Unofficial MCP server for exploring patents via the EPO Open Patent Services (OPS) API. Not affiliated with the EPO. Covers the full global patent database (EP, US, WO, JP, CN, and more).

This is an exploratory tool — useful for quick searches, reading individual patents, checking legal status, and getting an initial sense of a technology area. It works well in Claude Desktop and other consumer MCP clients, but these environments have limited context windows and are subject to API rate limits, so results for broad queries will be incomplete.

For exhaustive patent landscape analysis, systematic FTO assessments, or large-scale prior art searches, use specialised frameworks designed for parallel retrieval and structured knowledge bases.

1. Register at developers.epo.org for a Consumer Key and Secret (free tier available).

2. Add to your Claude Desktop config (~/Library/Application Support/Claude/claude_desktop_config.json on macOS):

{
  "mcpServers": {
    "ops-patent-search": {
      "command": "npx",
      "args": ["-y", "ops-patent-search"],
      "env": {
        "PATENT_CONSUMER_KEY": "your_consumer_key",
        "PATENT_CONSUMER_SECRET_KEY": "your_consumer_secret"
      }
    }
  }
}

The search_patents tool uses EPO's CQL (Contextual Query Language). Key fields:

ta (title+abstract), ti (title), ab (abstract), pa (applicant), in (inventor), cl (IPC+CPC), ic (IPC), cpc (CPC), pd (publication date), pn (publication number), ct (forward citations).

Operators: AND, OR, NOT (uppercase). Wildcards: * (right truncation, on ta/ti/ab/pa/in only).

ta="CRISPR" AND pd>=2023
pa="Novartis*" AND ta="cancer" AND ic="A61K"
ta="antibody drug conjugate" AND pa="Roche*"
ct="EP3750919"

Full-text fields (claims, desc, ftxt) are unreliable for phrase searches and don't support wildcards. Use ta= for CQL filtering, then search_in_patent_text for keyword analysis within specific patents.

Search for CRISPR patents by the Broad Institute since 2020 and summarise the top 5.

Is EP3750919 currently in force? Check its legal status.

Find prior art on antibody-drug conjugates targeting HER2 by Roche. Search the most relevant result for 'linker' and summarise the key claims.

When installed as a Claude Code plugin, guided workflow skills become available. These provide structured starting points for common patent tasks — but keep in mind this is an exploratory tool, not a substitute for professional patent search platforms.

npm install
npm run build              # Compile TypeScript → dist/
npm test                   # Integration tests (requires PATENT_CONSUMER_KEY and PATENT_CONSUMER_SECRET_KEY in .env)

Scenario tests:

npx tsx integration_tests/run-all.ts

Smoketest (end-to-end eval harness via headless Claude Code):

./smoketest/run.sh                          # all tests
./smoketest/run.sh basic-search             # single test
SMOKETEST_MODEL=sonnet ./smoketest/run.sh   # pick the evaluator model (default: CLI default)

Each smoketest runs a 3-message conversation: execute the task using the MCP tools, verify entities against the database (hallucination check), then collect structured feedback on what worked and what should be improved. Results land in smoketest/results/<timestamp>[_model]/ as .task.txt, .hallucination.txt, and .feedback.txt per test. The evaluator runs from a scratch directory outside the repo so the repo's own .mcp.json is not loaded a second time as a project server.

Three things measure the result, none of them the evaluator's own opinion: ground-truth assertions per scenario (smoketest/grade.py), a separate judge model that scores each report from the tool log and can compare two runs pairwise (smoketest/judge.py), and a findings index that tracks which issues recur across runs (smoketest/findings.py). Two scenarios are hold-outs whose critiques are never collected. The fix protocol, from reproduce-before-fix to marking a finding resolved, is in smoketest/README.md.

Run as Claude Code plugin (local dev):

claude --plugin-dir /path/to/ops-patent-search

.mcp.json is the plugin server manifest: its ${CLAUDE_PLUGIN_ROOT} path is only expanded when the server is loaded as a plugin. Enabling it as a plain project MCP server instead leaves the variable unexpanded and the server exits with Cannot find module '.../${CLAUDE_PLUGIN_ROOT}/dist/index.js'. Use --plugin-dir as above, or register a separate absolute-path server with claude mcp add.

This is a public repository. The following stay local and are enforced by both .gitignore and a pre-commit hook in .githooks/:

.claude-plugin/ is not in this list — it ships with the plugin.

The hook also scans staged content for credential-shaped strings and for client-identifying terms, so scenario prompts and examples stay generic. The term list itself is not in the repo — a curated list of client names would be the disclosure. Put it in .githooks/client-terms.local (gitignored), one regex per line; without that file the term check is inactive and the hook says so. The hook is enabled automatically by npm install; to enable it by hand:

git config core.hooksPath .githooks

A deliberate exception for one commit: ALLOW_SENSITIVE=1 git commit ...

This server communicates only with the EPO OPS API (ops.epo.org) using your credentials. No data is collected or sent to third parties.

MIT