outlines

Constrain token sampling to grammars and FSMs for valid JSON, XML, and code generation.

2|Updated Apr 12, 2026
One-click install
npx skills add https://github.com/Clay-HHK/claude-config --skill outlines-clay-hhk
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: outlines
Source: https://github.com/Clay-HHK/claude-config/tree/main/skills/AI-research-SKILLs/16-prompt-engineering/outlines
Command: npx skills add https://github.com/Clay-HHK/claude-config --skill outlines-clay-hhk

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes references (resource) components.

What problem does it solve?

Outlines eliminates invalid and malformed model outputs by enforcing schema-level constraints during generation so JSON, XML, and code are produced correctly the first time without expensive post-validation and retries.

Core Features & Use Cases

  • Deterministic structured generation using CFG-to-FSM token filtering to make invalid tokens impossible.
  • Pydantic and JSON Schema integration for type-safe, validated outputs that map directly to application models.
  • Local and high-throughput backends support (Transformers, llama.cpp, vLLM) to optimize latency and batching for production systems.
  • Use cases: reliable data extraction from text, structured classification, code and API spec generation, form processing and large-scale batch extraction.

Quick Start

Generate a Pydantic-backed JSON object extracting name, email, and age from the input text using a local Transformers or vLLM model.

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 structured generation from local models?

To guarantee valid JSON structured generation, this Skill constrains token sampling during inference using CFG and FSM filtering. It enforces Pydantic and JSON-schema constraints directly at the logit level, making invalid tokens impossible.

Can I use Pydantic models to enforce type-safety with vLLM backends?

Yes, you can use Pydantic models to enforce type-safety with vLLM backends. The Skill compiles your schemas into FSMs for logit-level filtering, ensuring high-throughput inference produces outputs that map directly to your application models.

What is the best way to prevent malformed outputs during data extraction from text?

The best way to prevent malformed outputs during data extraction is schema-level constraint enforcement during generation. By filtering tokens against compiled grammars, it eliminates invalid JSON or XML structures without expensive post-validation and retries.

Does structured generation with FSM token filtering work with Transformers and llama.cpp?

Yes, FSM token filtering works with Transformers and llama.cpp. It supports local and API model backends, compiling JSON-schema constraints to finite state machines to optimize latency and batching for zero-overhead inference.

Why do I need FSM token filtering instead of post-validation for JSON-schema compliance?

You need FSM token filtering instead of post-validation because it guarantees valid JSON-schema compliance during generation. Constraining token sampling to grammars prevents malformed outputs instantly, eliminating the latency and cost of retrying failed validation attempts.