[FEATURE] Load user-installed mods in cloud sessions and Projects, and draw their UI

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet. Closest related threads: #91870 (mods design) and #88214 (cloud sessions never install plugins from .claude/settings.json; /plugin unavailable). Neither asks for user-installed mods to load and draw in cloud sessions / Projects.
• [x] This is a single feature request (not multiple features)

Problem Statement

Today, user-installed mods (function-hook plugins) load and draw in the local CLI and in a local desktop Code tab (Claude Code 2.1.287+, desktop from 2.1.286). The same mods do not load in cloud sessions, and there is nowhere to draw their UI there.

That gap hits Projects hard: Projects are mostly cloud sessions. In the desktop Code tab's cloud environment, on claude.ai/code, and in project threads, a mod that already works locally is simply absent — no panes, bands, or guards — so the local workflow does not carry over.

Official docs (as of 8 Oct 2026) already describe this split:

• Cloud sessions: hooks only if the plugin reaches the session; drawings do not appear.
• Desktop: the plugin browser is unavailable in cloud sessions; plugins installed from the desktop app are not available there; a cloud session does not install plugins declared in the repo's .claude/settings.json.
• Cloud environment: user-scoped plugins in ~/.claude/settings.json do not carry over, and neither do enabledPlugins / extraKnownMarketplaces.

Proposed Solution

Load user-installed mods in cloud sessions and Projects the same way they load locally, and draw their mod UI there (desktop Code tab cloud environment, claude.ai/code, project threads).

Concretely:

1. Carry user-installed mods (and the settings that enable them) into cloud sessions / Projects so function-hook plugins actually run.
2. Provide a place to draw mod UI in those surfaces (panes, bands, guards, and the rest of the local mod UI), not only hooks-without-drawings.

Alternative Solutions

• Keep using mods only in local CLI / local desktop Code tab, and accept that cloud sessions and Projects have no mod UI. That drops the local workflow whenever work moves to the cloud.
• Rely on #88214-style fixes for repo .claude/settings.json plugins alone. That still would not load user-installed mods from the desktop/CLI install, nor give cloud surfaces a place to draw.

Priority

High - Significant impact on productivity

Feature Category

Developer tools/SDK

Use Case Example

1. I install a mod locally that draws panes, bands, and guards I already rely on in the Code tab.
2. I open the same project as a cloud session / Project thread (desktop cloud environment or claude.ai/code).
3. Today the mod does not load and has nowhere to draw, so I lose that UI and those guards.
4. With this change, the mod loads and draws there the same way it does locally.

Additional Context

• Related: #91870 (mods design thread) and #88214 (cloud sessions never install plugins from .claude/settings.json, /plugin unavailable).
• Docs as of 8 Oct 2026: cloud sessions (hooks only if the plugin reaches the session; drawings do not appear); desktop (plugin browser unavailable in cloud sessions; desktop-installed plugins not available there; cloud sessions do not install plugins from the repo .claude/settings.json); cloud environment (user-scoped plugins in ~/.claude/settings.json do not carry over; neither do enabledPlugins / extraKnownMarketplaces).
• Local baseline: Claude Code 2.1.287+ / desktop from 2.1.286.