outlines

Constrain AI generation to Pydantic JSON schemas with FSM validation.

Updated Apr 30, 2026
One-click install
npx skills add https://github.com/photonics-dhl/Hermes --skill outlines-photonics-dhl
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: outlines
Source: https://github.com/photonics-dhl/Hermes/tree/main/hermes-home/skills/mlops/inference/outlines
Command: npx skills add https://github.com/photonics-dhl/Hermes --skill outlines-photonics-dhl

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill requires outlines, transformers, vllm, pydantic.

What problem does it solve?

Outlines ensures outputs are structurally valid and type-safe by constraining generation to predefined data schemas, reducing post-processing errors and data inconsistencies.

Core Features & Use Cases

  • Constrained generation with CFG/FSM based on JSON schemas and Pydantic models to guarantee validity.
  • Local-model support (Transformers, llama.cpp, vLLM) for offline, high-throughput inference.
  • Use cases include data extraction, code generation, API contracts, and structured data validation at scale.

Quick Start

Provide a prompt that asks the AI to output a JSON object strictly conforming to your Pydantic model.

Frequently Asked Questions about outlines

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

FAQPage Schema
How do I guarantee structured JSON output from a local model generation?

Constrain local model generation using predefined Pydantic models and JSON schemas to guarantee structured JSON output. FSM-based validation ensures structural validity and type safety, eliminating post-processing errors and data inconsistencies during generation.

Does constrained generation work with vLLM and Transformers for offline inference?

Constrained generation works directly with vLLM and Transformers for offline inference. Local-model support enables high-throughput generation without external API calls, ensuring structured data validation at scale.

What is the best way to enforce type-safe outputs for data extraction tasks?

Enforce type-safe outputs for data extraction by constraining generation to predefined data schemas. FSM-based validation guarantees structural validity, reducing post-processing errors and data inconsistencies during extraction.

Can I use Pydantic models to define JSON schemas for local language models?

Use Pydantic models to define JSON schemas constraining local language model generation. FSM-based validation maps these schemas to guarantee that outputs strictly conform to the specified structure.

Why does my local model output invalid JSON when generating API contracts?

Local models output invalid JSON for API contracts due to unconstrained generation. Applying FSM-based validation forces generation to follow predefined JSON schemas, guaranteeing structurally valid and type-safe outputs.