Grammar API

Grammar Checker API

Q: What does the Grammar Checker API return?

It returns corrected text and a complete word-level diff with replace, insert and delete operations, plus issue details, edit count, input counts, execution time and remaining credits.

Q: How do I authenticate a grammar correction request?

Send the API key in the X-API-Key header. The key must include the grammar_checker scope.

Q: Which English variants can the grammar API use?

The target_variant field accepts auto, en-US, en-GB, en-CA, en-AU and en-IN. The endpoint currently corrects English text.

Q: What are the grammar API limits and credit cost?

A request must contain 5 to 10,000 words and no more than 75,000 characters. It costs 1 API credit per input word, and failed requests are refunded.

Q: What happens when submitted text needs no correction?

The response sets changed to false, returns an empty diff and returns corrected_text unchanged.

Correct English grammar, spelling and punctuation through your product. Each response includes the corrected text and a word-level record of every edit.

Create an API key ↗ Read the API reference ↗

1 credit per word
Up to 10,000 words
Complete diff returned

DOCUMENT 08 3 EDITS

ORIGINAL

The findings ~~demonstrates~~ demonstrate a clear pattern, but the conclusion is ~~somewhat difficult to understand~~ unclear without more context.

Edit history

See exactly what changed.

Use the corrected text as the final version, or use the ordered diff to show every insertion, deletion and replacement in your interface.

BEFORE 11 words

The report contain clear findings. However the supporting notes is incomplete.

replace insert replace

AFTER 3 edits

The report contains clear findings. However, the supporting notes are incomplete.

Offsets reference the original text Diff operations: replace, insert, delete Complete diff, never truncated

English variants

Match the English your users write.

Let the API detect the variant automatically, or choose US, UK, Canadian, Australian or Indian English.

Review target options ↗

target_variant "en-GB"

ORIGINAL

The team will analyze the final draft.

EN-GB

The team will analyse the final draft.

Correction request

Send text. Receive the correction and edit history.

Send content and, if needed, a target_variant. The response separates the finished corrected_text from the diff that identifies each edit.

Open request parameters ↗

POST /api/grammar/correct/

curl -X POST \
  https://developer-portal.proofademic.ai/api/grammar/correct/ \
  -H "X-API-Key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "content": "Text to correct",
    "target_variant": "en-CA"
  }'

01 Authorize Use a scoped key

02 Submit Send English text

03 Correct Receive corrected text

04 Compare Show each edit

Request contract

Check text limits and credit use.

The API validates word and character limits before correction. Each response reports the input counts, edit count, execution time and remaining credits.

Input envelope