Blockchain — entry 011 of 11
Watchdata
WatchData operates hosted JSON-RPC nodes across Ethereum, Polygon, BNB Smart Chain, and other networks, plus higher-level "Powered API" endpoints for token balances, transfer history, and block-timestamp lookups that would otherwise require custom indexing. Every call needs an api_key issued from the dashboard after a free signup, with a 100-million-unit free monthly allowance before paid plans apply. Responses are plain JSON-RPC.
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
Score61
Authentication15/25API key required
Pricing17/20Freemium tier available
Docs0/20No docs or spec available
Formats9/15Single response format
Freshness20/20Verified within 6 months
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<a href="https://greatapis.com/api/watchdata/"><img src="https://greatapis.com/badge/watchdata.svg" alt="Scored 61 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.