Uk Legislation MCP Server

@cyanheads/uk-legislation-mcp-server Search and read UK legislation at any date, resolve citations, list amendments, track changes via MCP. STDIO or Streamable HTTP. 6 Tools • 1 Resource

Public Hosted Server: https://uk-legislation.caseyjhand.com/mcp

Overview

The UK statute book from legislation.gov.uk: primary, secondary, and EU-origin legislation for the UK, England, Scotland, Wales, and Northern Ireland. Resolve citations, search by text or title, read any provision as it stands today, as enacted, or on a past date, and track amendments. No API key required.

Tools

Resources

The skill is served over MCP through the Agent Skills extension (io.modelcontextprotocol/skills, skill://{+path} template) and ships in skills/ in the npm package, the Docker image, and the .mcpb bundle. The tools do not depend on it.

Capability reference

uklaw_search_legislation tool

• text (full text: AND/OR, "quoted phrases", stemming) and/or title (every word must occur), or neither to list by type and year; limit 1–50 (default 20) with page
• Filters: types (codes such as ukpga, uksi, eur, or the groups all, primary, secondary, eu-origin, draft; default all, which excludes drafts), year or year_from / year_to (1267–2100), extent (england, wales, scotland, ni) with extent_match (applicable or exact), and as_of (YYYY-MM-DD); extent and as_of cannot be combined
• Each result carries the item path to pass to uklaw_get_document; has_more flags another page, and title searches and listings add facets (type counts and the newest 25 years)

uklaw_get_document tool

• item is a full path (ukpga/2018/12, uksi/2019/419, eur/2016/679, regnal ukpga/Eliz2/3-4/19) or a legislation.gov.uk URI; provision a path (section/45/2/f, schedule/2/paragraph/3) or shorthand (s. 45(2)(f), Sch. 2 para. 3); version current (default), enacted (or made, adopted, created), or a YYYY-MM-DD date; language en or cy
• kind is full (Markdown text with its annotations), outline (provision paths to read next, 100 per call from outline_offset), or pdf_only (links.pdf); text over 20,000 characters, or an item with more than 25 leaf provisions, comes back as an outline (a provision with no smaller provisions to list is returned whole up to 40,000 characters and cut past that, with a notice linking the full text), and match_text lists an item's provisions that contain a term
• editorial (document_status, outstanding_effects, caveat) and unapplied_effects (the first 20, at item or provision level; a provision read also lists the effects on its enclosing provisions and, on full text, the provisions inside it, and says when it could not check them) show how far the revised text can be relied on; version.available lists the versions to pass as version

uklaw_get_amendments tool

• item full or partial (uksi, ukpga/2018); direction affected (default: changes made to it) or affecting (changes it makes); filters counterpart (the other item, full or partial), status (all, unapplied, applied; default all), and provision (needs a full item; scans up to 1,500 effects per call)
• limit 1–100 (default 20), continued with next_cursor; each effect names both sides with their provisions, in_force dates, applied / outstanding, and notes; total counts effects before the provision filter, and scan reports its coverage
• Pre-1963 Acts are queried by calendar year (ukpga/1925/20) and drafts are not indexed: both fail as regnal_item / draft_item, with the route to take instead

uklaw_track_changes tool

• start_date (required) and end_date (defaults to start_date), a window of at most 31 days; filters content_type (legislation, changes, draft, associated-documents), direction (with changes only), category (primary, secondary, eu-origin; with legislation or associated-documents only), item, new_only, and event (published, withdrawn)
• limit 1–80 (default 40), continued with next_cursor; mode is day_walk (days newest first, up to 4 upstream requests per call) or item_log (a full item path reads that item's own log and reports read_back_to)
• A changes event carries no effect detail: uklaw_get_amendments on its item has it

uklaw_lookup_citation tool

• One citation of up to 300 characters: a numbered citation, a short title, or a legislation.gov.uk URI, optionally with a provision (forms below)
• Returns the canonical item path, plus provision_found for a cited provision, checked against the current version; a miss or an ambiguous title is found: false with guidance or up to 20 candidates, not an error

Any form can end with a provision (s. 45(2)(f), section 45, reg. 5, art. 28(3), r. 7, r. 3.4, Sch. 2 para. 3, Pt 3) or start with one followed by "of" or "of the": section 45 of the Data Protection Act 2018. uklaw_list_reference topic citation_formats returns the same list.

uklaw_list_reference tool

• topic: types, type_groups, extents, versions, document_status, annotation_types, effects, provision_paths, citation_formats, publication_log, coverage, or attribution
• Offline, with no request to legislation.gov.uk; each entry is a key, label, description, and optional details

skill://uk-legislation-guide/SKILL.md resource

• Markdown with YAML frontmatter: scope, identifier sources, the gates for in-force status, revised-text lag, container effects, dated reads, and date semantics, and workflows for commencement, point-in-time text, amendment history, and changes since a date
• Listed in resources/list; the skill://{+path} template reads any file under it

Features

Built on @cyanheads/mcp-ts-core: stdio and Streamable HTTP transports, pluggable auth (none / jwt / oauth), swappable storage (in-memory, filesystem, Supabase, Cloudflare KV/R2/D1), structured logging with optional OpenTelemetry tracing.

legislation.gov.uk-specific:

• Keyless client for legislation.gov.uk's API: CLML XML for documents, Atom feeds for search, effects, and the Publication Log
• Follows legislation.gov.uk's fair use policy: an identifying User-Agent on every request, one process-wide queue that spaces request starts (1 second apart by default) and adopts a longer robots.txt crawl delay set for this server, up to 60 seconds, and at most 4 upstream requests per tool call within a 45-second deadline
• Process-wide response cache, with lifetimes taken from upstream max-age (capped at one hour) and If-Modified-Since revalidation
• Citation shorthand (s. 45(2)(f), reg. 5, Sch. 2 para. 3) normalized to provision paths; pre-1963 regnal paths and Welsh-language text (language: "cy") supported
• PDF-only items are linked, never fetched, as legislation.gov.uk's robots.txt requires

Agent-friendly output:

• Every document read returns its editorial status with the text (`editoria