Content types

13 types, assigned at index time from page structure and markup rather than inferred from the URL — so the filter does what it claims.

Documentation

Official product, API and library documentation — reference material maintained by whoever built the thing.

Source files, repository content and code-bearing pages.

Papers, preprints and scholarly writing.

Reported news articles with a publication date and an identifiable outlet.

Long-form editorial writing that is not news reporting.

Encyclopedic and reference material — definitions, tables, standards.

Question-and-answer pages: one problem, one or more proposed solutions.

Threaded discussion: mailing lists, message boards, community threads.

Procedural content: step-by-step instructions for accomplishing a task.

Product and service pages, including pricing and specifications.

Explicitly argumentative writing: columns, editorials, position pieces.

Pages whose primary content is video, indexed via their text metadata and transcripts.

Standalone documents: PDFs, reports, filings and papers published as files.

10,000 free requests a month. The live vocabulary is served by /describe, so an agent can read it rather than hardcoding it.