🎯 What is APIM?
Fully managed service to publish, secure, transform, maintain, and monitor APIs in a centralized platform.
🧠 Core Purpose
| Purpose | Description |
|---|
| Centralized Gateway | Front door for all APIs (internal/external) |
| Security Layer | Authentication, rate limits, quotas |
| Developer Portal | Customizable portal for API exploration |
| Policy Control | Add caching, transformation without backend changes |
| Analytics | Usage patterns, health, performance metrics |
💪 Key Features
🔐 Security
OAuth 2.0, JWT, subscription keys
IP filtering and CORS policies
⚡ Performance
Response caching
Compression
CDN integration
🧩 Traffic Control
🔄 Transformation
Modify headers, query strings
Request/response manipulation
Protocol translation (REST ↔ SOAP)
📈 Monitoring
Azure Monitor integration
Real-time analytics dashboard
Custom alerts and metrics
🧰 Version Management
🌍 Global Distribution
Multi-region deployment
Low-latency access
High availability
👨💻 Developer Portal Features
✅ Self-service sign-up & subscription
📘 Auto-generated documentation
🔍 Interactive testing console
💳 Free/paid subscription plans
🔑 API key management
📊 Usage analytics for developers
🚀 Benefits Summary
| Category | Benefits |
|---|
| Security | Tokens, keys, IP filtering, throttling |
| Scalability | Handle thousands of concurrent calls |
| Flexibility | Modify API behavior via policies |
| Speed | Caching + compression = faster responses |
| Insights | Built-in monitoring and reporting |
| Monetization | Enable paid API subscriptions |
🧭 Common Use Cases
Microservices Gateway - Expose microservices securely
Partner Integration - Third-party API access
API Monetization - Paid subscription models
Governance - Lifecycle management and compliance
Legacy Modernization - Safely migrate old APIs
Mobile Backend - Unified API layer for apps
🏗️ Architecture Components
┌─────────────┐
│ Clients │ (Web, Mobile, Partners)
└──────┬──────┘
│
┌──────▼──────────────────────┐
│ Azure API Management │
│ ┌──────────────────────┐ │
│ │ Gateway (Proxy) │ │
│ └──────────────────────┘ │
│ ┌──────────────────────┐ │
│ │ Developer Portal │ │
│ └──────────────────────┘ │
│ ┌──────────────────────┐ │
│ │ Management Portal │ │
│ └──────────────────────┘ │
└──────┬──────────────────────┘
│
┌──────▼──────────────────────┐
│ Backend Services │
│ (APIs, Microservices) │
└─────────────────────────────┘
📋 Quick Policy Examples
Rate Limiting
xml
<rate-limit calls="100" renewal-period="60" />
Caching
xml
<cache-lookup vary-by-developer="true" /><cache-store duration="3600" />
IP Filtering
xml
<ip-filter action="allow"> <address>13.66.201.169</address></ip-filter>
Transform Response
xml
<set-header name="X-Powered-By" exists-action="delete" /><set-status code="200" reason="OK" />
🎓 Key Concepts
Product : Container for APIs with access control
Subscription : Key-based access to products
Policy : XML-based rules for API behavior
Operation : Individual endpoint within an API
Revision : Non-breaking API update mechanism
Version : Breaking change requiring new endpoint
💡 Best Practices
✓ Use policies for cross-cutting concerns
✓ Enable caching for read-heavy APIs
✓ Implement rate limiting per subscription
✓ Use named values for configuration
✓ Enable logging for troubleshooting
✓ Configure alerts for critical errors
✓ Use API versions for breaking changes
✓ Test policies in non-production first
📊 Pricing Tiers
| Tier | Use Case |
|---|
| Developer | Dev/test environments |
| Basic | Small production workloads |
| Standard | Medium production workloads |
| Premium | Enterprise with multi-region |
| Consumption | Serverless, pay-per-request |