CourtListener MCP Server

Production-ready Model Context Protocol (MCP) server for CourtListener legal data. It exposes legal research tools over MCP (stdio and HTTP), with deployment-ready support for local use, self-hosted remote deployments, hosted Cloudflare Workers OAuth, structured logging, caching, and CI testing.

What This Repository Provides

• MCP server built on @modelcontextprotocol/sdk
• 49 legal research tools backed by CourtListener API v4
• Three deployment contracts: local stdio, self-hosted remote HTTP, and hosted remote OAuth
• Hosted MCP OAuth transport via Cloudflare Workers OAuth Provider
• Worker-owned browser auth handoff for hosted sign-in and approval
• Built-in health checks and metrics endpoints for operations
• Prebuilt MCP client config examples in configs/

Repository Structure

• src/ core server, tool handlers, API integration, worker runtime
• configs/ ready-to-use MCP client configs for local, self-hosted, and hosted clients
• docs/ deployment, testing, and operational documentation
• test/ unit/integration/e2e test suites
• scripts/ deployment helpers, diagnostics, inspector tooling, key management

Quick Start

1. Use the hosted remote endpoint (fastest)

Best for ChatGPT, Claude, Codex, and other remote clients that should not run the server locally:

{
  "mcpServers": {
    "courtlistener": {
      "url": "https://courtlistener-mcp.<subdomain>.workers.dev/mcp",
      "transport": "streamable-http"
    }
  }
}

2. Run locally from a checkout

Best for privacy, local development, and bring-your-own-auth setups. The npm package is not currently published, so the local stdio server should be run from this repository checkout:

• Download ZIP: https://github.com/blakeox/courtlistener-mcp/archive/refs/heads/main.zip
• Download tar.gz: https://github.com/blakeox/courtlistener-mcp/archive/refs/heads/main.tar.gz

git clone https://github.com/blakeox/courtlistener-mcp.git
cd courtlistener-mcp
pnpm install
pnpm build
node dist/index.js --setup

Or run it directly:

node dist/index.js

If you want a local shell command after building:

npm link
courtlistener-mcp --setup

3. Self-host the HTTP runtime from source

git clone https://github.com/blakeox/courtlistener-mcp.git
cd courtlistener-mcp
pnpm install
pnpm build
node dist/http.js

4. Self-host with Docker

cp .env.production .env
docker compose -f docker-compose.prod.yml up -d

Publishing to npm

This repository is configured to publish from .github/workflows/release.yml when you push a version tag such as v1.0.5.

You have two supported auth paths:

1. Repository secret: create an npm publish token and store it as the GitHub Actions secret NPM_TOKEN.
2. Trusted publishing: connect the npm package to this GitHub repository and let npm trust GitHub Actions OIDC, with no token stored in GitHub.

Once one of those is configured, publish with:

git tag v1.0.5
git push origin v1.0.5

Deployment Modes

1. Local mode (stdio)

• Run the MCP server on the same machine as the client
• No hosted auth required
• Best for privacy-sensitive workflows, local development, and bring-your-own-hosting

2. Self-hosted remote mode

• Deploy the HTTP/streamable HTTP runtime on your own infrastructure
• Bring your own auth if you need it (OIDC_*, service token, proxy auth, etc.)
• Best for teams that want remote access without using the hosted CourtListener endpoint

3. Hosted remote mode

• Use the CourtListener Cloudflare Worker as the remote MCP endpoint
• The Worker is the MCP OAuth server and exposes /mcp, /oauth/authorize, /token, /register, and discovery metadata
• The Worker also owns the browser auth handoff routes on the same origin (/auth/start, /auth/callback, /oauth/approve, /oauth/logout)
• Legacy /authorize, /auth/approve, and /auth/logout aliases remain in the runtime for compatibility, but production now publishes the /oauth/* endpoints as canonical
• Keep Logto as the current upstream hosted identity provider if you want a managed OIDC tenant; the Worker-facing contract stays generic OIDC
• Best for ChatGPT, Claude, Codex, and browser-native remote clients

