Sapling

API

Grammar and spelling check API that returns corrections with character offsets

Price: Free trial key, then pay per use
Access: API key (Bearer or key field)

About

Sapling's REST API returns grammar, spelling and style corrections as JSON edits with offsets in 14 languages, plus spellcheck, AI-text detection and rephrasing. A trial key checks 50,000 characters a day; production is usage-billed, and self-hosting is an Enterprise option.

What you can do with it

Underline grammar and spelling mistakes in your app's editor with suggested fixes
Auto-correct text in one call and get the corrected version back
Score how likely a text is AI-generated, by document and by sentence

Get started

Register and generate an API key in Sapling's API settings
POST text to /api/v1/edits and apply the returned edits

Example

curl -X POST https://api.sapling.ai/api/v1/edits \
  -H "Authorization: Bearer $SAPLING_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"text": "Hi, how are you doing.", "session_id": "test session"}'

Details

Hosting: Hosted service, Self-hosted
Available in: Worldwide
Official SDKs: Python, JavaScript/TypeScript
MCP server: Remote