API Keys

No key on the direct API

Every request sent directly to /v2 is served at the free Basic tier, whoever sends it. There is no account, no signup, no header to set, and no key to lose or rotate. The paid tiers exist, and they are reached one way only: a RapidAPI subscription, whose requests arrive through RapidAPI's gateway and are served at the subscribed plan's caps. The discovery document states the reachable state as data, not prose. GET /v2 reports:

"capabilities": {
  "timezone_resolution": true,
  "place_lookup": true,
  "api_keys": true
}

api_keys: true means the paid tiers are reachable through the gateway. It does not mean a key is accepted here: no header and no parameter changes the tier of a request sent directly to www.cyclecalcs.com. Every response also names the tier it was actually served at, as caller_tier in /v2/conventions, so what you were granted is always checkable.

Every rate limit and every cap named on API Status and Limits applies to every direct caller, key or no key.

What sending a key does

If you send key= anything, the request is not rejected. key is a recognized parameter, and it is ignored: a RapidAPI key authenticates at RapidAPI's gateway host, in a header, and a key pasted into a CycleCalcs URL proves nothing, so the request is served at the tier of its entrance, which for a direct request is the free Basic tier. Sending it earns a parameter_ignored warning naming exactly that. You are never silently downgraded without disclosure, and a credential never belongs in a URL: URLs are logged, cached and shared in ways headers are not.

What a subscription buys

A paid tier (Pro, Ultra or Mega) buys exactly two things:

• A higher rate limit: a bigger number in the same windows published on API Status and Limits.
• A higher per-request range ceiling: larger row and day caps than the free Basic table, published as range_caps_by_shape on /v2/conventions.

A subscription does not buy different data, an extra endpoint, or a different answer from the one a free caller gets for the same request. Every field, every endpoint and every number is already available to every caller today.

The tier ladder

The free tier is the Basic tier and, inside /v2, its published limits can only ever go up. Three paid tiers, Pro at 5 US dollars a month, Ultra at 9 and Mega at 15, sell through the RapidAPI marketplace; subscribing there is the only signup that exists. Their numbers are on the API overview and in range_caps_by_shape on /v2/conventions. A subscriber's requests arrive through RapidAPI's gateway, which checks their key and forwards their plan; the origin serves that plan's caps and windows, and reports the tier it served as caller_tier. If the RapidAPI listing is not yet visible to you, the free Basic tier is not a fallback, it is the same full API.

Why the direct API has no key

The keyless direct tier is a deliberate choice, not an unfinished feature. Three error codes, INVALID_KEY, REVOKED_KEY and EXPIRED_KEY, remain reserved in the error registry for a direct key channel if one ever ships, precisely so that shipping it would change nothing else about how errors are structured. Until then there is nothing to sign up for and nothing to configure on the free tier: point a request at /v2 and go.