diff --git a/dsh-plugin-desktop/src/desktop-logger.ts b/dsh-plugin-desktop/src/desktop-logger.ts
index 0d347f3fb0..896313406c 100644
--- a/dsh-plugin-desktop/src/desktop-logger.ts
+++ b/dsh-plugin-desktop/src/desktop-logger.ts
@@ -1,4 +1,5 @@
 import type { LogFileSink } from './log-files.ts'
+import { maskSecrets } from './mask-secrets.ts'
 
 /** Logger for Electron-main-scope messages that bypass Cordis `ctx.logger`. */
 export interface DesktopLogger {
@@ -8,13 +9,48 @@ export interface DesktopLogger {
   errorCause(cause: unknown): void
 }
 
+/** Process events needed to make uncaught exceptions observable and fatal. */
+export interface DesktopUncaughtExceptionProcess {
+  once(event: 'uncaughtException', listener: (error: Error) => void): unknown
+  off(event: 'uncaughtException', listener: (error: Error) => void): unknown
+}
+
+/** Persist the first uncaught exception before requesting a fatal exit. */
+export function installDesktopUncaughtExceptionLogging(
+  proc: DesktopUncaughtExceptionProcess,
+  logger: DesktopLogger,
+  exit: (code: number) => void,
+): () => void {
+  let handled = false
+  const handler = (error: Error): void => {
+    if (handled) return
+    handled = true
+    proc.off('uncaughtException', handler)
+    logger.errorCause(error)
+    exit(1)
+  }
+  proc.once('uncaughtException', handler)
+  return () => { proc.off('uncaughtException', handler) }
+}
+
 /** DesktopLogger that writes to the shared sink and mirrors to process.stderr. */
 export class ElectronStderrLogger implements DesktopLogger {
   constructor(private readonly sink: LogFileSink) {}
 
+  /** Accept one fail-loud stderr diagnostic through the persistent logger. */
+  write(chunk: string): boolean {
+    this.error(chunk.replace(/\r?\n$/u, ''))
+    return true
+  }
+
   error(message: string): void {
-    this.sink.write('error', message)
-    process.stderr.write(`${message}\n`)
+    const masked = maskSecrets(message)
+    try {
+      this.sink.write('error', masked)
+    } catch {
+      // Persistent diagnostics are best-effort; stderr must remain available.
+    }
+    process.stderr.write(`${masked}\n`)
   }
 
   errorCause(cause: unknown): void {
diff --git a/dsh-plugin-desktop/src/file-exporter.ts b/dsh-plugin-desktop/src/file-exporter.ts
index 195c80d4f2..58d52efc30 100644
--- a/dsh-plugin-desktop/src/file-exporter.ts
+++ b/dsh-plugin-desktop/src/file-exporter.ts
@@ -1,7 +1,6 @@
 import { Logger, type Exporter, type Message } from '@deepseek-ai/cordis'
 import { shouldEmit, type LogLevel } from './log-level.ts'
 import { LogFileSink } from './log-files.ts'
-import { maskSecrets } from './mask-secrets.ts'
 
 function localTimestamp(ts: number): string {
   const d = new Date(ts)
@@ -40,6 +39,6 @@ export class FileExporter implements Exporter {
   private render(message: Message): string {
     const level = message.type.charAt(0).toUpperCase()
     const body = Logger.format(this, message)
-    return maskSecrets(`${localTimestamp(message.ts)} [${level}] [${message.name}] ${body}`)
+    return `${localTimestamp(message.ts)} [${level}] [${message.name}] ${body}`
   }
 }
diff --git a/dsh-plugin-desktop/src/log-files.ts b/dsh-plugin-desktop/src/log-files.ts
index 3e401e9979..8b85c28482 100644
--- a/dsh-plugin-desktop/src/log-files.ts
+++ b/dsh-plugin-desktop/src/log-files.ts
@@ -4,6 +4,7 @@ import {
 import { join } from 'node:path'
 import type { LogType } from './log-level.ts'
 import { isErrorType } from './log-level.ts'
+import { maskSecrets } from './mask-secrets.ts'
 
