outlines

Generate schema-conforming JSON, XML, and code outputs with finite-state constraints.

Updated May 2, 2026
One-click install
npx skills add https://github.com/AlvaroBiano/hermes-agent --skill outlines-alvarobiano
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: outlines
Source: https://github.com/AlvaroBiano/hermes-agent/tree/main/optional-skills/mlops/inference/outlines
Command: npx skills add https://github.com/AlvaroBiano/hermes-agent --skill outlines-alvarobiano

SYSTEM DOCUMENTATION & REQUIREMENTS

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

What problem does it solve?

Outlines enables deterministic generation of structured outputs that always conform to a defined schema or Pydantic model, reducing post-processing validation and errors.

Core Features & Use Cases

  • Constrained generation that enforces JSON/XML/code structure from schemas or Pydantic models
  • Native Pydantic integration for typed outputs and automatic validation
  • Local-model support (Transformers, llama.cpp, vLLM) with zero API dependencies
  • JSON schema compatibility and zero-overhead structured generation
  • Production-ready patterns for nested models, enums, and complex types

Quick Start

Describe the required output using a schema or model and let Outlines return a validated, typed result.

Frequently Asked Questions about outlines

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

FAQPage Schema
How do I generate structured JSON outputs that always conform to a Pydantic model?▼

You can generate structured JSON outputs by applying finite-state constraints during generation, which forces local models to produce text that always conforms to your Pydantic model and eliminates post-processing validation errors.

Does structured generation work with local models like vLLM and transformers?▼

Yes, structured generation works with local models like vLLM and transformers. It enforces schema-driven constraints natively, ensuring type-safe generation with zero API dependencies and robust error handling.

What is finite-state constrained generation for JSON schema compliance?▼

Finite-state constrained generation is a technique that pre-compiles validators from a JSON schema or Pydantic model, steering the model's token generation process to guarantee the output strictly matches the defined structure.

How do I enforce specific output formats like XML and code using local models?▼

You can enforce specific output formats like XML and code by defining the required structure through a schema or model, allowing the generation process to apply constraints that yield validated, typed results automatically.

Can I use Pydantic models for automatic validation of nested structures in LLM outputs?▼

Yes, you can use Pydantic models for automatic validation of nested structures, enums, and complex types. Native integration pre-compiles these models into validators to ensure type-safe, structured outputs.

Why do I need schema-driven generation instead of post-processing validation for local models?▼

Schema-driven generation is needed because it guarantees structural compliance during generation, dramatically reducing the post-processing validation overhead and runtime errors commonly associated with parsing unstructured local model outputs.