Finance — entry 002 of 47
Aletheia
Aletheia serves stock, bond, and cryptocurrency market data alongside company fundamentals — P/E ratio, EPS, earnings dates, quarterly growth, and insider-ownership percentage — over a single JSON REST API that keeps older endpoint versions live behind an Accept-Version header. Every call needs a free API key, with 5,000 requests/month included and higher volume available by custom quote rather than a published paid tier. It's also distributed as an official Microsoft Power Automate/Power Apps connector, a notable third-party integration beyond its own REST docs.
GreatAPIs Score
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<a href="https://greatapis.com/api/aletheia/"><img src="https://greatapis.com/badge/aletheia.svg" alt="Scored 75 on greatapis.com"></a>Auth quickstart
- Get a key at the provider
- 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
5,000 free API calls/month included on all accounts; additional usage available only via a custom quote