Guides12 min read

Complete Guide: API Monitoring and REST/GraphQL Services

Learn everything you need to know about API monitoring in 2025

What is API Monitoring?

API monitoring is the process of observing and analyzing the behavior of your application programming interfaces (APIs) to ensure they work correctly, respond quickly, and are available when your users need them.

Simply put, it's like having a watchman who constantly checks if your APIs are working well, alerting you immediately when something goes wrong.

80% of production problems are first detected by users, not by monitoring systems. Don't be part of that statistic.

Why is monitoring critical?

Detect problems before your users: A monitoring system alerts you seconds after a problem occurs, not hours later when customers start complaining.
Reduce downtime: The faster you know something is wrong, the faster you can fix it. Every minute of downtime can cost thousands of dollars in lost revenue.
Improve user trust: Users trust services that work consistently. 99.9% uptime is not a luxury, it's a minimum requirement.
Data to improve: Monitoring not only detects problems, it also gives you valuable information about the performance and usage of your APIs.

Real-world use cases

💼 E-commerce

An online store monitors its payment API. If it goes down, they lose sales. With real-time alerts, they can act before losing thousands of dollars.

🚀 B2B SaaS

A SaaS platform monitors its authentication APIs. If they fail, no customer can log in. Monitoring allows them to resolve the issue in minutes, not hours.

🛒 Mobile apps

A mobile app depends on backend APIs. If the notifications endpoint fails, users don't receive critical updates. Monitoring detects this immediately.

🔗 Integrations

Your service consumes third-party APIs (Stripe, SendGrid, etc). If those APIs fail, your application does too. Monitoring them gives you complete visibility.

Types of API Monitoring

1. Uptime Monitoring (Availability)

Constantly checks if your API is responding and accessible. It's the most basic but fundamental type of monitoring.

Example: Make a GET request to https://api.yourapp.com/health every minute and verify it returns a 200 status

2. Performance Monitoring (Latency)

Measures how fast your API responds. An available but slow API is almost as bad as a down API.

Example: Measure that your /api/users endpoint responds in less than 200ms. If it takes 5 seconds, there's a problem even though it technically 'works'.

3. Error Monitoring

Tracks specific errors occurring in your API: 500s, 404s, timeouts, unhandled exceptions, etc.

Example: Detect when your API starts returning 500 errors in 10% of requests, indicating a production problem.

4. Health Checks

Dedicated endpoints that verify not only if your API responds, but if all its dependent services (database, cache, external services) are working.

Example: A /health endpoint that checks PostgreSQL, Redis, and S3, returning the status of each.

Key Terms Glossary

Essential concepts you need to know to understand API monitoring:

Uptime / Availability

The percentage of time your API is working correctly. 99.9% uptime means your API can be down for a maximum of 43 minutes per month.

Downtime

The time during which your API is unavailable or not working correctly. Every minute of downtime can cost money and user trust.

Latency

The time it takes your API to respond to a request. Low latency (< 200ms) is critical for a good user experience.

Response Time

Similar to latency, but includes the total time from when the request is sent until the complete response is received.

Check Interval

The frequency with which your API is monitored. For example, every 1 minute, every 5 minutes, etc. Shorter intervals detect problems faster but cost more.

HTTP Status Codes

The codes your API returns: 200 (success), 404 (not found), 500 (server error), etc. Monitoring verifies these codes to detect problems.

Alerts

Notifications you receive when a problem occurs: emails, Telegram messages, SMS, webhooks, etc. Configuring alerts correctly is critical.

Status Page

A public page showing the current status of your services. Transparency that builds trust with your users.

How to Set Up Monitoring Step by Step

Practical guide to implement monitoring in your application:

Step 1: Identify what to monitor

You don't need to monitor EVERYTHING. Focus on critical endpoints:

✓ Authentication endpoint (/api/auth)
✓ Your main business APIs (/api/orders, /api/payments)
✓ Health check endpoint (/health)
✓ Third-party APIs you consume (Stripe, SendGrid, etc.)

Step 2: Set up health checks in your backend

Create a dedicated endpoint that verifies your dependencies:

Verify database connection
Verify cache service connection (Redis)
Verify connection to critical external services

Step 3: Choose a monitoring tool

You can build your own system or use a tool like AnkaPulse that already has everything set up. For most teams, a dedicated tool is the best option.

Step 4: Configure smart alerts

Define what should trigger an alert and who to notify. Avoid alert fatigue by setting reasonable thresholds.

Monitoring Best Practices

Check frequency

The ideal frequency depends on your use case:

1Critical production APIs: checks every 1 minute (detects problems within 60 seconds)
2Non-critical or development APIs: checks every 5-15 minutes (sufficient for most cases)
3Side projects or MVPs: checks every 30 minutes (balance between cost and utility)

What endpoints to monitor

Don't monitor everything, focus on what's important:

Revenue-generating endpoints (payments, checkout, subscriptions)
Authentication endpoints (login, registration, password recovery)
Main APIs your users use (listings, searches, content creation)
Critical third-party services (payment processors, email, SMS)

Alert configuration

Avoid alert fatigue with these rules:

Don't alert on first failure: wait for 2-3 failed checks to confirm it's a real problem, not a temporary blip
Use multiple channels: email for detailed context, Telegram/Slack for immediate notifications
Define cooldowns: don't send 100 alerts for the same problem. One initial alert, then updates every X minutes.

Data retention

How long to keep monitoring data?

Minimum 7 days for side projects and MVPs (enough to detect weekly patterns)
30-90 days for production (allows you to analyze monthly trends and recurring problems)

Recommended Tools

There are many options on the market, but for indie teams and startups in LATAM, we recommend:

🦅

AnkaPulse

Uptime monitoring designed specifically for indie developers and startups. Checks every minute, email and Telegram alerts, public status pages, and most importantly: accepts MercadoPago to avoid the 65% tax on international payments.

View AnkaPulse plans

Conclusion

API monitoring is not optional in 2025. It's the difference between finding out about a problem from your users (bad) or finding out before them (good). With modern tools, implementing robust monitoring is easier and more affordable than ever.

Ready to start monitoring your APIs? AnkaPulse offers checks every minute from $5/month.