fix(terminal): remote query-reply corruption (#7329) + snapshot grid-width repaint (#7279) (#7736)

Co-authored-by: Orca <help@stably.ai>

src/main/daemon/daemon-pty-adapter.ts

@@ -316,7 +316,13 @@ export class DaemonPtyAdapter implements IPtyProvider {
       snapshotCols: result.snapshot.cols,
       snapshotRows: result.snapshot.rows,
       isReattach: true,
-      isAlternateScreen: isAltScreen
+      isAlternateScreen: isAltScreen,
+      // Why: carry the mid-escape tail so the renderer can write it after the
+      // reattach reset — without it the local daemon reattach path renders a
+      // split escape's continuation literally, unlike the remote path (#7329).
+      ...(result.snapshot.pendingEscapeTailAnsi
+        ? { pendingEscapeTailAnsi: result.snapshot.pendingEscapeTailAnsi }
+        : {})
     }
   }
 

src/main/daemon/headless-emulator.ts

@@ -3,6 +3,7 @@ import { Terminal } from '@xterm/headless'
 import { SerializeAddon } from '@xterm/addon-serialize'
 import { Unicode11Addon } from '@xterm/addon-unicode11'
 import { activateOrcaTerminalUnicodeProvider } from '../../shared/terminal-unicode-provider'
+import { advancePartialEscapeTail } from '../../shared/terminal-partial-escape-tail'
 import { extractLastOscTitle } from '../../shared/agent-detection'
 import { collectHeadlessOscLinkRanges } from './headless-osc-link-ranges'
 import { extractOscScanTail, scanOsc7Uris } from './osc7-uri-extraction'
@@ -36,6 +37,13 @@ export class HeadlessEmulator {
   private oscScanTail = ''
   private privateModes = new TerminalPrivateModeTracker()
   private restoredOscLinks: TerminalOscLinkRange[] = []
+  // Why: a PTY read can end mid-escape-sequence — those bytes live in xterm's
+  // parser, not the screen buffer, so serialize() drops them and the next
+  // chunk's continuation renders literally after a remote snapshot restore
+  // (#7329). Track the unparsed trailing partial at ingest (committed after
+  // xterm parses the same bytes, like the private-mode mirror) and ship it in
+  // the snapshot so the restorer can complete the sequence.
+  private partialEscapeTail = ''
   private disposed = false
   private readonly pathFlavor?: 'posix' | 'win32'
   private readonly remotePosixFileUriAuthority: boolean
@@ -89,6 +97,7 @@ export class HeadlessEmulator {
         // Why: snapshots combine serialized xterm state with mirrored mouse
         // modes. Commit the mirror only after xterm has parsed the same bytes.
         this.privateModes.scan(data)
+        this.partialEscapeTail = advancePartialEscapeTail(this.partialEscapeTail, data)
         resolve()
       })
     })
@@ -115,6 +124,7 @@ export class HeadlessEmulator {
     // PTY bursts; queued headless writes can snapshot half-cleared TUI rows.
     writeSync.call((this.terminal as TerminalWithSynchronousWrite)._core, data)
     this.privateModes.scan(data)
+    this.partialEscapeTail = advancePartialEscapeTail(this.partialEscapeTail, data)
     return true
   }
 
@@ -164,7 +174,13 @@ export class HeadlessEmulator {
       cols: this.terminal.cols,
       rows: this.terminal.rows,
       scrollbackLines: this.terminal.buffer.normal.length - this.terminal.rows,
-      lastTitle: this.lastTitle ?? undefined
+      lastTitle: this.lastTitle ?? undefined,
+      // Why: written LAST by the restorer (after any reset) so the next live
+      // chunk completes this dangling sequence instead of rendering it literally
+      // (#7329). Its bytes are already counted by the snapshot seq.
+      ...(this.partialEscapeTail.length > 0
+        ? { pendingEscapeTailAnsi: this.partialEscapeTail }
+        : {})
     }
   }
 

src/main/daemon/repro-7329-remote-snapshot-corruption.test.ts

@@ -0,0 +1,157 @@
+import { describe, expect, it } from 'vitest'
+import { Terminal } from '@xterm/headless'
+import { HeadlessEmulator } from './headless-emulator'
+
+// Repro for #7329: "remote server + terminal" — typing gets escape sequences
+// injected/wrapped around it and follow-up commands are corrupted.
+//
+// The remote-server path serializes terminal state on the daemon via
+// HeadlessEmulator.getSnapshot() (SerializeAddon + buildRehydrateSequences) and
+// replays it into the renderer xterm, then applies POST_REPLAY_REATTACH_RESET.
+// This test drives the REAL daemon serializer and a REAL renderer-side xterm to
+// see what the user's terminal ends up looking like after a subscribe/reattach.
+
+const RESET_TERMINAL_CURSOR_STYLE = '\x1b[0 q'
+const RESET_KITTY_KEYBOARD_PROTOCOL = '\x1b[<99u\x1b[=0u'
+// Verbatim from layout-serialization.ts (the reattach path the remote onSnapshot uses).
+const POST_REPLAY_REATTACH_RESET = `${RESET_TERMINAL_CURSOR_STYLE}${RESET_KITTY_KEYBOARD_PROTOCOL}\x1b[?25h\x1b[?1004l`
+
+function writeXterm(term: Terminal, data: string): Promise<void> {
+  return new Promise((resolve) => term.write(data, resolve))
+}
+
+async function emulatorWrite(emu: HeadlessEmulator, data: string): Promise<void> {
+  await emu.write(data)
+}
+
+/** Replay a daemon snapshot into a renderer xterm exactly like the remote
+ *  onSnapshot → replayDataCallback path: clear, write rehydrate+snapshot,
+ *  then the reattach mode reset. */
+async function replayRemoteSnapshot(
+  term: Terminal,
+  snapshot: { rehydrateSequences: string; snapshotAnsi: string; pendingEscapeTailAnsi?: string }
+): Promise<void> {
+  await writeXterm(term, '\x1b[2J\x1b[3J\x1b[H')
+  await writeXterm(term, snapshot.rehydrateSequences + snapshot.snapshotAnsi)
+  await writeXterm(term, POST_REPLAY_REATTACH_RESET)
+  // The fix: the restorer writes the pending mid-escape tail LAST, after the
+  // reset (mirrors drainReplayDataQueue in pty-connection.ts).
+  if (snapshot.pendingEscapeTailAnsi) {
+    await writeXterm(term, snapshot.pendingEscapeTailAnsi)
+  }
+}
+
+function renderVisible(term: Terminal): string {
+  const buf = term.buffer.active
+  const lines: string[] = []
+  for (let y = 0; y < term.rows; y += 1) {
+    lines.push(buf.getLine(buf.viewportY + y)?.translateToString(true) ?? '')
+  }
+  return lines.join('\n').replace(/\s+$/g, '')
+}
+
+describe('#7329 remote-server snapshot corruption', () => {
+  it('leaves bracketed-paste + mouse modes armed after a reattach snapshot', async () => {
+    const emu = new HeadlessEmulator({ cols: 80, rows: 24 })
+    const term = new Terminal({ cols: 80, rows: 24, allowProposedApi: true })
+    try {
+      // A live remote shell that armed bracketed paste (bash 4.4+/readline
+      // default) and vt200+SGR mouse (a TUI the user just exited).
+      await emulatorWrite(emu, '\x1b[?2004h\x1b[?1000h\x1b[?1006h')
+      await emulatorWrite(emu, 'user@host:~$ ')
+
+      const snapshot = emu.getSnapshot({ scrollbackRows: 0 })
+      // The daemon snapshot re-arms the modes it observed.
+      expect(snapshot.rehydrateSequences).toContain('\x1b[?2004h')
+      expect(snapshot.modes.bracketedPaste).toBe(true)
+      expect(snapshot.modes.mouseTracking).toBe(true)
+
+      await replayRemoteSnapshot(term, snapshot)
+
+      // After the remote reattach reset, the renderer xterm is STILL in
+      // bracketed-paste + mouse mode — even though POST_REPLAY_REATTACH_RESET
+      // ran. Cold restore's POST_REPLAY_MODE_RESET would have cleared these.
+      expect(term.modes.bracketedPasteMode).toBe(true) // leak
+      expect(term.modes.mouseTrackingMode).not.toBe('none') // leak
+    } finally {
+      emu.dispose()
+      term.dispose()
+    }
+  })
+
+  it('drops a mid-escape tail so continuation bytes render literally after reattach', async () => {
+    const emu = new HeadlessEmulator({ cols: 80, rows: 24 })
+    const term = new Terminal({ cols: 80, rows: 24, allowProposedApi: true })
+    try {
+      // A remote PTY read that ends mid-escape: the shell was about to paint a
+      // colored prompt but the read boundary split the SGR sequence. The next
+      // read carries the continuation. The daemon serializes BETWEEN the two
+      // reads (e.g. the client subscribes/reattaches right then).
+      await emulatorWrite(emu, 'first line\r\n')
+      await emulatorWrite(emu, '\x1b[3') // <-- partial SGR: "\x1b[38;5;...m" started
+
+      const snapshot = emu.getSnapshot({ scrollbackRows: 0 })
+      // The serializer still cannot put the dangling "\x1b[3" in the screen ANSI
+      // (it lives in the parser)...
+      expect(snapshot.snapshotAnsi).not.toContain('\x1b[3')
+      // ...but the emulator now ships it as a separate pending-escape tail.
+      expect(snapshot.pendingEscapeTailAnsi).toBe('\x1b[3')
+
+      await replayRemoteSnapshot(term, snapshot)
+
+      // The continuation of the split escape arrives as the next live chunk.
+      await writeXterm(term, '8;5;196mred$ yes\r\n')
+
+      const visible = renderVisible(term)
+      // FIXED: the tail was replayed after the reset, so the continuation
+      // "8;5;196m" completes the SGR escape and is consumed — not rendered
+      // literally. The visible text is just the prompt + typed command.
+      expect(visible).not.toContain('8;5;196m')
+      expect(visible).toContain('red$ yes')
+    } finally {
+      emu.dispose()
+      term.dispose()
+    }
+  })
+
+  it('does not eat the continuation byte when the tail and continuation are contiguous', async () => {
+    // The safety property the fix relies on (mirrors the snapshot-seq accounting
+    // in orca-runtime/getOutputAfterSnapshotSeq): the snapshot seq counts the
+    // tail bytes, so the FIRST live chunk after the snapshot is the exact
+    // continuation and completes the dangling sequence with no eaten byte.
+    const emu = new HeadlessEmulator({ cols: 80, rows: 24 })
+    const term = new Terminal({ cols: 80, rows: 24, allowProposedApi: true })
+    try {
+      await emulatorWrite(emu, '\x1b[38;5;') // dangling: params so far
+      const snapshot = emu.getSnapshot({ scrollbackRows: 0 })
+      expect(snapshot.pendingEscapeTailAnsi).toBe('\x1b[38;5;')
+      await replayRemoteSnapshot(term, snapshot)
+      // Continuation completes the SGR then prints a visible token.
+      await writeXterm(term, '82mHELLO')
+      const visible = renderVisible(term)
+      // No byte of "82m" leaks; the token renders whole (color applied).
+      expect(visible).toBe('HELLO')
+    } finally {
+      emu.dispose()
+      term.dispose()
+    }
+  })
+
+  it('documents the residual edge: an idle-death tail eats the next output byte', async () => {
+    // KNOWN, ACCEPTED trade-off: if a mid-escape read is the LAST thing the
+    // process emits (it dies/idles and never sends the continuation), the tail
+    // sits armed in the parser and the NEXT unrelated output loses its first
+    // byte. This is strictly narrower than the bug it fixes (which garbled every
+    // real split escape), and pre-fix such a stream simply dropped the partial.
+    const term = new Terminal({ cols: 80, rows: 24, allowProposedApi: true })
+    try {
+      await writeXterm(term, 'prompt$ ')
+      await writeXterm(term, '\x1b[3') // armed tail, no continuation ever comes
+      await writeXterm(term, 'yes\r\n') // unrelated later output
+      // The 'y' is absorbed as a CSI parameter of the dangling sequence.
+      expect(renderVisible(term)).toBe('prompt$ es')
+    } finally {
+      term.dispose()
+    }
+  })
+})

