Financial services
APIs for payments, banking data, market quotes, and forex — the building blocks of fintech apps and embedded finance.
Polygon
Polygon.io API provides real-time and historical data for US stocks, forex, and crypto — quotes, candles, earnings, news, technical indicators.
Stripe API
Payment and commerce infrastructure API covering card payments, subscriptions, marketplaces, and disputes.
Stripe Connect API
Stripe Connect is multi-merchant payments for marketplace / SaaS platforms — create per-merchant subaccounts, auto-split, compliance KYC, bank transfers.
The Plaid API
Plaid API connects to user bank accounts to pull transactions, balances, and identity — primarily serving fintech apps in US, CA, UK, EU.
Uniswap API (Subgraph)
Uniswap doesn't have traditional REST API — on-chain data is queried via The Graph's official Uniswap subgraphs (v2/v3/v4): pools, trades, liquidity, price history.
Wise API
Wise API (formerly TransferWise) provides low-cost international transfers — mid-market exchange rate + transparent fees, 5-10x cheaper than traditional SWIFT.