tree-sitter-baml

Tree-sitter grammar for BAML, the AI agent programming language — classes, enums, interfaces with generics, LLM functions with Jinja prompts, an expression language (lambdas, match patterns, let/const bindings, loops, catch/throw, spawn/await), and more.

• Grammar name: baml · file type: .baml · scope: source.baml
• Queries shipped: queries/highlights.scm, queries/injections.scm (prompt bodies are injected as jinja)
• src/ contains the generated parser (parser.c) so editors can build this repo directly — do not edit it; it is regenerated from grammar.js on every sync.

Neovim (nvim-treesitter)

local parser_config = require('nvim-treesitter.parsers').get_parser_configs()
parser_config.baml = {
  install_info = {
    url = 'https://github.com/BoundaryML/baml-treesitter',
    files = { 'src/parser.c' },
    branch = 'main',
  },
  filetype = 'baml',
}
vim.filetype.add({ extension = { baml = 'baml' } })

Then :TSInstall baml. Copy queries/*.scm into ~/.config/nvim/queries/baml/ (or a plugin runtime path) for highlighting.

Helix

In ~/.config/helix/languages.toml:

[[language]]
name = "baml"
scope = "source.baml"
file-types = ["baml"]
comment-token = "//"

[[grammar]]
name = "baml"
# Pin a specific commit (git log on this repo for the latest) so the parser
# and your queries cannot drift apart; bump the rev deliberately.
source = { git = "https://github.com/BoundaryML/baml-treesitter", rev = "<commit-sha>" }

Then hx --grammar fetch && hx --grammar build, and copy queries/ to ~/.config/helix/runtime/queries/baml/.

Zed

Zed consumes tree-sitter grammars through extensions. In an extension's extension.toml:

[grammars.baml]
repository = "https://github.com/BoundaryML/baml-treesitter"
rev = "<commit sha>"

Building from source

npm install -D tree-sitter-cli   # 0.25.x
npx tree-sitter generate         # only needed after editing grammar.js
npx tree-sitter test             # corpus tests
npx tree-sitter parse file.baml

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⚠️ Read-only mirror

This repository is a read-only mirror, generated from typescript2/pkg-grammar-treesitter in the BAML monorepo (src/ is emitted by tree-sitter generate at sync time). Do not edit it by hand and do not open pull requests here — they will be overwritten by the next sync. Report issues or contribute changes in the monorepo instead.