BAML
ActiveDescription
BAML is an AI framework that adds engineering rigor to prompt engineering, offering type-safe prompt definitions, automatic testing, version management, and multi-model support across Python, TypeScript, Ruby, Java, C#, Rust, and Go.
Key Features
- Type-safe prompt definition language that transforms prompt engineering into schema engineering
- Built-in IDE plugins (VS Code / JetBrains) for rapid prompt testing and iteration
- SAP (Schema-Aligned Parsing) algorithm for reliable structured output even without native tool-calling support
- Switch between 100+ models (OpenAI, Anthropic, Gemini, Vertex, Bedrock, etc.) with a single line change
- Fully type-safe streaming with React hooks for building streaming UIs
- Runs completely offline, 100% open-source (Apache 2.0), no internet required
Use Cases
💡 Building AI workflows and agents requiring reliable structured outputs
💡 Rapidly iterating and testing prompts across different LLM models
💡 Unifying LLM prompt management across polyglot codebases
💡 Enabling structured outputs for models without native tool-calling support
💡 Building production-grade streaming AI application interfaces
Strengths & Limitations
✅ Strengths
- • Actively maintained, recent updates
- • High community interest (9.0k stars)
- • Permissive open-source license (Apache-2.0)
- • Established track record (2 years in production)
Categories
Quick Start
Install: pip install baml-py. Define function signatures and prompts in .baml files specifying client and output types. Run `baml-cli generate` to create type-safe clients. Import baml_client in Python/TS/Go/Ruby to call BAML functions. Use IDE plugins for real-time prompt testing.