BAML

BAML (Basically a Made-up Language) is the domain-specific language (DSL) that transforms LLM prompts into type-safe, polyglot functions for reliable, structured output generation.

BAML is the open-source DSL developed by Boundary to bring engineering rigor to AI workflows. It converts raw prompts into first-class, type-safe functions, eliminating the complex parsing boilerplate and ensuring reliable structured data extraction from any LLM (including OpenAI, Anthropic, and local models). Built on Rust, BAML provides a unified, high-speed development experience with native tooling, such as the VSCode Playground, which allows developers to test and iterate on prompts up to 10x faster. The resulting code is polyglot, generating clients for Python, TypeScript, Ruby, and Go, allowing teams to deploy robust, deterministic AI agents across diverse tech stacks.

https://boundaryml.com/