# Espacenet API

> Espacenet returns patent families, publication details, and reported legal events as a workflow and API.

Espacenet, also called EPO, uses a publication number or invention title to find a patent family and publication details. Get patent family returns reported legal events; coverage varies by country, and a grant alone does not establish that a patent is in force.

- Page: https://fous.com/workflows/espacenet
- Handle: `@espacenet`
- Category: [Legal](https://fous.com/workflows/category/legal)
- Source website: https://worldwide.espacenet.com
- Last verified: Sep 29, 2026
- Fous is not affiliated with Espacenet.

## Methods

### Get patent family

Operation `get_patent_family`, version 1. 1 credit per call.

Find a patent family, publication details, and reported legal events by patent number or invention title. Legal-event coverage varies by country; a grant alone does not establish that a patent is currently in force.

**Input**

| Field | Type | Required | Example | Description |
|---|---|---|---|---|
| `patent` | string | yes | `"Coherent LADAR using intra-pixel quadrature detection"` | Publication number or invention title, for example US10000000B2 or Coherent LADAR using intra-pixel quadrature detection. |

**Input schema**

```json
{
  "type": "object",
  "required": [
    "patent"
  ],
  "properties": {
    "patent": {
      "type": "string",
      "description": "Publication number or invention title, for example US10000000B2 or Coherent LADAR using intra-pixel quadrature detection.",
      "examples": [
        "Coherent LADAR using intra-pixel quadrature detection",
        "US10000000B2",
        "EP 1 000 000 B1"
      ]
    }
  },
  "additionalProperties": false,
  "examples": [
    {
      "patent": "Coherent LADAR using intra-pixel quadrature detection"
    },
    {
      "patent": "US10000000B2"
    },
    {
      "patent": "EP 1 000 000 B1"
    }
  ]
}
```

**Output**

| Field | Type | Example | Description |
|---|---|---|---|
| `title` | string or null | `"Coherent LADAR using intra-pixel quadrature detection"` |  |
| `family` | array |  |  |
| `family[].kind` | string | `"application"` |  |
| `family[].country` | string | `"European Patent Office"` |  |
| `family[].legal_status` | string | `"Granted; current status not confirmed"` |  |
| `family[].espacenet_link` | string | `"https://worldwide.espacenet.com/patent/search/family/055456961/publication/EP3268771A1"` |  |
| `family[].publication_date` | string or null | `"2018-01-17"` |  |
| `family[].publication_number` | string | `"EP3268771A1"` |  |
| `applicants` | array |  |  |
| `priority_date` | string or null | `"2015-03-10"` |  |
| `espacenet_link` | string | `"https://worldwide.espacenet.com/patent/search/family/055456961/publication/US10000000B2"` |  |
| `overall_status` | string | `"Granted publications in 4 jurisdictions; applications without a recorded grant in 0; recorded lapses in 0. Current prot` |  |
| `latest_legal_events` | array |  |  |
| `latest_legal_events[].date` | string or null | `"2026-04-20"` |  |
| `latest_legal_events[].event` | string | `"Annual fee paid to national office [announced via postgrant information from national office to epo]"` |  |
| `latest_legal_events[].country` | string | `"France"` |  |

**Example input**

```json
{
  "patent": "Coherent LADAR using intra-pixel quadrature detection"
}
```

**Example output**

```json
{
  "title": "Coherent LADAR using intra-pixel quadrature detection",
  "family": [
    {
      "kind": "application",
      "country": "European Patent Office",
      "legal_status": "Granted; current status not confirmed",
      "espacenet_link": "https://worldwide.espacenet.com/patent/search/family/055456961/publication/EP3268771A1",
      "publication_date": "2018-01-17",
      "publication_number": "EP3268771A1"
    },
    {
      "kind": "granted",
      "country": "European Patent Office",
      "legal_status": "Granted; current status not confirmed",
      "espacenet_link": "https://worldwide.espacenet.com/patent/search/family/055456961/publication/EP3268771B1",
      "publication_date": "2022-06-29",
      "publication_number": "EP3268771B1"
    }
  ],
  "applicants": [
    "RAYTHEON CO [US]"
  ],
  "priority_date": "2015-03-10",
  "espacenet_link": "https://worldwide.espacenet.com/patent/search/family/055456961/publication/US10000000B2",
  "overall_status": "Granted publications in 4 jurisdictions; applications without a recorded grant in 0; recorded lapses in 0. Current protection requires country-level confirmation.",
  "latest_legal_events": [
    {
      "date": "2026-04-20",
      "event": "Annual fee paid to national office [announced via postgrant information from national office to epo]",
      "country": "France"
    },
    {
      "date": "2026-04-13",
      "event": "Annual fee paid to national office [announced via postgrant information from national office to epo]",
      "country": "Germany"
    }
  ]
}
```

