Openlaw MCP

A free, open-source Model Context Protocol (MCP) server that exposes UK and EUopen law— judgments, statutes, regulations, regulator notices — to host LLMs such as Claude, ChatGPT, and Cursor.

Where general-purpose chatbots invent citations,openlaw-mcpfetches the real text from official open-data sources (The National Archives' Find Case Law, legislation.gov.uk, EUR-Lex, HUDOC, ICO, HMRC) and returns it with full provenance and licence attribution. Every tool result is cite-back ready.
- Free hosted endpoint— fastest path, zero install, point your client at our URL.
- Local stdio— runs inside Claude Desktop / Cursor / Claude Code vianpx.
- Self-hosted HTTP—node dist/http.jsafternpm run build.

A community endpoint is available athttps://openlawmcp.legalaispace.com/v1/mcp. No API key, no signup, no rate-limit gate beyond the per-IP throttle. Best-effort uptime — no SLA, may be rate-limited, throttled, or migrated as load grows.

codex mcp add openlaw --url https://openlawmcp.legalaispace.com/v1/mcp

claude mcp add --transport http openlaw https://openlawmcp.legalaispace.com/v1/mcp

{ "mcpServers": { "openlaw": { "url": "https://openlawmcp.legalaispace.com/v1/mcp" } } }

Health check:curl https://openlawmcp.legalaispace.com/healthzshould return{"status":"ok","service":"openlaw-mcp"}.

2. Claude Desktop / Cursor / Claude Code (stdio)

Runs locally — no dependency on the hosted endpoint.

{ "mcpServers": { "openlaw": { "command": "npx", "args": ["-y", "@legalaispace/openlaw-mcp"] } } }

npm install npm run build node dist/http.js # listens on PORT (default 3000), mount /v1/mcp

Behind a reverse proxy (nginx, Cloudflare, etc.), setTRUST_PROXYto the number of proxy hops soexpress-rate-limitkeys by the real client IP — seeConfiguration.

- "Quote paragraph 1 ofR (on the application of Miller) v The Prime Minister[2019] UKSC 41 verbatim, with the Find Case Law URL."
- "Find UK Supreme Court judgments from 2024 onwards that consider Article 8 of the ECHR. Return neutral citations with Find Case Law links and a one-line summary of each."
- "InUber BV v Aslam[2021] UKSC 5, find every paragraph that mentions the word 'control' and quote each one in full."
- "List judgments published on Find Case Law that citePepper v Hart[1992] UKHL 3. Return neutral citations and links — no treatment classification needed."
- "Search Find Case Law for First-tier Tribunal (Tax Chamber) decisions on IR35 / off-payroll working handed down in 2023, and return the first 10 hits."

Regulator material (search_fca_handbook,fetch_fca_notice,search_ico_guidance,fetch_hmrc_manual)

- "Give me the official handbook.fca.org.uk deep link for SYSC 4.1.1R."
- "Resolve these FCA rule references into deep links: SYSC 6.1.1R, COBS 9.2.1R, CASS 7.13.3R."
- "Find recent ICO enforcement actions (monetary penalty notices and enforcement notices) issued in 2025 — return the title, date, and source URL for each."
- "From the HMRC Business Income Manual, give me the section on the badges of trade (BIM20205). Return the bodyText and the gov.uk URL."
- "From the HMRC Employment Status Manual (ESM), summarise the contents page (just the navigation tree, not the bodies)."

- "Fetch CELEX 32016R0679 (the GDPR) and return Article 5 in full, with the EUR-Lex source URL."
- "Fetch CELEX 32024R1689 (the EU AI Act) and tell me which articles deal with prohibited AI practices."

- "Pull the full English text of the ECHR judgment inBărbulescu v Romania(Application 61496/08) and quote the operative paragraphs."
- "Search HUDOC for Grand Chamber judgments where the United Kingdom was the respondent state between 2020 and 2024."

- "Format the following bundle of UK cases in OSCOLA, one per line:Donoghue v Stevenson[1932] AC 562;Pepper v Hart[1992] UKHL 3;R (Miller) v The Prime Minister[2019] UKSC 41."
- "Convert this sloppy reference into OSCOLA and produce a working Find Case Law URL: 'Uber BV v Aslam, 2021 Supreme Court, UKSC 5'."

