How it works
GET /v1/lookup?url= turns a public link into the one endpoint that serves it. Each endpoint declares URL templates such as github.com/{owner}/{repo}, and the API matches your link against them with plain string rules, no guessing. This page runs the same rules against the current 65 templates for 33 sites, so you can see the endpoint, its credit price, the parameters pulled out of the URL and a curl to try it, before you spend a credit. See URL lookup for the response format.
The matching rules: the scheme must be http or https, the host is lower-cased and a leading www., m. or mobile. is dropped, a trailing slash and the #fragment are ignored, and extra query parameters are ignored. When several templates on one host fit, the one with more fixed segments wins (github.com/orgs/{org} beats github.com/{owner}/{repo}). The values it extracts must also pass the endpoint's own parameter rules, otherwise the URL does not resolve. A link that matches nothing gets a free 422 UNSUPPORTED_URL. Your link is matched in this page only; it is never fetched or sent anywhere.