Mapping Your API Dependencies Before They Map You

The Dependency You Forgot Will Be the One That Breaks

Every modern application is a web of API dependencies. Your app calls Stripe for payments, Auth0 for authentication, SendGrid for email, Cloudflare for CDN, GitHub Actions for CI/CD — and each of those services has its own dependencies.

The problem? Most teams don't have a complete picture of what they depend on. The dependency they forgot to document will be the one that causes their next outage.

Why Dependency Mapping Matters

The Invisible Dependency Story

A real scenario: A SaaS company's checkout flow stops working. Engineering investigates their own code, database, and primary cloud provider — all healthy. After 45 minutes, someone notices that their address validation service (a small third-party API) is down. Nobody had documented this dependency or set up monitoring for it.

Total time to resolution: 90 minutes. Time it should have taken with monitoring: 5 minutes.

What You Don't Know Can Hurt You

• Direct dependencies: Services your code explicitly calls
• Transitive dependencies: Services your dependencies depend on
• Build-time dependencies: Services needed to ship code (npm, Docker Hub, GitHub)
• Infrastructure dependencies: DNS providers, CDN, certificate authorities
• Operational dependencies: Monitoring tools, incident management, communication platforms

How to Map Your Dependencies

Step 1: Audit Your Codebase

Search for external API calls in your code:

• HTTP client usage (axios, fetch, HttpClient, requests)
• SDK imports (stripe, aws-sdk, @sendgrid/mail)
• Environment variables pointing to external URLs
• Configuration files with API endpoints

Step 2: Check Your Infrastructure

Review infrastructure-level dependencies:

• DNS records (CNAME entries pointing to third-party services)
• CDN configuration (Cloudflare, Fastly, CloudFront)
• SSL certificate providers
• CI/CD pipeline integrations
• Container registries (Docker Hub, ECR, GCR)
• Package registries (npm, PyPI, Maven Central)

Step 3: Survey Your Team

Developers often know about dependencies that aren't in the code yet:

• Planned integrations
• Local development tools that depend on cloud services
• Services used by specific features or teams
• Shadow IT — tools adopted by individuals without central approval

Step 4: Document Everything

For each dependency, record:

Step 5: Visualize the Dependency Graph

A flat list is good; a visual graph is better. Map out:

• Which services depend on which other services
• Single points of failure (services with no fallback)
• Chains of dependency (A depends on B depends on C)
• Shared dependencies (multiple critical services depending on the same provider)

Monitoring Your Dependencies

Once you've mapped your dependencies, monitor them:

Automated Status Monitoring

Use ServiceAlert.ai to track the status of all your dependencies from one dashboard. We monitor 600+ cloud services and alert you via Slack, Teams, Discord, or email when any of them have issues.

Health Checks

For critical dependencies, add active health checks:

• Synthetic transactions (e.g., create a test payment through Stripe every 5 minutes)
• Endpoint monitoring (ping critical API endpoints)
• Integration tests that run against live services

Dependency-Aware Alerting

When a dependency goes down, correlate it with your own metrics:

• If Stripe status changes to degraded AND your payment error rate spikes, that's a confirmed impact
• If Auth0 goes down AND your login success rate drops, activate your fallback auth flow

Keeping Your Map Current

Dependency maps rot quickly. Keep yours current:

• Quarterly review: Walk through the map with each team lead
• PR automation: Flag PRs that add new external service imports
• Onboarding: Include dependency awareness in new developer onboarding
• Incident updates: After every incident, check if the dependency map needs updating

Start Today

You don't need to map everything at once. Start with your most critical path — the flow that generates revenue — and expand from there.

Browse 600+ services | Set up monitoring