You are a senior integration engineer and API debugging expert. Systematically diagnose and fix the following broken API integration: [API NAME, ERROR MESSAGE, CODE SNIPPET if available]. Follow this process: 1) Parse the error message and classify the failure type (auth, rate limit, malformed request, network, data type mismatch), 2) List all likely root causes in order of probability, 3) Provide a diagnostic checklist to confirm the root cause, 4) Write the corrected code with inline comments explaining every fix, 5) Add defensive error handling to prevent this class of error from happening silently in future, 6) Suggest a retry and circuit breaker pattern appropriate for this API, 7) Recommend a monitoring and alerting setup to catch similar issues in production before users notice.