

# 2. Install dependencies
npm install

# 3. Copy env
cp .env.example .env

# 4. Push database schema
npm run db:push

# 5. Start dev server
npm run dev

Stack

Runtime: Node.js 20 + TypeScript
API: Fastify + Mercurius (GraphQL)
Database: PostgreSQL + TimescaleDB
Cache: Redis
Queue: BullMQ
Stellar: @stellar/stellar-sdk

Salmatcre8/Lens

README