When MCP shines (and when it doesn't)

- Strongest payoff:"verbatim text of section X" prompts, point-in-time statute lookups, FCA Handbook deep-link resolution, and any request that needscurrentin-force wording or a recent ICO/HMRC publication. Generic web search either guesses or gets blocked by upstream JS challenges (notably legislation.gov.uk's AWS WAF); the MCP server is allow-listed and returns parsed, cite-ready XML.
- Marginal payoff:quoting a famous paragraph from a landmark judgment, or formatting a textbook citation. The host LLM often gets these from training data alone — MCP still adds provenance and reduces hallucination risk, but the wording would have been correct anyway.
- No payoff:purely conceptual questions ("explain the difference between the FCA and the PRA"). These should be answered without calling any tool; if your host LLM fires MCP tools here, treat it as an over-eager router rather than a useful grounding.

Clients that support MCP resources can also read:

How tools and resources work technically

- a source client (src/sources/*.ts) that performs HTTP fetches via sharedFetcher, or
- a local computation path (FCA link resolvers, citation formatter) with no network call.

- search_caselaw: receives search filters (query, optionalcourt/date/page), fetches TNA Atom feed, parses entries into normalized judgment refs, returns paged hits + provenance.
- fetch_judgment: receives neutral citation or TNA URI, resolves to/data.xml, parses Akoma Ntoso intometa,header,paragraphs, returns full structured judgment + provenance.
- grep_judgment: same fetch/parsing asfetch_judgment, then runs JS regex across parsed paragraph text, returns match list/snippets + provenance.
- lookup_statute: receives legislation type/year/number/section (+ optionalas_of), fetches CLML section XML, extracts title/text/version metadata/extent/prospective flags, returns normalized section document + provenance.
- legislation_toc: receives legislation type/year/number, fetches CLML contents XML, flattens parts/chapters/sections into entries, returns TOC + provenance.
- fetch_eurlex: receives CELEX, validates/normalizes it, blocks out-of-scope national sectors (7/8), fetches from Cellar with content negotiation (XHTML then HTML fallback), returns raw body + detected media type + provenance.
- fetch_hudoc: receives eitheritemidor search query. Search path fetches JSON results and suppresses out-of-policy records. Item path fetches metadata then body only when language/doctype/translation guard passes. Returns records/body + provenance + suppression note when applicable.
- search_fca_handbook: receives parsed handbook reference inputs, computes deterministic deep link locally, returns metadata + local provenance (urn:openlaw-mcp:local) without FCA content fetch.
- fetch_fca_notice: receives known notice slug (+ category), computes deterministic FCA deep link locally, returns metadata + local provenance; listing path intentionally errors (scraping disabled).
- search_ico_guidance: receives optional type/sector/date/page filters, posts to ICO/api/search, shapes response into enforcement list items, returns paged results + provenance.
- fetch_hmrc_manual: receives manual slug (+ optional section slug), fetches GOV.UK Content API JSON, returns either manual navigation tree or section body (bodyHtml+bodyText) + provenance.
- format_oscola: receives citation text + formatting options, parses and formats locally (OSCOLA/Bluebook), optionally emits derived Find Case Law URL for neutral citations, returns formatted output + local provenance.
- citator_lite: receives neutral citation, searches TNA Atom with quoted query to find citing judgments, trims to limit, returns citing list + disclaimer + provenance.

- judgment://.../header: MCP resource vars (slug,year,number) are validated/parsed, server fetches TNA judgment XML once, extracts plain-text header, returnstext/plain.
- judgment://.../index: same fetch path, maps parsed paragraphs to{ eId, num, preview }, returnsapplication/json.
- judgment://.../para/{eId}: same fetch path, selects one paragraph by exact Akoma NtosoeId, returnstext/plain([num] textwhennumexists).
- statute://.../section/{section}: validates resource vars, fetches legislation.gov.uk section XML via legislation client, returns parsed section document JSON.

