Credentials and privacy
Keep API keys server-side, separate environments, rotate exposed credentials, mask secrets in logs, and restrict access to price-watch email destinations.
Identity, freshness, and source evidence
Test exact variant matching, display observation times, keep missing data visible, and make the underlying source available when a user needs to verify a price.
Retries and monitoring
Bound retry attempts, honor Retry-After, alert on sustained 401, 429, and 5xx rates, and record request identifiers so support can trace failed calls.
Verify complete customer flows
Before launch, test search to offers, multi-product comparison, history with every supported range, and the full create-update-pause-delete watch lifecycle.