Federal policy structured data options

What are all our options for APIs, XML downloads, and structured permalinks for US federal policy documents, available from official government websites?

Todo: https://www.govinfo.gov/developers

Statute

Documentation:

• Document Type Definition files - House of Representatives

Individual statute

• StatViewer, unique links to public law pages (PDFs embedded in page) - example: https://uscode.house.gov/statviewer.htm?volume=95&page=788 - House of Representatives - not sure if documented
• Pages at uscode.house.gov have permalinks to individual paragraphs - example: https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title42-section1320b-7&num=0&edition=prelim#substructure-location_d - not sure if documented

Codified (US Code)

• Bulk XML downloads of public law - House of Representatives

Regulation

Individual Federal Register documents

• JSON API - Documents, metadata, search - back to ~1994 - FederalRegister.gov
• Unique links (not sure if documented) - https://www.federalregister.gov/citation/##-FR-##### - FederalRegister.gov - partial info for documents, some back before 1994

Histories of Federal Register document "families"

• RIN data in XML - RegInfo.gov - not sure if documented - example: https://www.reginfo.gov/public/do/eAgendaViewRule?pubId=201210&RIN=0938-AR18&operation=OPERATION_EXPORT_XML (page where that's linked). Resources: XML reports for rules under review + Unified Agendas.

Comments on documents

• Individual document API - Regulations.gov
• Bulk data download - Regulations.gov

Codified (CFR)

• JSON & XML API - Current and past text - back to ~2017 - eCFR.gov

Subregulatory guidance

I don't know of any APIs for this, other than ours, at any agency??