MCP Client Configuration

Prebuilt configs are provided in configs/:

• local-stdio.json
• self-hosted-remote-http.json
• hosted-remote-claude.json
• hosted-oauth-chatgpt.json
• hosted-oauth-codex.json
• claude-desktop.json
• claude-desktop-remote.json
• cursor.json
• continue-dev.json
• vscode-copilot.json
• zed.json
• openai-chatgpt.json
• codex.json

Explicit contract examples:

• configs/local-stdio.json for local stdio
• configs/self-hosted-remote-http.json for self-hosted remote HTTP
• configs/hosted-remote-claude.json for hosted remote use with Claude-style clients
• configs/hosted-oauth-chatgpt.json for hosted remote OAuth with ChatGPT-style clients
• configs/hosted-oauth-codex.json for hosted remote OAuth with Codex-style clients

Legacy filenames are still shipped for compatibility:

• configs/codex.json for direct HTTP transport
• configs/openai-chatgpt.json for hosted OAuth
• configs/claude-desktop-remote.json for hosted remote use
• mcp-config.json for local/bridge variants used in development

Tool Catalog (33)

Search and discovery

• search_opinions
• search_cases
• advanced_search
• smart_search

Cases and opinions

• get_case_details
• get_related_cases
• get_opinion_text
• lookup_citation
• analyze_case_authorities
• analyze_legal_argument
• get_citation_network
• get_comprehensive_case_analysis

Courts and judges

• list_courts
• get_judges
• get_judge
• get_comprehensive_judge_profile

Dockets and RECAP

• get_dockets
• get_docket
• get_docket_entries
• get_recap_documents
• get_recap_document
• get_enhanced_recap_data

Financial and parties

• get_financial_disclosures
• get_financial_disclosure
• get_financial_disclosure_details
• get_parties_and_attorneys

Analytics and monitoring

• get_visualization_data
• get_bulk_data
• get_bankruptcy_data
• manage_alerts
• validate_citations

Oral arguments

• get_oral_arguments
• get_oral_argument

For authoritative tool schema/arguments, use MCP tools/list from your client.

Local Development

Prerequisites

• Node.js 18+
• pnpm
• CourtListener API token (recommended for higher limits)

Install and build

pnpm install
pnpm build

Run

pnpm run mcp

Diagnostics

pnpm run doctor
pnpm run cloudflare:check
pnpm run ci:auth-release-gate

Deployment (Cloudflare Workers)

pnpm install
wrangler secret put COURTLISTENER_API_KEY
wrangler secret put MCP_UI_SESSION_SECRET
wrangler secret put OIDC_ISSUER
wrangler secret put OIDC_AUDIENCE
wrangler secret put MCP_OAUTH_REGISTRATION_TOKEN_SECRET
# Optional shared token auth
wrangler secret put MCP_AUTH_TOKEN
# Optional: set MCP_OAUTH_REGISTRATION_TOKEN_TTL_SECONDS in wrangler vars (defaults to 86400)
# Optional: set MCP_TRUST_CLOUDFLARE_ACCESS_ACKNOWLEDGED=true only if intentionally trusting Cloudflare Access assertions/identity headers
pnpm run cloudflare:check
pnpm run cloudflare:deploy

Endpoints after deploy:

• GET /health
• POST /mcp (primary MCP endpoint)
• GET /sse (legacy SSE compatibility path)
• GET/POST /authorize
• POST /token
• POST /register
• GET /.well-known/oauth-authorization-server
• GET /.well-known/oauth-protected-resource

Web UX Wave (SPA)

• ✅ UX15–UX19 complete: accessibility AA hardening, design-system consolidation, performance UX optimizations, and dark-mode visual parity are now shipped.
• ✅ Validation safety pass: pnpm run test:spa, pnpm run build, and pnpm run typecheck are the required UX-wave release gate.
• Control Center (/app/control-center): live session/auth/key/runtime posture with a guided MCP checklist.
• Protocol explorer: initialize/tool/resource/prompt discovery surfaced directly in Control Center metadata panels.
• Async operator workspace (/app/playground): queue async tool calls (__mcp_async), monitor lifecycle state, deep-link job details, cancel/retry, and fetch results.
• Recovery UX: cross-page recovery status banners plus safe fallback routes back to login, keys, and Control Center.

