outlines

Enforce valid JSON, XML, and code structures via grammar-based FSM constraints.

Updated Mar 7, 2026
One-click install
npx skills add https://github.com/Simon-Copilot-Studio/ai-content-hub --skill outlines-simon-copilot-studio
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: outlines
Source: https://github.com/Simon-Copilot-Studio/ai-content-hub/tree/main/mlops/inference/outlines
Command: npx skills add https://github.com/Simon-Copilot-Studio/ai-content-hub --skill outlines-simon-copilot-studio

SYSTEM DOCUMENTATION & REQUIREMENTS

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

What problem does it solve?

Guarantees that generated outputs adhere to valid JSON/XML/code structures and provides type safety through Pydantic, enabling reliable, schema-conformant results across local-model backends.

Core Features & Use Cases

  • Constrained generation using grammar-based FSMs to guarantee valid structures.
  • Pydantic integration for type-safe outputs and automatic schema translation.
  • Local-model backends support (Transformers, llama.cpp, vLLM) for low-latency, private deployments.
  • Rapid, deterministic generation suitable for data extraction, form processing, and structured data workflows.

Quick Start

Load a local model, define your Pydantic schema, and generate structured outputs that are guaranteed valid.

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 schema outputs from local language models?

Pydantic integration translates Python type definitions into JSON schemas, applying grammar-based FSM constraints during generation. This guarantees type-safe, valid structured outputs directly from local-model backends.

Does structured generation work with vLLM and Transformers for high-throughput inference?

Constrained generation uses FSM-based token filtering and CFG-to-FSM pipelines to restrict token selection during decoding. This guarantees valid JSON, XML, or code structures in the generated output.

Why do local models output invalid JSON when extracting structured data?

Local models output invalid JSON due to unconstrained probabilistic token sampling. FSM-based grammar constraints filter tokens during generation, guaranteeing valid JSON structures for data extraction workflows.

Can I use Pydantic models to enforce type-safe structured generation?

Pydantic integration translates Python type definitions into JSON schemas, applying grammar-based FSM constraints during generation. This guarantees type-safe, valid structured outputs directly from local-model backends.

What are the limitations of grammar-based structured generation?

Grammar-based structured generation relies on local-model backends like Transformers and vLLM, requiring local deployment. It enforces output validity via FSM token filtering, which may limit generation diversity.