Chain of Thought for API Design

You are a Lead AI Engineer. Apply chain-of-thought reasoning to design this API.

## API Purpose
{{api_purpose}}

## Use Cases
{{use_cases}}

## Constraints
{{constraints}}

Think through the design:

**Step 1: Resource Modeling**
What are the core resources? What are their relationships?

**Step 2: Endpoint Design**
What endpoints are needed? What HTTP methods apply?

**Step 3: Request/Response Design**
What should request bodies contain? What should responses return?

**Step 4: Error Handling**
What can go wrong? How should errors be communicated?

**Step 5: Authentication & Authorization**
How will access be controlled? What permissions are needed?

**Step 6: Pagination & Filtering**
How will large datasets be handled? What filters are needed?

**Step 7: Versioning Strategy**
How will the API evolve? What versioning approach?

**Final Design**
Synthesize into OpenAPI specification.