 /** Sink configuration with its size ceilings. */
 export interface LogFileSinkOptions {
@@ -46,8 +47,9 @@ export class LogFileSink {
   write(type: LogType, line: string): void {
     const suffix = localDateSuffix(new Date())
     if (suffix !== this.currentDate) this.rollDate(suffix)
-    this.append('all', line)
-    if (isErrorType(type)) this.append('error', line)
+    const masked = maskSecrets(line)
+    this.append('all', masked)
+    if (isErrorType(type)) this.append('error', masked)
   }
 
   /** Write a startup header line to the current full-log file (before ordinary lines). */
diff --git a/dsh-plugin-desktop/src/main.ts b/dsh-plugin-desktop/src/main.ts
index 51c76fdee1..e4612a1424 100644
--- a/dsh-plugin-desktop/src/main.ts
+++ b/dsh-plugin-desktop/src/main.ts
@@ -18,7 +18,11 @@ import {
   installDesktopPnpmRuntime,
 } from './desktop-runtime-environment.ts'
 import { desktopProductVersion, ElectronDesktopRuntime } from './electron-runtime.ts'
-import { ElectronStderrLogger } from './desktop-logger.ts'
+import {
+  ElectronStderrLogger,
+  installDesktopUncaughtExceptionLogging,
+  type DesktopLogger,
+} from './desktop-logger.ts'
 import { FileExporter } from './file-exporter.ts'
 import { DESKTOP_SETTINGS_NAMESPACE, type DesktopSettings } from './index.ts'
 import { LogFileSink } from './log-files.ts'
@@ -52,19 +56,18 @@ const BIN_NAME = 'dsh-plugin-desktop'
 const PRODUCT_NAME = 'DSH Desktop'
 
 /** Report profile recovery without changing startup or rollback outcomes. */
-function notifyProfileRecovery(runtime: ElectronDesktopRuntime, body: string): void {
+function notifyProfileRecovery(runtime: ElectronDesktopRuntime, logger: DesktopLogger, body: string): void {
   try {
     runtime.updates.notify({ title: 'Unable to Open Profile', body })
   } catch (cause) {
-    process.stderr.write(
-      `${BIN_NAME}: failed to show profile recovery notification: ${cause instanceof Error ? cause.message : String(cause)}\n`,
-    )
+    logger.error(`${BIN_NAME}: failed to show profile recovery notification: ${cause instanceof Error ? cause.message : String(cause)}`)
   }
 }
 
 /** Report optional user UI plugins skipped to keep startup recoverable. */
 function notifySkippedOptionalEntries(
   runtime: ElectronDesktopRuntime,
+  logger: DesktopLogger,
   entries: readonly SkippedOptionalEntry[],
 ): void {
   if (entries.length === 0) return
@@ -76,22 +79,21 @@ function notifySkippedOptionalEntries(
       body: `${names[0]} is not installed in this profile${suffix}.`,
     })
   } catch (cause) {
-    process.stderr.write(
-      `${BIN_NAME}: failed to show skipped plugin notification: ${cause instanceof Error ? cause.message : String(cause)}\n`,
-    )
+    logger.error(`${BIN_NAME}: failed to show skipped plugin notification: ${cause instanceof Error ? cause.message : String(cause)}`)
   }
 }
 
 /** Surface path/volume risks that otherwise become obscure sandbox or pnpm failures later. */
-function warnWindowsVolumeConcerns(concerns: readonly WindowsVolumeConcern[]): void {
+function warnWindowsVolumeConcerns(logger: DesktopLogger, concerns: readonly WindowsVolumeConcern[]): void {
   for (const concern of concerns) {
-    process.stderr.write(`${BIN_NAME}: Windows volume warning: ${formatWindowsVolumeConcern(concern)}\n`)
+    logger.error(`${BIN_NAME}: Windows volume warning: ${formatWindowsVolumeConcern(concern)}`)
   }
 }
 
