diff --git a/src/main/__tests__/stdiodAccountSwitch.test.ts b/src/main/__tests__/stdiodAccountSwitch.test.ts
new file mode 100644
index 0000000..0fb5656
--- /dev/null
+++ b/src/main/__tests__/stdiodAccountSwitch.test.ts
@@ -0,0 +1,105 @@
+import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest'
+
+// Controller side effects are mocked so the tests never touch launchctl or
+// write config.toml. Each mock is a spy we assert against.
+let launchAgentLoaded = true
+const uninstallMock = vi.fn(async (..._args: unknown[]) => ({ ok: true }) as const)
+const resetMock = vi.fn(async (..._args: unknown[]) => ({ ok: true }) as const)
+
+vi.mock('../stdiod/controller', () => ({
+  isLaunchAgentLoaded: async () => launchAgentLoaded,
+  uninstall: (...args: unknown[]) => uninstallMock(...(args as [])),
+  resetStdiod: (...args: unknown[]) => resetMock(...(args as []))
+}))
+
+vi.mock('../stdiod/stdiodLog', () => ({ stdiodLog: () => {} }))
+
+// Active-account credentials. Overridden per test.
+let apiBaseUrl: string | null = 'https://api.testedison.example'
+let creds: { apiKey: string; edisonSecretKey?: string } | null = {
+  apiKey: 'test-key',
+  edisonSecretKey: 'test-secret'
+}
+
+vi.mock('../infra/setupConfig', () => ({
+  getApiBaseUrl: () => apiBaseUrl,
+  getCredentialsForEnv: () => creds
+}))
+
+import {
+  reprovisionStdiodForActiveAccount,
+  teardownStdiodForSignOut
+} from '../stdiod/accountSwitch'
+
+describe('teardownStdiodForSignOut', () => {
+  beforeEach(() => {
+    uninstallMock.mockClear()
+    resetMock.mockClear()
+    delete process.env.EDISON_DRY_RUN
+  })
+
+  it('unloads the daemon but keeps config.toml (purge:false)', async () => {
+    await teardownStdiodForSignOut()
+    expect(uninstallMock).toHaveBeenCalledTimes(1)
+    expect(uninstallMock).toHaveBeenCalledWith({ purge: false })
+    expect(resetMock).not.toHaveBeenCalled()
+  })
+
+  it('swallows uninstall failures so sign-out never blocks', async () => {
+    uninstallMock.mockRejectedValueOnce(new Error('launchctl exploded'))
+    await expect(teardownStdiodForSignOut()).resolves.toBeUndefined()
+  })
+})
+
+describe('reprovisionStdiodForActiveAccount', () => {
+  beforeEach(() => {
+    uninstallMock.mockClear()
+    resetMock.mockClear()
+    launchAgentLoaded = true
+    apiBaseUrl = 'https://api.testedison.example'
+    creds = { apiKey: 'test-key', edisonSecretKey: 'test-secret' }
+    delete process.env.EDISON_DRY_RUN
+  })
+  afterEach(() => {
+    delete process.env.EDISON_DRY_RUN
+  })
+
+  it('does nothing when the daemon is not installed', async () => {
+    launchAgentLoaded = false
+    await reprovisionStdiodForActiveAccount()
+    expect(resetMock).not.toHaveBeenCalled()
+    expect(uninstallMock).not.toHaveBeenCalled()
+  })
+
+  it('resets the daemon onto the active account when installed', async () => {
+    await reprovisionStdiodForActiveAccount()
+    expect(resetMock).toHaveBeenCalledTimes(1)
+    expect(resetMock).toHaveBeenCalledWith({
+      backend: 'https://api.testedison.example',
+      apiKey: 'test-key',
+      edisonSecretKey: 'test-secret'
+    })
+    expect(uninstallMock).not.toHaveBeenCalled()
+  })
+
+  it('stops the daemon when installed but the active account has no credentials', async () => {
+    creds = null
+    await reprovisionStdiodForActiveAccount()
+    expect(resetMock).not.toHaveBeenCalled()
+    expect(uninstallMock).toHaveBeenCalledWith({ purge: false })
+  })
+
+  it('never re-points onto stale credentials when the backend url is missing', async () => {
+    apiBaseUrl = null
+    await reprovisionStdiodForActiveAccount()
+    expect(resetMock).not.toHaveBeenCalled()
+    expect(uninstallMock).toHaveBeenCalledWith({ purge: false })
+  })
+
+  it('is a no-op under EDISON_DRY_RUN (no launchctl probe in e2e)', async () => {
+    process.env.EDISON_DRY_RUN = '1'
+    await reprovisionStdiodForActiveAccount()
+    expect(resetMock).not.toHaveBeenCalled()
+    expect(uninstallMock).not.toHaveBeenCalled()
+  })
+})
diff --git a/src/main/ipc/ipcHandlers.ts b/src/main/ipc/ipcHandlers.ts
index cf99a73..b6de975 100644
--- a/src/main/ipc/ipcHandlers.ts
+++ b/src/main/ipc/ipcHandlers.ts
@@ -37,6 +37,10 @@ import {
 import { showFeedbackWindow } from '../dialogs/feedbackWindow'
 import { restoreAllQuarantinedServers } from '../runtime/mcpConfigActions'
 import { applyAppIntegrations } from '../runtime/mcpConfigWriter'
+import {
+  reprovisionStdiodForActiveAccount,
+  teardownStdiodForSignOut
+} from '../stdiod/accountSwitch'
 import { registerMcpSubmitHandlers } from './ipcHandlersMcpSubmit'
 import { registerStdiodHandlers } from './ipcHandlersStdiod'
 import {
@@ -170,7 +174,10 @@ export function registerIpcHandlers(deps: IpcHandlerDeps): void {
     }
   })
 