Auth Model by Deployment Mode

Hosted remote mode: Worker OAuth

Cloudflare OAuth is the primary hosted auth path for remote MCP routes.

• The Worker is the OAuth authorization/resource server for MCP clients

• The Worker serves the minimal auth handoff routes on the same origin

• Remote MCP clients connect directly to the Worker

• OAuth endpoints:

  • GET/POST /authorize
  • POST /token
  • POST /register

• Discovery endpoints:

  • GET /.well-known/oauth-authorization-server
  • GET /.well-known/oauth-protected-resource

• /authorize resolves identity from:

  • Signed UI session (clmcp_ui) when present
  • Cloudflare Access identity headers (cf-access-authenticated-user-id or cf-access-authenticated-user-email) only when MCP_TRUST_CLOUDFLARE_ACCESS_IDENTITY_HEADERS=true
  • MCP_OAUTH_DEV_USER_ID only when MCP_ALLOW_DEV_FALLBACK=true (development fallback only; unsafe outside controlled dev and blocked by startup invariants when NODE_ENV=production)

• If unresolved, /authorize redirects to same-origin /auth/start?return_to=<authorize_url> when Worker-native hosted auth config is present

• POST /api/session/bootstrap remains the Worker-native bearer-to-session bootstrap endpoint for trusted same-origin/session handoff cases

• Same-origin Worker auth handoff:

  • GET /auth/start
  • GET /auth/callback
  • GET/POST /auth/approve
  • GET/POST /auth/logout (GET renders a confirmation form; POST performs the logout)
  • Worker-native hosted auth expects OIDC_ISSUER, MCP_UI_SESSION_SECRET, and a complete upstream OIDC client pair
  • Required upstream pair: MCP_AUTH_OIDC_CLIENT_ID + MCP_AUTH_OIDC_CLIENT_SECRET
  • As an alternative browser-auth boundary, protect /authorize and /auth/approve with Cloudflare Access and enable MCP_TRUST_CLOUDFLARE_ACCESS_IDENTITY_HEADERS=true plus MCP_TRUST_CLOUDFLARE_ACCESS_ACKNOWLEDGED=true; the Worker will bootstrap its own same-origin UI session from trusted Access identity headers before rendering the approval step
  • Partial MCP_AUTH_OIDC_CLIENT_* config fails closed
  • Dynamic client-registration management tokens should use a dedicated MCP_OAUTH_REGISTRATION_TOKEN_SECRET; otherwise they fall back to MCP_UI_SESSION_SECRET or COURTLISTENER_API_KEY
  • MCP_OAUTH_REGISTRATION_TOKEN_TTL_SECONDS defaults to 86400 and should be set explicitly for hosted deployments
  • Browser-session authorization now stops at an explicit same-site approval screen before the Worker completes /authorize
  • Hosted-auth probe responses emit X-Hosted-Auth-* readiness headers with a concrete reason, coarse failure category, stable low-cardinality signal/failure flags, stable flow correlation ID, flow outcome, credential source, and config-error count
  • Route-level rate limit controls:
    • MCP_SESSION_BOOTSTRAP_RATE_LIMIT_MAX
    • MCP_SESSION_BOOTSTRAP_RATE_LIMIT_WINDOW_SECONDS
    • MCP_SESSION_BOOTSTRAP_RATE_LIMIT_BLOCK_SECONDS

• Usage dashboard endpoint:

  • GET /api/usage returns per-user counters (totalRequests, dailyRequests, byRoute, lastSeenAt)

