BAML

BAML is a programming language for agents that compiles typed functions and traces executions locally.

BAML is a programming language designed specifically for agents and structured data generation. It offers TypeScript-like syntax, Rust-like correctness, Go-like concurrency, and Python-like dynamism. The language features local function tracing and profiling, schema-aligned parsing to repair malformed model output, green threads, and automated test generation from production traces. It runs standalone or integrates into projects using Python, TypeScript, Java, .NET, C++, Rust, and other languages. The compiler and toolchain provide an LSP for developers and dedicated tools for agents to read traces and write code.

BAML at a glance

Best for: Software engineer
Runs on: macOS, Linux, Windows, API, self-hosted, open source
Pricing: Free and open source
Released: October 2023
Category: AI coding tool
Website: boundaryml.com

Key features

Schema-aligned output parsing
Local function tracing and profiling
Type-safe data declaration
Automated test generation
Green threads with awaitable returns
Cross-language integration bridge

Use it for

Building type-safe agent workflows
Generating and grading AI tests
Tracing agent function execution locally

Alternatives to BAML

Llmll — The compiler proves each function against its contract with Z3 before merging.
Golem — Provides type-safe agent abstractions and zero-dependency Go implementation.
mabl — It builds, runs, and recovers tests autonomously to keep pace with development.
Agentloop — Provides a clean agent loop with provider-agnostic LLM access, hooks, and safety budgets.
Lloyal — Builds apps with embedded models that run offline without user API keys.
Ax — Develop and improve AI features with consistent, type-safe code across six languages.
VoltAgent — Offers open-source flexibility with built-in supervisor agent orchestration and RAG.
BLA (bla-agents) — Protects software artifacts against automated AI reverse engineering while preserving runtime behavior.
jevgrep — Reduces coding agent costs by providing targeted, relevant repository context.
bb — Runs locally with support for multiple AI models and full customization.
LangChain — Compose exactly the agent your use case needs from model, tools, prompt, and middleware.
Alook — Connects existing local coding agents to team communication channels.

All BAML alternatives