feat(desktop): browser pages as resource tabs, agent works in a background tab by waleedlatif1 · Pull Request #7745 · simstudioai/sim

waleedlatif1 · 2026-09-10T22:57:01Z

Summary

Each live desktop browser page is now its own resource tab in the Chat panel, projected from the desktop app's tab list. The inner browser tab strip, the singleton "Browser" resource, tab pinning, duplicate, reorder, and the native tab context menu are removed, along with their IPC channels and bridge methods. Browser resources are no longer persisted on the chat row; the desktop restores its own pages and legacy rows are dropped on read.
The agent works in a background tab. The desktop's automation cursor already drove pages independently of the visible one; the renderer no longer force-activates the browser on every tool call or auto-switches the panel to the agent's tab. The agent's tab is announced as resource activity, so the existing view policy shows it or badges it depending on whether the user has taken over selection. Strip-driven switch-tab no longer claims the page for the user, and a user closing the agent's tab leaves the agent cursor unset.
Mentions and attachments point at exact tabs; the "tagged the Browser as a whole" context is gone. The copilot tool catalog is unchanged: browser_open_tab / switch_tab / close_tab / list_tabs still map to native tabs, which are now the resource tabs.
Resource tab titles ellipsize at 200px for one or two tabs, 180px for three, and 160px from four on.
Bridge snapshot regenerated (additive: claim on switch-tab; new-tab kept only as the fallback for shells without openTab). MIN_DESKTOP_VERSION unchanged.

Type of Change

New feature

Testing

Unit: new use-browser-tab-resources tests (projection, in-flight close, pending-to-durable migration, selection/follow without ping-pong, agent announce, chat links), plus updated desktop session/driver/ipc/store tests. apps/sim home + browser suites and the full apps/desktop suite pass.
In the desktop app against a local build: opening tabs from + Browser, navigating, titles and favicons, switching, closing, the width cap at 1/3/4 tabs, tabs surviving a chat switch, and tabs restored after quitting and relaunching the app.
Lint, check:audits, check:desktop-bridge, and type-check pass.

Checklist

Code follows project style guidelines
Self-reviewed my changes
Tests added/updated and passing
No new warnings introduced
I confirm that I have read and agree to the terms outlined in the Contributor License Agreement (CLA)

…kground Each live desktop browser page is now its own resource tab in the Chat panel, derived from the desktop app's tab list instead of a persisted singleton "Browser" resource with a second tab strip inside it. The inner browser tab strip, tab pinning, duplicate, reorder, the native tab context menu, and the auto-replacement of a closed last tab are removed. The agent drives its own tab (the desktop's automation cursor) without moving the user's visible page: the renderer no longer force-activates the browser on every tool call nor auto-switches the panel to the agent's tab. The agent's tab is announced as resource activity, so the existing view policy shows it or badges it depending on whether the user has taken over selection. Mentions and attachments point at exact tabs; the chat row never stores browser resources, and legacy rows are dropped on read.

…th cap Review and in-app verification of the resource-tab browser model found five problems, all fixed here with tests: - The strip's switch and follow effects could trade `switch-tab` calls forever after a native switch; the switch effect is now keyed on the selection alone and ignores the switch it requested itself. - Migrating a pending chat onto its durable id briefly removed and re-added every browser tab; a missing store bucket is no longer read as closed. - Chat hydration could replace the resource list underneath a fresh add, dropping restored tabs on return; a tab stays projected until its resource is seen. Hydration also falls back to the last server-held resource instead of whichever tab happened to land first. - Strip-driven `switch-tab` no longer claims the page for the user (`claim: false`), so the agent can still close or adopt it; a user closing the agent's tab leaves the agent cursor unset rather than announcing the neighbour as agent activity. - The driver marked every restored scope as material, refusing pending chat migration after an empty restore; only a restore that yields pages does now, matching the session layer. The bridge snapshot is regenerated with the documented `'new-tab'` fallback. Resource tab titles ellipsize at 200px for one or two tabs, 180px for three, and 160px from four on, one small step at a time.

vercel · 2026-09-10T22:57:04Z

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated
docs	Ready	Preview	Sep 10, 2026 11:15pm UTC

greptile-apps · 2026-09-10T23:01:28Z

Confidence Score: 5/5

The PR appears safe to merge, with no outstanding correctness, security, or repository-rule violations identified.

Summary

Removes the inner browser tab strip, pinning, duplication, and native context-menu actions.
Allows agent automation to continue in a background tab without overriding user selection.
Migrates mentions and attachments from the former singleton browser resource to exact browser tabs.
Updates desktop IPC, bridge contracts, persistence, resource events, and tests for the new tab model.
Replaces the loader’s inline animation duration with a configurable CSS custom property, fully addressing the previous review finding.

