diff --git a/src/main/claude/claude-model-catalog-probe.test.ts b/src/main/claude/claude-model-catalog-probe.test.ts
index 3f7792b33de..e77d63d90b0 100644
--- a/src/main/claude/claude-model-catalog-probe.test.ts
+++ b/src/main/claude/claude-model-catalog-probe.test.ts
@@ -59,8 +59,8 @@ function listedResult(): DiscoverResult {
 }
 
 describe('claude model catalog probe', () => {
-  it.each([`"${process.execPath}"`, 'npx claude', '/missing/claude', './claude'])(
-    'lists with the session executable for Command %s',
+  it.each([`"${process.execPath}"`, ''])(
+    'lists with the session executable for Command %j',
     async (command) => {
       const deps = probeDeps(command)
       const captured: DiscoverInput[] = []
@@ -134,6 +134,16 @@ describe('claude model catalog probe', () => {
     await expect(probe('/homes/a')).rejects.toThrow(/listed no models/)
   })
 
+  it.each(['npx claude', 'claude --verbose', '/missing/claude', './claude'])(
+    'lists nothing, and never probes the stock CLI, for Command %s',
+    async (command) => {
+      const discover = vi.fn()
+      const probe = createClaudeModelCatalogProbe({ ...probeDeps(command), discover })
+      await expect(probe('/homes/a')).rejects.toMatchObject({ reason: 'agentCommandNotRunnable' })
+      expect(discover).not.toHaveBeenCalled()
+    }
+  )
+
   it.runIf(process.platform !== 'win32')(
     'lists through a supervised one-shot that answers after its input ends',
     async () => {
diff --git a/src/main/codex/codex-model-catalog-probe.test.ts b/src/main/codex/codex-model-catalog-probe.test.ts
index d7f3edff47b..a3aeeebc4af 100644
--- a/src/main/codex/codex-model-catalog-probe.test.ts
+++ b/src/main/codex/codex-model-catalog-probe.test.ts
@@ -13,8 +13,8 @@ const MODEL_ROW = {
 }
 
 describe('codex model catalog probe', () => {
-  it.each([`"${process.execPath}"`, 'npx codex', '/missing/codex', './codex'])(
-    'lists with the session executable for Command %s',
+  it.each([`"${process.execPath}"`, ''])(
+    'lists with the session executable for Command %j',
     async (command) => {
       // The env a user's shell/config resolves for sessions, PATH included.
       const resolveEnvironment = async (): Promise<NodeJS.ProcessEnv> => ({
@@ -111,4 +111,23 @@ describe('codex model catalog probe', () => {
     })
     await expect(probe('/homes/a')).rejects.toThrow(/listed no models/)
   })
+
+  it.each(['npx codex', 'codex --profile work', '/missing/codex', './codex'])(
+    'lists nothing, and never probes the stock CLI, for Command %s',
+    async (command) => {
+      const runSession = vi.fn()
+      const probe = createCodexModelCatalogProbe({
+        resolveEnvironment: async () => ({ PATH: '/bin' }),
+        resolveCommand: (options) =>
+          resolveStructuredAgentCommand(
+            'codex',
+            { agentCmdOverrides: { codex: command } },
+            options
+          ),
+        runSession
+      })
+      await expect(probe('/homes/a')).rejects.toMatchObject({ reason: 'agentCommandNotRunnable' })
+      expect(runSession).not.toHaveBeenCalled()
+    }
+  )
 })
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-adapter.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-adapter.ts
index b05e89136f0..f111081ab44 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-adapter.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-adapter.ts
@@ -133,6 +133,7 @@ export type AgentSessionPreSpawnReason = Extract<
   | 'accountSwitchInProgress'
   | 'managedAccountUnsupported'
   | 'launchFolderMissing'
+  | 'agentCommandNotRunnable'
 >
 
 /** Acquisition failed with first-hand proof that no provider process existed. */
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-failure-text.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-failure-text.test.ts
index b508cc9e757..c49b79b06e6 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-failure-text.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-failure-text.test.ts
@@ -99,6 +99,10 @@ describe('structuredAgentSessionStartFailure', () => {
     [
       'managedAccountUnsupported',
       'While a Claude account is added in WSL, Claude chats need a Windows Claude account. Choose or add one in Claude Accounts settings, then send your message again.'
+    ],
+    [
+      'agentCommandNotRunnable',
+      "Claude's Command in Settings → Agents must be a program path or name Orca can find, with no arguments or variables. Change it or reset it."
     ]
   ] as const)('words a start refused for %s by that situation', (reason, sentence) => {
     const code = 'agent_session_operation_invalid'
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-failure-text.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-failure-text.ts
index 75f7769e7a7..a48848fb717 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-failure-text.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-failure-text.ts
@@ -29,7 +29,8 @@ const TYPED_START_REFUSALS = [
   'managedAccountEnvOverride',
   'accountSwitchInProgress',
   'managedAccountUnsupported',
-  'launchFolderMissing'
+  'launchFolderMissing',
+  'agentCommandNotRunnable'
 ] as const satisfies readonly (AgentSessionFailureKind &
   AgentSessionRefusalReason<'agent_session_operation_invalid'>)[]
 
