Grammarly Incident Runbook

Overview

Incident response procedures for Grammarly writing API integration failures. Covers text check timeouts, suggestion quality degradation, OAuth token failures, and rate limit storms. Grammarly powers real-time writing assistance, so API incidents directly impact user-facing text checking, scoring workflows, and content quality pipelines. Classify severity immediately using the matrix below and follow the corresponding playbook.

Severity Levels

Diagnostic Steps

# Test API health (unauthenticated)
curl -s -o /dev/null -w "HTTP %{http_code}\n" \
  https://api.grammarly.com/ecosystem/api/v2/scores

# Test authenticated scoring
curl -s -w "\nHTTP %{http_code}\n" \
  -H "Authorization: Bearer $GRAMMARLY_ACCESS_TOKEN" \
  -H "Content-Type: application/json" \
  -X POST https://api.grammarly.com/ecosystem/api/v2/scores \
  -d '{"text": "Test sentence for Grammarly API diagnostic health check."}'

# Check OAuth token validity
curl -s -o /dev/null -w "HTTP %{http_code}\n" \
  -H "Authorization: Bearer $GRAMMARLY_ACCESS_TOKEN" \
  https://api.grammarly.com/ecosystem/api/v2/account

Incident Playbooks

API Outage

1. Confirm with unauthenticated health check (see diagnostics)
2. Check Grammarly status page and developer announcements
3. Activate fallback mode — return placeholder scores to avoid blocking users
4. Queue text submissions for retry when API recovers
5. Notify downstream consumers that scores are unavailable

Authentication Failure

1. Test token validity with the account endpoint diagnostic above
2. If 401: OAuth access token has expired — trigger token refresh flow
3. If refresh token also fails: re-authorize via OAuth consent flow
4. Verify client ID and client secret are correct in environment config
5. Deploy refreshed tokens and confirm scoring requests succeed

Data Sync Failure

1. Identify if scoring results are stale or inconsistent across requests
2. Check if Grammarly updated their scoring model (review changelog)
3. Compare current scores against known baseline text samples
4. If quality drift confirmed: log evidence and file support ticket
5. Consider pinning API version if Grammarly supports versioned endpoints

Communication Template

**Incident**: Grammarly Integration [Outage/Degradation]
**Status**: [Investigating/Identified/Mitigating/Resolved]
**Started**: YYYY-MM-DD HH:MM UTC
**Impact**: [Text scoring unavailable / elevated latency / OAuth failure affecting N users]
**Current action**: [Fallback scores active / token refresh in progress / rate limit backoff enabled]
**Next update**: HH:MM UTC

Post-Incident

• [ ] Document timeline from detection to resolution
• [ ] Identify root cause (Grammarly outage / token expiry / rate limit exceeded)
• [ ] Verify all scoring pipelines resumed with accurate results
• [ ] Add proactive token refresh before expiry (buffer by 10 min)
• [ ] Implement rate limit monitoring with alerting at 80% threshold
• [ ] Update fallback logic if edge cases were discovered

Error Handling

Resources

• Grammarly Developer Docs
• Grammarly API Support

Next Steps

See grammarly-observability for monitoring setup and alerting thresholds.