Diagram

%%{init: {'theme': 'neutral'}}%%
flowchart LR
    A[Desktop browser session] -->|tab snapshots and events| B[Desktop bridge / IPC]
    B --> C[Browser-tab resource projection]
    C --> D[Chat resource tabs]
    D -->|selection without user claim| B
    E[Agent browser tools] -->|automation tab| A
    A -->|resource activity| C
    C -->|follow or badge according to view policy| D
    F[Mentions and attachments] -->|exact scope and tab IDs| D

_{Reviews (3) · Last reviewed commit: "fix(emcn): drive the loader spin period ..."}

…itles Reordering a browser tab in the resource strip now reorders the desktop's native tab list too, so restore and the agent's tab list keep the strip's order (`reorderTab` returns as an optional bridge method). Dragging a tab into the chat carries the strip's live title rather than the title captured when the tab was added. The fork route test follows the new policy that stored browser rows are dropped.

waleedlatif1 · 2026-09-10T23:07:00Z

@greptile

waleedlatif1 · 2026-09-10T23:07:01Z

@cubic-dev-ai review this PR

cubic-dev-ai · 2026-09-10T23:07:07Z

@cubic-dev-ai review this PR

@waleedlatif1 I have started the AI code review. It will take a few minutes to complete.

…f an inline style

waleedlatif1 · 2026-09-10T23:13:40Z

@greptile

waleedlatif1 · 2026-09-10T23:13:41Z

@cubic-dev-ai review this PR

cubic-dev-ai · 2026-09-10T23:13:46Z

@cubic-dev-ai review this PR

@waleedlatif1 I have started the AI code review. It will take a few minutes to complete.

waleedlatif1 added 2 commits September 10, 2026 15:56

vercel Bot temporarily deployed to Preview September 10, 2026 22:57 Inactive

vercel Bot temporarily deployed to Preview September 10, 2026 23:07 Inactive

greptile-apps Bot reviewed Sep 10, 2026

View reviewed changes

Comment thread ...rkspaceId]/home/components/mothership-view/components/resource-registry/browser-tab-icon.tsx Outdated

fix(emcn): drive the loader spin period from a CSS variable instead o…

c8cec17

…f an inline style

vercel Bot deployed to Preview September 10, 2026 23:15 View deployment

waleedlatif1 merged commit 1a82a17 into staging Sep 10, 2026
28 checks passed

waleedlatif1 deleted the feat/mothership-background-tab branch September 10, 2026 23:17

This was referenced Sep 11, 2026

improvement(desktop): make each terminal its own resource tab #7749

Merged

v0.8.33: kb fixes, chat ui cleanup, connectors instructions improvements #7762

Merged

Navigation Menu

Uh oh!

feat(desktop): browser pages as resource tabs, agent works in a background tab - #7745

feat(desktop): browser pages as resource tabs, agent works in a background tab#7745
waleedlatif1 merged 4 commits into
stagingfrom
feat/mothership-background-tab

waleedlatif1 commented Sep 10, 2026

Uh oh!

vercel Bot commented Sep 10, 2026 •

edited

Loading

Uh oh!

greptile-apps Bot commented Sep 10, 2026 •

edited

Loading

Diagram

Uh oh!

waleedlatif1 commented Sep 10, 2026

Uh oh!

waleedlatif1 commented Sep 10, 2026

Uh oh!

cubic-dev-ai Bot commented Sep 10, 2026

Uh oh!

Uh oh!

waleedlatif1 commented Sep 10, 2026

Uh oh!

waleedlatif1 commented Sep 10, 2026

Uh oh!

cubic-dev-ai Bot commented Sep 10, 2026

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

1 participant

Uh oh!

Conversation

waleedlatif1 commented Sep 10, 2026

Summary

Type of Change

Testing

Checklist

Uh oh!

vercel Bot commented Sep 10, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

greptile-apps Bot commented Sep 10, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Confidence Score: 5/5

Summary

Diagram

Uh oh!

waleedlatif1 commented Sep 10, 2026

Uh oh!

waleedlatif1 commented Sep 10, 2026

Uh oh!

cubic-dev-ai Bot commented Sep 10, 2026

Uh oh!

Uh oh!

waleedlatif1 commented Sep 10, 2026

Uh oh!

waleedlatif1 commented Sep 10, 2026

Uh oh!

cubic-dev-ai Bot commented Sep 10, 2026

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

1 participant

vercel Bot commented Sep 10, 2026 •

edited

Loading

greptile-apps Bot commented Sep 10, 2026 •

edited

Loading