Getting Started

Reliable, deterministic, multilingual spellcheck as an API. 49 languages, real Hunspell suggestion engine, frequency + bigram context ranking. Same input, same output, every time.

1. Try it in 30 seconds

No install, no key. The anonymous free tier handles 100 requests per hour per IP:

curl -X POST https://reglegbrief.com/whisk/api/v1/spellcheck/apply \
  -H "Content-Type: application/json" \
  -d '{"text":"Ths is a smple sentnce.","language":"en"}'

You'll get back:

{
  "language": "en",
  "total_words": 5,
  "corrected_text": "This is a simple sentence.",
  "changes": [
    {"offset": 0, "before": "Ths", "after": "This", "kind": "spell"},
    {"offset": 9, "before": "smple", "after": "simple", "kind": "spell"},
    {"offset": 15, "before": "sentnce", "after": "sentence", "kind": "spell"}
  ],
  "unresolved": []
}

Every response carries an X-Request-ID header. Quote it when you report a bug.

2. Get a free API key

Anonymous is fine for exploring. For real usage, grab a key at /whisk/keys/ — no signup, no email, no tracking. The free tier with a key is 10,000 requests/hour.

Send it in the X-Api-Key header:

curl -X POST https://reglegbrief.com/whisk/api/v1/spellcheck/apply \
  -H "X-Api-Key: rlbwhisk_live_..." \
  -H "Content-Type: application/json" \
  -d '{"text":"Ths is a smple sentnce.","language":"en"}'

3. Pick your surface

Python SDK pip install rlbwhisk — sync + async client with typed exceptions. JavaScript / TypeScript npm install @rlbwhisk/client — fetch-based, works in Node + browser. MCP for Claude / Cursor Add rlbwhisk-mcp in three lines and any MCP-compatible AI can call Whisk. Raw HTTP API OpenAPI spec, endpoint reference, request/response schemas.

4. Two modes

Manual — get structured findings

POST /api/v1/spellcheck returns each misspelling with its top-5 suggestions. Use when you want a UI that lets the human pick.

Auto — get corrected text

POST /api/v1/spellcheck/apply returns the corrected string, ready to display or store. Use when you want a fixed sentence, not a review.

5. Rate limits

Tier	Limit	Auth
Anonymous	100 requests/hour per IP	none
Free key	10,000 requests/hour per key	`X-Api-Key`
Studio (future)	100,000/hour	paid tier, TBA

Every response carries X-RateLimit-Limit, X-RateLimit-Remaining, and X-RateLimit-Reset headers. A 429 also includes Retry-After (seconds). Our SDKs auto-retry with backoff.

6. Verify offline / privacy

The Whisk web app has an ✈ Airplane mode toggle. When on, the full Hunspell + spylls stack runs in your browser via Pyodide. Nothing hits the server. Verify with your browser's Network tab or by flipping wifi off after a "Save for offline" click.

See privacy for the server-mode contract details.