fix(desktop): fix background tab spawning

apps/desktop/src/main/browser-agent/session.test.ts

@@ -1099,26 +1099,27 @@ describe('browser-agent session', () => {
     expect(session.getTabsState().activeTabId).toBe(visible.id)
   })
 
-  it('moves the next agent action to a background copy after the user claims its tab', () => {
+  it('keeps agent actions on a tab after the user selects it', () => {
     const visible = session.ensureTab()
     session.switchTab(visible.id)
 
     const agent = session.ensureAutomationTab()
 
-    expect(agent.id).not.toBe(visible.id)
+    expect(agent.id).toBe(visible.id)
     expect(session.getTabsState().activeTabId).toBe(visible.id)
-    expect(session.getTabsState().automationTabId).toBe(agent.id)
+    expect(session.getTabsState().automationTabId).toBe(visible.id)
+    expect(session.listTabs()).toHaveLength(1)
   })
 
-  it('does not create a background tab until the agent resumes after a toolbar action', () => {
+  it('keeps agent actions on a tab after a toolbar action claims it', () => {
     const visible = session.ensureTab()
 
     expect(session.claimActiveTabForUser()?.id).toBe(visible.id)
     expect(session.listTabs()).toHaveLength(1)
 
     const agent = session.ensureAutomationTab()
-    expect(agent.id).not.toBe(visible.id)
-    expect(session.listTabs()).toHaveLength(2)
+    expect(agent.id).toBe(visible.id)
+    expect(session.listTabs()).toHaveLength(1)
   })
 
   it('does not treat a passive native focus event as user takeover', () => {
@@ -1134,7 +1135,7 @@ describe('browser-agent session', () => {
     expect(session.listTabs()).toHaveLength(1)
   })
 
-  it('moves automation to a background copy after real page interaction', () => {
+  it('keeps automation on the same tab after real page interaction', () => {
     const visible = session.ensureTab()
     const contents = (visible.view as unknown as MockView).webContents
     const beforeMouse = contents.on.mock.calls.find(
@@ -1143,9 +1144,9 @@ describe('browser-agent session', () => {
 
     beforeMouse?.({}, { type: 'mouseDown' })
 
-    expect(session.ensureAutomationTab().id).not.toBe(visible.id)
+    expect(session.ensureAutomationTab().id).toBe(visible.id)
     expect(session.getTabsState().activeTabId).toBe(visible.id)
-    expect(session.listTabs()).toHaveLength(2)
+    expect(session.listTabs()).toHaveLength(1)
   })
 
   it('clears automation indicators instead of moving them when their tab closes', () => {

apps/desktop/src/main/browser-agent/session.ts

@@ -1489,21 +1489,7 @@ function addTabInternal({
   return tab
 }
 
-/** Forks the agent cursor before the user takes over the same live page. */
-function yieldAutomationTabToUser(tab: AgentTab): void {
-  if (currentScope.automationTabId !== tab.id) return
-  const replacement = addTabInternal({ activate: false, notify: false })
-  currentScope.automationTabId = replacement.id
-  const url = sanitizeRestorableUrl(tabUrl(tab))
-  if (url && url !== 'about:blank') {
-    void replacement.view.webContents.loadURL(url).catch(() => {})
-  }
-  applyActiveTabThrottling()
-  persistBrowserSession()
-  events?.onTabsChanged()
-}
-
-/** Marks the visible page as user-owned; automation forks only if it acts again. */
+/** Marks the visible page as user-selected without blocking automation on it. */
 export function claimActiveTabForUser(): AgentTab | null {
   const tab = activeTab()
   if (!tab) return null
@@ -1590,10 +1576,6 @@ export function addAutomationTab(): AgentTab {
 export function ensureAutomationTab(): AgentTab {
   restoreBrowserSession()
   let tab = automationTab()
-  if (tab?.id === currentScope.activeTabId && currentScope.visibleTabUserSelected) {
-    yieldAutomationTabToUser(tab)
-    tab = automationTab()
-  }
   if (tab) return tab
   tab = activeTab()
   if (tab) {
@@ -1608,11 +1590,7 @@ export function ensureAutomationTab(): AgentTab {
 /** Current agent target without creating one. */
 export function requireAutomationTab(): AgentTab {
   restoreBrowserSession()
-  let tab = automationTab()
-  if (tab?.id === currentScope.activeTabId && currentScope.visibleTabUserSelected) {
-    yieldAutomationTabToUser(tab)
-    tab = automationTab()
-  }
+  const tab = automationTab()
   if (!tab) {
     throw new SessionError('No page is open yet — call browser_navigate or browser_open_tab first.')
   }

