LMQL

LMQL (Language Model Query Language) is a programming language for working with LLMs that makes prompts more reliable, modular, and easier to control.

Programmable prompts, not just text

Instead of writing one-off prompt text, LMQL lets you define model queries using templates and types, and apply constraints to the output. This helps teams reuse prompt components, reduce unpredictable responses, and make model behavior more consistent.

Optimizing runtime

LMQL includes a runtime that optimizes how queries are executed against an LLM. This is useful when speed, cost, and generation stability matter—such as in production systems or when building multi-step query chains.

Built for developers and teams

LMQL is a good fit for engineers building LLM-powered features who want a more structured approach than manual prompting:

• Reusable prompt components
• Checkable output constraints
• More controlled, predictable generation