Every tool response carries aprovenanceblock:

{ "data": { }, "provenance": { "source": "Find Case Law", "source_url": "https://caselaw.nationalarchives.gov.uk/uksc/2024/12/data.xml", "fetched_at": "2026-05-12T12:00:00Z", "content_hash": "sha256-...", "cache_hit": false, "licence": "Open Justice Licence v2.0", "licence_url": "https://caselaw.nationalarchives.gov.uk/open-justice-licence", "attribution": "Contains information licensed under the Open Justice — Licence v2.0" }, "learn_more": "https://legalaispace.com" }

If you redistribute the content downstream, preserve the attribution.

- No BAILII.BAILII's terms prohibit programmatic re-use; the client blocks all outbound requests to it.
- No FCA scraping or full text.FCA Handbook and Notices are link-only / metadata-only by design. Known slugs and references are converted into deep links; the server does not enumerate FCA notices or fetch FCA page/PDF bodies without written permission.
- HUDOC scope.Only English/French Court-authored judgments. Third-party translations are excluded.
- Find Case Law coverageis E&W courts and tribunals from 2001 onwards. Older judgments are out of scope.
- EUR-Lex Member State legislationreached via N-Lex is excluded; only EU-authored content is fetched.
- legislation.gov.uk WAF.www.legislation.gov.ukis fronted by an AWS WAF that issues a JavaScript challenge (HTTP 202 Acceptedwithx-amzn-waf-action: challengeand an empty body) to clients whose IPs it considers suspicious — typically datacenter egress. From a residential network or an allow-listed deployment the API serves XML normally. Affected calls (lookup_statute,legislation_toc) surface a clear error and retry with backoff; we do not bypass the challenge by fingerprint-spoofing.
- Caselaw is not training data.openlaw-mcpfetches on demand for individual user queries; it does not maintain a persistent cross-user index of fetched content.

lookup_statute/legislation_tocfail with an AWS WAF challenge

The error you see in your host LLM will read something like:

upstream responded with an AWS WAF JavaScript challenge (HTTP 202) on every attempt

www.legislation.gov.ukis fronted by an AWS WAF that issues a JavaScript challenge to clients whose IPs it considers suspicious — typically datacenter egress, some VPNs, and an evolving list of residential prefixes. The server detects the challenge (HTTP 202,x-amzn-waf-action: challenge, empty body) and surfaces a structured error rather than spoof fingerprints to bypass it. SeeLimitationsfor the design rationale.

- Run from a residential or allow-listed network, or point your host LLM at thefree hosted endpoint, which runs from an allow-listed IP.
- The legislation tools (lookup_statute,legislation_toc) are the only tools affected by the legislation.gov.uk WAF. Caselaw (search_caselaw,fetch_judgment,grep_judgment), ICO, HMRC, EUR-Lex, HUDOC, FCA Handbook, and OSCOLA formatting all use independent upstreams and continue to work.
- Quick sanity check from your shell:

curl -s -o /dev/null -w "%{http_code}\n" https://www.legislation.gov.uk/ukpga/2010/23/section/1/data.xml

- Confirmnode --versionis>= 22(engines.nodeinpackage.json). On Windows, install Node vianvm-windowsorfnm; on Linux, prefer your distribution's Node 22+ package orVolta.
- First-runnpxdownloads the package; subsequent runs are cached. If your host LLM kills the spawn before the download completes, runnpm install -g @legalaispace/openlaw-mcponce and switch the config to{ "command": "openlaw-mcp" }.

Cached responses live in~/.cache/openlaw-mcp/http-cache.sqlite(override withOPENLAW_CACHE_DIR; disable withOPENLAW_DISABLE_CACHE=1). Delete the file to force a fresh fetch from upstreams. SeeCachefor the multi-tenant guidance.

npm install npm run dev:stdio # run the stdio server locally npm run dev:http # run the Streamable HTTP server with watch npm test # unit tests, MCP protocol tests, and the ICO fixture test npm run lint && npm run typecheck npm run build npm pack --dry-run # verify npm package contents; runs release gates

Development assisted by AI andDaman Kaur.

FCA materials arelink-only / metadata-only. The server does not fetch FCA Handbook or notice body text, and notice listing is disabled unless FCA grants written permission for automated access. Users are pointed to the FCA's own site for authoritative content. SeeATTRIBUTIONS.mdfor the legal posture.↩↩2

AI incident detection, classification, and regulatory reporting — covers EU AI Act Article 62, NIST AI RMF, and OECD frameworks