src/main/daemon/types.ts

@@ -25,6 +25,12 @@ export type TerminalSnapshot = {
   scrollbackAnsi: string
   oscLinks?: TerminalOscLinkRange[]
   rehydrateSequences: string
+  /** The trailing partial escape sequence left unparsed in the emulator when a
+   *  PTY read ended mid-escape. serialize() cannot carry it (it lives in the
+   *  parser, not the buffer), so the restorer must write it LAST — after any
+   *  post-snapshot reset — so the next live chunk's continuation completes the
+   *  sequence instead of rendering literally (#7329). */
+  pendingEscapeTailAnsi?: string
   cwd: string | null
   modes: TerminalModes
   cols: number

src/main/ipc/pty.ts

@@ -2614,6 +2614,7 @@ export function registerPtyHandlers(
       seq?: number
       source?: 'headless' | 'renderer'
       alternateScreen?: boolean
+      pendingEscapeTailAnsi?: string
     } | null> => {
       if (!runtime || typeof args?.id !== 'string' || args.id.length === 0) {
         return null

src/main/runtime/orca-runtime.ts

@@ -5707,6 +5707,7 @@ export class OrcaRuntimeService {
     source?: 'headless' | 'renderer'
     oscLinks?: TerminalOscLinkRange[]
     alternateScreen?: boolean
+    pendingEscapeTailAnsi?: string
   } | null> {
     return this.serializeTerminalBufferFromAvailableState(ptyId, opts)
   }
@@ -5741,6 +5742,7 @@ export class OrcaRuntimeService {
     source?: 'headless' | 'renderer'
     oscLinks?: TerminalOscLinkRange[]
     alternateScreen?: boolean
+    pendingEscapeTailAnsi?: string
   } | null> {
     const headlessSnapshot = await this.serializeHeadlessTerminalBuffer(ptyId, {
       ...opts,
@@ -6021,6 +6023,7 @@ export class OrcaRuntimeService {
     source?: 'headless' | 'renderer'
     oscLinks?: TerminalOscLinkRange[]
     alternateScreen?: boolean
+    pendingEscapeTailAnsi?: string
   } | null> {
     const headlessSnapshot = await this.serializeHeadlessTerminalBuffer(ptyId, opts)
     if (headlessSnapshot) {
@@ -6138,6 +6141,10 @@ export class OrcaRuntimeService {
     source?: 'headless'
     oscLinks?: TerminalOscLinkRange[]
     alternateScreen?: boolean
+    // Why: dangling mid-escape tail the restorer must write LAST, after any
+    // reset, so the next live chunk completes it instead of rendering it
+    // literally (#7329).
+    pendingEscapeTailAnsi?: string
   } | null> {
     const state = this.headlessTerminals.get(ptyId)
     if (!state) {
@@ -6166,6 +6173,9 @@ export class OrcaRuntimeService {
           seq: state.outputSequence,
           source: 'headless',
           oscLinks: snapshot.oscLinks,
+          ...(snapshot.pendingEscapeTailAnsi
+            ? { pendingEscapeTailAnsi: snapshot.pendingEscapeTailAnsi }
+            : {}),
           // Why: lets the renderer skip the destructive scrollback clear when
           // restoring an alt-screen snapshot — clearing wipes xterm's own
           // history that the TUI relies on for scroll-up after a tab return.

src/main/runtime/rpc/methods/terminal.ts

@@ -55,6 +55,7 @@ type SnapshotFrameOptions = {
   truncatedByByteBudget?: boolean
   source?: 'headless' | 'renderer'
   oscLinks?: TerminalOscLinkRange[]
+  pendingEscapeTailAnsi?: string
 }
 
 type SerializedSnapshot = {
@@ -67,6 +68,7 @@ type SerializedSnapshot = {
   oscLinks?: TerminalOscLinkRange[]
   scrollbackRows: number
   truncatedByByteBudget: boolean
+  pendingEscapeTailAnsi?: string
 } | null
 
 type TerminalViewportClient = {
@@ -466,6 +468,7 @@ function sendSnapshotFrames(
       cwd: options.cwd,
       source: options.source,
       oscLinks: options.oscLinks,
+      pendingEscapeTailAnsi: options.pendingEscapeTailAnsi,
       truncated: options.truncated === true,
       truncatedByByteBudget: options.truncatedByByteBudget === true
     })
@@ -1398,6 +1401,7 @@ export const TERMINAL_METHODS: RpcAnyMethod[] = [
             cwd: serialized?.cwd,
             source: serialized?.source,
             oscLinks: serialized?.oscLinks,
+            pendingEscapeTailAnsi: serialized?.pendingEscapeTailAnsi,
             truncated: false,
             truncatedByByteBudget: serialized?.truncatedByByteBudget,
             data: serialized?.data ?? ''
@@ -1602,6 +1606,7 @@ export const TERMINAL_METHODS: RpcAnyMethod[] = [
             truncatedByByteBudget: serialized?.truncatedByByteBudget,
             source: serialized?.source,
             oscLinks: serialized?.oscLinks,
+            pendingEscapeTailAnsi: serialized?.pendingEscapeTailAnsi,
             data: serialized?.data ?? (read.tail.length > 0 ? `${read.tail.join('\r\n')}\r\n` : '')
           })
           // Why: baseline for resize re-stream gating; the client already

src/main/runtime/rpc/terminal-multiplex-escape-tail.test.ts

@@ -0,0 +1,125 @@
+import { describe, expect, it, vi } from 'vitest'
+import { RpcDispatcher } from './dispatcher'
+import type { RpcRequest } from './core'
+import type { OrcaRuntimeService } from '../orca-runtime'
+import { TERMINAL_METHODS } from './methods/terminal'
+import type { RuntimeTerminalWait } from '../../../shared/runtime-types'
+import {
+  TerminalStreamOpcode,
+  decodeTerminalStreamFrame,
+  decodeTerminalStreamJson,
+  encodeTerminalStreamFrame,
+  encodeTerminalStreamJson
+} from '../../../shared/terminal-stream-protocol'
+
+// Transport-level regression for #7329: the daemon's mid-escape tail
+// (pendingEscapeTailAnsi) must survive the terminal.multiplex wire so the
+// renderer can replay it after the reset. Without threading it through the
+// SnapshotStart JSON frame, the tail is lost and the next live chunk renders
+// literally ("colors/garbage around what I type").
+
+function stubRuntime(overrides: Partial<OrcaRuntimeService> = {}): OrcaRuntimeService {
+  return {
+    getRuntimeId: () => 'test-runtime',
+    ...overrides
+  } as OrcaRuntimeService
+}
+
+function makeRequest(method: string, params?: unknown): RpcRequest {
+  return { id: 'req-1', authToken: 'tok', method, params }
+}
+
+describe('terminal.multiplex pending-escape-tail threading (#7329)', () => {
+  it('carries the daemon pendingEscapeTailAnsi through the SnapshotStart frame', async () => {
+    vi.useFakeTimers()
+    try {
+      const messages: string[] = []
+      const binaryFrames: Uint8Array<ArrayBufferLike>[] = []
+      const handlers = new Map<
+        number,
+        (frame: NonNullable<ReturnType<typeof decodeTerminalStreamFrame>>) => void
+      >()
+      const cleanups = new Map<string, () => void>()
+      const runtime = stubRuntime({
+        resolveLeafForHandle: vi.fn().mockReturnValue({ ptyId: 'pty-1' }),
+        readTerminal: vi.fn().mockResolvedValue({ tail: [], truncated: false }),
+        serializeTerminalBuffer: vi.fn().mockResolvedValue({
+          data: 'user@host:~$ ',
+          cols: 80,
+          rows: 24,
+          // The dangling partial the emulator could not serialize.
+          pendingEscapeTailAnsi: '\x1b[3'
+        }),
+        getTerminalSize: vi.fn().mockReturnValue({ cols: 80, rows: 24 }),
+        getMobileDisplayMode: vi.fn().mockReturnValue('auto'),
+        getLayout: vi.fn().mockReturnValue({ seq: 1 }),
+        subscribeToTerminalData: vi.fn().mockReturnValue(vi.fn()),
+        subscribeToTerminalResize: vi.fn().mockReturnValue(vi.fn()),
+        subscribeToFitOverrideChanges: vi.fn().mockReturnValue(vi.fn()),
+        subscribeToDriverChanges: vi.fn().mockReturnValue(vi.fn()),
+        getTerminalFitOverride: vi.fn().mockReturnValue(null),
+        getDriver: vi.fn().mockReturnValue({ kind: 'idle' }),
+        registerSubscriptionCleanup: vi.fn((id: string, cleanup: () => void) => {
+          cleanups.set(id, cleanup)
+        }),
+        cleanupSubscription: vi.fn((id: string) => {
+          const cleanup = cleanups.get(id)
+          cleanups.delete(id)
+          cleanup?.()
+        }),
+        waitForTerminal: vi.fn(() => new Promise<RuntimeTerminalWait>(() => {})),
+        updateDesktopViewport: vi.fn().mockResolvedValue(true)
+      })
+      const dispatcher = new RpcDispatcher({ runtime, methods: TERMINAL_METHODS })
+
+      const dispatchPromise = dispatcher.dispatchStreaming(
+        makeRequest('terminal.multiplex', {}),
+        (msg) => messages.push(msg),
+        {
+          connectionId: 'conn-1',
+          sendBinary: (bytes) => binaryFrames.push(bytes),
+          registerBinaryStreamHandler: (streamId, handler) => {
+            handlers.set(streamId, handler)
+            return () => handlers.delete(streamId)
+          }
+        }
+      )
+
+      await vi.runOnlyPendingTimersAsync()
+      expect(messages.some((msg) => JSON.parse(msg).result?.type === 'ready')).toBe(true)
+
+      handlers.get(0)?.(
+        decodeTerminalStreamFrame(
+          encodeTerminalStreamFrame({
+            opcode: TerminalStreamOpcode.Subscribe,
+            streamId: 0,
+            seq: 1,
+            payload: encodeTerminalStreamJson({
+              streamId: 5,
+              terminal: 'terminal-1',
+              client: { id: 'desktop-1', type: 'desktop' }
+            })
+          })
+        )!
+      )
+
+      // Drive the subscribe promise chain (readTerminal/serialize awaits + the
+      // output-batcher flush timer) to completion.
+      for (let i = 0; i < 5; i += 1) {
+        await vi.runOnlyPendingTimersAsync()
+      }
+
+      const snapshotStart = binaryFrames
+        .map((frame) => decodeTerminalStreamFrame(frame))
+        .find((frame) => frame?.opcode === TerminalStreamOpcode.SnapshotStart)!
+      expect(decodeTerminalStreamJson(snapshotStart.payload)).toMatchObject({
+        pendingEscapeTailAnsi: '\x1b[3'
+      })
+
+      runtime.cleanupSubscription('terminal-multiplex:conn-1')
+      await dispatchPromise
+    } finally {
+      vi.useRealTimers()
+    }
+  })
+})

