BAML Quick Reference

BAML (Boundary AI Markup Language) is a DSL for building LLM applications with structured, type-safe outputs. It generates client code for Python, TypeScript, Go, and Ruby.

How BAML Works

• All .baml files in baml_src/ are globally accessible to each other
• Generate the client with baml-cli generate
• The generated baml_client/ provides type-safe functions you import and call
• BAML types become Pydantic models (Python), TypeScript types, Go structs, or Sorbet types (Ruby)

Essential Syntax

Types