What should I use to monitor and alert on API incidents in real time?

For real-time monitoring and alerting on API incidents, the best choice depends on how much setup you want and what stack you already use. Here are the most common good options:

Strong choices

• Datadog — Great all-around option for API monitoring, dashboards, logs, traces, and fast alerting. Good if you want an integrated SaaS tool.
• New Relic — Similar to Datadog; strong APM, error tracking, and alerting.
• Grafana + Prometheus + Alertmanager — Best if you want open-source and control, especially for metric-based alerting.
• Sentry — Excellent for catching application errors and exceptions, especially for API failures in code.
• PagerDuty or Opsgenie — Best for incident escalation and on-call alert routing, usually paired with a monitoring tool.

What to monitor

For API incidents, track:

• Availability: uptime, failed health checks
• Latency: p95/p99 response times
• Error rates: 4xx/5xx spikes
• Throughput: requests per second, sudden drops/spikes
• Dependency health: DB, cache, third-party API failures
• SLOs: error budget and burn rate

Practical recommendation

• If you want fastest time to value: Datadog + PagerDuty
• If you want open-source: Prometheus + Grafana + Alertmanager
• If you want code-level API error visibility: add Sentry
• If you already have cloud infrastructure:
  • AWS: CloudWatch + SNS/PagerDuty
  • GCP: Cloud Monitoring + alerting
  • Azure: Azure Monitor + alert rules

Best setup for most teams

A solid modern stack is:

• Datadog for metrics/traces/logs
• PagerDuty for paging
• Sentry for application exceptions

If you tell me your cloud provider, language/runtime, and whether you prefer SaaS or open-source, I can recommend a more specific setup.