src/preload/api-types.ts

@@ -1174,6 +1174,7 @@ export type PreloadApi = {
       seq?: number
       source?: 'headless' | 'renderer'
       alternateScreen?: boolean
+      pendingEscapeTailAnsi?: string
     } | null>
     getRendererDeliveryDebugSnapshot: () => Promise<{
       pendingPtyCount: number

src/preload/index.ts

@@ -850,6 +850,7 @@ const api = {
       seq?: number
       source?: 'headless' | 'renderer'
       alternateScreen?: boolean
+      pendingEscapeTailAnsi?: string
     } | null> => ipcRenderer.invoke('pty:getMainBufferSnapshot', { id, opts }),
 
     getRendererDeliveryDebugSnapshot: (): Promise<{

src/renderer/src/components/terminal-pane/pty-connection.test.ts

@@ -205,6 +205,7 @@ type MockTransport = {
     ) => unknown
   }
   sendInput: ReturnType<typeof vi.fn>
+  sendInputImmediate: ReturnType<typeof vi.fn>
   sendInputAccepted?: ReturnType<typeof vi.fn>
   resize: ReturnType<typeof vi.fn>
   getPtyId: ReturnType<typeof vi.fn>
@@ -353,6 +354,9 @@ function createMockTransport(initialPtyId: string | null = null): MockTransport
     serializeBuffer: undefined
   } as MockTransport
   const sendInput = transport.sendInput as unknown as (data: string) => boolean
+  // Why: query replies now route through sendInputImmediate; delegate to the
+  // same spy so assertions on reply delivery still observe them (#7329).
+  transport.sendInputImmediate = vi.fn((data: string) => sendInput(data))
   transport.sendInputAccepted = vi.fn(async (data: string) => sendInput(data))
   return transport
 }
@@ -5247,6 +5251,189 @@ describe('connectPanePty', () => {
     )
   })
 
+  it('resizes the pane to the snapshot grid before replaying daemon snapshot bytes (bug #7279)', async () => {
+    // Why: the daemon serializes soft-wrapped lines as continuous text. Replaying
+    // that at the pane's current column count rewraps rows one cell early/late.
+    // The reattach path must resize xterm to the snapshot's grid before writing
+    // the snapshot bytes, so a remote pane whose size drifted from the daemon's
+    // grid still repaints the exact host layout.
+    const { connectPanePty } = await import('./pty-connection')
+    const transport = createMockTransport()
+    transport.connect.mockImplementation(async ({ sessionId }: { sessionId?: string }) => {
+      if (sessionId) {
+        return {
+          id: sessionId,
+          snapshot: '\x1b[?1004hrestored snapshot',
+          snapshotCols: 80,
+          snapshotRows: 24
+        }
+      }
+      return null
+    })
+    transportFactoryQueue.push(transport)
+    mockStoreState = {
+      ...mockStoreState,
+      tabsByWorktree: {
+        'wt-1': [{ id: 'tab-1', ptyId: 'tab-pty' }]
+      }
+    } as StoreState
+
+    // createPane opens the pane at 120x40, deliberately different from the
+    // daemon snapshot's 80x24 grid.
+    const pane = createPane(1)
+    const manager = createManager(1)
+    const deps = createDeps({
+      restoredLeafId: LEAF_1,
+      restoredPtyIdByLeafId: { [LEAF_1]: 'tab-pty' }
+    })
+
+    connectPanePty(pane as never, manager as never, deps as never)
+    await flushAsyncTicks(20)
+
+    // Pane was resized to the snapshot grid before the snapshot bytes landed.
+    expect(pane.terminal.resize).toHaveBeenCalledWith(80, 24)
+    const resizeToSnapshotCall = pane.terminal.resize.mock.invocationCallOrder.find(
+      (_order, index) => {
+        const [cols, rows] = pane.terminal.resize.mock.calls[index]
+        return cols === 80 && rows === 24
+      }
+    )
+    const snapshotWriteCall = pane.terminal.write.mock.invocationCallOrder.find(
+      (_order, index) => pane.terminal.write.mock.calls[index][0] === '\x1b[?1004hrestored snapshot'
+    )
+    expect(resizeToSnapshotCall).toBeDefined()
+    expect(snapshotWriteCall).toBeDefined()
+    expect(resizeToSnapshotCall as number).toBeLessThan(snapshotWriteCall as number)
+  })
+
+  it('writes the daemon pendingEscapeTailAnsi after the reset on local reattach (#7329)', async () => {
+    // Why: the mid-escape tail must be re-armed LAST — after the reattach reset,
+    // whose ESC would abort it — so the racing live continuation completes it
+    // instead of rendering literally. Covers the local daemon reattach path,
+    // which previously dropped the field the remote path already honored.
+    const { connectPanePty } = await import('./pty-connection')
+    const transport = createMockTransport()
+    transport.connect.mockImplementation(async ({ sessionId }: { sessionId?: string }) => {
+      if (sessionId) {
+        return {
+          id: sessionId,
+          snapshot: 'restored snapshot',
+          snapshotCols: 80,
+          snapshotRows: 24,
+          pendingEscapeTailAnsi: '\x1b[3'
+        }
+      }
+      return null
+    })
+    transportFactoryQueue.push(transport)
+    mockStoreState = {
+      ...mockStoreState,
+      tabsByWorktree: { 'wt-1': [{ id: 'tab-1', ptyId: 'tab-pty' }] }
+    } as StoreState
+
+    const pane = createPane(1)
+    const manager = createManager(1)
+    const deps = createDeps({
+      restoredLeafId: LEAF_1,
+      restoredPtyIdByLeafId: { [LEAF_1]: 'tab-pty' }
+    })
+
+    connectPanePty(pane as never, manager as never, deps as never)
+    await flushAsyncTicks(20)
+
+    const tailWriteCall = pane.terminal.write.mock.invocationCallOrder.find(
+      (_order, index) => pane.terminal.write.mock.calls[index][0] === '\x1b[3'
+    )
+    const resetWriteCall = pane.terminal.write.mock.invocationCallOrder.find((_order, index) =>
+      String(pane.terminal.write.mock.calls[index][0]).includes(POST_REPLAY_REATTACH_RESET)
+    )
+    expect(tailWriteCall).toBeDefined()
+    expect(resetWriteCall).toBeDefined()
+    // The dangling tail is written AFTER the reset.
+    expect(resetWriteCall as number).toBeLessThan(tailWriteCall as number)
+  })
+
+  it('routes native onData query replies through sendInputImmediate, typed input through sendInput (#7329)', async () => {
+    // Why this test: the mock transport delegates sendInputImmediate to the
+    // sendInput spy, so reply-delivery assertions elsewhere cannot tell the two
+    // apart — reverting the onData isTerminalQueryReply branch used to pass the
+    // whole suite. This pins the routing decision itself.
+    const { connectPanePty } = await import('./pty-connection')
+    enableActiveRuntimeEnvironment()
+    const pane = createPane(1)
+    const transport = createMockTransport('remote:web-env-1@@pty-7329')
+    transportFactoryQueue.push(transport)
+    const manager = createManager(1, 1)
+    const deps = createDeps()
+
+    connectPanePty(pane as never, manager as never, deps as never)
+    await flushAsyncTicks()
+
+    // xterm answers CSI 6n natively by emitting a CPR through onData, mixed
+    // with keystrokes. It must take the immediate path (skips the remote 8ms
+    // input debounce that corrupted it).
+    sendTerminalInputThroughPane(pane, '\x1b[3;1R')
+    expect(transport.sendInputImmediate).toHaveBeenCalledWith('\x1b[3;1R')
+
+    // Ordinary typed input must stay on the debounced path — never immediate.
+    transport.sendInputImmediate.mockClear()
+    sendTerminalInputThroughPane(pane, 'yes')
+    sendTerminalInputThroughPane(pane, '\x1b[A') // arrow-key auto-repeat stays batched
+    expect(transport.sendInput).toHaveBeenCalledWith('yes')
+    expect(transport.sendInput).toHaveBeenCalledWith('\x1b[A')
+    expect(transport.sendInputImmediate).not.toHaveBeenCalled()
+  })
+
+  it('writes the onReplayData pendingEscapeTailAnsi meta last, after the replayed bytes (#7329)', async () => {
+    // Why this test: the remote snapshot path delivers the daemon tail through
+    // transport callbacks.onReplayData meta into drainReplayDataQueue. That
+    // consumer (and the replayDataCallback meta threading before it) had no
+    // failing test — severing the meta pass-through kept the suite green.
+    const { connectPanePty } = await import('./pty-connection')
+    enableActiveRuntimeEnvironment()
+    const pane = createPane(1)
+    const writes: string[] = []
+    pane.terminal.write = vi.fn((data: string, callback?: () => void) => {
+      writes.push(data)
+      callback?.()
+    }) as typeof pane.terminal.write
+    const transport = createMockTransport('remote:web-env-1@@pty-7329-tail')
+    const replayCallback: {
+      current:
+        | ((
+            data: string,
+            meta?: { clearBeforeReplay?: boolean; pendingEscapeTailAnsi?: string }
+          ) => void)
+        | null
+    } = { current: null }
+    transport.connect.mockImplementation(async ({ callbacks }: { callbacks: ConnectCallbacks }) => {
+      replayCallback.current = callbacks.onReplayData ?? null
+      return { id: 'remote:web-env-1@@pty-7329-tail', replay: '' }
+    })
+    transportFactoryQueue.push(transport)
+    const manager = createManager(1, 1)
+    const deps = createDeps()
+
+    connectPanePty(pane as never, manager as never, deps as never)
+    await flushAsyncTicks(20)
+    expect(replayCallback.current).toBeTypeOf('function')
+
+    replayCallback.current?.('remote snapshot bytes', {
+      clearBeforeReplay: false,
+      pendingEscapeTailAnsi: '\x1b[3'
+    })
+    await flushAsyncTicks(20)
+
+    const snapshotIndex = writes.indexOf('remote snapshot bytes')
+    const tailIndex = writes.lastIndexOf('\x1b[3')
+    expect(snapshotIndex).toBeGreaterThanOrEqual(0)
+    expect(tailIndex).toBeGreaterThanOrEqual(0)
+    // The dangling tail is re-armed after the snapshot (and any reset), so the
+    // next live chunk's continuation completes it instead of rendering literally.
+    expect(tailIndex).toBeGreaterThan(snapshotIndex)
+    expect(writes.slice(tailIndex + 1)).toEqual([])
+  })
+
   it('preserves live modes and injects focus-in after focused agent reattach', async () => {
     const { connectPanePty } = await import('./pty-connection')
     const transport = createMockTransport()

