outlines

Constrain language model outputs to schemas and typed formats.

Updated May 5, 2026
One-click install
npx skills add https://github.com/yanochka11/harness_bro --skill outlines-yanochka11
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: outlines
Source: https://github.com/yanochka11/harness_bro/tree/main/.claude/skills/ported/outlines
Command: npx skills add https://github.com/yanochka11/harness_bro --skill outlines-yanochka11

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes references (resource) components.

What problem does it solve?

This Skill solves the problem of unreliable language model outputs by enforcing valid structured generation with schemas, types, and constraints.

Core Features & Use Cases

  • Schema-Constrained Generation: Generate JSON, regex-matched text, and typed outputs that follow predefined structures using grammar-based constraints.
  • Pydantic Integration: Build type-safe LLM workflows with automatic validation for extraction, classification, and structured data generation.
  • Use Case: Apply this Skill when building ML applications that need dependable outputs from local models such as Transformers, llama.cpp, or vLLM for document extraction or API generation.

Quick Start

Use the outlines skill to generate a Pydantic-validated JSON response from my language model output.

Frequently Asked Questions about outlines

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I ensure my LLM generates valid JSON matching a Pydantic schema?

To enforce structured LLM generation, you constrain model outputs using grammar-based constraints and Pydantic schema validation. This guarantees valid JSON extraction by forcing the language model to generate text that strictly matches your predefined types.

What is the best way to constrain local model outputs to a specific format?

The best way to constrain local model outputs is through grammar-based generation. Applying schema validation restricts models like Transformers, llama.cpp, or vLLM to produce typed formats and regex-matched text, guaranteeing reliable structured outputs for ML workflows.

Does structured generation work with vLLM and Transformers for local inference?

Yes, structured generation integrates with vLLM and Transformers for local inference workflows. It applies grammar-based constraints and schema validation to these backends, enabling reliable JSON extraction, classification, and code generation directly on local models.

Why do I need schema validation for LLM document extraction?

You need schema validation for LLM document extraction because raw language model outputs are unreliable and often break downstream parsing. Enforcing structured generation with schemas and grammar-based constraints guarantees that extracted data matches your exact Pydantic types and JSON structures.

When should I use constrained output generation instead of prompt engineering?

Use constrained output generation instead of prompt engineering when you need guaranteed structured outputs. Grammar-based constraints mathematically enforce valid JSON and typed formats, eliminating the unpredictability of prompt-based approaches for dependable ML engineering workflows.