[DOCS + FEATURE] Cross-marketplace plugin dependencies: docs cite an allowlist but never define it

[chrisvaillancourt]

Summary

plugin.json dependencies can include a marketplace field to reference
a plugin in another marketplace. The docs say an allowlist gates this
feature but never document it. Users cannot declare cross-marketplace
dependencies.

The documentation gap

From plugin-dependencies.md,
the marketplace field reads:

A different marketplace to resolve name in. Cross-marketplace
dependencies are blocked unless the target marketplace is allowlisted
in the root marketplace's marketplace.json.

Neither plugin-marketplaces.md
nor the plugins reference
specifies:

• The allowlist's JSON field name in marketplace.json
• The allowlist entry schema (bare name? owner/repo? source object?)
• A worked example
• Whether the mechanism is implemented, stubbed, or admin-only

strictKnownMarketplaces is managed-settings-only and controls which
marketplaces users can add — unrelated to dependency resolution.

Real-world impact

I maintain a private curated marketplace. One of its embedded plugins
needed to extend agents from pr-review-toolkit in
anthropics/claude-plugins-official. Declaring
{"name": "pr-review-toolkit"} failed with
pr-review-toolkit@<my-marketplace> not installed — the resolver
scoped to my own marketplace. I found no documented way to declare a
cross-marketplace dependency.

Workaround: I copied the agent files verbatim under Apache-2.0
attribution, with per-file blob-SHA tracking and drift-detection tooling.
A usable marketplace field would eliminate this overhead.

Requested resolution

One or both of:

1. DOCS: Specify the allowlist's field name, schema, and an example
   on plugin-marketplaces.md, linked from plugin-dependencies.md.
2. FEATURE: If the allowlist is not production-ready, add a
   requiredMarketplaces field to marketplace.json that prompts users
   to add any missing companion marketplace at install time.

Related

• [FEATURE] Cross-marketplace plugin references (proxy entries) #26122 — Cross-marketplace plugin references (stale-closed with no
  Anthropic engagement)
• [DOCS] Plugin docs missing plugin.json dependency declarations and auto-install behavior #48864 — [DOCS] Plugin docs missing plugin.json dependency
  declarations and auto-install behavior
• [DOCS] Plugins reference missing dependency version requirement and recovery docs #49311 — [DOCS] Plugins reference missing dependency version
  requirement and recovery docs

[github-actions]

Found 2 possible duplicate issues:

1. [FEATURE] Cross-marketplace plugin references (proxy entries) #26122
2. [FEATURE] Support marketplace references inside marketplace.json #33568

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[github-actions]

This issue has been automatically closed as a duplicate of #26122.

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[github-actions]

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