## Quick start

Call the API with a Fous API key (`FOUS_API_KEY`). To create one, turn on Developer mode in Fous Studio, then open Keys & connections → API keys (https://app.fous.com/keys).

```bash
# First set your key: export FOUS_API_KEY='YOUR_FOUS_API_KEY'
: "${FOUS_API_KEY:?Set FOUS_API_KEY before running this example}"

curl 'https://api.fous.com/v1/query' \
  --fail-with-body --silent --show-error --max-time 120 \
  -H "Authorization: Bearer $FOUS_API_KEY" \
  -H 'Content-Type: application/json' \
  --data-raw '{
  "api": "@espacenet",
  "visibility": "public",
  "operation": "get_patent_family",
  "version": 1,
  "input": {
    "patent": "Coherent LADAR using intra-pixel quadrature detection"
  },
  "response": {
    "format": "json"
  }
}'
```

```python
# Save as fous.py and run with python3 fous.py. No packages needed.
# First set your key: export FOUS_API_KEY='YOUR_FOUS_API_KEY'
import json
import os
import urllib.error
import urllib.request

api_key = os.environ.get("FOUS_API_KEY")
if not api_key:
    raise RuntimeError("Set FOUS_API_KEY before running this example")

body = json.loads("{\n  \"api\": \"@espacenet\",\n  \"visibility\": \"public\",\n  \"operation\": \"get_patent_family\",\n  \"version\": 1,\n  \"input\": {\n    \"patent\": \"Coherent LADAR using intra-pixel quadrature detection\"\n  },\n  \"response\": {\n    \"format\": \"json\"\n  }\n}")
request = urllib.request.Request(
    "https://api.fous.com/v1/query",
    data=json.dumps(body).encode("utf-8"),
    headers={
        "Authorization": f"Bearer {api_key}",
        "Content-Type": "application/json",
    },
    method="POST",
)
try:
    with urllib.request.urlopen(request, timeout=120) as response:
        result = json.load(response)
except urllib.error.HTTPError as error:
    raise RuntimeError(f"HTTP {error.code}: {error.read().decode('utf-8', errors='replace')}") from error
if result.get("success") is False:
    raise RuntimeError(result.get("error", {}).get("message", "Request failed"))
print(json.dumps(result["data"]["output"], indent=2))
```

```typescript
// Save as fous.mts and run with npx tsx fous.mts.
// First set your key: export FOUS_API_KEY='YOUR_FOUS_API_KEY'
const apiKey = process.env.FOUS_API_KEY;
if (!apiKey) throw new Error("Set FOUS_API_KEY before running this example");

const response = await fetch("https://api.fous.com/v1/query", {
  method: "POST",
  headers: {
    "Authorization": `Bearer ${apiKey}`,
    "Content-Type": "application/json",
  },
  signal: AbortSignal.timeout(120_000),
  body: JSON.stringify({
  "api": "@espacenet",
  "visibility": "public",
  "operation": "get_patent_family",
  "version": 1,
  "input": {
    "patent": "Coherent LADAR using intra-pixel quadrature detection"
  },
  "response": {
    "format": "json"
  }
}),
});
type ApiResult = { success: boolean; data?: { output: unknown }; error?: { message: string } };
const result: ApiResult = await response.json();
if (!response.ok || result.success === false) {
  throw new Error(result.error?.message ?? `HTTP ${response.status}`);
}
if (!result.data) throw new Error("Missing API response data");
console.log(result.data.output);
```

Or describe the data in plain language: send `{"api":"@espacenet","prompt":"Describe the data you need, with every detail"}` to the same URL. Fous fills in the input, runs the method that fits and returns only the fields you asked for; `data.route.calls[].request` is the exact call it made. Routing is free; the run costs the same.

## Use cases

- Find related publications for a patent.
- Review applicants and priority dates across a patent family.
- Check reported legal events by country.
- Compare publication dates and numbers across family members.

## FAQ

### Is Fous affiliated with Espacenet?

No. Fous is not affiliated with Espacenet. This workflow reads the public worldwide.espacenet.com website and returns its data.

### How much does it cost?

Each run costs 1 credit. With pay-as-you-go, a credit costs 1¢; monthly plans cost less per credit.

### Do I need a Espacenet account?

No. You only need a Fous account.

### How current is the data?

Fous gets the data from worldwide.espacenet.com when you run it; repeating the same request within a day may return the saved result. Fous checks this workflow automatically; it last passed a check on Sep 29, 2026.

### Which publications belong to a patent family?

Get patent family returns family publications for a publication number or invention title.

### What legal events are reported for a patent?

Get patent family returns reported legal events and their dates and countries; coverage varies by country.

## Related

- [Google Patents API](https://fous.com/workflows/google-patents.md): Google Patents searches public records and provides patent details and company summaries; legal status is estimated, and citations, claims, and company breakdowns have record limits.
- [USPTO API](https://fous.com/workflows/uspto.md): USPTO provides U.S. trademark records, name searches for matching filings, and current status and prosecution history for selected marks.
- [EUR-Lex API](https://fous.com/workflows/eur-lex.md): EUR-Lex provides official EU legislation, relevance-ranked filtered searches, and article text from the latest consolidation when available, with stated general application dates.
- [WIPO API](https://fous.com/workflows/wipo.md): Search trademark records in the WIPO Global Brand Database.
- [Federal Register API](https://fous.com/workflows/federal-register.md): Search United States federal rules, proposed rules, notices, and presidential documents.
- [PubMed API](https://fous.com/workflows/pubmed.md): PubMed searches medical and life-science articles by topic and retrieves one article’s abstract and publication details; abstracts and free full-text links may be unavailable.
- [Find Case Law API](https://fous.com/workflows/find-case-law.md): Search official UK court judgments and tribunal decisions from The National Archives.
- [GLEIF API](https://fous.com/workflows/gleif.md): GLEIF provides official global LEI search, returning entity records with freshness shown by last-update dates—not renewal dates—and reported accounting parents and LEI-registered direct children.
- [All Legal workflows](https://fous.com/workflows/category/legal)