Self-hosted remote mode: bring your own auth

• Optional OIDC bearer validation:
  • OIDC_ISSUER
  • OIDC_AUDIENCE
  • OIDC_JWKS_URL
  • OIDC_REQUIRED_SCOPE
• Optional trusted Cloudflare Access header acceptance:
  • MCP_TRUST_CLOUDFLARE_ACCESS_JWT_ASSERTION=true only when the Worker is deployed behind Cloudflare Access or another edge that strips/spoof-proofs CF-Access-Jwt-Assertion
  • MCP_TRUST_CLOUDFLARE_ACCESS_IDENTITY_HEADERS=true only when /authorize is deployed behind Cloudflare Access or another edge that strips/spoof-proofs cf-access-authenticated-user-*
  • MCP_TRUST_CLOUDFLARE_ACCESS_ACKNOWLEDGED=true is required by deploy checks before either scoped trust flag is allowed
  • Without those explicit per-surface flags, the Worker ignores CF-Access-Jwt-Assertion and cf-access-authenticated-user-*
  • MCP_TRUST_CLOUDFLARE_ACCESS_HEADERS is deprecated and ignored
• Optional service-token path:
  • MCP_AUTH_TOKEN
  • MCP_SERVICE_TOKEN_HEADER

Use this mode when you want the CourtListener MCP runtime but need to keep identity, secrets, and deployment policy inside your own infrastructure.

Local mode: no hosted auth required

• Local stdio clients do not need the hosted OAuth surface
• Users typically provide their own COURTLISTENER_API_KEY
• This is the simplest path for desktop-local MCP clients and development

Removed Legacy UI/Auth Endpoints

The following legacy UI endpoints are disabled in the hard cutover and return 410:

• /api/login*
• /api/logout*
• /api/signup*
• /api/password*
• /api/keys*
• /oauth/consent

Canonical hosted OAuth contract values (paths, grants, response types, scopes, PKCE methods, priority clients) live in src/auth/oauth-contract.ts.

Hosted auth rollout checks

Before promoting a hosted Worker deploy, verify:

• pnpm run cloudflare:check is clean except for intentional deprecation warnings
• https://<worker>/auth/start?continue=1 returns 302
• a real /authorize browser journey reaches /auth/approve before OAuth completion
• DCR management token rotation is independent of UI session rotation by setting MCP_OAUTH_REGISTRATION_TOKEN_SECRET
• any Cloudflare Access trust flags are paired with MCP_TRUST_CLOUDFLARE_ACCESS_ACKNOWLEDGED=true

Runtime and Observability

When metrics are enabled, local server endpoints include:

• GET http://localhost:3001/health
• GET http://localhost:3001/metrics
• GET http://localhost:3001/cache

Useful runtime variables:

• CACHE_ENABLED
• CACHE_TTL
• LOG_LEVEL
• LOG_FORMAT
• METRICS_ENABLED
• METRICS_PORT
• NODE_ENV

Testing

Core tests

pnpm run test:unit
pnpm run test:integration
# install Chromium once before running the default browser-inclusive suite
pnpm exec playwright install chromium
# default repository gate: unit + integration + targeted SPA auth Vitest + auth Playwright
pnpm test
pnpm run coverage
pnpm run coverage:check

MCP protocol and inspector

pnpm run test:mcp
pnpm run ci:test-inspector:enhanced
pnpm run ci:test-inspector:enhanced:extended
pnpm run ci:test-inspector:performance

Release hardening performance gates

pnpm run ci:load-profile-suite -- --light --base-url http://127.0.0.1:3002
pnpm run ci:perf-gate -- baseline.json current.json
pnpm run ci:hardening:soak-leak-checks -- --light --base-url http://127.0.0.1:3002
pnpm run ci:release-readiness-gate -- --light --base-url http://127.0.0.1:3002

CI runs these gates in warn mode for pull requests/non-protected branches, and strict fail mode for main/master/release/* and v* tags.

Optional local GitHub Actions simulation

act -W .github/workflows/ci.yml

Security and Contribution

• Security policy: SECURITY.md
• Contribution guide: CONTRIBUTING.md
• Architecture details: ARCHITECTURE.md

License

MIT. See LICENSE.