APIDirectory started as a 2022 side project: a crawler, 1,425 public APIs, and a SQLite file. This month we rebuilt it as a proper registry — and before adding anything new, we re-checked every link we had. The results are a small case study in how fast the API economy rots.
16% of the 2022 index is gone
Of the entries we seeded from our 2022 crawl, 227 are dead or unreachable — hard 404s, expired domains, a couple of parked pages wearing a redirect like a trench coat. That's roughly one in six public APIs, gone in under four years. Another 300+ had quietly moved: we adopted their redirect targets as the new canonical links and filed each move as a change event.
| STATUS | ENTRIES |
|---|---|
| alive (reachable or bot-walled) | 1,212 |
| gone (404 / expired / parked) | 227 |
| links adopted after a permanent move | 300+ |
Dead entries stay listed, marked as dead. A registry that quietly deletes its failures isn't a registry; it's a brochure.
What the crawler could actually observe
We then visited every live entry and recorded only what we could verify: 41 published OpenAPI/Swagger specs (parsed into structured endpoint pages), 759 usable descriptions from the sites' own metadata, auth models for 343 APIs (269 api-key, 72 OAuth2), and pricing signals for ~180. Everything else says unknown — on purpose. The gaps are the honest part: 1,096 APIs whose auth model isn't stated anywhere a crawler can see it is itself a finding about the state of API documentation.
The index today
1,440 entries across 52 categories, including a new Artificial Intelligence category that didn't exist — couldn't have existed — in the 2022 data. Every entry carries a registry record (auth, spec, pricing, link health, last crawl), a changelog of observed changes, and a claim flow: owners verify by domain email or DNS record, and the stamp flips to VERIFIED OWNER.
Everything here is queryable: a free JSON API, an MCP server for agents, and the dataset itself. If one of these 1,440 entries is yours — go claim it. It takes five minutes, and it's free.