Back to course
Free Previewintermediate18 min
What Are AI Agents?
Understand the agent loop, tools, and frameworks that power modern agentic AI systems.
## What Are AI Agents?
An **AI agent** is an LLM that can take actions — not just generate text. It uses **tools** (functions it can call) to interact with the world: search the web, run code, read files, call APIs.
### The Agent Loop
```
1. Receive a goal ("Research and summarise the top 5 AI papers from 2025")
2. Plan: what tools do I need? (web search, summariser)
3. Act: call search tool → get results
4. Observe: read results
5. Plan next step: are results sufficient?
6. Repeat until goal is achieved
7. Return final answer
```
### Frameworks
| Framework | Language | Best For |
|-----------|----------|----------|
| LangChain | Python/JS | General purpose |
| LlamaIndex | Python | RAG / knowledge bases |
| AutoGen | Python | Multi-agent |
| Vercel AI SDK | TypeScript | Web apps |