API Documentation

Getting Started

Welcome to the GrammarCheck.ai API. Our API provides developers with high-performance text processing tools, including real-time grammar checking, intelligent paraphrasing, and plagiarism detection.

To start using the API, you first need to generate an API Key from your Access Credentials tab. Once you have a key, you can authenticate your requests by including it in your HTTP headers.

Authentication

GrammarCheck.ai uses API keys to authenticate requests. All API requests should be made over HTTPS. Unauthorized requests will return a 401 Unauthorized error.

API Key

Authorization: Bearer YOUR_SECRET_KEY

Limitation Page

Our API has certain limitations based on your subscription plan. These include word limits per request and rate limits per minute.

For most plans, the maximum word limit per request is 1000 words. If you need higher limits, please contact our support team or upgrade your plan.

Grammar Check

Analyze text for grammatical errors, spelling mistakes, and punctuation issues.

curl -X POST "https://staging.grammarcheck.ai/api/user/grammarcheck-api" -H "Authorization: Bearer YOUR_SECRET_KEY" -H "Content-Type: application/json" -d '{"text": "Your text here"}'

Parameters

Parameter	Type	Description
`text`	string	The text you want to check for grammar.
`lang`	string	Optional. Language code (e.g., 'en', 'es', 'fr'). Default: 'en'

Examples

Basic Grammar Check Request

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{
    "text": "Your long text here...",
    "lang": "en"  // default: en
}

Example Response

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{
    "status": true,
    "data": {
        "message": "Success",
        "original": "This is a example.",
        "corrected": "This is an example.",
        "tagged": "This is <span class=\"grammarCheck_api\">an</span> example."
    },
}

AI Paraphrasing

Rewrite sentences while maintaining their original meaning using our advanced AI models.

curl -X POST "https://staging.grammarcheck.ai/api/user/paraphrase" -H "Authorization: Bearer YOUR_SECRET_KEY" -H "Content-Type: application/json" -d '{"text": "Your text here", "mode": 1}'

Parameters

Parameter	Type	Description
`text`	string	The text you want to paraphrase.
`mode`	integer	1 for Standard, 2 for Simple, 3 for Formal.

Examples

Basic Paraphrasing Request

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{
    "text": "The quick brown fox jumps over the lazy dog.",
    "mode": 1
}

Example Response

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{
    "status": true,
    "data": {
        "message": "success",
        "text": "A fast brown fox leaps over a sleepy dog."
    }
}

AI Humanizer

Transform AI-generated text into human-like content that bypasses AI detectors while maintaining readability.

curl -X POST "https://staging.grammarcheck.ai/api/user/humanizer" -H "Authorization: Bearer YOUR_SECRET_KEY" -H "Content-Type: application/json" -d '{"text": "Your text here", "mode": 1, "lang": "en"}'

Parameters

Parameter	Type	Description
`text`	string	The AI-generated text you want to humanize.
`mode`	integer	1 for Light, 2 for Advanced.
`lang`	string	Language code (e.g., 'en', 'es', 'fr')

Examples

Basic Humanizer Request

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{
    "text": "Artificial intelligence is a branch of computer science...",
    "mode": 1,
    "lang": "en"
}

Example Response

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{
    "status": true,
    "data": {
        "message": "success",
        "text": "The field of artificial intelligence involves creating computer systems..."
    },
}

Plagiarism Detection

Check your content against millions of web pages to ensure originality and avoid accidental plagiarism.

curl -X POST "https://staging.grammarcheck.ai/api/user/plagiarism-checker" -H "Authorization: Bearer YOUR_SECRET_KEY" -H "Content-Type: application/json" -d '{"text": "Your text here"}'

Parameters

Parameter	Type	Description
`text`	string	The text you want to check for plagiarism.

Examples

Basic Plagiarism Request

123

{
    "text": "The quick brown fox jumps over the lazy dog."
}

Example Response

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{
    "sources": [],
    "totalQueries": 1,
    "plagPercent": 0,
    "uniquePercent": 100,
    "unique_sentences": 1,
    "plagiarized_sentence": 0,
    "details"
            [
                {
                    "unique": true,
                    "percentage": 0,
                    "query": "The quick brown fox jumps over the lazy dog.",
                    "display": null
                },
                {
                    "unique": false,
                    "percentage": 100,
                    "query": "their main concept in one click.",
                    "display": {
                        "url": "https://www.kmacims.com.ng/why-summarizing-is-important-for-teachers/",
                        "des": "allows you to summarize long texts paragraphs and articles with their main concept in one click It analyzes the entire document and summarizes the text by"
                    }
                }
            ]
}

Punctuation Checker

Fix punctuation errors and improve the readability of your text with our intelligent checker.

curl -X POST "https://staging.grammarcheck.ai/api/user/punctuation-checker" -H "Authorization: Bearer YOUR_SECRET_KEY" -H "Content-Type: application/json" -d '{"text": "Your text here"}'

Parameters

Parameter	Type	Description
`text`	string	The text you want to check for punctuation errors.

Examples

Basic Punctuation Request

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{
    "text": "The quick brown fox jumps over the lazy dog"
}

Example Response

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{
    "status": true,
    "data": {
        "message": "Success",
        "original": "The quick brown fox jumps over the lazy dog",
        "corrected": "The quick brown fox jumps over the lazy dog.",
        "tagged": "The quick brown fox jumps over the lazy dog<span class=\"punctuationCheck\">.</span>"
    },
}

AI Checker

Detect whether a piece of content was written by a human or generated by an AI model like ChatGPT, Gemini, or Claude.

curl -X POST "https://staging.grammarcheck.ai/api/user/ai-checker" -H "Authorization: Bearer YOUR_SECRET_KEY" -H "Content-Type: application/json" -d '{"text": "Your text here"}'

Parameters

Parameter	Type	Description
`text`	string	The text you want to check for AI-generated content.

Examples

Basic AI Checker Request

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{
    "text": "Artificial intelligence is transforming the way we live and work."
}

Example Response

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{
    "ai_percentage": 0,
    "ai_sentence_count": 0,
    "human_percentage": 100,
    "human_sentence_count": 1,
    "output_html": "<span class=\"human\" data-probability=\"1\">Artificial intelligence...</span>",
    "total_sentences": 1,
    "ok": true
}

Rate Limits

To ensure fair usage and system stability, we implement rate limiting on all API endpoints. The number of allowed requests depends on your plan.

Standard plans typically allow 20 requests per minute. Exceeding this limit will result in a 429 Too Many Requests error.

Error Codes

Grammarcheck.ai uses standard HTTP status codes to indicate the success or failure of an API request.

Common Errors

STATUS	ERROR	DESCRIPTION
401	Unauthorized	1. API key is required. 2. Incorrect API key provided.
413	Payload Too Large	The text in the request exceeds the maximum allowed words limit for your plan.
417	Expectation Failed	1. An internal error occurred while processing the request. 2. Unable to paraphrase the text. 3. Unable to check plagiarism. 4. An unexpected error occurred.
422	Unprocessable Entity	One or more request parameters are invalid or missing.
429	Too Many Requests	The rate limit of requests per minute depends on your plan.