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Chapter 40: FastAPI for Agents

You will build a FastAPI skill BEFORE you learn FastAPI.

This chapter follows the Skill-First Learning Pattern: In Lesson 0, you create a fastapi-agent-api skill using tools from Chapter 3. Then you spend the chapter understanding what you built and making it better. By the end, you don't just "know FastAPI"—you OWN a production-ready skill.

Prerequisites​

  • Chapter 3: skill-creator and fetching-library-docs
  • Chapter 34: OpenAI Agents SDK (Agent, Runner, function_tool)
  • Chapters 37-38: MCP experience (HTTP/SSE patterns)
  • Part 5: Python Fundamentals (async/await, type hints, Pydantic)

The Running Example​

Lessons 1-10: Build a Task API—production-ready CRUD with testing, database, auth, and dependency injection.

Lessons 11-15: Add infrastructure and agent integration—middleware, lifespan, streaming, and the key insight: APIs are functions, functions become tools, agents use tools.

What You'll Own​

.claude/skills/
├── skill-creator/           # From Chapter 3
├── fetching-library-docs/   # From Chapter 3
└── fastapi-agent-api/       # NEW - this chapter

This skill joins your growing Digital FTE toolkit.

The Mindset Shift​

Traditional: "Teach me FastAPI" Agent Factory: "I own a FastAPI skill—help me make it better"

You're not here to learn. You're here to build assets.

Start with Lesson 0: Build Your FastAPI Skill.