Add ChatPluginMarketplaces enterprise policy

[Miaku]

Add ChatPluginMarketplaces enterprise policy

Summary

Adds a policy block to the existing chat.plugins.marketplaces configuration so that the list of plugin marketplaces queried by chat (Agent Customizations) can be locked down by enterprise admins via Group Policy / Intune / .plist, per the enterprise policies docs.

Motivation

Today, chat.plugins.marketplaces (chat.contribution.ts#L873-L882) defaults to:

["github/copilot-plugins", "github/awesome-copilot"]

…and is freely overridable in user settings. Enterprises that want their developers to only consume plugins from an internal, vetted marketplace (e.g. a curated repo on GitHub Enterprise or a private org) currently have no way to enforce this. Any user can point chat at an arbitrary repo by editing settings.json.

Adding a policy block exposes the setting through the same managed-config channels as ChatApprovedAccountOrganizations, ChatAgentMode, ExtensionGalleryServiceUrl, etc. — making this safe to deploy in regulated/compliance-sensitive environments.

Change

Single change: extend the existing schema entry with a policy block (mirrors the pattern used by chat.approvedAccountOrganizations, which is also a type: 'array' policy):

[ChatConfiguration.PluginMarketplaces]: {
    type: 'array',
    items: { type: 'string' },
    markdownDescription: nls.localize('chat.plugins.marketplaces', "..."),
    default: ['github/copilot-plugins', 'github/awesome-copilot'],
    scope: ConfigurationScope.APPLICATION,
    tags: ['experimental'],
    policy: {
        name: 'ChatPluginMarketplaces',
        category: PolicyCategory.InteractiveSession,
        minimumVersion: '1.NNN',  // <-- to be set by VS Code maintainers
        localization: {
            description: { ... }
        }
    }
}

When the policy is set, the list is locked: accountPolicyService / multiplexPolicyService will override the user setting and only the policy-supplied marketplaces are queried.

Open questions for maintainers

1. minimumVersion — placeholder 1.NNN needs to be replaced with the target Insiders/stable version.
2. policyData.jsonc entry — once minimumVersion is fixed, a corresponding entry should be added to build/lib/policies/policyData.jsonc so the ADMX/.plist artifacts pick it up.
3. Stability — the setting is currently tags: ['experimental']. Adding a policy implies some commitment to schema stability; happy to defer if the team would rather wait for GA.
4. Workspace-level extraKnownMarketplaces (workspacePluginSettingsService.ts) — should the policy also override these, or is it acceptable for workspace JSON to add additional marketplaces on top of policy-pinned ones? My read: policy should be the floor (always present) but workspace extraKnownMarketplaces should still be additive. Open to either interpretation.

Testing

• Schema change compiles (npm run compile).
• Manual: set ChatPluginMarketplaces via registry / defaults write, confirm user setting is overridden.
• policyData.jsonc regeneration once minimumVersion is finalized.

Notes

Filed as a draft to start the conversation. Happy to address the open questions above and follow up with the policyData.jsonc entry once version is settled.

[Copilot]

Pull request overview

Adds an enterprise policy hook to the existing chat.plugins.marketplaces setting so enterprise admins can manage/lock down the marketplaces queried by chat via managed policy channels.

Changes:

• Adds a policy block to chat.plugins.marketplaces with name ChatPluginMarketplaces under PolicyCategory.InteractiveSession.

Show a summary per file

File	Description
src/vs/workbench/contrib/chat/browser/chat.contribution.ts	Adds an enterprise policy definition for the plugin marketplaces configuration setting.

Copilot's findings

Comments suppressed due to low confidence (1)

src/vs/workbench/contrib/chat/browser/chat.contribution.ts:886

• minimumVersion must match the PolicyDefinition.minimumVersion type (${number}.${number}), so '1.NNN' will fail TypeScript compilation. Please replace this placeholder with a concrete VS Code version like the other policies in this file (e.g. '1.116').

				name: 'ChatPluginMarketplaces',
				category: PolicyCategory.InteractiveSession,
				minimumVersion: '1.NNN',
				localization: {

• Files reviewed: 1/1 changed files
• Comments generated: 1