apps/desktop/src/main/terminal/index.ts

@@ -1133,33 +1133,14 @@ export class TerminalService {
   private requireSession(args: TerminalToolArgs): TerminalSession {
     const requested = typeof args.terminalId === 'string' ? args.terminalId : null
     if (requested) {
-      if (requested === this.activeId && this.activeTerminalUserSelected) {
-        const claimed = this.sessions.get(requested)
-        if (claimed?.alive && requested === this.agentActiveId) {
-          return this.spawn(claimed.currentCwd ?? this.startingCwd(), claimed.cols, claimed.rows, {
-            activateVisible: false,
-            activateAgent: true,
-          })
-        }
-        throw new TerminalError(
-          'INVALID_REQUEST',
-          'That terminal is currently being used by the user. Open or switch to another agent terminal first.'
-        )
-      }
       const session = this.sessions.get(requested)
       if (!session?.alive) {
         throw new TerminalError('NO_SUCH_TERMINAL', unknownTerminal(requested))
       }
       return session
     }
 
-    let active = this.agentActiveId ? this.sessions.get(this.agentActiveId) : null
-    if (active?.terminalId === this.activeId && this.activeTerminalUserSelected) {
-      active = this.spawn(active.currentCwd ?? this.startingCwd(), active.cols, active.rows, {
-        activateVisible: false,
-        activateAgent: true,
-      })
-    }
+    const active = this.agentActiveId ? this.sessions.get(this.agentActiveId) : null
     if (active?.alive) return active
 
     const spawned = this.spawn(this.startingCwd(), 80, 24, {

apps/desktop/src/main/terminal/registry.ts

@@ -1,11 +1,12 @@
 import { statSync } from 'node:fs'
-import type {
-  TerminalCommandEvent,
-  TerminalOperation,
-  TerminalStartOptions,
-  TerminalTabsState,
-  TerminalToolArgs,
-  TerminalToolResponse,
+import {
+  describeRunningCommand,
+  type TerminalCommandEvent,
+  type TerminalOperation,
+  type TerminalStartOptions,
+  type TerminalTabsState,
+  type TerminalToolArgs,
+  type TerminalToolResponse,
 } from '@sim/terminal-protocol'
 import { type BrowserWindow, dialog, type WebContents } from 'electron'
 import type { TerminalSessionSnapshot } from '@/main/desktop-chat-session-store'
@@ -239,7 +240,7 @@ export class TerminalRegistry {
               dialog.showMessageBoxSync(ownerWindow, {
                 type: 'warning',
                 title: 'Close Running Terminal?',
-                message: `${running} is still running.`,
+                message: `${describeRunningCommand(running)} is still running.`,
                 detail: 'Closing this terminal will stop the process.',
                 buttons: ['Close Terminal', 'Cancel'],
                 defaultId: 1,

apps/desktop/src/main/terminal/service.test.ts

@@ -232,7 +232,7 @@ describe('focus-gated shortcuts', () => {
     expect(runShortcut(terminal, 'new-tab', renderer.window)).toBe(false)
   })
 
-  it('moves agent work to a background shell after the user claims the visible terminal', async () => {
+  it('keeps agent work in the visible terminal after the user focuses it', async () => {
     const terminal = service()
     const started = terminal.start({ cols: 80, rows: 24 })
     const visibleId = started.activeTerminalId as string
@@ -243,9 +243,10 @@ describe('focus-gated shortcuts', () => {
     const result = response.result as { terminalId: string } | undefined
 
     expect(response.ok).toBe(true)
-    expect(result?.terminalId).not.toBe(visibleId)
+    expect(result?.terminalId).toBe(visibleId)
+    expect(terminal.getTabs().tabs).toHaveLength(1)
     expect(terminal.getTabs().activeTerminalId).toBe(visibleId)
-    expect(terminal.getTabs().agentActiveTerminalId).toBe(result?.terminalId)
+    expect(terminal.getTabs().agentActiveTerminalId).toBe(visibleId)
   })
 
   it('keeps a running terminal open when close confirmation is declined', () => {

apps/sim/app/workspace/[workspaceId]/home/components/mothership-view/components/resource-content/components/terminal-session/terminal-session.tsx

@@ -35,7 +35,11 @@ import { WebglAddon } from '@xterm/addon-webgl'
 import { type IBufferRange, Terminal } from '@xterm/xterm'
 import { useTheme } from 'next-themes'
 import '@xterm/xterm/css/xterm.css'
-import type { TerminalTabState, TerminalTabsState } from '@sim/terminal-protocol'
+import {
+  describeRunningCommand,
+  type TerminalTabState,
+  type TerminalTabsState,
+} from '@sim/terminal-protocol'
 import { SIM_RESOURCE_DRAG_TYPE } from '@/lib/copilot/resource-types'
 import { TERMINAL_SESSION_RESOURCE_ID } from '@/lib/copilot/resources/types'
 import { getDesktopBridge } from '@/lib/desktop'
@@ -686,7 +690,9 @@ const TerminalView = memo(function TerminalView({
   const closeThisTerminal = useCallback(() => {
     if (
       running &&
-      !window.confirm(`${running} is still running. Close this terminal and stop it?`)
+      !window.confirm(
+        `${describeRunningCommand(running)} is still running. Close this terminal and stop it?`
+      )
     ) {
       return
     }
@@ -978,7 +984,9 @@ export function TerminalSession({ visible, scopeId }: TerminalSessionProps) {
       const tab = tabs.find((entry) => entry.terminalId === terminalId)
       if (
         tab?.running &&
-        !window.confirm(`${tab.running} is still running. Close this terminal and stop it?`)
+        !window.confirm(
+          `${describeRunningCommand(tab.running)} is still running. Close this terminal and stop it?`
+        )
       ) {
         return
       }