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-pre-spawn-first-answer.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-pre-spawn-first-answer.test.ts
index e6c3cead931..7dfd624b496 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-pre-spawn-first-answer.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-pre-spawn-first-answer.test.ts
@@ -163,6 +163,12 @@ describe('a create that fails before any process spawns', () => {
       'launchFolderMissing',
       'The folder this chat ran in no longer exists. Restore it to continue this chat.'
     ],
+    [
+      'a Command setting that names no runnable program',
+      'the claude Command setting is not a runnable program',
+      'agentCommandNotRunnable',
+      "Claude's Command in Settings → Agents must be a program path or name Orca can find, with no arguments or variables. Change it or reset it."
+    ],
     [
       "Orca's own reason",
       'claude sessions pin CLAUDE_CONFIG_DIR, not CODEX_HOME',
diff --git a/src/main/native-chat/structured-agent-command-resolution.test.ts b/src/main/native-chat/structured-agent-command-resolution.test.ts
index 3fa758cfe5b..a2fc166a1a3 100644
--- a/src/main/native-chat/structured-agent-command-resolution.test.ts
+++ b/src/main/native-chat/structured-agent-command-resolution.test.ts
@@ -5,6 +5,11 @@ import { afterEach, describe, expect, it } from 'vitest'
 import { resolveStructuredAgentCommand } from './structured-agent-command-resolution'
 import { resolveCliCommand } from '../../shared/node-cli-command-resolution'
 
+const NOT_RUNNABLE = expect.objectContaining({
+  name: 'AgentSessionPreSpawnError',
+  reason: 'agentCommandNotRunnable'
+})
+
 const scratch: string[] = []
 afterEach(() => {
   for (const dir of scratch.splice(0)) {
@@ -62,7 +67,12 @@ describe('structured agent executable resolution', () => {
     expect(resolveStructuredAgentCommand('claude', settings)).toBe(second.command)
   })
 
-  it('uses the stock executable for missing files, directories, relative paths and shell lines', () => {
+  it.each(['', '   ', undefined])('uses the stock executable when the Command is %j', (command) => {
+    const settings = command === undefined ? {} : { agentCmdOverrides: { claude: command } }
+    expect(resolveStructuredAgentCommand('claude', settings)).toBe(resolveCliCommand('claude'))
+  })
+
+  it('refuses missing files, directories, relative paths and command lines instead of the stock executable', () => {
     const { directory } = executable()
     const folder = join(directory, 'folder')
     mkdirSync(folder)
@@ -71,18 +81,89 @@ describe('structured agent executable resolution', () => {
       folder,
       './claude',
       'npx claude',
-      'wrapper --flag'
+      'wrapper --flag',
+      'FOO=1 claude',
+      '$HOME/bin/claude'
     ]) {
       const settings = { agentCmdOverrides: { claude: command } }
-      expect(resolveStructuredAgentCommand('claude', settings)).toBe(resolveCliCommand('claude'))
+      expect(() => resolveStructuredAgentCommand('claude', settings)).toThrow(NOT_RUNNABLE)
     }
   })
 
