Patent by Ouroboros

Patent by Ouroboros is a remote MCP server for inventors, startup founders, patent agents and attorneys, and engineers who need to check whether an idea already appears in the public patent record.

It searches the USPTO Open Data Portal and, when you add a free consumer key, EPO Open Patent Services. Google Patents is used only as a link. Every patent number in a tool result is copied from an office response. The server does not fill in numbers when an office does not answer.

This is not legal advice. It is not a substitute for a registered patent attorney or agent. A result is not an opinion on patentability, infringement, validity, or freedom to operate.

Connect

The MCP address is your deployment origin plus /mcp. Locally that is http://127.0.0.1:8787/mcp.

Sign in when the assistant opens OAuth. Leave the client id and secret empty. The server supports OAuth 2.1 dynamic client registration and PKCE (S256). Do not paste a password or an office API key into the assistant.

Cursor, in ~/.cursor/mcp.json or a project .cursor/mcp.json:

{
  "mcpServers": {
    "patent": {
      "url": "http://127.0.0.1:8787/mcp"
    }
  }
}

Claude Code:

claude mcp add --transport http patent http://127.0.0.1:8787/mcp

ChatGPT, Claude, Gemini, Grok, and any other Streamable HTTP client: add the same URL, choose OAuth, and leave client id and secret blank. Full steps are on /connect.

A new account includes 14 days of search access. After the trial, Pro continues through Stripe Checkout. The amount is shown by Stripe, not in this repository.

server.json is the MCP Registry manifest (io.github.LAHutchins91/patent). Its icon is https://patent-mcp.vercel.app/logo.jpg. Before you publish the registry entry, set remotes[0].url and websiteUrl to the public origin. The file currently uses https://patent-mcp.vercel.app/mcp as the intended Vercel path.

Tools

• search_patents — keywords, claim language, CPC class, assignee, inventor, and dates
• get_patent — abstract, claims, status, family, and citations for one record
• find_patent_citations — documents that cite a patent, and documents that patent cites
• search_prior_art — an idea description in, the closest office records and their Google Patents links out

Citation coverage is the USPTO grant document, USPTO office-action citations, and EPO citation search. The legacy PatentsView citation graph is not available: USPTO paused the PatentsView PatentSearch API when PatentsView moved to the Open Data Portal on 20 March 2026.

Run locally

npm install
cp .env.example .env
npm run dev

The server listens on port 8787. GET /health returns JSON. billingConfigured is true only when STRIPE_SECRET_KEY, STRIPE_PRICE_MONTHLY, and STRIPE_PRICE_YEARLY are all set.

npm test
npm run typecheck

Tests call the public USPTO and EPO hosts. Office payloads that require keys are mocked. With USPTO_API_KEY or EPO consumer credentials in the environment, the live test uses those credentials instead of expecting the unauthenticated response.

Environment

Lawrence needs to supply:

Variable	Purpose
APP_BASE_URL	Public origin used as the OAuth issuer and Stripe return URL
AUTH_SECRET	Signs browser sessions. Required in production
USPTO_API_KEY	Free USPTO Open Data Portal key, sent as X-API-KEY
EPO_CONSUMER_KEY	EPO OPS consumer key
EPO_CONSUMER_SECRET	EPO OPS consumer secret
STRIPE_SECRET_KEY	Existing Stripe secret
STRIPE_PRICE_MONTHLY	Existing monthly price id
STRIPE_PRICE_YEARLY	Existing yearly price id
STRIPE_WEBHOOK_SECRET	Stripe webhook signature secret
STORAGE_BACKEND	memory (default), file, http, or blob
STORAGE_PATH	JSON file used when the backend is file
STORAGE_URL	GET/PUT URL for one JSON document when the backend is http
STORAGE_TOKEN	Optional bearer token for that URL
BLOB_READ_WRITE_TOKEN	Vercel Blob read-write token. Vercel injects this for a linked store. Required when STORAGE_BACKEND=blob
STORAGE_BLOB_PATH	Blob pathname for the account document. Default patent/accounts.json

Do not create Stripe products or prices in this app. Do not commit secrets.

USPTO key

1. Create a USPTO.gov account.
2. Verify and link ID.me. That link is one time.
3. Open Open Data Portal getting started and request an API key.
4. Set USPTO_API_KEY.

Old PatentsView API keys do not work on the Open Data Portal.

EPO key

1. Register at developers.epo.org.
2. Create an app. EPO shows a consumer key and consumer secret.
3. Set EPO_CONSUMER_KEY and EPO_CONSUMER_SECRET.

OPS is free within the EPO fair-use policy. The server sends grant_type=client_credentials to https://ops.epo.org/3.2/auth/accesstoken.

Accounts and storage

Patent tools are stateless searches of public offices. Trial and subscription state, OAuth clients, and tokens live in one JSON document behind AccountStore.

• memory keeps that document in the process. It is the default and is what local tests use. It does not survive a restart or a second serverless instance.
• file writes STORAGE_PATH (default ./data/patent-store.json). Use it for Docker or a long-running Node process.
• http GETs and PUTs the same document at STORAGE_URL. Point it at storage you already run. This server does not create a database.
• blob stores the same document in Vercel Blob at STORAGE_BLOB_PATH (default patent/accounts.json). Set STORAGE_BACKEND=blob on Vercel. The Blob client uses BLOB_READ_WRITE_TOKEN, which Vercel injects when a Blob store is connected. Reads bypass the CDN cache. Writes send ifMatch and retry when another instance updated the document first.

OAuth clients, authorization codes, access tokens, and refresh tokens are fields in that document. The consent screen posts the authorization request with the approval; nothing about the grant is kept in process memory. Expired codes and refresh tokens are removed on each write.

Deploy

Vercel: the Express app is the default export of api/index.ts. vercel.json sends every path to that function and bundles logo.jpg into it, so /logo.jpg is served by the app and repository files such as /package.json are not static assets. Set the environment variables above, including STORAGE_BACKEND=blob. Point the Stripe webhook at https://<your-host>/billing/webhook.

Docker:

docker build -t patent-mcp .
docker run --env-file .env -p 8787:8787 patent-mcp

What was verified

Locally, over Streamable HTTP: tools/list and each of the four tools, OAuth registration with PKCE, trial expiry, Stripe checkout request shape, and webhook signature verification. The USPTO host answered without a key (unauthorized). The EPO token host answered without consumer credentials. No live Stripe charge was made, and the server was not deployed to Vercel from this workspace.