Newton vs USGS Earthquake Hazards Program

Newton is a keyless calculator API deployed as a Vercel serverless function: the operation (simplify, factor, derive, integrate, and more) and expression are both encoded directly in the URL path, and it answers with a small JSON object containing the result. It's a solo open-source project (aunyks/newton-api) rather than a commercial service, so there's no pricing tier or rate limit to opt into.

The USGS Earthquake Hazards Program's FDSNWS Event Web Service is a keyless REST API for querying the agency's global earthquake catalog by region, time window, magnitude, or depth, returning real-time and historical seismic event data. Requests default to QuakeML XML but can also return GeoJSON, CSV, or KML via a format parameter, and the whole service is free and unauthenticated, run directly by the federal government.