API Documentation

Grammar Check API

Use this endpoint to check grammar and spelling programmatically. API key authentication is required.

Back to checker

Endpoint

POST /api/grammar-check

Authentication

Send your key in the X-API-KEY header (or use Authorization: Bearer <key>).

Request Body

{
  "text": "She don't like going to school.",
  "language": "en-US"
}

language can be auto, en-US, or en-GB.

Response

{
  "ok": true,
  "request_id": "9b0b9b12-7e51-49e5-9b3b-4312d5e4c7e3",
  "latency_ms": 132,
  "matches": [
    {
      "message": "Use \"doesn't\" with third-person singular.",
      "offset": 0,
      "length": 7,
      "replacements": [{ "value": "She doesn't" }],
      "context": { "text": "She don't like..." },
      "rule": { "category": { "name": "Custom Grammar" } }
    }
  ],
  "highlightedText": "She don’t like going to school.",
  "correctedText": "She doesn't like going to school.",
  "stats": { "issues": 1, "words": 6, "characters": 33 }
}

Rate Limits

Default limit is 60 requests per minute per API key.