diff --git a/src/renderer/src/components/terminal-pane/pty-connection.test.ts b/src/renderer/src/components/terminal-pane/pty-connection.test.ts
index cf834fab5..393996707 100644
--- a/src/renderer/src/components/terminal-pane/pty-connection.test.ts
+++ b/src/renderer/src/components/terminal-pane/pty-connection.test.ts
@@ -6390,7 +6390,7 @@ describe('connectPanePty', () => {
     expect(transport.sendInput).not.toHaveBeenCalled()
   })
 
-  it('sends fast startup commands via sendInput for SSH connections', async () => {
+  it('waits for shell-ready before unhinted SSH startup commands', async () => {
     // Capture the setTimeout callback directly so we can fire it without vi.useFakeTimers() (which would also replace beforeEach's rAF mock).
     const pendingTimeouts: (() => void)[] = []
     const originalSetTimeout = globalThis.setTimeout
@@ -6414,7 +6414,7 @@ describe('connectPanePty', () => {
       )
       transportFactoryQueue.push(transport)
 
-      // SSH connection: connectionId set; relay gets command metadata for spawn context but the renderer owns fast command delivery.
+      // SSH connection: the relay gets command metadata while the renderer owns delivery.
       mockStoreState = {
         ...mockStoreState,
         tabsByWorktree: { 'wt-1': [{ id: 'tab-1', ptyId: null }] },
@@ -6430,14 +6430,17 @@ describe('connectPanePty', () => {
       connectPanePty(pane as never, manager as never, deps as never)
       expect(capturedDataCallback.current).not.toBeNull()
 
-      // Simulate shell prompt arriving — queues the debounce timer
       capturedDataCallback.current?.('user@remote $ ')
+      expect(transport.sendInput).not.toHaveBeenCalled()
 
-      // Fire all queued setTimeout callbacks (the debounce)
-      for (const fn of pendingTimeouts) {
+      capturedDataCallback.current?.('\x1b]777;orca-shell-ready\x07user@remote $ ')
+      for (const fn of pendingTimeouts.splice(0)) {
         fn()
       }
 
+      expect(createdTransportOptions[0]).toEqual(
+        expect.objectContaining({ startupCommandDelivery: 'shell-ready' })
+      )
       expect(transport.sendInput).toHaveBeenCalledWith("claude 'say test'\r")
     } finally {
       globalThis.setTimeout = originalSetTimeout
@@ -8234,7 +8237,10 @@ describe('connectPanePty', () => {
       connectPanePty(pane as never, manager as never, deps as never)
       await flushAsyncTicks(20)
       capturedDataCallback.current?.('user@remote $ ')
-      for (const fn of pendingTimeouts) {
+      expect(transport.sendInput).not.toHaveBeenCalled()
+
+      capturedDataCallback.current?.('\x1b]777;orca-shell-ready\x07user@remote $ ')
+      for (const fn of pendingTimeouts.splice(0)) {
         fn()
       }
 
