Science & Math — entry 016 of 28

Newton

Verified Jul 2026

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.

Newton is a single keyless GET endpoint shaped as newton.vercel.app/api/v2/:operation/:expression — the math operation (simplify, factor, derive, integrate, zeroes, and more) and a URL-encoded expression both live in the path, and the response is a small JSON object echoing the operation, expression, and result.

mathcalculatoralgebrakeylessserverless
AuthenticationNone requiredCall it straight away — no key, no signup.
HTTPSSupportedTraffic is encrypted in transit.
CORSEnabledCallable directly from browser JavaScript.
PricingFreeNo paid tier — free for the documented use case.
FormatsJSONResponses can be requested as JSON.

GreatAPIs Score

Score88out of 100
Authentication25/25No authentication required
Pricing20/20Free to use
Docs14/20Documentation URL provided
Formats9/15Single response format
Freshness20/20Verified within 6 months

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Scored 88 on greatapis.com
<a href="https://greatapis.com/api/newton/"><img src="https://greatapis.com/badge/newton.svg" alt="Scored 88 on greatapis.com"></a>

Auth quickstart

  1. No account or key required — call any operation as a plain GET; there's nothing to register or attach.
  2. The expression must be URL-encoded in the path, not passed as a query string — ^ becomes %5E, + becomes %2B, and a literal / (fraction division) must be percent-encoded as %2F. Confirmed live this run: .../simplify/1%2F2 returns "result":"1/2", while the unencoded .../simplify/1/2 silently 404s (the host treats the second / as an extra path segment, not part of the expression).
Stored keyNo key stored

Your key is stored only in this browser (localStorage) and sent directly to the API — never to greatapis.

Simplify an algebraic expression

GEThttps://newton.vercel.app/api/v2/simplify/2%5E2%2B2(2)

200 application/json; charset=utf-8

{"operation":"simplify","expression":"2^2+2(2)","result":"8"}

Captured byte-for-byte from this run's live probe.

Developer reference

Base URLhttps://newton.vercel.app/api/v2

Gotchas & limits

  • An unknown operation doesn't 404 — .../bogusop/2%2B2 returns HTTP 400 with a JSON body {"error":"Unknown operation"}, confirmed live this run. Check the status code, not just whether a body came back.
  • A literal, unencoded / inside the expression breaks routing rather than erroring cleanly: .../simplify/1/2 returns Vercel's generic Next.js 404 HTML page (not Newton's own JSON error shape), while the percent-encoded .../simplify/1%2F2 succeeds with "result":"1/2" — confirmed live this run.
  • There is no discoverable list-of-operations route: both the bare /api/v2 root and an operation with no expression (.../simplify alone) return the same generic 404 page as a bogus path, confirmed live this run. The ~15 supported operations are documented only in the project's own README, not in a machine-readable endpoint.
  • CORS is wide open — a live probe with Origin: https://example.com returns Access-Control-Allow-Origin: * unconditionally, confirmed this run, so the endpoint can be called directly from browser JS.