Registries

Registries are sources where bz reads module metadata and content. bz supports several registry types.

HTTP Registry

Connect to any BCR-compatible HTTP registry:

# Bazel Central Registry
bcr = registry.http("https://bcr.bazel.build")

# Custom HTTP registry
internal = registry.http("https://registry.internal.example.com")

With Authentication

private_registry = registry.http(
    url = "https://private.example.com",
    auth = auth.bearer(token = env("REGISTRY_TOKEN")),
)

File Registry

Read from a local filesystem path:

# Absolute path
local = registry.file("/var/bazel-registry")

# Relative path (from config file location)
local = registry.file("./bazel-registry")

# Home directory
local = registry.file("~/bazel-registry")

Git Registry

Clone and read from a git repository:

# Public repository
bcr_fork = registry.git(
    url = "https://github.com/myorg/bazel-central-registry.git",
)

# With specific branch
bcr_fork = registry.git(
    url = "https://github.com/myorg/bazel-central-registry.git",
    branch = "custom-modules",
)

# With authentication
private_repo = registry.git(
    url = "https://github.com/myorg/private-registry.git",
    auth = auth.bearer(token = env("GITHUB_TOKEN")),
)

Registry Structure

All registries must follow the BCR directory structure:

modules/
├── rules_go/
│   ├── metadata.json
│   ├── 0.50.0/
│   │   ├── MODULE.bazel
│   │   └── source.json
│   └── 0.50.1/
│       ├── MODULE.bazel
│       └── source.json
└── rules_python/
    ├── metadata.json
    └── ...

metadata.json

Contains module metadata:

{
  "versions": ["0.50.0", "0.50.1"],
  "yanked_versions": {}
}

MODULE.bazel

The module’s Bazel module file.

source.json

Specifies how to fetch the module source:

{
  "url": "https://github.com/org/repo/archive/v0.50.1.tar.gz",
  "integrity": "sha256-...",
  "strip_prefix": "repo-0.50.1"
}

Registry Methods

All registry types support these methods:

Method	Description
`GetMetadata(module)`	Get module metadata
`GetModuleBazel(module, version)`	Get MODULE.bazel content
`GetSource(module, version)`	Get source.json content
`ListModules()`	List all modules (if supported)

Examples

Multiple Registries

# Primary: Bazel Central Registry
bcr = registry.http("https://bcr.bazel.build")

# Fallback: Internal mirror
mirror = registry.http("https://bcr-mirror.internal")

# Custom modules
custom = registry.file("/opt/custom-modules")

Development Setup

# Use local BCR fork for development
bcr_dev = registry.file("../bazel-central-registry")

# Or use git with a feature branch
bcr_feature = registry.git(
    url = "https://github.com/myuser/bazel-central-registry.git",
    branch = "add-new-module",
)