   it.skipIf(process.platform === 'win32')('requires executable permission on Unix', () => {
     const { command } = executable()
     chmodSync(command, 0o644)
-    expect(
+    expect(() =>
       resolveStructuredAgentCommand('claude', { agentCmdOverrides: { claude: `"${command}"` } })
-    ).toBe(resolveCliCommand('claude'))
+    ).toThrow(NOT_RUNNABLE)
+  })
+
+  it('keeps the saved value out of the refusal, since a command line can carry a secret', () => {
+    expect(() =>
+      resolveStructuredAgentCommand('codex', {
+        agentCmdOverrides: { codex: 'TOKEN=sk-secret codex' }
+      })
+    ).toThrow(expect.not.objectContaining({ message: expect.stringContaining('sk-secret') }))
+  })
+
+  describe('on Windows', () => {
+    function fileIn(directory: string, name: string): string {
+      const file = join(directory, name)
+      writeFileSync(file, '')
+      return file
+    }
+
+    it('refuses an extensionless path, which Windows cannot spawn', () => {
+      const { directory } = executable()
+      const command = fileIn(directory, 'claude')
+      fileIn(directory, 'claude.cmd')
+      expect(() =>
+        resolveStructuredAgentCommand(
+          'claude',
+          { agentCmdOverrides: { claude: command } },
+          { platform: 'win32' }
+        )
+      ).toThrow(NOT_RUNNABLE)
+    })
+
+    it('refuses a name whose only match on PATH is extensionless', () => {
+      const { directory } = executable()
+      fileIn(directory, 'my-claude')
+      expect(() =>
+        resolveStructuredAgentCommand(
+          'claude',
+          { agentCmdOverrides: { claude: 'my-claude' } },
+          { platform: 'win32', pathEnv: directory, homePath: directory }
+        )
+      ).toThrow(NOT_RUNNABLE)
+    })
+
+    it.each(['claude.exe', 'claude.com', 'claude.cmd', 'claude.bat'])(
+      'runs an explicit %s path',
+      (name) => {
+        const { directory } = executable()
+        const command = fileIn(directory, name)
+        expect(
+          resolveStructuredAgentCommand(
+            'claude',
+            { agentCmdOverrides: { claude: `"${command}"` } },
+            { platform: 'win32' }
+          )
+        ).toBe(command)
+      }
+    )
+
+    it('finds the .cmd shim for a bare name, as the stock lookup does', () => {
+      const { directory } = executable()
+      fileIn(directory, 'my-claude')
+      const shim = fileIn(directory, 'my-claude.cmd')
+      expect(
+        resolveStructuredAgentCommand(
+          'claude',
+          { agentCmdOverrides: { claude: 'my-claude' } },
+          { platform: 'win32', pathEnv: directory, homePath: directory }
+        )
+      ).toBe(shim)
+    })
   })
 })
diff --git a/src/main/native-chat/structured-agent-command-resolution.ts b/src/main/native-chat/structured-agent-command-resolution.ts
index 7ce9afcb77b..9cc1f28bd01 100644
--- a/src/main/native-chat/structured-agent-command-resolution.ts
+++ b/src/main/native-chat/structured-agent-command-resolution.ts
@@ -4,7 +4,11 @@ import {
   resolveCliCommand,
   resolveExecutableCommand
 } from '../../shared/node-cli-command-resolution'
-import { structuredAgentCommandToken } from '../../shared/tui-agent-launch-command-override'
+import {
+  hasExplicitTuiLaunchCommand,
+  structuredAgentCommandToken
+} from '../../shared/tui-agent-launch-command-override'
+import { AgentSessionPreSpawnError } from './agent-session-wire/structured-agent-session-adapter'
 
 type CommandSettings = Partial<Pick<GlobalSettings, 'agentCmdOverrides' | 'agentDefaultEnv'>>
 type CommandOptions = NonNullable<Parameters<typeof resolveExecutableCommand>[1]>
@@ -24,11 +28,28 @@ function resolveOverride(
     : null
 }
 
-/** Re-read the existing setting for every session acquisition and catalog probe. */
+// Windows starts .exe/.com directly and .cmd/.bat through Orca's shim handling; an extensionless
+// file would fail to spawn with no word about the setting.
+function spawnableOn(platform: NodeJS.Platform, command: string): boolean {
+  return platform !== 'win32' || /\.(exe|com|cmd|bat)$/i.test(command)
+}
+
+/** Re-read the existing setting for every session acquisition and catalog probe. A set Command
+ *  that names no runnable program refuses the start rather than quietly running the stock CLI. */
 export function resolveStructuredAgentCommand(
   agent: 'claude' | 'codex',
   settings: CommandSettings,
   options: CommandOptions = {}
 ): string {
-  return resolveOverride(agent, settings, options) ?? resolveCliCommand(agent, options)
+  if (!hasExplicitTuiLaunchCommand(settings, agent)) {
+    return resolveCliCommand(agent, options)
+  }
+  const command = resolveOverride(agent, settings, options)
+  if (!command || !spawnableOn(options.platform ?? process.platform, command)) {
+    // The value stays out of the message: a saved command line can carry a secret.
+    throw new AgentSessionPreSpawnError(`the ${agent} Command setting is not a runnable program`, {
+      reason: 'agentCommandNotRunnable'
+    })
+  }
+  return command
 }
diff --git a/src/main/runtime/orca-runtime-structured-launch-settings-wiring.test.ts b/src/main/runtime/orca-runtime-structured-launch-settings-wiring.test.ts
index e9738615b5f..dd81e303b41 100644
--- a/src/main/runtime/orca-runtime-structured-launch-settings-wiring.test.ts
+++ b/src/main/runtime/orca-runtime-structured-launch-settings-wiring.test.ts
@@ -37,9 +37,13 @@ describe('execution host structured launch settings wiring', () => {
     settings.agentDefaultArgs = { claude: '--model second', codex: '' }
     expect(await deps?.resolveLaunchArgs?.('claude')).toEqual(['--model', 'second'])
     expect(await deps?.resolveLaunchArgs?.('codex')).toEqual([])
+    const notRunnable = expect.objectContaining({ reason: 'agentCommandNotRunnable' })
     settings.agentCmdOverrides = { claude: 'wrapper --arg' }
-    expect(deps?.resolveClaudeCommand?.()).toBe(resolveCliCommand('claude'))
+    expect(() => deps?.resolveClaudeCommand?.()).toThrow(notRunnable)
     settings.agentCmdOverrides = { codex: '/missing/codex' }
+    expect(() => deps?.resolveCodexCommand?.()).toThrow(notRunnable)
+    settings.agentCmdOverrides = {}
+    expect(deps?.resolveClaudeCommand?.()).toBe(resolveCliCommand('claude'))
     expect(deps?.resolveCodexCommand?.()).toBe(resolveCliCommand('codex'))
   })
 })
diff --git a/src/main/runtime/rpc/methods/orchestration-worker-start-mode.test.ts b/src/main/runtime/rpc/methods/orchestration-worker-start-mode.test.ts
index 93e9bb25a8b..aee3bfefb6d 100644
--- a/src/main/runtime/rpc/methods/orchestration-worker-start-mode.test.ts
+++ b/src/main/runtime/rpc/methods/orchestration-worker-start-mode.test.ts
@@ -87,7 +87,7 @@ describe('a structured default this dispatch cannot honour', () => {
     expect(decide({ params: { agent: 'codex', worktree: 'current' } }).mode).toBe('structured')
   })
 
