rules_odin

Bazel rules for the Odin programming language.

Overview

rules_odin provides hermetic Bazel build rules for Odin, a data-oriented systems programming language. The ruleset automatically downloads and manages the Odin compiler toolchain, requiring no system-wide Odin installation.

Features

• Hermetic Odin toolchain management (no system install required)
• odin_binary rule for compiling executables
• odin_library rule for sharing packages via collection imports
• odin_test rule for running @(test)-annotated Odin procedures
• bzlmod-first (no WORKSPACE file needed)
• Multi-platform support: Linux (x86-64, ARM64), macOS (x86-64, ARM64), Windows (x86-64)
• Bazel 7.x, 8.x, and 9.x compatible

Quick Start

Add to your MODULE.bazel:

bazel_dep(name = "rules_odin", version = "0.1.0")

odin = use_extension("@rules_odin//odin:extensions.bzl", "odin")
odin.toolchain(odin_version = "dev-2026-06")
use_repo(odin, "odin_toolchains")

register_toolchains("@odin_toolchains//:all")

Then in your BUILD.bazel:

load("@rules_odin//odin:defs.bzl", "odin_binary", "odin_library", "odin_test")

odin_library(
    name = "greetings",
    srcs = glob(["lib/*.odin"]),
)

odin_binary(
    name = "hello",
    srcs = glob(["hello/*.odin"]),
    deps = [":greetings"],
)

odin_test(
    name = "greetings_test",
    srcs = glob(["tests/*.odin"]),
    deps = [":greetings"],
)

Import the library in your Odin code using the collection name (the odin_library target name) and the package directory name:

import greetings "greetings:lib"  // collection:name → lib/ directory

Rules

odin_binary

Compiles an Odin package (directory of .odin files) into an executable.

Attribute	Type	Default	Description
srcs	label_list	required	Odin source files (must share a package)
deps	label_list	[]	odin_library targets to import as collections
optimization	string	"none"	One of: none, minimal, speed, size, aggressive
debug	bool	True	Include debug symbols
defines	string_dict	{}	Compile-time -define: values
extra_compiler_flags	string_list	[]	Additional flags passed to odin build
vet	bool	False	Enable -vet checks

odin_library

Groups Odin source files into a library that can be imported by odin_binary targets via Odin's collection system. The library's target name becomes the collection name.

Attribute	Type	Default	Description
srcs	label_list	required	Odin source files (must share a package)

odin_test

Compiles and runs Odin tests using the built-in test runner. Source files must contain at least one procedure annotated with @(test). The test binary is compiled at build time (cacheable) and executed by Bazel's test runner.

Attribute	Type	Default	Description
srcs	label_list	required	Odin source files with @(test) procedures
deps	label_list	[]	odin_library targets to import as collections
optimization	string	"none"	One of: none, minimal, speed, size, aggressive
debug	bool	True	Include debug symbols
defines	string_dict	{}	Compile-time -define: values (see below)
extra_compiler_flags	string_list	[]	Additional flags passed to the Odin compiler
vet	bool	False	Enable -vet checks

Test runner defines (passed via defines):

Key	Default	Description
ODIN_TEST_FANCY	false	ANSI progress display (auto-disabled)
ODIN_TEST_THREADS	0 (auto)	Worker thread count
ODIN_TEST_NAMES	—	Comma-separated test filter
ODIN_TEST_RANDOM_SEED	random	Fixed seed for reproducibility
ODIN_TEST_FAIL_ON_BAD_MEMORY	false	Treat memory leaks as failures
ODIN_TEST_LOG_LEVEL	info	Minimum log level

Supported Odin Versions

Version	Status
dev-2026-06	Supported
dev-2026-05	Supported

See COMPATIBILITY.md for the full version matrix.

Requirements

• Bazel 7.x, 8.x, or 9.x
• Linux: clang or gcc (for linking)
• macOS: Xcode Command Line Tools
• Windows: MSVC "Desktop development with C++" workload

Contributing

See CONTRIBUTING.md for development setup and guidelines.

License

Apache License 2.0 - see LICENSE.