Fundamentals

• generateText: Basic async text generation with model and prompt
• Unified interface: Switch models (GPT-4o, Perplexity, Gemini) by changing one line
• Tool calling: Define tools with name, description, parameters, and execute function; model decides when to call them
• maxSteps: Enables multi-step agent loops — model calls tools, gets results, continues until text output or max steps

Structured Output

• generateObject: Returns typed objects using Zod schemas
• Zod's describe function adds detailed instructions per field

Deep Research Clone (218 lines)

1. Generate sub-queries from the main topic
2. Web search each query using Exa API
3. Evaluate results (relevant/irrelevant) with tool-calling agent
4. Extract learnings and follow-up questions
5. Recurse with depth/breadth parameters, accumulating research state
6. Generate final report in markdown using all accumulated data

Key architecture: recursive deepResearch function with accumulated state, duplicate source prevention, and system prompt engineering for the final report.