Series · 3 posts
Build your first AI agent
Build an AI agent in TypeScript step by step: tool calling, MCP, RAG, security, evaluation and cost.
What is an AI agent? 200 messages a day at a small café
What is an AI agent, and how is it different from a chatbot or a workflow? Three ways to answer a café's customers, compared with TypeScript code that runs.
Call an LLM API in TypeScript: a chatbot for a small café
Call an LLM API in TypeScript with Claude's official SDK, write a system prompt for a café chatbot, and see why it confidently invents order statuses.
What is tool calling? Letting a café chatbot look up orders
What is tool calling and how does it work? Describe tools to an LLM, read the tool_use block, run your real function and send a tool_result back, in TypeScript.