apps/sim/app/workspace/[workspaceId]/home/home.tsx

@@ -212,14 +212,13 @@ export function Home({ chatId, userName, userId, tableViewsEnabled }: HomeProps)
   activeResourceParamRef.current = activeResourceParam
 
   function handleResourceEvent(resourceId: string) {
-    // Agent work should always make the resource surface available. Expanding
-    // the panel is independent from selecting a resource: once the user has
-    // chosen another resource, the agent may work in the background without
-    // taking that selection away.
+    // Agent work should always make the resource surface available, but it
+    // must never replace an existing selection. Activity in another resource
+    // stays in the background and gets an attention marker instead.
     if (isResourceCollapsedRef.current) setIsResourceCollapsed(false)
 
     const activeResourceId = activeResourceParamRef.current
-    if (userOwnsResourceViewRef.current && activeResourceId && activeResourceId !== resourceId) {
+    if (activeResourceId && activeResourceId !== resourceId) {
       setResourceActivityIds((current) => new Set(current).add(resourceId))
       return
     }

packages/terminal-protocol/package.json

@@ -17,15 +17,19 @@
   },
   "scripts": {
     "type-check": "tsc --noEmit",
+    "test": "vitest run",
     "lint": "biome check --write --unsafe .",
     "lint:check": "biome check .",
     "format": "biome format --write .",
     "format:check": "biome format ."
   },
-  "dependencies": {},
+  "dependencies": {
+    "@sim/utils": "workspace:*"
+  },
   "devDependencies": {
     "@sim/tsconfig": "workspace:*",
     "@types/node": "24.2.1",
-    "typescript": "^7.0.2"
+    "typescript": "^7.0.2",
+    "vitest": "^4.1.0"
   }
 }

packages/terminal-protocol/src/index.test.ts

@@ -0,0 +1,51 @@
+import { describeRunningCommand } from '@sim/terminal-protocol'
+import { describe, expect, it } from 'vitest'
+
+describe('describeRunningCommand', () => {
+  it('names the program of a bare command', () => {
+    expect(describeRunningCommand('bun run dev')).toBe('bun')
+  })
+
+  it('takes the basename of an absolute program path', () => {
+    expect(describeRunningCommand('/opt/homebrew/bin/claude --resume')).toBe('claude')
+  })
+
+  it('drops the cd/export preamble an agent-launched terminal carries', () => {
+    const command =
+      'cd /Users/someone/Desktop/sim && export PATH="/opt/homebrew/bin:$PATH" && claude "Fix this runtime error in this repo: file upload fails"'
+    expect(describeRunningCommand(command)).toBe('claude')
+  })
+
+  it('ignores separators inside quotes', () => {
+    expect(describeRunningCommand('claude "build && test; deploy | ship"')).toBe('claude')
+    expect(describeRunningCommand("claude 'a && b'")).toBe('claude')
+  })
+
+  it('honors backslash escapes only where the shell does', () => {
+    // Escaped quote keeps the double-quoted run open, so `&&` stays quoted.
+    expect(describeRunningCommand('claude "say \\" && rm -rf /"')).toBe('claude')
+    // A backslash is literal inside single quotes, so that run closes and the
+    // following `&&` is a real separator.
+    expect(describeRunningCommand("claude 'a\\' && jest")).toBe('jest')
+  })
+
+  it('skips environment assignments and wrapper words', () => {
+    expect(describeRunningCommand('NODE_ENV=test bun test')).toBe('bun')
+    expect(describeRunningCommand('sudo /usr/bin/docker compose up')).toBe('docker')
+    expect(describeRunningCommand('env FOO=1 nohup python train.py')).toBe('python')
+  })
+
+  it('reads the last stage of a pipeline', () => {
+    expect(describeRunningCommand('cat log.txt | grep error | less')).toBe('less')
+  })
+
+  it('bounds a label it cannot reduce to a program name', () => {
+    const label = describeRunningCommand(`--${'x'.repeat(200)}`)
+    expect(label.length).toBeLessThanOrEqual(33)
+    expect(label.endsWith('…')).toBe(true)
+  })
+
+  it('describes an unannounced command rather than returning nothing', () => {
+    expect(describeRunningCommand('   ')).toBe('a command')
+  })
+})