outlines

Generate structured JSON, regex, and Pydantic-constrained outputs from local LLMs.

Updated Jun 7, 2026
One-click install
npx skills add https://github.com/Chensihakniroth/ANAKOT-AGENT --skill outlines-chensihakniroth
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: outlines
Source: https://github.com/Chensihakniroth/ANAKOT-AGENT/tree/main/optional-skills/mlops/inference/outlines
Command: npx skills add https://github.com/Chensihakniroth/ANAKOT-AGENT --skill outlines-chensihakniroth

SYSTEM DOCUMENTATION & REQUIREMENTS

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

What problem does it solve? LLMs often produce malformed JSON or free-form text that breaks downstream parsing. This Skill guarantees structurally valid outputs by constraining token generation at the logit level using finite state machines, eliminating retry loops and validation failures. ## Core Features & Use Cases - Schema-Constrained Generation: Generate outputs matching Pydantic models, JSON schemas, regex patterns, enums, or fixed choice lists with guaranteed validity. - Multiple Local Backends: Works with Transformers, llama.cpp (GGUF), and vLLM for development through high-throughput production serving. - Zero-Overhead FSM Filtering: Compiles schemas into finite state machines that filter invalid tokens during generation, running as fast as unconstrained decoding. - Use Case: Extract structured company information (name, founded year, industry, employees) from hundreds of unstructured text documents into validated Pydantic objects for a data pipeline. ## Quick Start Use the outlines skill to extract a user's name, age, and email from this text into a validated Pydantic model.

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 from an LLM in Python?▼

Use outlines.generate.json with a Pydantic model or JSON schema to constrain generation. Outlines compiles the schema into a finite state machine that filters invalid tokens during decoding, guaranteeing the output matches your schema without retries.

Outlines vs Instructor for structured LLM outputs?▼

Outlines excels with local models (Transformers, llama.cpp, vLLM) and offers zero-overhead FSM-based generation plus regex constraints. Instructor is better for API models like OpenAI with automatic retrying, but adds post-generation validation overhead.

Does Outlines support vLLM for production deployment?▼

Yes, Outlines supports vLLM via outlines.models.vllm, including tensor parallelism for multi-GPU setups, AWQ/GPTQ quantization, and high-throughput batch processing with configurable concurrent sequences.

Can I use Pydantic models with Outlines constrained generation?▼

Yes, Outlines has native Pydantic support including nested models, enums, Literal types, field constraints like min_length and pattern, optional fields, and lists of nested objects. Pass the model class directly to outlines.generate.json.

What are the limitations of Outlines with OpenAI models?▼

OpenAI support in Outlines is limited compared to local backends. FSM-based token filtering is unavailable with API models, so some advanced constrained generation features may not work. Local models provide full functionality.

How do I run Outlines on Apple Silicon or CPU-only machines?▼

Use the llama.cpp backend with GGUF quantized models like Q4_K_M. Set n_gpu_layers to -1 for Metal GPU acceleration on Macs, or configure n_threads for CPU inference with memory-mapped model loading.