 /** Notify once after the UI is ready; stderr carries the exact paths. */
 function notifyWindowsVolumeConcerns(
   runtime: ElectronDesktopRuntime,
+  logger: DesktopLogger,
   concerns: readonly WindowsVolumeConcern[],
 ): void {
   if (concerns.length === 0) return
@@ -101,9 +103,7 @@ function notifyWindowsVolumeConcerns(
       body: `${concerns[0]?.label ?? 'A configured path'} is on a volume that may break sandboxed commands or plugin installs.`,
     })
   } catch (cause) {
-    process.stderr.write(
-      `${BIN_NAME}: failed to show Windows volume warning: ${cause instanceof Error ? cause.message : String(cause)}\n`,
-    )
+    logger.error(`${BIN_NAME}: failed to show Windows volume warning: ${cause instanceof Error ? cause.message : String(cause)}`)
   }
 }
 
@@ -120,6 +120,7 @@ async function start(): Promise<void> {
   let profileStatePath: string | undefined
   let shutdown: DesktopShutdown | undefined
   let removeShutdownRequests: (() => void) | undefined
+  let removeUncaughtExceptionLogging: (() => void) | undefined
   let disposeDshRuntime: (() => void) | undefined
   let disposePnpmRuntime: (() => void) | undefined
   let fileExporter: FileExporter | undefined
@@ -132,17 +133,16 @@ async function start(): Promise<void> {
   logSink.purgeOlderThan(7)
   logSink.writeHeader(`--- ${BIN_NAME} ${PRODUCT_NAME} ${desktopProductVersion()} ${process.platform} node ${process.version} run ${Date.now()} ---`)
   const electronLogger = new ElectronStderrLogger(logSink)
-  process.on('uncaughtException', (error) => { electronLogger.errorCause(error) })
-  process.on('unhandledRejection', (reason) => {
-    electronLogger.error(`dsh-plugin-desktop: unhandled rejection: ${reason instanceof Error ? reason.stack ?? reason.message : String(reason)}`)
-  })
   const nativeExit = createDesktopExitCoordinator(
     {
       prepareToQuit: () => { runtime.prepareToQuit() },
       relaunch: () => { app.relaunch() },
       exit: code => { app.exit(code) },
     },
-    () => { removeShutdownRequests?.() },
+    () => {
+      removeShutdownRequests?.()
+      removeUncaughtExceptionLogging?.()
+    },
   )
   let restartRequested = false
   runtime = new ElectronDesktopRuntime(async () => {
@@ -176,6 +176,11 @@ async function start(): Promise<void> {
     finalExit,
   )
   const requestQuit = (code: number): void => { void shutdown.request(code) }
+  removeUncaughtExceptionLogging = installDesktopUncaughtExceptionLogging(
+    process,
+    electronLogger,
+    requestQuit,
+  )
   removeShutdownRequests = installShutdownRequests(process, app, requestQuit)
 
   app.on('second-instance', () => { runtime.show() })
@@ -195,12 +200,12 @@ async function start(): Promise<void> {
     { label: 'desktop user data', path: app.getPath('userData') },
     { label: 'DSH home', path: homeDir },
   ])
-  warnWindowsVolumeConcerns(windowsVolumeConcerns)
+  warnWindowsVolumeConcerns(electronLogger, windowsVolumeConcerns)
 
