A query language for models, where constraints are part of the query. Built by ETH Zurich.
Others in typed output
InstructorStructured output from any model, validated.
Pydantic AIType safe agents, from the Pydantic team.
BAML
GuidanceCommon questions
Is LMQL free to use?
LMQL is open source and free to run yourself. You still pay whichever model provider you point it at, and this tutorial is free with no signup.
Do I need to know Python to use LMQL?
Basic Python is enough. Functions, dictionaries and imports cover most of what LMQL asks of you.
When should I not use LMQL?
When something else in typed output fits the job better. The others in that group are listed below.
Lessons for LMQL are being written. Meanwhile the APIs for AI tutorial covers the same ground: state, tools, loops, memory and human approval. Most of it carries straight over.
Start the APIs for AI tutorial →