Financial services
APIs for payments, banking data, market quotes, and forex — the building blocks of fintech apps and embedded finance.
Payment Initiation API
UK Open Banking Payment Initiation API (PIS) lets authenticated third parties initiate transfers from user bank accounts with user consent (A2A payments).
PayPal API
PayPal API provides integration of the world's most recognized payment method — one-time payments, subscriptions, payouts, merchant tools, Venmo (US).
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.