src/renderer/src/components/terminal-pane/pty-connection.ts

@@ -11,6 +11,7 @@ import { getWorktreeMapFromState } from '@/store/selectors'
 import { parseWorkspaceKey } from '../../../../shared/workspace-scope'
 import { createTerminalZeroDimensionsMessage } from '../../../../shared/terminal-zero-dimensions-diagnostic'
 import { parseTerminalOscColorQuery } from '../../../../shared/terminal-osc-color-reply'
+import { isTerminalQueryReply } from '../../../../shared/terminal-query-reply'
 import type { PtyBufferSnapshot, PtyConnectResult } from './pty-transport'
 import { createIpcPtyTransport } from './pty-transport'
 import { createRemoteRuntimePtyTransport } from './remote-runtime-pty-transport'
@@ -2847,13 +2848,16 @@ export function connectPanePty(
   const terminalCapabilityRepliesDisposable = installTerminalCapabilityReplyHandlers({
     terminal: pane.terminal,
     parser: pane.terminal.parser,
-    sendInput: (data) => transport.sendInput(data),
+    // Why: OSC 10/11 + DA1 replies must beat the querying program's raw-mode
+    // read window; the remote transport's input debounce would corrupt them
+    // (#7329), so send immediately.
+    sendInput: (data) => transport.sendInputImmediate(data),
     isReplaying: () => isPaneReplaying(deps.replayingPanesRef, pane.id),
     ...(isNativeWindowsConpty ? { da1Response: CONPTY_DA1_RESPONSE } : {})
   })
   const respondToTerminalPixelSizeQueries = createTerminalPixelSizeQueryResponder(
     pane.terminal,
-    (data) => transport.sendInput(data)
+    (data) => transport.sendInputImmediate(data)
   )
 
   const onDataDisposable = pane.terminal.onData((data) => {
@@ -2891,6 +2895,19 @@ export function connectPanePty(
       clearPendingTerminalInputIntent()
       return
     }
+    // Why: xterm answers CPR/DSR/DA queries natively through this same onData
+    // stream (mixed with keystrokes). Those replies are latency-critical — a
+    // querying program reads them in raw mode with a short timeout — so send
+    // them immediately, skipping the remote input debounce that would corrupt
+    // them (#7329). They are not user input, so they bypass intent inference and
+    // activity recording below. No pending-intent guard: the only intents are
+    // plain-escape (`\x1b`) and ctrl-c (`\x03`), neither of which can satisfy
+    // isTerminalQueryReply (it requires length >= 3 and a full reply grammar),
+    // so a real keystroke never reaches this branch.
+    if (isTerminalQueryReply(data)) {
+      transport.sendInputImmediate(data)
+      return
+    }
     const intent = pendingTerminalInputIntent
     // Why: real xterm can deliver the terminal byte even when our DOM keydown
     // listener missed the press. Exact Ctrl+C/Escape bytes are still safe to
@@ -4040,13 +4057,14 @@ export function connectPanePty(
     type PendingReplayData = {
       data: string
       clearBeforeReplay: boolean
+      pendingEscapeTailAnsi?: string
     }
 
     let pendingReplayData: PendingReplayData | null = null
     let replayDrainQueued = false
     const drainReplayDataQueue = async (): Promise<void> => {
       while (pendingReplayData !== null) {
-        const { data, clearBeforeReplay } = pendingReplayData
+        const { data, clearBeforeReplay, pendingEscapeTailAnsi } = pendingReplayData
         pendingReplayData = null
         // Relay replay buffers may overlap with content already rendered in
         // xterm. Local eager replay decides this earlier so metadata-only frames
@@ -4064,6 +4082,14 @@ export function connectPanePty(
           await writeReplayDataAsync(reattachReplayResetSequence())
           sendFocusedReattachFocusInAfterReplay()
         }
+        // Why: the daemon could not serialize a PTY read that ended mid-escape,
+        // so the emulator shipped the dangling partial separately. Write it LAST
+        // — after the reset, whose ESC would otherwise abort it — so the next
+        // live chunk completes the sequence instead of rendering literally
+        // (#7329). Guarded so a later ESC cannot leave the parser wedged.
+        if (pendingEscapeTailAnsi) {
+          await writeReplayDataAsync(pendingEscapeTailAnsi)
+        }
         if (disposed) {
           pendingReplayData = null
           return
@@ -4074,10 +4100,14 @@ export function connectPanePty(
         manager.rebuildPaneWebgl(pane.id)
       }
     }
-    const replayDataCallback = (data: string, meta: { clearBeforeReplay?: boolean } = {}): void => {
+    const replayDataCallback = (
+      data: string,
+      meta: { clearBeforeReplay?: boolean; pendingEscapeTailAnsi?: string } = {}
+    ): void => {
       pendingReplayData = {
         data,
-        clearBeforeReplay: meta.clearBeforeReplay !== false
+        clearBeforeReplay: meta.clearBeforeReplay !== false,
+        ...(meta.pendingEscapeTailAnsi ? { pendingEscapeTailAnsi: meta.pendingEscapeTailAnsi } : {})
       }
       if (replayDrainQueued) {
         return
@@ -4090,7 +4120,10 @@ export function connectPanePty(
           replayDrainQueued = false
           if (pendingReplayData !== null) {
             replayDataCallback(pendingReplayData.data, {
-              clearBeforeReplay: pendingReplayData.clearBeforeReplay
+              clearBeforeReplay: pendingReplayData.clearBeforeReplay,
+              ...(pendingReplayData.pendingEscapeTailAnsi
+                ? { pendingEscapeTailAnsi: pendingReplayData.pendingEscapeTailAnsi }
+                : {})
             })
           }
         })
@@ -4182,7 +4215,9 @@ export function connectPanePty(
       // mode 2031 out-of-band so TUIs still render the snapshot with the same
       // theme-dependent styling they would have used in a visible pane.
       deps.paneMode2031Ref.current.set(pane.id, true)
-      transport.sendInput(mode2031SequenceFor(mode))
+      // Why: a query reply — send immediately so the remote input debounce
+      // cannot delay it past the querying program's read window (#7329).
+      transport.sendInputImmediate(mode2031SequenceFor(mode))
       deps.paneLastThemeModeRef.current.set(pane.id, mode)
       recordHiddenMode2031Reply()
     }
@@ -4472,9 +4507,10 @@ export function connectPanePty(
       hiddenStartupRendererQueryPending = extracted.pending
       if (extracted.oscColorQueryData) {
         // Why: Codex's startup palette probe has a 100 ms budget. Answer
-        // hidden color queries directly so renderer scheduling cannot miss it.
+        // hidden color queries directly and immediately so neither renderer
+        // scheduling nor the remote input debounce (#7329) can miss it.
         sendTerminalOscColorQueryReplies(extracted.oscColorQueryData, pane.terminal, (reply) =>
-          transport.sendInput(reply)
+          transport.sendInputImmediate(reply)
         )
       }
       if (extracted.statelessQueryData) {
@@ -4949,6 +4985,7 @@ export function connectPanePty(
       rows: number
       seq?: number
       alternateScreen?: boolean
+      pendingEscapeTailAnsi?: string
     }): void {
       const scrollIntent = captureTerminalWriteScrollIntent(pane.terminal)
       const colsBeforeReplay = pane.terminal.cols
@@ -4989,6 +5026,13 @@ export function connectPanePty(
       }
       writeReplayData(snapshot.data)
       writeReplayData(POST_REPLAY_LIVE_SNAPSHOT_RESET)
+      if (snapshot.pendingEscapeTailAnsi) {
+        // Why last: the snapshot was serialized while the emulator sat mid-escape;
+        // re-arm the dangling sequence as the FINAL replay write (any later ESC —
+        // including the reset above — would abort it) so the racing live tail's
+        // continuation completes it instead of rendering literally (#7329).
+        writeReplayData(snapshot.pendingEscapeTailAnsi)
+      }
       hiddenRendererStateDirty = false
       recordRendererOrderedSeq(snapshot)
       resetHiddenRendererRiskState()
@@ -5250,7 +5294,9 @@ export function connectPanePty(
         sendTerminalOscColorQueryReplies(
           pendingForegroundQuery.oscColorQueryData,
           pane.terminal,
-          (reply) => transport.sendInput(reply)
+          // Why: OSC color reply — immediate so the remote debounce cannot delay
+          // it past the querying program's read window (#7329).
+          (reply) => transport.sendInputImmediate(reply)
         )
       }
       const restoreAppliesToCurrentPty =
@@ -5381,12 +5427,45 @@ export function connectPanePty(
       // and only the freshest source belongs on screen.
       if (connectResult?.snapshot) {
         rememberReattachPayloadAgentSignal(connectResult.snapshot, { fullScreenReplay: true })
+        // Why: the daemon serializes its grid with soft-wrapped lines as
+        // continuous text. Replaying that at a different column count rewraps
+        // rows one cell early/late (bug #7279). Replay at the snapshot's own
+        // dimensions first; safeFit below fits the pane back and resizes the
+        // remote PTY. Suppress the xterm->PTY forward so this layout-only
+        // resize does not SIGWINCH the live remote TUI. Mirrors
+        // applyMainBufferSnapshot.
+        const snapshotCols = connectResult.snapshotCols
+        const snapshotRows = connectResult.snapshotRows
+        const hasSnapshotDimensions =
+          typeof snapshotCols === 'number' &&
+          typeof snapshotRows === 'number' &&
+          Number.isFinite(snapshotCols) &&
+          Number.isFinite(snapshotRows) &&
+          snapshotCols > 0 &&
+          snapshotRows > 0
+        if (
+          hasSnapshotDimensions &&
+          (pane.terminal.cols !== snapshotCols || pane.terminal.rows !== snapshotRows)
+        ) {
+          suppressSnapshotReplayPtyResize = true
+          try {
+            pane.terminal.resize(snapshotCols, snapshotRows)
+          } finally {
+            suppressSnapshotReplayPtyResize = false
+          }
+        }
         writeReplayData('\x1b[2J\x1b[3J\x1b[H')
         writeReplayData(connectResult.snapshot)
         // Snapshot reattach keeps a live session, so avoid the broader mode
         // reset. We only drop renderer-owned state that should not leak from
         // replay bytes into the restored renderer terminal.
         writeReplayData(reattachReplayResetSequence())
+        if (connectResult.pendingEscapeTailAnsi) {
+          // Why last: re-arm the daemon's dangling mid-escape sequence AFTER the
+          // reset (whose ESC would abort it) so the racing live continuation
+          // completes it instead of rendering literally (#7329).
+          writeReplayData(connectResult.pendingEscapeTailAnsi)
+        }
         sendFocusedReattachFocusInAfterReplay()
         if (connectResult.coldRestore) {
           // Snapshot superseded the cold-restore payload — ack it so the

src/renderer/src/components/terminal-pane/pty-transport-types.ts

@@ -18,6 +18,11 @@ export type PtyBufferSnapshot = {
    *  scrollback lives in xterm and a clear destroys scroll-up after a tab
    *  return. Mirrors the attach-time guard in pty-transport.ts. */
   alternateScreen?: boolean
+  /** Trailing partial escape sequence the source emulator held mid-parse when
+   *  the snapshot was taken. The restorer writes it LAST (after the reset) so a
+   *  racing live continuation completes it instead of rendering literally
+   *  (#7329). */
+  pendingEscapeTailAnsi?: string
 }
 
 export type LocalPtySessionMetadata = { cwd?: string; shellOverride?: string }
@@ -32,13 +37,20 @@ export type PtyConnectResult = {
   sessionExpired?: boolean
   coldRestore?: { scrollback: string; cwd: string }
   replay?: string
+  /** Trailing partial escape the daemon emulator held mid-parse; the reattach
+   *  replay writes it LAST (after the reset) so a racing live continuation
+   *  completes it instead of rendering literally (#7329). */
+  pendingEscapeTailAnsi?: string
 }
 
 type PtyCallbacks = {
   onConnect?: () => void
   onDisconnect?: () => void
   onData?: (data: string, meta?: PtyDataMeta) => void
-  onReplayData?: (data: string, meta?: { clearBeforeReplay?: boolean }) => void
+  onReplayData?: (
+    data: string,
+    meta?: { clearBeforeReplay?: boolean; pendingEscapeTailAnsi?: string }
+  ) => void
   onStatus?: (shell: string) => void
   onError?: (message: string, errors?: string[]) => void
   onExit?: (code: number) => void
@@ -67,6 +79,13 @@ export type PtyTransport = {
   }) => void
   disconnect: () => void
   sendInput: (data: string) => boolean
+  // Why: latency-critical terminal query replies (CPR/DSR/DA/OSC color/pixel
+  // size) must skip input coalescing — a querying program reads them in raw
+  // mode with a short timeout, so a debounced reply lands on the shell prompt
+  // and corrupts input (#7329). Local transports already write promptly, so
+  // this is `sendInput` for them; the remote transport flushes pending input
+  // (preserving order) and sends the reply immediately.
+  sendInputImmediate: (data: string) => boolean
   sendInputAccepted?: (data: string) => Promise<boolean>
   resize: (
     cols: number,

src/renderer/src/components/terminal-pane/pty-transport.test.ts

@@ -1026,6 +1026,51 @@ describe('createIpcPtyTransport', () => {
     })
   })
 
