Anthropic Incident Runbook

Overview

Respond to Anthropic API incidents in production — outages, sustained 529 errors, authentication failures, and timeouts. Covers status page checking, severity classification, model fallback activation, communication, and post-incident review.

Step 1: Confirm the Issue

# Check Anthropic status
curl -s https://status.anthropic.com/api/v2/status.json | python3 -c "
import json, sys
d = json.load(sys.stdin)
print(f\"Status: {d['status']['description']} ({d['status']['indicator']})\")"

# Test API directly
curl -s -w "\nHTTP %{http_code} in %{time_total}s\n" \
  https://api.anthropic.com/v1/messages \
  -H "x-api-key: $ANTHROPIC_API_KEY" \
  -H "claude-version: 2023-06-01" \
  -H "content-type: application/json" \
  -d '{"model":"claude-haiku-4-5-20251001","max_tokens":5,"messages":[{"role":"user","content":"ping"}]}'

Step 2: Classify Severity

Symptom	Severity	Action
529 overloaded (intermittent)	Low	SDK auto-retries handle this
529 overloaded (sustained 5+ min)	Medium	Switch to fallback model
401/403 on all requests	High	API key issue — check console
All requests timing out	High	Check status page, activate fallback
Status page shows incident	Varies	Follow status page updates

Step 3: Activate Fallback

async function callWithFallback(params: Anthropic.MessageCreateParams) {
  try {
    return await client.messages.create(params);
  } catch (err) {
    if (err instanceof Anthropic.APIError && (err.status === 529 || err.status === 500)) {
      // Try a different model
      if (params.model.includes('opus')) {
        return await client.messages.create({ ...params, model: 'claude-sonnet-4-20250514' });
      }
      if (params.model.includes('sonnet')) {
        return await client.messages.create({ ...params, model: 'claude-haiku-4-5-20251001' });
      }
    }
    throw err;
  }
}