Grammarly Common Errors

Error Reference

400 Bad Request — Text Too Short

Cause: Text has fewer than 30 words. Fix: Ensure minimum 30 words. Pad short texts with context if needed.

401 Unauthorized

Cause: Token expired or invalid. Fix: Re-authenticate with client credentials grant.

413 Payload Too Large

Cause: Text exceeds 100,000 characters or 4 MB. Fix: Split into chunks using paragraph boundaries. See grammarly-sdk-patterns for chunking function.

429 Too Many Requests

Cause: Rate limit exceeded. Fix: Implement exponential backoff. See grammarly-rate-limits.

Plagiarism Check Stuck on "pending"

Cause: Large document processing or service delay. Fix: Poll every 3-5 seconds, timeout after 90 seconds.

AI Detection — Inconsistent Scores

Cause: Short text produces unreliable results. Fix: AI detection works best on 200+ words. Scores on short text are less reliable.

Quick Diagnostics

# Test API connectivity
curl -s -o /dev/null -w "%{http_code}" \
  -H "Authorization: Bearer $GRAMMARLY_ACCESS_TOKEN" \
  https://api.grammarly.com/ecosystem/api/v2/scores

# Test with sample text
curl -X POST https://api.grammarly.com/ecosystem/api/v2/scores \
  -H "Authorization: Bearer $GRAMMARLY_ACCESS_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"text": "This is a test sentence that has more than thirty words so that the API will accept it and return a valid writing score for our diagnostic purposes."}' | python3 -m json.tool

Overview

This reference triages common integration failures without retaining the text, suggestions, credentials, or account metadata that caused them. Use a bounded synthetic input and correlation IDs for every diagnostic.

Prerequisites

• A synthetic test string, redacted correlation ID, endpoint class, and HTTP status.
• A scoped read-only diagnostic credential and a named owner for configuration or access changes.

Instructions

1. Classify the status and operation before modifying a client, credential, or retry policy.
2. Reproduce once with synthetic input; capture only status, latency band, quota state, and correlation ID.
3. Check scope, request shape, size limit, quota, and asynchronous job state in that order.
4. Apply one reversible change at a time and escalate with a redacted bundle if the failure persists.

Output

Return error class, correlation ID, environment, probe outcome, remediation attempted, and next owner. Do not include text, suggestions, tokens, or identities.

Error Handling

Treat unknown destination, failed redaction, access-scope change, or repeated non-idempotent request as a stop condition. Do not retry by broadening access or logging rejected text.

Examples

status=413; env=sandbox; correlation=req-opaque-11; action=bounded-chunking; synthetic_probe=recovered supports a safe handoff.

Resources

• Grammarly API Support

Next Steps

For debugging tools, see grammarly-debug-bundle.