Grammar & spell check API

Check text for grammar and spelling issues (LanguageTool), returning each problem with a message, the offending span, and suggested fixes. For writing/editing/content agents. Answers 'proofread this', 'check this text for grammar', 'fix spelling and grammar', 'is this sentence correct'.

Price$0.01per request

MethodPOST

Route/v1/text/grammar

StatusLive

MIME typeapplication/json

Rate limit20/minute

Cache3600s public

textgrammarspellingproofreadwritinglanguagetooleditingnlp

API URLhttps://x402.hexl.dev/v1/text/grammar

Integration docs

Example request

{
  "text": "She dont likes apple.",
  "language": "en-US"
}

Example response

{
  "language": "English (US)",
  "matchCount": 2,
  "matches": [
    {
      "message": "Did you mean 'doesn't'?",
      "offset": 4,
      "length": 4,
      "suggestions": [
        "doesn't"
      ],
      "context": "She dont likes apple.",
      "category": "Grammar",
      "ruleId": "DONT_VBZ"
    }
  ]
}

Input schema

{
  "type": "object",
  "required": [
    "text"
  ],
  "properties": {
    "text": {
      "type": "string",
      "examples": [
        "She dont likes apple."
      ]
    },
    "language": {
      "type": "string",
      "default": "en-US"
    }
  }
}

Output schema

{
  "type": "object",
  "additionalProperties": true
}