Buildathons.ai

Build a ReAct agent with tool use Course

Implement the ReAct (Reason + Act) pattern from scratch: an agent that plans, uses tools, observes results, and iterates until it reaches a goal. Follow this…

Course overview

Implement the ReAct (Reason + Act) pattern from scratch: an agent that plans, uses tools, observes results, and iterates until it reaches a goal.

Define your tools

Tools are functions the agent can call. Define them with OpenAI's function calling schema.

Implement tool execution

Handle each tool call with real implementations.

Build the ReAct agent loop

The core agentic loop: think, act, observe, repeat. In production, add tool call timeouts, retry logic, and a way to interrupt infinite loops. Consider LangChain or LlamaIndex for battle-tested agent implementations.