-  ipcMain.handle('setup:reset', () => {
+  ipcMain.handle('setup:reset', async () => {
+    // In-app sign-out. Stop the daemon like the tray sign-out does, else it
+    // keeps tunneling under the old account.
+    await teardownStdiodForSignOut()
     markSetupIncomplete()
     return { ok: true }
   })
@@ -309,6 +316,10 @@ export function registerIpcHandlers(deps: IpcHandlerDeps): void {
       }
     }
 
+    // Re-point the daemon at the new account (or stop it) so it doesn't keep
+    // tunneling under the old credentials.
+    await reprovisionStdiodForActiveAccount()
+
     return { ok: true }
   })
 
diff --git a/src/main/stdiod/accountSwitch.ts b/src/main/stdiod/accountSwitch.ts
new file mode 100644
index 0000000..2897eb9
--- /dev/null
+++ b/src/main/stdiod/accountSwitch.ts
@@ -0,0 +1,60 @@
+// Keep the daemon bound to the active account on sign-out and account switch.
+// config.toml only changes on `login`, so otherwise the daemon stays on the
+// previous account.
+
+import { getApiBaseUrl, getCredentialsForEnv } from '../infra/setupConfig'
+
+import { isLaunchAgentLoaded, resetStdiod, uninstall } from './controller'
+import { stdiodLog } from './stdiodLog'
+
+// Stop the daemon on sign-out. purge=false keeps config.toml for a quick
+// re-enable; unloading the unit is what stops the old tunnel.
+export async function teardownStdiodForSignOut(): Promise<void> {
+  try {
+    await uninstall({ purge: false })
+  } catch (err) {
+    stdiodLog(`sign-out teardown failed: ${err instanceof Error ? err.message : String(err)}`)
+  }
+}
+
+// On account switch: reset an installed daemon onto the new account (keeping
+// its device identity), leave it off if it was off, stop it if there are no
+// credentials.
+export async function reprovisionStdiodForActiveAccount(): Promise<void> {
+  // Don't probe launchctl in tests.
+  if (process.env.EDISON_DRY_RUN === '1') return
+
+  let installed = false
+  try {
+    installed = await isLaunchAgentLoaded()
+  } catch {
+    installed = false
+  }
+  if (!installed) return
+
+  const backend = getApiBaseUrl()
+  const creds = getCredentialsForEnv()
+  if (!backend || !creds?.apiKey) {
+    stdiodLog('account switch: no credentials for the active account; stopping the daemon')
+    await teardownStdiodForSignOut()
+    return
+  }
+
+  stdiodLog('account switch: re-pointing the daemon at the active account')
+  try {
+    const result = await resetStdiod({
+      backend,
+      apiKey: creds.apiKey,
+      edisonSecretKey: creds.edisonSecretKey
+    })
+    if (!result.ok) {
+      stdiodLog(
+        `account switch: reprovision failed: ${result.errorMessage ?? result.errorCode ?? 'unknown'}`
+      )
+    }
+  } catch (err) {
+    stdiodLog(
+      `account switch: reprovision threw: ${err instanceof Error ? err.message : String(err)}`
+    )
+  }
+}