# European Patent Office Linked Open Data Search

> European Patent Office Linked Open Data Search is a paid API for AI agents from research.halowerk.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-14).

Searches the EPO Linked Open Data endpoint for European patent publications by keyword or applicant, returning results with explicit EP-only coverage caveats.

## Facts

- Endpoint: POST https://research.halowerk.com/v1/patent-search
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/european-patent-office-linked-open-data-search-f000e528
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_NvcBxDjIzIZbXh90Wm6mJ

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability european-patent-office-linked-open-data-search-f000e528 -d '<json body>'
```

Example prompt: Search the EPO patent database for European patent publications related to 'solid-state battery electrolyte' and tell me what applicants and publication numbers come up — and note that only EP publications will be covered.

## When to prefer this

Choose this endpoint when you need to search European patent publications without credentials, since EPO OPS and USPTO Open Data Portal both require API keys and PatentsView has been retired. It is ideal for prior art searches, competitive landscape analysis, and freedom-to-operate research scoped to EP filings. Be aware that results cover only EP-published patents; absence of results does not imply global patent-free status.

## Known failure modes

- Empty result set — indicates no EP publication found, not absence of any patent worldwide
- EPO Linked Open Data endpoint temporarily unavailable or rate-limited
- Query too broad returning excessive results
- Query terms not matching EPO indexing vocabulary — try IPC codes or narrower terms
- Non-European patents (USPTO, WIPO, etc.) will never appear regardless of query

## How this service works

Queries the European Patent Office Linked Open Data endpoint, which is the only patent source still reachable without a key: PatentsView has been retired, and both EPO OPS and the USPTO Open Data Portal answer 403 without credentials. Coverage is therefore EP publications and this is stated in every response, because an empty result here proves only that no European publication exists, not that no patent does.

## Output

A list of European patent publications matching the query, each including publication number, title, applicant(s), filing and publication dates, IPC classification, and abstract where available. Every response explicitly states that coverage is limited to EP publications only, so an empty result means no matching European patent exists — not that no patent exists globally.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "to": {
   "type": "string",
   "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
   "description": "Latest publication date, ISO."
  },
  "ipc": {
   "type": "string",
   "pattern": "^[A-H]\\d{2}[A-Z]\\d{1,4}-\\d{2,6}$",
   "description": "IPC class in EPO notation, for example B28B7-00. Combine with from/to."
  },
  "from": {
   "type": "string",
   "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
   "description": "Earliest publication date, ISO."
  },
  "limit": {
   "type": "integer",
   "default": 10,
   "maximum": 25,
   "minimum": 1,
   "description": "Maximum number of publications."
  },
  "applicant": {
   "type": "string",
   "maxLength": 80,
   "minLength": 3,
   "description": "Applicant name or part of it, matched case sensitively as it is written on the publication, for example Siemens."
  },
  "publication_number": {
   "type": "string",
   "pattern": "^(EP)?\\s?\\d{6,8}$",
   "description": "EP publication number, for example EP1000000 or 1000000. The precise axis."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/european-patent-office-linked-open-data-search-f000e528/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from research.halowerk.com](https://www.zero.xyz/host/research.halowerk.com/llms.txt)