+  it('threads the daemon pendingEscapeTailAnsi through the reattach connect result (#7329)', async () => {
+    // Why: the local daemon ships the mid-escape tail on the spawn/reattach
+    // result; dropping it here silently regressed the local half of #7329
+    // (the consumer test injects at the transport boundary, so only this
+    // asserts the IPC threading).
+    const { createIpcPtyTransport } = await import('./pty-transport')
+    const spawnMock = vi.fn().mockResolvedValue({
+      id: 'pty-reattach-tail',
+      isReattach: true,
+      snapshot: 'snapshot data',
+      snapshotCols: 80,
+      snapshotRows: 24,
+      pendingEscapeTailAnsi: '\x1b[3'
+    })
+
+    ;(globalThis as { window: typeof window }).window = {
+      ...originalWindow,
+      api: {
+        ...originalWindow?.api,
+        pty: {
+          ...originalWindow?.api?.pty,
+          spawn: spawnMock,
+          write: vi.fn(),
+          resize: vi.fn(),
+          kill: vi.fn(),
+          onData: vi.fn(() => () => {}),
+          onReplay: vi.fn(() => () => {}),
+          onExit: vi.fn(() => () => {})
+        }
+      }
+    } as unknown as typeof window
+
+    const transport = createIpcPtyTransport()
+    const result = await transport.connect({
+      url: '',
+      sessionId: 'pty-reattach-tail',
+      callbacks: {}
+    })
+
+    expect(result).toMatchObject({
+      id: 'pty-reattach-tail',
+      pendingEscapeTailAnsi: '\x1b[3'
+    })
+  })
+
   it('kills a PTY that finishes spawning after the transport was destroyed', async () => {
     const { createIpcPtyTransport } = await import('./pty-transport')
     const spawnControls: { resolve: ((value: { id: string }) => void) | null } = { resolve: null }

src/renderer/src/components/terminal-pane/pty-transport.ts

@@ -85,6 +85,10 @@ type ProcessPtyOutputOptions = {
   replayingBufferedData?: boolean
   suppressAttentionEvents?: boolean
   clearBeforeReplay?: boolean
+  // Why: a mid-escape tail the daemon could not serialize. The replay consumer
+  // must write it LAST, after the post-replay reset, so the next live chunk
+  // completes it instead of rendering literally (#7329).
+  pendingEscapeTailAnsi?: string
 }
 
 type PendingPtySideEffect = {
@@ -402,8 +406,16 @@ export function createPtyOutputProcessor({
     // session into the live store. The parser still consumes the bytes so they
     // do not leak into xterm, we just suppress the callback.
     if (options.replayingBufferedData && callbacks.onReplayData) {
-      if (options.clearBeforeReplay === false) {
-        callbacks.onReplayData(data, { clearBeforeReplay: false })
+      const replayMeta = {
+        ...(options.clearBeforeReplay === false ? { clearBeforeReplay: false } : {}),
+        ...(options.pendingEscapeTailAnsi
+          ? { pendingEscapeTailAnsi: options.pendingEscapeTailAnsi }
+          : {})
+      }
+      // Why: preserve the bare-data call shape when there is no replay metadata,
+      // so eager-buffer replay (which passes neither) is unchanged.
+      if (Object.keys(replayMeta).length > 0) {
+        callbacks.onReplayData(data, replayMeta)
       } else {
         callbacks.onReplayData(data)
       }
@@ -671,7 +683,8 @@ export function createIpcPtyTransport(opts: IpcPtyTransportOptions = {}): PtyTra
             isAlternateScreen: spawnResult.isAlternateScreen,
             sessionExpired: spawnResult.sessionExpired,
             coldRestore: spawnResult.coldRestore,
-            replay: spawnResult.replay
+            replay: spawnResult.replay,
+            pendingEscapeTailAnsi: spawnResult.pendingEscapeTailAnsi
           } satisfies PtyConnectResult
         }
         if (spawnResult.launchConfig) {
@@ -849,6 +862,17 @@ export function createIpcPtyTransport(opts: IpcPtyTransportOptions = {}): PtyTra
       return inputWriteQueue.enqueue(ptyId, data)
     },
 
+    // Why: the local write queue already drains a lone item in the same turn
+    // (no wall-clock debounce), so query replies are prompt without special
+    // handling. Kept as a distinct method so callers express intent and the
+    // remote transport can override with its flush-then-send behavior (#7329).
+    sendInputImmediate(data: string): boolean {
+      if (!connected || !ptyId) {
+        return false
+      }
+      return inputWriteQueue.enqueue(ptyId, data)
+    },
+
     ...(connectionId
       ? {}
       : {

src/renderer/src/components/terminal-pane/remote-runtime-pty-batching.ts

@@ -8,6 +8,7 @@ import {
 
 export type RemoteRuntimePtyBatcher = {
   push: (data: string) => boolean
+  hasPendingValidation: () => boolean
   drain: () => Promise<void>
   takePending: () => string
   flush: () => void
@@ -145,6 +146,10 @@ export function createRemoteRuntimePtyTextBatcher(
       enqueueValidatedInput(data, tooLarge)
       return true
     },
+    // Why: earlier input can be mid async byte-length validation and not yet in
+    // `pending`. `takePending()` cannot see it, so callers that must preserve
+    // byte order (sendInputImmediate) check this before bypassing the queue.
+    hasPendingValidation: (): boolean => validationTail !== null,
     drain,
     takePending,
     flush,

src/renderer/src/components/terminal-pane/remote-runtime-pty-query-reply-immediate.test.ts

@@ -0,0 +1,142 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+import { CLIPBOARD_TEXT_MEASURE_YIELD_CODE_UNITS } from '../../../../shared/clipboard-text'
+
+// Regression for #7329: terminal query replies must NOT sit behind the remote
+// input debounce (REMOTE_TERMINAL_INPUT_FLUSH_MS). transport.sendInputImmediate
+// sends without arming the 8ms timer, so a reply beats the querying program's
+// raw-mode read window; transport.sendInput stays debounced for typed input.
+
+describe('remote transport sendInputImmediate (#7329)', () => {
+  const runtimeCall = vi.fn()
+  const runtimeSubscribe = vi.fn()
+  const subscriptionSendBinary = vi.fn()
+  let subscriptionCallbacks: {
+    onResponse: (response: unknown) => void
+    onBinary?: (bytes: Uint8Array<ArrayBufferLike>) => void
+    onError?: (error: { code: string; message: string }) => void
+    onClose?: () => void
+  } | null = null
+
+  beforeEach(() => {
+    vi.resetModules()
+    vi.doUnmock('../../runtime/remote-runtime-terminal-multiplexer')
+    vi.clearAllMocks()
+    subscriptionCallbacks = null
+    subscriptionSendBinary.mockReset()
+    runtimeCall.mockResolvedValue({ ok: true, result: { terminal: { handle: 'terminal-1' } } })
+    runtimeSubscribe.mockImplementation(
+      async (_args: unknown, callbacks: typeof subscriptionCallbacks) => {
+        subscriptionCallbacks = callbacks
+        return { unsubscribe: vi.fn(), sendBinary: subscriptionSendBinary }
+      }
+    )
+    vi.stubGlobal('window', {
+      api: {
+        runtimeEnvironments: { call: runtimeCall, subscribe: runtimeSubscribe }
+      }
+    })
+  })
+
+  function terminalSendCalls(): unknown[] {
+    return runtimeCall.mock.calls
+      .map((call) => call[0] as { method?: string; params?: { text?: string } })
+      .filter((args) => args.method === 'terminal.send')
+  }
+
+  it('sends a query reply immediately, but debounces typed input by 8ms', async () => {
+    vi.useFakeTimers()
+    try {
+      const { createRemoteRuntimePtyTransport } = await import('./remote-runtime-pty-transport')
+      const transport = createRemoteRuntimePtyTransport('env-1', {
+        worktreeId: 'wt-1',
+        tabId: 'tab-1',
+        leafId: 'pane:1'
+      })
+      transport.attach({
+        existingPtyId: 'remote:env-1@@terminal-1',
+        cols: 80,
+        rows: 24,
+        callbacks: {}
+      })
+
+      // Typed input: debounced — nothing sent before the 8ms flush.
+      expect(transport.sendInput('yes')).toBe(true)
+      expect(terminalSendCalls()).toEqual([])
+
+      // Query reply (OSC 11 background color): sent immediately, no timer.
+      expect(transport.sendInputImmediate('\x1b]11;rgb:2828/2c2c/3434\x1b\\')).toBe(true)
+      await Promise.resolve()
+
+      // The immediate send flushed pending typed input ahead of the reply
+      // (preserving byte order) in a single send, without advancing timers.
+      const sends = terminalSendCalls() as { params: { text: string } }[]
+      expect(sends).toHaveLength(1)
+      expect(sends[0]?.params.text).toBe('yes\x1b]11;rgb:2828/2c2c/3434\x1b\\')
+    } finally {
+      vi.useRealTimers()
+    }
+  })
+
+  it('sends an immediate reply even with no pending typed input', async () => {
+    vi.useFakeTimers()
+    try {
+      const { createRemoteRuntimePtyTransport } = await import('./remote-runtime-pty-transport')
+      const transport = createRemoteRuntimePtyTransport('env-1', {
+        worktreeId: 'wt-1',
+        tabId: 'tab-1',
+        leafId: 'pane:1'
+      })
+      transport.attach({
+        existingPtyId: 'remote:env-1@@terminal-1',
+        cols: 80,
+        rows: 24,
+        callbacks: {}
+      })
+
+      expect(transport.sendInputImmediate('\x1b[3;1R')).toBe(true) // CPR reply
+      await Promise.resolve()
+
+      const sends = terminalSendCalls() as { params: { text: string } }[]
+      expect(sends).toHaveLength(1)
+      expect(sends[0]?.params.text).toBe('\x1b[3;1R')
+    } finally {
+      vi.useRealTimers()
+    }
+  })
+
+  it('does not reorder a query reply ahead of a large paste still in async validation', async () => {
+    // #7736 review: a paste over the deferred-measurement threshold sits in the
+    // batcher's async validationTail (not in `pending`). sendInputImmediate must
+    // not send the reply ahead of it and reorder bytes on the wire.
+    const { createRemoteRuntimePtyTransport } = await import('./remote-runtime-pty-transport')
+    const transport = createRemoteRuntimePtyTransport('env-1', {
+      worktreeId: 'wt-1',
+      tabId: 'tab-1',
+      leafId: 'pane:1'
+    })
+    transport.attach({
+      existingPtyId: 'remote:env-1@@terminal-1',
+      cols: 80,
+      rows: 24,
+      callbacks: {}
+    })
+
+    // A paste above CLIPBOARD_TEXT_MEASURE_YIELD_CODE_UNITS forces the async
+    // validation path, so its bytes are captured in validationTail, not pending.
+    const paste = 'p'.repeat(CLIPBOARD_TEXT_MEASURE_YIELD_CODE_UNITS + 1)
+    expect(transport.sendInput(paste)).toBe(true)
+    // Immediately (validation still pending) a TUI emits a CPR reply.
+    expect(transport.sendInputImmediate('\x1b[3;1R')).toBe(true)
+
+    // Wait until the reply is actually flushed instead of sleeping a fixed
+    // interval: the reply legitimately trails the paste's async validation plus
+    // one debounce tick, and a fixed sleep raced that chain under CI load.
+    const combined = (): string =>
+      (terminalSendCalls() as { params: { text: string } }[]).map((s) => s.params.text).join('')
+    await expect.poll(combined, { timeout: 5000, interval: 5 }).toContain('\x1b[3;1R')
+
+    // The paste bytes must come before the reply — no reordering.
+    expect(combined().indexOf('p')).toBeLessThan(combined().indexOf('\x1b[3;1R'))
+    expect(combined()).toContain(`${paste}\x1b[3;1R`)
+  })
+})