   const failLoudProcess: FailLoudProcess = {
     on: (event, handler) => process.on(event, handler),
     off: (event, handler) => process.off(event, handler),
-    stderr: process.stderr,
+    stderr: electronLogger,
     exit: finalExit,
   }
   installFailLoud(BIN_NAME, failLoudProcess, async () => {
@@ -322,16 +327,17 @@ async function start(): Promise<void> {
       homeDir: prepared.homeDir,
     })
     await runtime.mountScheduled()
-    notifySkippedOptionalEntries(runtime, prepared.skippedOptionalEntries)
-    notifyWindowsVolumeConcerns(runtime, windowsVolumeConcerns)
+    notifySkippedOptionalEntries(runtime, electronLogger, prepared.skippedOptionalEntries)
+    notifyWindowsVolumeConcerns(runtime, electronLogger, windowsVolumeConcerns)
     if (profileStartup.rolledBackFrom !== undefined) {
       notifyProfileRecovery(
         runtime,
+        electronLogger,
         `Reopened last-known-good profile ${activeProfileName}.`,
       )
     }
   } catch (cause) {
-    process.stderr.write(`${BIN_NAME}: ${cause instanceof Error ? cause.stack ?? cause.message : String(cause)}\n`)
+    electronLogger.errorCause(cause)
     let exitCode = 1
     if (profileStartup !== undefined && profileStatePath !== undefined) {
       const retryLastKnownGood = profileStartup.profileName !== profileStartup.state.lastKnownGood
@@ -342,11 +348,12 @@ async function start(): Promise<void> {
           exitCode = 0
           notifyProfileRecovery(
             runtime,
+            electronLogger,
             `Reopening last-known-good profile ${profileStartup.state.lastKnownGood}.`,
           )
         }
       } catch (stateCause) {
-        process.stderr.write(`${BIN_NAME}: failed to roll back desktop profile state: ${stateCause instanceof Error ? stateCause.message : String(stateCause)}\n`)
+        electronLogger.error(`dsh-plugin-desktop: failed to roll back desktop profile state: ${stateCause instanceof Error ? stateCause.message : String(stateCause)}`)
       }
     }
     await shutdown.request(exitCode)
diff --git a/dsh-plugin-desktop/src/mask-secrets.ts b/dsh-plugin-desktop/src/mask-secrets.ts
index 93bd80c049..7c9d8b501f 100644
--- a/dsh-plugin-desktop/src/mask-secrets.ts
+++ b/dsh-plugin-desktop/src/mask-secrets.ts
@@ -1,20 +1,45 @@
 /** Mask secret-shaped substrings in a rendered log line. */
 
 const MASK = '****'
+const COOKIE_HEADER = /\b(Set-Cookie|Cookie)\s*:[^\r\n]*/giu
+const WEB_URL = /https?:\/\/[^\s<>"']+/giu
+const SENSITIVE_QUERY_KEY = /(?:auth|code|credential|key|password|secret|signature|token)/iu
+const NAMED_SECRET = /\b(api[_-]?key|auth|client[_-]?secret|credential|password|passwd|refresh[_-]?token|secret|session(?:id)?|signature|token)\b(\s*[:=]\s*)[^\s,;&]+/giu
 
 /** Secret-shaped patterns applied in order to a rendered log line. */
 const SECRET_PATTERNS: readonly RegExp[] = [
   /\bsk-[A-Za-z0-9]{12,}/gu, // OpenAI/DeepSeek-style sk- keys
   /\b[a-zA-Z0-9]{32,}\b/gu, // long hex/base64 tokens
   /Bearer\s+[A-Za-z0-9._-]+/giu, // Authorization bearer tokens
+  /Basic\s+[A-Za-z0-9+/]+={0,2}/giu, // Authorization basic credentials
 ]
 
