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Backend deployment

The backend was originally hosted on Railway at pesalo-api-production.up.railway.app. The DNS for that hostname stopped resolving recently — see Limitations for the user-visible consequences.

Stack​

  • Express (Node 22) — backend/src/index.ts.
  • Postgres — Railway managed. Holds:
    • early_access (email submissions from the landing form).
    • rates_cache (Yield-Market state snapshots, refreshed every 30s).
    • positions_cache (per-address Soroban contract reads, refreshed lazily on hit).
  • Stellar SDK — talks to Horizon + Soroban RPC. The full @stellar/stellar-sdk (no polyfill drama because it's Node-native).
  • Custom domain target was api.pesalo.fun (CNAME → Railway). Currently unconfigured.

Required env vars​

PORT=3001
DATABASE_URL=postgresql://...     # Railway-provided
SOROBAN_RPC_URL=https://soroban-testnet.stellar.org
HORIZON_URL=https://horizon-testnet.stellar.org
NETWORK_PASSPHRASE=Test SDF Network ; September 2015

# Contract addresses (same set as mobile/.env.local)
ROUTER_CONTRACT_ID=CCUG7VF4LPNVFO4JJ2SGAKNLBQLRMZHXRY3YX4YHGNHRUKCKFNQQINL7
USDC_MARKET_CONTRACT_ID=CBTVKJUEU42FVIWGVW5HCTQKLGFVAPZE72BGBOWLP2RNFJE6YO5PLSEL
# ... etc.

Build + deploy​

cd backend
npm install
npm run build       # tsc → dist/
npm run start       # node dist/index.js

Railway runs the same npm run build then npm run start automatically.

Bringing it back online​

The simplest path to get rates/prices/positions working again is:

  1. Re-deploy on Railway (the existing project may just be paused). Restore env vars from the previous deploy.
  2. Or migrate to another host (Fly.io, Render, Vercel functions). The stack is plain Express; any Node hosting works.
  3. Or remove the backend entirely and read everything from Horizon / a public price oracle (CoinGecko's simple/price endpoint for USD prices, on-chain reads for rates).

Option 3 is more invasive but eliminates a moving part. The mobile app already does it for Activity — see mobile/lib/stellar/horizonActivity.ts. Doing the same for rates + prices requires:

  • A small getMarketState(market_id) Soroban read for each open market → derive boost APY.
  • A small getExchangeRate(sy_id) Soroban read + a delta against the previous snapshot → derive auto-earn APY.
  • A CoinGecko fetch for XLM_USD (USDC/EURC are pegged ≈ 1).

For positions, the read is per-PT-contract balance(owner) for each market — same as the indexer does today, just client-side.