# Instructor

> MIT Pydantic structured outputs for any LLM; free library

**Category:** Python  
**Pricing:** open-source  
**URL:** https://python.useinstructor.com  
**GitHub:** https://github.com/instructor-ai/instructor  
**Added:** 2026-09-04

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## The Hook

Instructor is validated structured extraction when raw JSON mode and hand-rolled retries are the weekend you lose.

## What's Good

MIT. Pydantic models → typed LLM outputs with auto-retry on validation failure. 15+ providers (OpenAI, Anthropic, Gemini, Ollama, …). Streaming/partials. Ports in TS/Go/Ruby/etc. Millions of monthly downloads.

## The Catch

Library not an agent framework (pair with your orchestrator). Provider token costs remain. Vs native structured-output APIs: Instructor shines on validation/retry DX across providers, not on replacing tool-calling agents.

## Verdict

MIT structured LLM outputs. Free forever; you pay model APIs.