The Stacks project

Overview of the API

It is possible to query the Stacks project yourself through an API. This way you don"t have to scrape the information from the HTML pages and it is consistent with our goal that the content of the Stacks project be as open as possible.

We can think of several applications:

  • developing smartphone apps / mobile versions of the Stacks website;
  • extracting meta-information about the Stacks project;
  • ... (please make suggestions!)

If you intend to use this API, please contact us at This interface is not stable, please get in touch to discuss this with us.

The current API has less features than the previous one. If this causes problems, please get in touch. We intend to improve it over time.


To get the structure of the Stacks project, one can ask for a JSON file at‹tag›/structure

example: 0ELT

For now you need to treat the 9 different parts in the Stacks project separately.


There are two different possibilities to get the statement of a tag:

  1. HTML, without proof:‹tag›/content/statement

    example: HTML statement for tag 015I

  2. HTML, with proof:‹tag›/content/full

    example: HTML statement (with proof) for tag 015I

Because the mathematics is parsed by MathJax, the HTML output contains raw LaTeX math. It is up to the user to handle this (e.g. either use MathJax, or some image generation tool).

Previously it was also possible to get the TeX code of a tag. This is not possible at the moment, but if necessary we can implement this again.