Bazel

The two-way linking model applies to Bazel modules just as it does to other ecosystems. A module recommends through package-author metadata it ships with the module, and an extension targets the module through a Bazel purl.

The Bazel registry (Bzlmod / Bazel Central Registry) does not provide a first-class field for arbitrary package metadata. Following the pattern other sidecar-based ecosystems use (see Go modules and SwiftPM), AXM reads an agent-extensions.json sidecar shipped at the module root. After Bazel fetches the module, AXM reads the sidecar from the extracted external-repository directory (external/<repo>/agent-extensions.json).

Add an agent-extensions.json file at the module root, alongside MODULE.bazel, with an agentExtensions array. Each entry is an extension reference (@owner/<type>/<name>):

// agent-extensions.json
{
  "$schema": "https://axm.sh/schemas/agent-extensions.schema.json",
  "agentExtensions": [{ "ref": "@acme/packs/widget-kit" }],
}

Keep recommendations identity-only — omit versionRange. AXM resolves the reference to the newest matching extension version and pins it in the user's axm.lock. Prefer recommending a single pack so you keep one stable reference while its contents evolve. Add a semver versionRange only when your module genuinely pairs with a bounded major line of the extension.

On the extension manifest (skill.json, pack.json, subagent.json, …), add a packages array with a Bazel purl:

// pack.json
{
  "packages": [{ "purl": "pkg:bazel/rules_widget" }],
}

Use the module name as registered in the Bazel Central Registry as the purl name.

Default to identity-only. Add a VERS versionRange with the bazel scheme only when the extension depends on module APIs introduced or removed in a known range:

{
  "packages": [
    {
      "purl": "pkg:bazel/rules_widget",
      "versionRange": "vers:bazel/>=1.0.0|<2.0.0",
    },
  ],
}

When the Bazel module recommends an extension through the AgentXM Registry and that extension names the module as a companion via its purl, AXM derives official status for the pair — no extra flag. See Official extensions.

The Bazel package-author metadata convention is still being finalized. The sidecar location above mirrors the documented sidecar ecosystems; the pkg:bazel purl is the stable identity an extension uses to target a module. Confirm the current shape against the polyglot-examples fixtures before relying on it.