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.
AuthenticationAPI KeySign up with the provider to obtain credentials.
HTTPSSupportedTraffic is encrypted in transit.
CORSEnabledCallable directly from browser JavaScript.
PricingFreemiumA usable free tier exists, with paid plans for more volume.
FormatsJSONResponses can be requested as JSON.
GreatAPIs Score
Score75
Authentication15/25API key required
Pricing17/20Freemium tier available
Docs14/20Documentation URL provided
Formats9/15Single response format
Freshness20/20Verified within 6 months
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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
- 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.
Stored keyNo key stored
Your key is stored only in this browser (localStorage) and sent directly to the API — never to greatapis.