+function maskUrl(raw: string): string {
+  const trailing = /[),.;]+$/u.exec(raw)?.[0] ?? ''
+  const value = trailing === '' ? raw : raw.slice(0, -trailing.length)
+  try {
+    const url = new URL(value)
+    if (url.username !== '') url.username = MASK
+    if (url.password !== '') url.password = MASK
+    for (const name of url.searchParams.keys()) {
+      if (SENSITIVE_QUERY_KEY.test(name)) url.searchParams.set(name, MASK)
+    }
+    return `${url.href}${trailing}`
+  } catch {
+    return raw
+  }
+}
+
 /** Replace secret-shaped substrings, preserving a short leading prefix. */
 export function maskSecrets(text: string): string {
   let out = text
+    .replace(COOKIE_HEADER, (_match, name: string) => `${name}: ${MASK}`)
+    .replace(WEB_URL, maskUrl)
+    .replace(NAMED_SECRET, (_match, name: string, separator: string) => `${name}${separator}${MASK}`)
   for (const pattern of SECRET_PATTERNS) {
     out = out.replace(pattern, (match) => {
-      if (match.startsWith('Bearer')) return 'Bearer ****'
+      const authorizationScheme = /^(Bearer|Basic)/iu.exec(match)?.[1]
+      if (authorizationScheme !== undefined) return `${authorizationScheme} ****`
       return `${match.slice(0, 3)}${MASK}`
     })
   }
diff --git a/dsh-plugin-desktop/tests/desktop-logger.spec.ts b/dsh-plugin-desktop/tests/desktop-logger.spec.ts
index 62edbe106c..5d65222e18 100644
--- a/dsh-plugin-desktop/tests/desktop-logger.spec.ts
+++ b/dsh-plugin-desktop/tests/desktop-logger.spec.ts
@@ -1,8 +1,12 @@
+import { EventEmitter } from 'node:events'
 import { mkdtempSync, readFileSync } from 'node:fs'
 import { tmpdir } from 'node:os'
 import { join } from 'node:path'
 import { describe, expect, it, vi } from 'vitest'
-import { ElectronStderrLogger } from '../src/desktop-logger.ts'
+import {
+  ElectronStderrLogger,
+  installDesktopUncaughtExceptionLogging,
+} from '../src/desktop-logger.ts'
 import { LogFileSink } from '../src/log-files.ts'
 
