Where the X API documentation actually lives.
Three places. One is the official platform, gated behind a project review and a paid tier. The second is an independent third-party reference, free to read and quick to test against. The third is a long-standing community catalogue of the advanced-search operators — the same operators both surfaces understand.
This page is the index. The annotation below each entry tells you when it is, and is not, the right place to look.
The Index
developer.x.com
The first-party documentation set. Canonical endpoint reference, authentication flows (OAuth 1.0a + 2.0), rate-limit tables, paid-tier capability matrix, and code samples across several languages.
When you already hold a Pro or Enterprise account, or when you need behavior to be authoritative — bug reports, conformance work, compliance review.
docs.twitterapi.io
An independent reference for the TwitterAPI.io API surface — REST endpoints (search, user, followers, tweet, list) and the WebSocket real-time stream. Free to read. An API key is only required to issue real calls.
When you're evaluating without an approved official account, prototyping quickly, or your workload sits below the official paid tiers' floor.
github.com/igorbrigadir/twitter-advanced-search
The most complete public catalogue of advanced-search operators (from:, since:, until:, filter:, near:, lang:, and the long tail of date / engagement / language qualifiers). Maintained by working researchers.
When you're building query strings beyond bare keyword search. Both official and third-party APIs honor the same operator vocabulary, so this reference applies to either side.
Cross-reference
If your account already carries a Pro or Enterprise subscription, the first stop is developer.x.com — first-party guarantees, first-party documentation.
If you have no official account and want a working request before lunch, the first stop is docs.twitterapi.io. The endpoint shapes differ; the use cases — search, user lookup, follower graph, real-time stream — map cleanly across.
When the request itself is the problem — you need since:, from:, filter:replies, or any of the eighty-odd qualifiers Twitter accumulated over a decade — the community operator catalogue is the only reference that documents them in one place.
Notes & Queries
- 01
Where are the official X / Twitter API docs?
developer.x.com is the canonical official documentation. Endpoint reference, authentication flows, rate-limit tables, code samples in multiple languages. Access requires an approved developer account.
- 02
Where are the TwitterAPI.io docs?
docs.twitterapi.io — third-party API reference covering all endpoints we expose (search, user lookup, follower graphs, real-time stream). No login required to read; an API key from /dashboard is needed to make actual calls.
- 03
Do the official docs cover third-party APIs?
No. developer.x.com only documents the official X Developer Platform. Third-party providers — TwitterAPI.io, Apify, Bright Data, Scrapfly, and others — each maintain their own reference at their own domain.
- 04
Which docs should I start with?
If you already have official Pro or Enterprise access, start at developer.x.com for canonical behavior. If not — and you're evaluating — start at docs.twitterapi.io: the API surface is conceptually similar and a working request takes about five minutes from sign-in.
See also
- PILLARX API — an overviewWhat the X API ecosystem actually is and what it can return.
- REF.003How to issue an X API keyTwo real paths to a working credential, plus storage and rotation.
- PRICINGX API pricingPer-call rates and tier comparison.
- REF.004Twitter API rate limitsPer-tier ceilings and practical workarounds.
The reference is finite; the reading is not. Begin with the documentation that matches your access, and the rest will resolve itself.