mlc-ai/xgrammar

Fast, Flexible and Portable Structured Generation

62
/ 100
Established

This is a tool for developers who integrate large language models (LLMs) into applications. It ensures that the text generated by an LLM strictly follows a predefined structure, like JSON, regular expressions, or custom formats. Developers provide a grammar and an LLM, and the tool outputs text that is guaranteed to conform to the specified structure. It's intended for engineers building LLM-powered applications that require reliable, structured output.

1,581 stars. Actively maintained with 20 commits in the last 30 days.

Use this if you are developing applications that need LLMs to produce perfectly formatted data, such as JSON for API calls or text conforming to a specific template.

Not ideal if you are an end-user simply interacting with an LLM and don't require its output to adhere to strict programmatic formats.

LLM application development structured output grammar enforcement API integration AI engineering
No Package No Dependents
Maintenance 17 / 25
Adoption 10 / 25
Maturity 16 / 25
Community 19 / 25

How are scores calculated?

Stars

1,581

Forks

131

Language

C++

License

Apache-2.0

Last pushed

Mar 13, 2026

Commits (30d)

20

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