Finnhub

Real-Time RESTful APIs and Websocket for Stocks, Currencies, and Crypto

Finnhub provides real-time market data via REST APIs and WebSocket for stocks, forex, and crypto. Beyond price data, it offers company fundamentals, earnings estimates, SEC filings, insider transactions, ESG scores, and alternative data like social sentiment and patent filings. The API is well-designed with clean JSON responses. For OpenClaw agents, Finnhub stands out for its generous free tier and breadth of data. Your agent can monitor stock prices via WebSocket, fetch company news, check earnings calendars, analyze insider trading patterns, and get real-time market sentiment — making it ideal for building a comprehensive market intelligence assistant.

Tags: data, finance

Category: Finance

Use Cases

  • Monitor stock prices in real-time via WebSocket and alert on significant moves
  • Check earnings calendar and send weekly earnings preview summaries
  • Track insider trading activity for stocks in your watchlist

Tips

  • Use WebSocket for real-time monitoring instead of polling the REST API
  • The /company-news endpoint is great for building a market news digest skill
  • Combine quote data with the earnings calendar for pre-earnings alerting

Known Issues & Gotchas

  • Free tier is US-market focused — international data may require paid plans
  • WebSocket connection has a limit on simultaneous symbol subscriptions
  • Some alternative data endpoints (patents, lobbying) are premium-only

Frequently Asked Questions

Is Finnhub better than Alpha Vantage for free use?

Yes, significantly. Finnhub's free tier offers 60 calls/minute vs Alpha Vantage's 25/day. Finnhub also includes WebSocket for real-time data, company fundamentals, and news — all free.

Does Finnhub provide WebSocket data for free?

Yes. The free tier includes WebSocket access for real-time US stock trades. This is unusual — most competitors charge for streaming data.

Does it cover international markets?

The free tier covers US markets. International exchanges, forex, and crypto are available but some require paid plans for real-time data. Delayed data is available free for most markets.