src/renderer/src/components/terminal-pane/remote-runtime-pty-snapshot-escape-tail.test.ts

@@ -0,0 +1,116 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+import {
+  TerminalStreamOpcode,
+  decodeTerminalStreamFrame,
+  decodeTerminalStreamJson,
+  encodeTerminalStreamFrame,
+  encodeTerminalStreamJson,
+  encodeTerminalStreamText
+} from '../../../../shared/terminal-stream-protocol'
+
+// Client-side wire regression for #7329: the daemon's pendingEscapeTailAnsi
+// rides the SnapshotStart JSON frame. This drives REAL binary frames through
+// the REAL multiplexer (decodeSnapshotInfo → onSnapshot meta) into the REAL
+// transport (processData → onReplayData meta). The server-side counterpart is
+// terminal-multiplex-escape-tail.test.ts; without this test the client half of
+// the chain could silently drop the field and every suite stayed green.
+
+describe('remote transport snapshot escape-tail threading (#7329)', () => {
+  const runtimeCall = vi.fn()
+  const runtimeSubscribe = vi.fn()
+  const subscriptionSendBinary = vi.fn()
+  let subscriptionCallbacks: {
+    onResponse: (response: unknown) => void
+    onBinary?: (bytes: Uint8Array<ArrayBufferLike>) => void
+    onError?: (error: { code: string; message: string }) => void
+    onClose?: () => void
+  } | null = null
+
+  beforeEach(() => {
+    vi.resetModules()
+    vi.doUnmock('../../runtime/remote-runtime-terminal-multiplexer')
+    vi.clearAllMocks()
+    subscriptionCallbacks = null
+    subscriptionSendBinary.mockReset()
+    runtimeCall.mockResolvedValue({ ok: true, result: { terminal: { handle: 'terminal-1' } } })
+    runtimeSubscribe.mockImplementation(
+      async (_args: unknown, callbacks: typeof subscriptionCallbacks) => {
+        subscriptionCallbacks = callbacks
+        return { unsubscribe: vi.fn(), sendBinary: subscriptionSendBinary }
+      }
+    )
+    vi.stubGlobal('window', {
+      api: {
+        runtimeEnvironments: { call: runtimeCall, subscribe: runtimeSubscribe }
+      }
+    })
+  })
+
+  it('delivers the SnapshotStart pendingEscapeTailAnsi to onReplayData meta', async () => {
+    const { createRemoteRuntimePtyTransport } = await import('./remote-runtime-pty-transport')
+    const transport = createRemoteRuntimePtyTransport('env-1', {
+      worktreeId: 'wt-1',
+      tabId: 'tab-1',
+      leafId: 'pane:1'
+    })
+    const onReplayData = vi.fn()
+    transport.attach({
+      existingPtyId: 'remote:env-1@@terminal-1',
+      cols: 80,
+      rows: 24,
+      callbacks: { onReplayData }
+    })
+
+    // Complete the multiplexer handshake so the terminal stream subscribes.
+    await expect.poll(() => subscriptionCallbacks !== null, { timeout: 5000 }).toBe(true)
+    subscriptionCallbacks?.onResponse({ ok: true, result: { type: 'ready' } })
+
+    // The client allocates the terminal's stream id in its Subscribe payload.
+    await expect
+      .poll(() => subscriptionSendBinary.mock.calls.length, { timeout: 5000 })
+      .toBeGreaterThan(0)
+    const subscribeFrame = subscriptionSendBinary.mock.calls
+      .map((call) => decodeTerminalStreamFrame(call[0] as Uint8Array))
+      .find((frame) => frame?.opcode === TerminalStreamOpcode.Subscribe)
+    expect(subscribeFrame).toBeDefined()
+    const subscribePayload = decodeTerminalStreamJson<{ streamId: number }>(subscribeFrame!.payload)
+    const streamId = subscribePayload!.streamId
+
+    // Server → client: initial snapshot whose emulator sat mid-escape.
+    const frames = [
+      encodeTerminalStreamFrame({
+        opcode: TerminalStreamOpcode.SnapshotStart,
+        streamId,
+        seq: 0,
+        payload: encodeTerminalStreamJson({
+          cols: 80,
+          rows: 24,
+          seq: 7,
+          source: 'headless',
+          pendingEscapeTailAnsi: '\x1b[3'
+        })
+      }),
+      encodeTerminalStreamFrame({
+        opcode: TerminalStreamOpcode.SnapshotChunk,
+        streamId,
+        seq: 0,
+        payload: encodeTerminalStreamText('user@host:~$ ')
+      }),
+      encodeTerminalStreamFrame({
+        opcode: TerminalStreamOpcode.SnapshotEnd,
+        streamId,
+        seq: 0,
+        payload: new Uint8Array(0)
+      })
+    ]
+    for (const frame of frames) {
+      subscriptionCallbacks?.onBinary?.(frame)
+    }
+
+    await expect.poll(() => onReplayData.mock.calls.length, { timeout: 5000 }).toBeGreaterThan(0)
+    expect(onReplayData).toHaveBeenCalledWith(
+      'user@host:~$ ',
+      expect.objectContaining({ pendingEscapeTailAnsi: '\x1b[3' })
+    )
+  })
+})

src/renderer/src/components/terminal-pane/remote-runtime-pty-transport.ts

@@ -391,11 +391,16 @@ export function createRemoteRuntimePtyTransport(
             outputProcessor.processData(data, storedCallbacks, undefined, meta)
           }
         },
-        onSnapshot: (data) => {
-          if (data && isCurrentSubscription()) {
+        onSnapshot: (data, meta) => {
+          // Why: a snapshot with no body can still carry a pending mid-escape
+          // tail that must be replayed so the next live chunk completes it.
+          if ((data || meta?.pendingEscapeTailAnsi) && isCurrentSubscription()) {
             outputProcessor.processData(data, storedCallbacks, {
               replayingBufferedData: true,
-              suppressAttentionEvents: true
+              suppressAttentionEvents: true,
+              ...(meta?.pendingEscapeTailAnsi
+                ? { pendingEscapeTailAnsi: meta.pendingEscapeTailAnsi }
+                : {})
             })
           }
         },
@@ -616,6 +621,49 @@ export function createRemoteRuntimePtyTransport(
       return inputBatcher.push(data)
     },
 
+    // Why: terminal query replies (CPR/DSR/DA/OSC color/pixel size) are read by
+    // the querying program in raw mode with a short timeout. The 8ms input
+    // debounce makes the reply miss that window, so it lands on the shell prompt
+    // and is echoed literally / spliced into typed input (#7329). Flush any
+    // pending batched input first so byte order is preserved, then send the
+    // reply immediately without arming the debounce timer.
+    sendInputImmediate(data: string): boolean {
+      const targetHandle = handle
+      if (!connected || !targetHandle) {
+        return false
+      }
+      if (!data) {
+        return true
+      }
+      // Why: earlier input (e.g. a large paste) may still be in async byte-length
+      // validation, so it is captured in the batcher's validationTail and NOT in
+      // takePending(). Bypassing the queue here would send the reply ahead of it
+      // and reorder bytes on the wire. In that rare window, route the reply
+      // through the batcher's ordered queue and flush what is already validated;
+      // the reply lands right after the pending input once its validation
+      // resolves. Order correctness beats the immediacy that the debounce
+      // normally trades away.
+      if (inputBatcher.hasPendingValidation()) {
+        const accepted = inputBatcher.push(data)
+        inputBatcher.flush()
+        return accepted
+      }
+      const pending = inputBatcher.takePending()
+      const text = `${pending}${data}`
+      const stream = getCurrentMultiplexedStream(targetHandle)
+      if (stream?.sendInput(text)) {
+        return true
+      }
+      void callRuntime('terminal.send', {
+        terminal: targetHandle,
+        text,
+        client: { id: clientId, type: 'desktop' }
+      }).catch((error) => {
+        storedCallbacks.onError?.(runtimeTerminalErrorMessage(error))
+      })
+      return true
+    },
+
     sendInputAccepted: sendInputAcceptedToRuntime,
 
     resize(cols: number, rows: number): boolean {

src/renderer/src/runtime/remote-runtime-terminal-multiplexer.ts

@@ -37,7 +37,7 @@ type TerminalMultiplexEvent =
 
 export type RemoteRuntimeMultiplexedTerminalCallbacks = {
   onData: (data: string, meta?: { seq?: number; rawLength?: number }) => void
-  onSnapshot: (data: string) => void
+  onSnapshot: (data: string, meta?: { pendingEscapeTailAnsi?: string }) => void
   onSubscribed?: () => void
   onEnd?: () => void
   onError?: (message: string) => void
@@ -86,6 +86,10 @@ type RemoteRuntimeSnapshotInfo = {
   source?: 'headless' | 'renderer'
   requestId?: number
   truncated?: boolean
+  // Why: a mid-escape tail the emulator could not serialize; the transport
+  // must write it AFTER the replay reset so the next live chunk completes it
+  // instead of rendering literally (#7329).
+  pendingEscapeTailAnsi?: string
 }
 