 function todaySuffix(): string {
@@ -43,4 +47,68 @@ describe('ElectronStderrLogger', () => {
     const day = todaySuffix()
     expect(readFileSync(join(dir, `dsh-${day}.log`), 'utf8')).toContain('crash here')
   })
+
+  it('masks secrets in the file and stderr outputs', () => {
+    const { s, dir } = sink()
+    const stderrSpy = vi.spyOn(process.stderr, 'write').mockImplementation(() => true)
+    const logger = new ElectronStderrLogger(s)
+
+    logger.error('request failed with Bearer abc.def.secret')
+
+    const day = todaySuffix()
+    const text = readFileSync(join(dir, `dsh-${day}.log`), 'utf8')
+    expect(text).toContain('Bearer ****')
+    expect(text).not.toContain('abc.def.secret')
+    expect(stderrSpy).toHaveBeenCalledWith('request failed with Bearer ****\n')
+    stderrSpy.mockRestore()
+  })
+
+  it('accepts fail-loud stderr chunks without adding a second newline', () => {
+    const { s, dir } = sink()
+    const stderrSpy = vi.spyOn(process.stderr, 'write').mockImplementation(() => true)
+    const logger = new ElectronStderrLogger(s)
+
+    logger.write('dsh-plugin-desktop: fatal load failure: Bearer abc.def.secret\n')
+
+    const day = todaySuffix()
+    const text = readFileSync(join(dir, `dsh-${day}.log`), 'utf8')
+    expect(text).toContain('fatal load failure: Bearer ****\n')
+    expect(text).not.toContain('abc.def.secret')
+    expect(stderrSpy).toHaveBeenCalledWith('dsh-plugin-desktop: fatal load failure: Bearer ****\n')
+    stderrSpy.mockRestore()
+  })
+
+  it('logs the first uncaught exception and requests a fatal exit', () => {
+    const { s, dir } = sink()
+    const stderrSpy = vi.spyOn(process.stderr, 'write').mockImplementation(() => true)
+    const logger = new ElectronStderrLogger(s)
+    const proc = new EventEmitter()
+    const exit = vi.fn()
+
+    const remove = installDesktopUncaughtExceptionLogging(proc, logger, exit)
+    proc.emit('uncaughtException', new Error('fatal Bearer abc.def.secret'))
+    proc.emit('uncaughtException', new Error('second failure'))
+
+    const day = todaySuffix()
+    const text = readFileSync(join(dir, `dsh-${day}.log`), 'utf8')
+    expect(text).toContain('fatal Bearer ****')
+    expect(text).not.toContain('abc.def.secret')
+    expect(text).not.toContain('second failure')
+    expect(exit).toHaveBeenCalledOnce()
+    expect(exit).toHaveBeenCalledWith(1)
+    expect(proc.listenerCount('uncaughtException')).toBe(0)
+    remove()
+    stderrSpy.mockRestore()
+  })
+
+  it('falls back to masked stderr when the file sink fails', () => {
+    const { s } = sink()
+    vi.spyOn(s, 'write').mockImplementation(() => { throw new Error('disk full') })
+    const stderrSpy = vi.spyOn(process.stderr, 'write').mockImplementation(() => true)
+    const logger = new ElectronStderrLogger(s)
+
+    expect(() => { logger.error('failed with Bearer abc.def.secret') }).not.toThrow()
+    expect(stderrSpy).toHaveBeenCalledWith('failed with Bearer ****\n')
+    stderrSpy.mockRestore()
+  })
 })
diff --git a/dsh-plugin-desktop/tests/log-files.spec.ts b/dsh-plugin-desktop/tests/log-files.spec.ts
index 9db67d3034..5842361918 100644
--- a/dsh-plugin-desktop/tests/log-files.spec.ts
+++ b/dsh-plugin-desktop/tests/log-files.spec.ts
@@ -67,4 +67,15 @@ describe('LogFileSink', () => {
     expect(text.split('\n')[0]).toBe('--- dsh 2.0.0 darwin run 123 ---')
     expect(text).toContain('after header')
   })
+
+  it('masks secrets at the file boundary', () => {
+    const { s, dir } = sink()
+
+    s.write('error', 'Authorization: Bearer abc.def.secret')
+
+    const day = todaySuffix()
+    const text = readFileSync(join(dir, `dsh-${day}.log`), 'utf8')
+    expect(text).toContain('Bearer ****')
+    expect(text).not.toContain('abc.def.secret')
+  })
 })
diff --git a/dsh-plugin-desktop/tests/mask-secrets.spec.ts b/dsh-plugin-desktop/tests/mask-secrets.spec.ts
index 42ae8ce023..eebef669c5 100644
--- a/dsh-plugin-desktop/tests/mask-secrets.spec.ts
+++ b/dsh-plugin-desktop/tests/mask-secrets.spec.ts
@@ -14,6 +14,31 @@ describe('maskSecrets', () => {
     expect(masked).not.toContain('abc.def.ghi')
   })
 
+  it('masks basic authorization credentials', () => {
+    const masked = maskSecrets('Authorization: Basic dXNlcjpwYXNzd29yZA==')
+    expect(masked).toBe('Authorization: Basic ****')
+    expect(masked).not.toContain('dXNlcjpwYXNzd29yZA==')
+  })
+
+  it('masks cookie header values', () => {
+    const masked = maskSecrets('Cookie: session=short-secret; theme=dark')
+    expect(masked).toBe('Cookie: ****')
+    expect(masked).not.toContain('short-secret')
+  })
+
+  it('masks URL userinfo and sensitive query values', () => {
+    const masked = maskSecrets('GET https://user:pass@example.com/api?token=short&mode=fast')
+    expect(masked).toBe('GET https://****:****@example.com/api?token=****&mode=fast')
+    expect(masked).not.toContain('user:pass')
+    expect(masked).not.toContain('token=short')
+  })
+
+  it('masks named secret fields even when their values are short', () => {
+    const masked = maskSecrets('api_key=short password: hunter2 mode=fast')
+    expect(masked).toBe('api_key=**** password: **** mode=fast')
+    expect(masked).not.toContain('hunter2')
+  })
+
   it('leaves ordinary prose untouched', () => {
     expect(maskSecrets('hello world, profile "desktop"')).toBe('hello world, profile "desktop"')
   })