BoundaryML/baml

BAML is a simple prompting language for building reliable AI workflows and agents.

BAML makes prompt engineering easy by turning it into schema engineering -- where you mostly focus on the models of your prompt -- to get more reliable outputs. You don't need to write your whole app in BAML, only the prompts! You can wire-up your LLM Functions in any language of your choice! See our quickstarts for Python, TypeScript, Ruby and Go, and more.

BAML comes with all batteries included -- with full typesafety, streaming, retries, wide model support, even when they don't support native tool-calling APIs

The fundamental building block in BAML is a function. Every prompt is a function that takes in parameters and returns a type.

Every function additionally defines which models it uses and what its prompt is.

Below we call the ChatAgent function we defined in BAML through Python. BAML's Rust compiler generates a "baml_client" to access and call them.

You can write any kind of agent or workflow using chained BAML functions. An agent is a while loop that calls a Chat BAML Function with some state.

And if you need to stream, add a couple more lines:

And get fully type-safe outputs for each chunk in the stream.