@@ -8243,6 +8249,7 @@ describe('connectPanePty', () => {
         2,
         expect.objectContaining({
           command: "codex '--dangerously-bypass-approvals-and-sandbox' 'resume' 'codex-session-1'",
+          startupCommandDelivery: 'shell-ready',
           env: expect.objectContaining({
             ORCA_PANE_KEY: paneKey,
             ORCA_TAB_ID: 'tab-1',
diff --git a/src/renderer/src/components/terminal-pane/pty-connection.ts b/src/renderer/src/components/terminal-pane/pty-connection.ts
index dea08c2af..908d703b1 100644
--- a/src/renderer/src/components/terminal-pane/pty-connection.ts
+++ b/src/renderer/src/components/terminal-pane/pty-connection.ts
@@ -128,8 +128,6 @@ import {
 } from '../../../../shared/terminal-mode-reset-profiles'
 import { buildFreshShellViewportBlankingSequence } from './terminal-restored-viewport'
 import { createShellReadyMarkerScanState, scanForShellReadyMarker } from './shell-ready-marker-scan'
-import { shouldUseShellReadyStartupDelivery } from '../../../../shared/codex-startup-delivery'
-import { resolveSetupAgentSequenceLaunchCommand } from '../../../../shared/setup-agent-sequencing'
 import { getSystemPrefersDark } from '@/lib/terminal-theme'
 import {
   INITIAL_MODE_2031_REPLY_SCAN_STATE,
@@ -3810,7 +3808,9 @@ export function connectPanePty(
     command: shouldDeliverStartupViaTerminalPaste ? undefined : paneStartup?.command,
     startupCommandDelivery: shouldDeliverStartupViaTerminalPaste
       ? undefined
-      : paneStartup?.startupCommandDelivery,
+      : connectionId && paneStartup?.command
+        ? 'shell-ready'
+        : paneStartup?.startupCommandDelivery,
     connectionId,
     executionHostId,
     worktreeId: deps.worktreeId,
@@ -4794,21 +4794,31 @@ export function connectPanePty(
           ? { command: paneStartup.command }
           : null
         : null
-    const startupShellReadyCommandHint = resolveSetupAgentSequenceLaunchCommand(
-      paneStartup?.env ?? {},
-      paneStartup?.command
-    )
+    // Why: every renderer-delivered SSH command needs the relay's readiness marker;
+    // the existing fallback preserves shells that cannot emit it.
     const shouldWaitForSshShellReady =
       Boolean(connectionId) &&
-      shouldUseShellReadyStartupDelivery({
-        command: startupShellReadyCommandHint,
-        startupCommandDelivery: paneStartup?.startupCommandDelivery
-      }) &&
+      Boolean(pendingStartupCommand) &&
       !shouldDeliverStartupViaTerminalPaste
-    const sshShellReadyMarkerScan = shouldWaitForSshShellReady
+    let sshShellReadyMarkerScan = shouldWaitForSshShellReady
       ? createShellReadyMarkerScanState()
       : null
     let sshStartupShellReady = !shouldWaitForSshShellReady
+    const armSshStartupShellReady = (): void => {
+      if (!connectionId || !pendingStartupCommand || shouldDeliverStartupViaTerminalPaste) {
+        return
+      }
+      if (startupInjectTimer !== null) {
+        clearTimeout(startupInjectTimer)
+        startupInjectTimer = null
+      }
+      if (sshShellReadyFallbackTimer !== null) {
+        clearTimeout(sshShellReadyFallbackTimer)
+        sshShellReadyFallbackTimer = null
+      }
+      sshShellReadyMarkerScan = createShellReadyMarkerScanState()
+      sshStartupShellReady = false
+    }
     const markSshStartupShellReady = (): void => {
       if (sshStartupShellReady) {
         return
@@ -5121,7 +5131,8 @@ export function connectPanePty(
       return transport.sendInput('\r')
     }
     const schedulePendingStartupCommandDelivery = (): void => {
-      if (!pendingStartupCommand) {
+      const startup = pendingStartupCommand
+      if (!startup) {
         return
       }
       if (!sshStartupShellReady) {
@@ -5142,8 +5153,7 @@ export function connectPanePty(
       startupInjectTimer = setTimeout(() => {
         startupInjectTimer = null
         void (async () => {
-          const startup = pendingStartupCommand
-          if (!startup || disposed) {
+          if (pendingStartupCommand !== startup || disposed) {
             return
           }
           if (shouldDeliverStartupViaTerminalPaste) {
@@ -5242,6 +5252,7 @@ export function connectPanePty(
         // must still submit the resume command to the fresh remote shell.
         pendingStartupCommand = { command: startupOverride.command }
       }
+      armSshStartupShellReady()
       const coldRestoreOverride =
         startupOverride && 'launchConfig' in startupOverride
           ? (startupOverride as ColdRestoreAgentResumeStartup)
@@ -5264,6 +5275,9 @@ export function connectPanePty(
         cols,
         rows,
         ...(startupOverride?.command ? { command: startupOverride.command } : {}),
+        ...(connectionId && startupOverride?.command
+          ? { startupCommandDelivery: 'shell-ready' as const }
+          : {}),
         ...(startupOverride?.env
           ? { env: mergeStartupEnvWithPaneIdentity(startupOverride.env) }
           : {}),