Cryptocurrency — entry 049 of 53
Poloniex
Poloniex's REST and WebSocket APIs cover spot trading, margin, and futures across hundreds of markets, with public market-data endpoints open with no key and private trading/account endpoints secured by an API key and HMAC-signed requests. The exchange, founded in the US, has changed hands several times (Circle, then a Justin Sun-linked consortium via Polo Digital Assets) and suffered a major 2023 hot-wallet hack, though its documented API has remained live and versioned since.
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<a href="https://greatapis.com/api/poloniex/"><img src="https://greatapis.com/badge/poloniex.svg" alt="Scored 84 on greatapis.com"></a>Auth quickstart
- Sign up with the provider to get an API key.
- Send it on every request as a header
Authorization: <key> - The exact header isn't documented — Authorization is a common default; confirm in the provider's docs.
Your key is stored only in this browser (localStorage) and sent directly to the API — never to greatapis.
Developer reference
WebSocket API: 500 requests/second per established connection, with a single IP capped at 2,000 simultaneous connections per public/private channel; the Spot REST API's tier auto-links to the account's fee level since a 2025-03-13 change, no fixed number published, per api-docs.poloniex.com/spot/websocket/