outlines

Enforce JSON, XML, or regex output formats using Pydantic models and constrained sampling.

Updated Jan 30, 2026
One-click install
npx skills add https://github.com/gagan114662/content_books --skill outlines-gagan114662
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: outlines
Source: https://github.com/gagan114662/content_books/tree/main/AI-research-SKILLs/16-prompt-engineering/outlines
Command: npx skills add https://github.com/gagan114662/content_books --skill outlines-gagan114662

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill requires outlines, transformers, vllm, pydantic, and includes scripts (resource) and references (resource) components.

What problem does it solve?

This Skill guarantees valid JSON, XML, or code structure during LLM generation, ensuring reliable and type-safe outputs, especially when working with local models.

Core Features & Use Cases

  • Guaranteed Structure: Ensure outputs conform to JSON, XML, or regex patterns.
  • Type-Safe Outputs: Use Pydantic models for robust data validation.
  • Local Model Support: Works seamlessly with Transformers, vLLM, and llama.cpp.
  • Maximized Inference Speed: Achieves high performance through zero-overhead structured generation.
  • Use Case: Extracting structured user profiles from free-form text into a Pydantic model, ensuring the output is always valid JSON matching the defined schema.

Quick Start

Use the outlines skill to generate a JSON object representing a user with name and age.

Frequently Asked Questions about outlines

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

FAQPage Schema
How do I guarantee valid JSON output from a local LLM?

Ensure valid JSON output from local LLMs by applying FSM-based constrained sampling during generation. This enforces schema conformity, guaranteeing type-safe results without manual validation.

Can I use Pydantic models to validate structured LLM generation?

Use Pydantic models to define schemas for structured LLM generation. FSM-based constrained sampling guarantees generated text conforms exactly to your Pydantic schema, ensuring type-safe outputs.

Does structured text generation work with vLLM and Transformers?

Structured text generation works seamlessly with vLLM and Transformers backends. It achieves high-speed, zero-overhead inference by integrating constrained sampling directly into local model pipelines.

What is the best way to extract structured data from free-form text using local models?

Extract structured data from free-form text using local models by applying FSM-based constrained sampling with Pydantic schemas. This method guarantees valid JSON output without post-processing.

Why does my LLM output invalid JSON when using local models?

LLM output becomes invalid JSON due to unconstrained sampling. Fix this by enforcing regex or JSON schemas during generation using FSM-based constrained sampling to guarantee valid structure.