Every record goes through the same steps. This page explains where the information on a catalog page comes from, and which parts are verified and which are not.
Each record starts from the provider's own documentation. Whether an API is official or a community-run wrapper is recorded separately, because that distinction changes what you can expect about its longevity and we do not hide it. Documentation, pricing, terms, and privacy pages are stored as separate links so any claim can be traced back to its source.
Authentication method, what the free tier actually covers, and rate limits are read from the documentation. We do not guess here: if a provider does not publish a limit, the field stays marked as not specified. The word "free" on a marketing page and the real quota in the developer docs are frequently not the same thing, and surfacing that gap is much of the catalog's value.
Where an API supports it, a real endpoint is called and the request, the response, and the test date are attached to the record. You can run the same call yourself in the browser through Test Lab. A single successful test is not an uptime guarantee — it only shows that the endpoint responded as expected on that date.
For a record to count as indexable it needs a sufficient summary, use cases, and verification notes in both languages, a working example, and a review by a human. Records that do not meet all of these stay in the catalog but are not indexed by search engines. When a provider changes its terms the record is reviewed again and the last-checked date is updated.
The catalog is built for developers who need to answer one question before integrating anything: which source is right for this job, and is it genuinely free? Someone building a side project cares about keyless options they can start with in minutes; someone building a production system cares about rate limits, the authentication model, and the terms of use. The guides on the blog complete that picture by working through specific domains end to end — weather, payments, geocoding, open data.