GitHub - 2fd/graphdoc: Static page generator for documenting GraphQL Schema · GitHub and GitHub - brettchalupa/graphql-docs: Easily generate beautiful documentation from your GraphQL schema. · GitHub are the two that crop up easiest from a Google search. I just investigated using graphdoc and it was pretty easy to setup, these are the basic steps:

npm install -g @2fd/graphdoc
mix absinthe.schema.json --schema MySchema --pretty path/to/schema.json
graphdoc -s path/to/schema.json -o doc/schema

Although instead of actually using absinthe.schema.json I grabbed the same schema that Graphiql downloads

apiDoc supports Elixir comment syntax:

@apidoc """
@api {get} /user/:id Request User information
@apiName GetUser
@apiGroup User

@apiParam {Number} id Users unique ID.

@apiSuccess {String} firstname Firstname of the User.
@apiSuccess {String} lastname  Lastname of the User.
"""
def get_user(conn, %{"id" => id} = params) do
  # do something here
end

But you need Node.js to generate it:

$ npm install apidoc -g
$ apidoc -i lib/ -o doc/

I use phoenix_swagger to generate an API spec from the code, then use bureaucrat to merge example API request/responses with the swagger into markdown files. Compile the markdown to HTML with a static site generator and copy to the priv/static dir of the Phoenix app.

Now the app serves its own docs that are always up to date and have tested examples. There’s a swagger-ui for interactive requests.