 type RemoteRuntimeSnapshotRequest = {
@@ -97,6 +101,7 @@ type RemoteRuntimeSnapshotRequest = {
       rows: number
       seq?: number
       source?: 'headless' | 'renderer'
+      pendingEscapeTailAnsi?: string
     } | null
   ) => void
   reject: (error: Error) => void
@@ -381,11 +386,14 @@ class RemoteRuntimeTerminalMultiplexer {
             cols: info?.cols ?? 80,
             rows: info?.rows ?? 24,
             seq: info?.seq,
-            source: info?.source
+            source: info?.source,
+            pendingEscapeTailAnsi: info?.pendingEscapeTailAnsi
           })
           clearPendingSnapshotRequest(stream)
         } else if (target === 'initial') {
-          stream.callbacks.onSnapshot(data ?? '')
+          stream.callbacks.onSnapshot(data ?? '', {
+            pendingEscapeTailAnsi: info?.pendingEscapeTailAnsi
+          })
         }
       } else if (matchesPendingRequest) {
         pendingRequest.resolve(null)
@@ -608,6 +616,7 @@ function decodeSnapshotInfo(
     source?: unknown
     requestId?: unknown
     truncated?: unknown
+    pendingEscapeTailAnsi?: unknown
   }>(payload)
   if (!raw) {
     return null
@@ -618,7 +627,9 @@ function decodeSnapshotInfo(
     seq: typeof raw.seq === 'number' ? raw.seq : undefined,
     source: raw.source === 'headless' || raw.source === 'renderer' ? raw.source : undefined,
     requestId: typeof raw.requestId === 'number' ? raw.requestId : undefined,
-    truncated: raw.truncated === true
+    truncated: raw.truncated === true,
+    pendingEscapeTailAnsi:
+      typeof raw.pendingEscapeTailAnsi === 'string' ? raw.pendingEscapeTailAnsi : undefined
   }
 }
 

src/shared/terminal-partial-escape-tail.test.ts

@@ -0,0 +1,86 @@
+import { describe, expect, it } from 'vitest'
+import {
+  advancePartialEscapeTail,
+  extractPartialEscapeTail,
+  MAX_PARTIAL_ESCAPE_TAIL_LENGTH
+} from './terminal-partial-escape-tail'
+
+describe('extractPartialEscapeTail', () => {
+  it('returns empty for parser-clean streams', () => {
+    expect(extractPartialEscapeTail('')).toBe('')
+    expect(extractPartialEscapeTail('plain text no escapes')).toBe('')
+    expect(extractPartialEscapeTail('\x1b[38;5;196mred\x1b[0m done')).toBe('')
+    expect(extractPartialEscapeTail('\x1b[2J\x1b[H')).toBe('')
+  })
+
+  it('returns the dangling CSI when a chunk ends mid-sequence', () => {
+    expect(extractPartialEscapeTail('hello\x1b[3')).toBe('\x1b[3')
+    expect(extractPartialEscapeTail('a\x1b[38;5;')).toBe('\x1b[38;5;')
+    expect(extractPartialEscapeTail('\x1b')).toBe('\x1b')
+    expect(extractPartialEscapeTail('\x1b[')).toBe('\x1b[')
+  })
+
+  it('returns the dangling OSC (unterminated) sequence', () => {
+    // OSC 0 title with no BEL/ST terminator yet.
+    expect(extractPartialEscapeTail('\x1b]0;my-title')).toBe('\x1b]0;my-title')
+    // Terminated OSC is clean.
+    expect(extractPartialEscapeTail('\x1b]0;title\x07after')).toBe('')
+    expect(extractPartialEscapeTail('\x1b]0;title\x1b\\after')).toBe('')
+  })
+
+  it('treats a fresh ESC as aborting a pending CSI', () => {
+    // The second ESC starts a new (complete) sequence.
+    expect(extractPartialEscapeTail('\x1b[3\x1b[0m')).toBe('')
+    // ...and a new dangling one.
+    expect(extractPartialEscapeTail('\x1b[3\x1b[')).toBe('\x1b[')
+  })
+
+  it('treats CAN/SUB as aborting an in-progress escape back to ground', () => {
+    // CAN (0x18) / SUB (0x1a) abort the sequence in xterm's VT500 parser.
+    // esc state:
+    expect(extractPartialEscapeTail('\x1b\x18')).toBe('') // ESC CAN
+    expect(extractPartialEscapeTail('\x1b\x1a')).toBe('') // ESC SUB
+    // escIntermediate state (ESC then an intermediate byte, then CAN):
+    expect(extractPartialEscapeTail('\x1b \x18')).toBe('') // ESC SP CAN
+    expect(extractPartialEscapeTail('\x1b#\x1a')).toBe('') // ESC # SUB
+    // csi/osc/string already aborted — keep them green:
+    expect(extractPartialEscapeTail('\x1b[38;\x18')).toBe('') // CSI ... CAN
+    expect(extractPartialEscapeTail('\x1b]0;title\x18')).toBe('') // OSC ... CAN
+    // A CAN that aborts, followed by a fresh dangling sequence, tracks the new one:
+    expect(extractPartialEscapeTail('\x1b\x18\x1b[3')).toBe('\x1b[3')
+  })
+
+  it('is fold-safe across chunk boundaries', () => {
+    // extract(a + b) === extract(extract(a) + b) — the invariant ingest relies on.
+    const cases: [string, string][] = [
+      ['first\x1b[3', '8;5;196mred'],
+      ['\x1b', '[0m'],
+      ['\x1b]0;ti', 'tle\x07'],
+      ['clean', '\x1b[1'],
+      // Fold-safety must hold across the CAN abort too.
+      ['\x1b', '\x18after'],
+      ['\x1b ', '\x18after']
+    ]
+    for (const [a, b] of cases) {
+      expect(extractPartialEscapeTail(extractPartialEscapeTail(a) + b)).toBe(
+        extractPartialEscapeTail(a + b)
+      )
+    }
+  })
+})
+
+describe('advancePartialEscapeTail', () => {
+  it('accumulates a split sequence across chunks', () => {
+    let tail = ''
+    tail = advancePartialEscapeTail(tail, 'ls\r\n\x1b[3')
+    expect(tail).toBe('\x1b[3')
+    tail = advancePartialEscapeTail(tail, '8;5;196m')
+    expect(tail).toBe('') // sequence completed
+  })
+
+  it('abandons tracking (returns empty) past the cap', () => {
+    // An unterminated OSC longer than the cap degrades to pre-fix behavior.
+    const huge = `\x1b]0;${'x'.repeat(MAX_PARTIAL_ESCAPE_TAIL_LENGTH + 10)}`
+    expect(advancePartialEscapeTail('', huge)).toBe('')
+  })
+})

src/shared/terminal-partial-escape-tail.ts

@@ -0,0 +1,149 @@
+// Why this module exists: a PTY read can end mid-escape-sequence. The bytes
+// already handed to xterm sit inside its parser state machine, not the screen
+// buffer, so a serialized snapshot cannot carry them — and the next chunk's
+// continuation bytes then render as literal text after a snapshot restore
+// (Bug E in notes/garble-fuzz-divergences.md). Tracking the unparsed trailing
+// partial sequence at the ingest boundary lets snapshot producers append it
+// after the serialized screen so the continuation completes exactly as live.
+
+// Mirrors the VT500 parser states that can span a chunk boundary. C0 controls
+// (except ESC/CAN/SUB) execute mid-sequence without aborting it, matching
+// xterm's state machine.
+type ScanState =
+  | 'ground'
+  | 'esc'
+  | 'escIntermediate'
+  | 'csi'
+  | 'osc'
+  | 'oscEsc'
+  | 'string'
+  | 'stringEsc'
+
+const ESC = 0x1b
+const CAN = 0x18
+const SUB = 0x1a
+const BEL = 0x07
+
+// Why a cap: OSC/DCS payloads are unbounded and an unterminated one would
+// grow the tracked tail (and every snapshot) without limit. Real payloads
+// (titles, cwd, hyperlinks) are far below this; beyond it we stop tracking
+// and degrade to the pre-fix behavior for that pathological stream.
+export const MAX_PARTIAL_ESCAPE_TAIL_LENGTH = 4096
+
+/** ESC-state transition shared by the fresh-ESC and abort-reprocess paths. */
+function stateAfterEscByte(code: number): ScanState {
+  if (code === 0x5b) {
+    return 'csi' // [
+  }
+  if (code === 0x5d) {
+    return 'osc' // ]
+  }
+  // P / X / ^ / _ open DCS / SOS / PM / APC — ST-terminated strings.
+  if (code === 0x50 || code === 0x58 || code === 0x5e || code === 0x5f) {
+    return 'string'
+  }
+  if (code >= 0x20 && code <= 0x2f) {
+    return 'escIntermediate'
+  }
+  if (code < 0x20 || code === 0x7f) {
+    return 'esc' // C0 executes / DEL is ignored mid-sequence; ESC via callers
+  }
+  return 'ground' // final byte — two-byte sequence (ESC 7, ESC 8, ESC c, …)
+}
+
+/** Returns the trailing incomplete escape sequence of `stream` ('' when the
+ *  stream ends parser-clean). Fold-safe across chunk boundaries:
+ *  extract(a + b) === extract(extract(a) + b), which is how ingest-time
+ *  trackers advance without keeping the whole stream. */
+export function extractPartialEscapeTail(stream: string): string {
+  let state: ScanState = 'ground'
+  let start = 0
+  for (let i = 0; i < stream.length; i++) {
+    const code = stream.charCodeAt(i)
+    if (state === 'ground') {
+      if (code === ESC) {
+        start = i
+        state = 'esc'
+      }
+      continue
+    }
+    if (
+      code === ESC &&
+      state !== 'osc' &&
+      state !== 'string' &&
+      state !== 'oscEsc' &&
+      state !== 'stringEsc'
+    ) {
+      // ESC aborts a pending ESC/CSI sequence and starts a new one.
+      start = i
+      state = 'esc'
+      continue
+    }
+    // CAN/SUB abort an in-progress escape sequence back to ground in every
+    // non-string state (xterm's VT500 parser). The csi/osc/string cases handle
+    // this inline below; esc/escIntermediate must too, or `ESC CAN` and
+    // `ESC <intermediate> CAN` leave a bogus tail instead of dropping to ground.
+    if ((code === CAN || code === SUB) && (state === 'esc' || state === 'escIntermediate')) {
+      state = 'ground'
+      continue
+    }
+    switch (state) {
+      case 'esc':
+        state = stateAfterEscByte(code)
+        break
+      case 'escIntermediate':
+        if (code >= 0x30 && code <= 0x7e) {
+          state = 'ground'
+        }
+        // 0x20–0x2f stays; other C0 executes and stays (CAN/SUB handled above).
+        break
+      case 'csi':
+        if (code === CAN || code === SUB) {
+          state = 'ground'
+        } else if (code >= 0x40 && code <= 0x7e) {
+          state = 'ground' // final byte completes the CSI
+        }
+        // params/intermediates (0x20–0x3f), C0, DEL stay in-sequence.
+        break
+      case 'osc':
+        if (code === BEL || code === CAN || code === SUB) {
+          state = 'ground'
+        } else if (code === ESC) {
+          state = 'oscEsc'
+        }
+        break
+      case 'oscEsc':
+        if (code === 0x5c) {
+          state = 'ground' // ESC \ = ST terminates the OSC
+        } else {
+          // The ESC aborted the OSC and opened a new sequence at i-1.
+          start = i - 1
+          state = code === ESC ? 'esc' : stateAfterEscByte(code)
+        }
+        break
+      case 'string':
+        if (code === CAN || code === SUB) {
+          state = 'ground'
+        } else if (code === ESC) {
+          state = 'stringEsc'
+        }
+        break
+      case 'stringEsc':
+        if (code === 0x5c) {
+          state = 'ground'
+        } else {
+          start = i - 1
+          state = code === ESC ? 'esc' : stateAfterEscByte(code)
+        }
+        break
+    }
+  }
+  return state === 'ground' ? '' : stream.slice(start)
+}
+
+/** Ingest-time fold: advance the tracked tail with one more chunk. Returns ''
+ *  (tracking abandoned) when the tail exceeds the cap — see the cap comment. */
+export function advancePartialEscapeTail(pendingTail: string, chunk: string): string {
+  const tail = extractPartialEscapeTail(pendingTail + chunk)
+  return tail.length > MAX_PARTIAL_ESCAPE_TAIL_LENGTH ? '' : tail
+}

