X API reference

Eight things we had to establish before writing any code

Everything here was checked against X’s own documentation on 2026-09-07, which matters more than usual: the tiers most articles still describe stopped accepting new signups in February 2026, and the pricing model that replaced them works differently enough to change how a product is built.

Why these pages exist

Costing out a bookmarks product means answering a short list of questions X does not answer in one place: what a read is billed as, how often you can afford to run, what the rate limits really constrain, and what you are obliged to do with content once you have stored it. We had to answer them to decide whether the product was viable at a consumer price, so the working is written up here rather than left in a private document.

One structural change drives most of it. On 6 February 2026 X closed its Free, Basic and Pro tiers to new signups and moved to prepaid credits spent per resource returned. Almost everything published before then — and a good deal published since — describes a system that no longer exists. That is why each page below carries a verification date and a link to its primary source on docs.x.com: X flags prices and caps as subject to change, and a dated page is honest about the possibility of being out of date.

The numberValueWhere it comes up
Posts: Read$0.005 per post object returnedPost read — and every cost estimate downstream of it
Owned Read$0.001, conditionalOwned read — the condition excludes multi-tenant products
Deduplication window24-hour UTC dayResource deduplication — sets the sync schedule
Bookmarks rate limit180 requests / 15 min, per user, no per-app limitBookmarks endpoint — why capacity is not the bottleneck
Monthly cap3,000,000 post reads per billing cyclePay-per-use — the point at which Enterprise starts
max_results1 to 100, default 10Pagination — page size is the cost unit
Every figure in the table is repeated in context, with its source, on the page named beside it.

Where this leads

If you are here to work out what a bookmarks tool costs to run, the cost calculator applies these rates to a library size in the browser. If you are here because you have bookmarks you want out of X, the export destination pages cover the file and what to do with it.