Open Data — entry 001 of 44
18F
18F's API-All-the-X is a community-maintained library of guidance, checklists, and primers for US federal agencies building public APIs, covering agency strategy, procurement, security, and release practices. Originally published as a GitHub Pages site, the project's content now lives directly in its GitHub repository's /pages folder after the old custom-domain site stopped resolving (GitHub Pages returns "site not found"). It isn't a callable API itself but a foundational reference many federal API teams still cite.
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.
FormatsMarkdownResponses can be requested as Markdown.
GreatAPIs Score
Score74
Authentication25/25No authentication required
Pricing20/20Free to use
Docs0/20No docs or spec available
Formats9/15Single response format
Freshness20/20Verified within 6 months
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<a href="https://greatapis.com/api/18f/"><img src="https://greatapis.com/badge/18f.svg" alt="Scored 74 on greatapis.com"></a>Auth quickstart
- No key needed — call it now.
Stored keyNo key stored
Your key is stored only in this browser (localStorage) and sent directly to the API — never to greatapis.