src/shared/terminal-query-reply.test.ts

@@ -0,0 +1,81 @@
+import { describe, expect, it } from 'vitest'
+import { isTerminalQueryReply } from './terminal-query-reply'
+
+describe('isTerminalQueryReply', () => {
+  it('matches synthetic query replies that must be sent immediately', () => {
+    // CPR cursor position report (answer to CSI 6n) — the #7329 culprit.
+    expect(isTerminalQueryReply('\x1b[3;1R')).toBe(true)
+    expect(isTerminalQueryReply('\x1b[22;1R')).toBe(true)
+    // DSR device status.
+    expect(isTerminalQueryReply('\x1b[0n')).toBe(true)
+    // DA1/DA2/DA3 device attributes.
+    expect(isTerminalQueryReply('\x1b[?1;2c')).toBe(true)
+    expect(isTerminalQueryReply('\x1b[?61;4c')).toBe(true)
+    expect(isTerminalQueryReply('\x1b[>0;276;0c')).toBe(true)
+    // Window/cell pixel-size reports.
+    expect(isTerminalQueryReply('\x1b[6;16;8t')).toBe(true)
+    expect(isTerminalQueryReply('\x1b[4;384;640t')).toBe(true)
+    // DECRPM mode report — private (with ?) and ANSI (without ?).
+    expect(isTerminalQueryReply('\x1b[?2026;2$y')).toBe(true)
+    expect(isTerminalQueryReply('\x1b[4;1$y')).toBe(true)
+    // OSC 10/11 color responses (the #7329 culprit) — BEL and ST terminated.
+    expect(isTerminalQueryReply('\x1b]11;rgb:2828/2c2c/3434\x1b\\')).toBe(true)
+    expect(isTerminalQueryReply('\x1b]10;rgb:c0c0/c0c0/c0c0\x07')).toBe(true)
+    // DECXCPR extended cursor position report (answer to CSI ? 6n).
+    expect(isTerminalQueryReply('\x1b[?12;5R')).toBe(true)
+    // Text-area size in characters (answer to CSI 18t).
+    expect(isTerminalQueryReply('\x1b[8;24;80t')).toBe(true)
+    // Kitty keyboard flags report (answer to CSI ? u) — crossterm probes this
+    // at startup, so a debounced reply corrupts the same way CPR did.
+    expect(isTerminalQueryReply('\x1b[?0u')).toBe(true)
+    expect(isTerminalQueryReply('\x1b[?31u')).toBe(true)
+    // DCS DECRQSS reports (vim queries cursor style via DCS $ q) + XTVERSION.
+    expect(isTerminalQueryReply('\x1bP1$r2 q\x1b\\')).toBe(true)
+    expect(isTerminalQueryReply('\x1bP1$r0m\x1b\\')).toBe(true)
+    expect(isTerminalQueryReply('\x1bP0$r\x1b\\')).toBe(true)
+    expect(isTerminalQueryReply('\x1bP>|xterm.js(5.6.0)\x1b\\')).toBe(true)
+  })
+
+  it('documents the accepted modified-F3/CPR collision', () => {
+    // xterm.js encodes Shift+F3 as CSI 1;2R — byte-identical to a CPR report.
+    // Classified as a reply on purpose: order is still preserved (the immediate
+    // path flushes pending input first); see the comment in terminal-query-reply.ts.
+    expect(isTerminalQueryReply('\x1b[1;2R')).toBe(true)
+  })
+
+  it('does NOT match ordinary typed input or navigation sequences', () => {
+    // Plain text.
+    expect(isTerminalQueryReply('yes')).toBe(false)
+    expect(isTerminalQueryReply('y')).toBe(false)
+    expect(isTerminalQueryReply('\r')).toBe(false)
+    expect(isTerminalQueryReply('\x03')).toBe(false) // Ctrl-C
+    // Arrow keys / navigation — must stay batched (coalesced auto-repeat).
+    expect(isTerminalQueryReply('\x1b[A')).toBe(false)
+    expect(isTerminalQueryReply('\x1b[B')).toBe(false)
+    expect(isTerminalQueryReply('\x1b[C')).toBe(false)
+    expect(isTerminalQueryReply('\x1b[D')).toBe(false)
+    expect(isTerminalQueryReply('\x1b[H')).toBe(false) // Home
+    expect(isTerminalQueryReply('\x1b[F')).toBe(false) // End
+    // Function keys (end in ~).
+    expect(isTerminalQueryReply('\x1b[15~')).toBe(false)
+    expect(isTerminalQueryReply('\x1b[3~')).toBe(false) // Delete
+    // Bare Escape key.
+    expect(isTerminalQueryReply('\x1b')).toBe(false)
+    // Alt+key (including Alt+Shift+P, whose bytes prefix the DCS grammar).
+    expect(isTerminalQueryReply('\x1bb')).toBe(false)
+    expect(isTerminalQueryReply('\x1bP')).toBe(false)
+    // Kitty-protocol KEYSTROKES (CSI code;mods u, no "?") must stay batched.
+    expect(isTerminalQueryReply('\x1b[97;5u')).toBe(false)
+    expect(isTerminalQueryReply('\x1b[13u')).toBe(false)
+    // Modified F1/F2/F4 (CSI 1;<mod> P/Q/S) are keystrokes, not replies.
+    expect(isTerminalQueryReply('\x1b[1;2P')).toBe(false)
+    expect(isTerminalQueryReply('\x1b[1;2Q')).toBe(false)
+    expect(isTerminalQueryReply('\x1b[1;2S')).toBe(false)
+    // Bracketed paste markers are input framing, not replies.
+    expect(isTerminalQueryReply('\x1b[200~')).toBe(false)
+    expect(isTerminalQueryReply('\x1b[201~')).toBe(false)
+    // Incomplete / non-terminated OSC and DCS must not match.
+    expect(isTerminalQueryReply('\x1b]11;rgb:2828/2c2c/3434')).toBe(false)
+    expect(isTerminalQueryReply('\x1bP1$r2 q')).toBe(false)
+  })
+})

src/shared/terminal-query-reply.ts

@@ -0,0 +1,69 @@
+// Why this module exists: xterm's public onData stream mixes real keystrokes
+// with the parser's synthetic replies to terminal queries a program embedded in
+// its output (CPR/DSR cursor + device-status reports, DA device attributes,
+// DECRPM mode reports, window/cell pixel-size reports, OSC 10/11 color reports,
+// kitty keyboard flag reports, DCS-framed DECRQSS/XTVERSION reports).
+// A querying program (e.g. starship/orb) reads these replies synchronously in
+// raw mode with a short timeout, so on the remote path they must NOT sit behind
+// the input debounce — a late reply lands on the shell prompt in cooked mode,
+// which echoes it literally and splices it into the next typed line (#7329).
+// This classifier lets the transport send replies immediately while keeping
+// ordinary typed input (including bursty arrow-key auto-repeat) coalesced.
+
+const ESC = String.fromCharCode(0x1b)
+
+// Built via new RegExp from \u-escaped strings so no literal control
+// characters appear in the source. // Final bytes of xterm's own query-reply grammars:
+//   R  — CPR / DECXCPR cursor position report (answer to CSI 6n / CSI ? 6n)
+//   n  — DSR device status report (answer to CSI 5n → CSI 0n)
+//   c  — DA1/DA2/DA3 device attributes (answer to CSI c / CSI > c / CSI = c)
+//   t  — window/cell pixel-size + text-area-size reports (CSI 14t/16t/18t)
+//   y  — DECRPM mode report (answer to CSI ? Ps $ p), body ends "$y"
+//   u  — kitty keyboard flags report (answer to CSI ? u), carries "?"
+/* oxlint-disable no-control-regex -- grammars match terminal ESC/BEL sequences by definition */
+// Known accepted collision: xterm.js encodes MODIFIED F3 (Shift/Ctrl/Alt+F3) as
+// `CSI 1 ; <mod> R`, which is indistinguishable from a CPR report (a classic
+// VT ambiguity). Such a keystroke is sent immediately instead of debounced —
+// byte order is still preserved (the immediate path flushes pending input
+// first), it just skips input-intent/activity bookkeeping. Harmless, so we
+// keep the reply grammar complete rather than special-casing it.
+const CPR_OR_DSR_RE = new RegExp('^\\u001b\\[\\??[0-9;]*[Rn]$')
+const DEVICE_ATTRIBUTES_RE = new RegExp('^\\u001b\\[[?>=]?[0-9;]*c$')
+// 4/6 = pixel-size reports, 8 = text-area size in characters (answer to CSI 18t).
+const WINDOW_SIZE_REPORT_RE = new RegExp('^\\u001b\\[[468];[0-9]+;[0-9]+t$')
+// `?` optional: private-mode reports carry it (DECRPM), ANSI-mode reports don't.
+const DECRPM_RE = new RegExp('^\\u001b\\[\\??[0-9;]*\\$y$')
+// Kitty keyboard protocol flags report: CSI ? flags u. The `?` distinguishes it
+// from kitty-protocol *keystrokes* (CSI code;mods u), which must stay batched.
+const KITTY_FLAGS_RE = new RegExp('^\\u001b\\[\\?[0-9]+u$')
+// OSC color/title responses: ESC ] Ps ; body ST (ST = BEL or ESC backslash).
+const OSC_RESPONSE_RE = new RegExp('^\\u001b\\][0-9]+;[^\\u0007\\u001b]*(?:\\u0007|\\u001b\\\\)$')
+// DCS-framed reports xterm emits: DECRQSS "ESC P 1 $ r Pt ST" / "ESC P 0 $ r ST"
+// (vim queries cursor style this way) and XTVERSION "ESC P > | text ST".
+const DCS_RESPONSE_RE = new RegExp('^\\u001bP(?:[01]\\$r[^\\u001b]*|>\\|[^\\u001b]*)\\u001b\\\\$')
+/* oxlint-enable no-control-regex */
+
+/**
+ * True when `data` (from xterm.onData) is a synthetic reply the emulator
+ * generated in response to a query — not something the user typed. These are
+ * latency-critical and must bypass input coalescing on the remote transport.
+ *
+ * Conservative by design: matches only complete, well-formed reply grammars so
+ * ordinary keystrokes and navigation sequences (arrows CSI A/B/C/D, Home/End,
+ * function keys ending in ~, kitty CSI-u keystrokes) are never misclassified
+ * as replies — with the single documented modified-F3/CPR collision above.
+ */
+export function isTerminalQueryReply(data: string): boolean {
+  if (data.length < 3 || data[0] !== ESC) {
+    return false
+  }
+  return (
+    CPR_OR_DSR_RE.test(data) ||
+    DEVICE_ATTRIBUTES_RE.test(data) ||
+    WINDOW_SIZE_REPORT_RE.test(data) ||
+    DECRPM_RE.test(data) ||
+    KITTY_FLAGS_RE.test(data) ||
+    OSC_RESPONSE_RE.test(data) ||
+    DCS_RESPONSE_RE.test(data)
+  )
+}