Search API

Prior art and similar

Search with a patent's own words. Prior art uses its first independent claim and only returns documents published before its earliest claimed filing date. Similar uses the abstract and has no date limit.

GEThttps://api.patentgrep.com/v1/patents/{doc_id}/prior-art

GEThttps://api.patentgrep.com/v1/patents/{doc_id}/similar

Both return a search response with the seed text, the cutoff and the family members left out, and mark hits the patent already cites.

Response200Recorded 11 Oct 2026

{
  "total": 199190,
  "sourceDocId": "US12756070B2",
  "intent": "prior-art",
  "seed": {
    "kind": "independent-claim",
    "claimNumber": 1,
    "text": "1 a self protecting functional separator for a battery cell the…",
    "strategy": "lexical-v1",
    "terms": [
      "1",
      "self",
      "protecting"
      // 9 more
    ]
  },
  "cutoff": {
    "date": "2023-01-18",
    "operator": "lt",
    "candidateDateBasis": "publication",
    "sourceDateBasis": "earliest-claimed-filing"
  },
  "exclusion": {
    "scope": "known-family",
    "complete": false,
    "docIds": ["US12756070B2", "US20240243436A1"],
    "applicationNumbers": ["18098392"]
  },
  "hits": [
    {
      "doc_id": "US7318984B2",
      "title": "Adhesive composition-supporting separator for battery and electr…",
      "date": 20080115,
      "match": 0.32,
      "alreadyCited": false,
      "citedByExaminer": false
    },
    {
      "doc_id": "US7267909B2",
      "title": "Battery separators containing reactive functional groups",
      "date": 20070911,
      "match": 0.52,
      "alreadyCited": false,
      "citedByExaminer": false
    }
    // 23 more
  ],
  "citationMarking": {
    "state": "available",
    "source": "patentgrep-rows",
    "reason": null,
    "retryable": false
  }
}

Query parameters

qstring

Your own edit of the seed text. The cutoff and exclusions still apply.

type, cpc, assignee, sort, page, after, facets

As in Search patents.

curl -G https://api.patentgrep.com/v1/patents/US12756070B2/similar \
  -H "X-Api-Key: $PATENTGREP_KEY" \
  -d type=grant

What's added to the response

seedobject

The text searched with: its kind (claim or abstract), claimNumber, text (cut at 500 characters) and terms.

cutoffobject or null

Prior art only: hits were published before date, the source's earliest claimed filing.

exclusionobject

The source and the family members left out. complete is false when the family may be larger.

hits[].alreadyCitedboolean or null

The source already cites this hit. citedByExaminer says if the examiner added it.

If a document has no claim, abstract or priority date to work from, prior art answers 409 rather than searching without a cutoff.