BAML

BAML (by Boundary) is a domain-specific language and toolchain for building reliable, type-safe LLM workflows. You define functions, types, and clients in .baml files, then BAML generates language clients (e.g., Python/TypeScript) that call providers like OpenAI or Anthropic and return validated, structured results. The VS Code/Cursor extension includes an integrated playground with prompt preview and raw cURL visibility. BAML supports streaming typed outputs, multimodal inputs (PDFs, images, audio, video—depending on provider), checks/asserts for validation, dynamic types via a TypeBuilder, and a Collector for usage and raw response inspection. You can also expose functions as REST endpoints with an OpenAPI spec and generate clients for other languages.