-  // A custom launch command applies to terminal launches only; native chat ignores it.
+  // A custom launch command never decides the surface; native chat runs it as the program.
   it.each([
     ['claude', 'claude-wrapper'],
     ['codex', 'codex-nightly']
diff --git a/src/renderer/src/components/native-chat/NativeChatLaunchRetry.command-failure.test.tsx b/src/renderer/src/components/native-chat/NativeChatLaunchRetry.command-failure.test.tsx
new file mode 100644
index 00000000000..74faee5fcff
--- /dev/null
+++ b/src/renderer/src/components/native-chat/NativeChatLaunchRetry.command-failure.test.tsx
@@ -0,0 +1,43 @@
+// @vitest-environment happy-dom
+import { cleanup, render, screen } from '@testing-library/react'
+import { afterEach, expect, it } from 'vitest'
+import { sayAgentSessionFailureEnglish } from '../../../../shared/agent-session-failure-copy'
+import { agentSessionFailureSentence } from '../../../../shared/agent-session-failure-words'
+import { agentSessionRefusalFailure } from '../../../../shared/agent-session-write-failure'
+import { NativeChatLaunchRetry } from './NativeChatLaunchRetry'
+
+afterEach(cleanup)
+
+it('names the Command setting when it is not a program Orca can run', () => {
+  const failure = agentSessionRefusalFailure({
+    code: 'agent_session_operation_invalid',
+    details: { reason: 'agentCommandNotRunnable' }
+  })
+  render(
+    <NativeChatLaunchRetry
+      lifecycle="failed"
+      failure={failure}
+      agentLabel="Claude"
+      onRetry={() => {}}
+    />
+  )
+  expect(
+    screen.getByText(
+      "Chat could not be started. Claude's Command in Settings → Agents must be a program path or name Orca can find, with no arguments or variables. Change it or reset it."
+    )
+  ).toBeTruthy()
+  expect(screen.getByRole('button', { name: 'Retry' })).toBeTruthy()
+})
+
+it('reads naturally where no agent name is known', () => {
+  expect(
+    agentSessionFailureSentence(
+      { kind: 'agentCommandNotRunnable' },
+      'row',
+      {},
+      sayAgentSessionFailureEnglish
+    )
+  ).toBe(
+    "The agent's Command in Settings → Agents must be a program path or name Orca can find, with no arguments or variables. Change it or reset it."
+  )
+})
diff --git a/src/renderer/src/components/native-chat/agent-session-failure-words-text.ts b/src/renderer/src/components/native-chat/agent-session-failure-words-text.ts
index 2c455769a78..0fa34b19aaa 100644
--- a/src/renderer/src/components/native-chat/agent-session-failure-words-text.ts
+++ b/src/renderer/src/components/native-chat/agent-session-failure-words-text.ts
@@ -108,6 +108,12 @@ const PIECES: Record<AgentSessionFailureCopyId, (values: AgentSessionFailureCopy
         'components.native-chat.failureWords.launchFolderMissing',
         COPY.launchFolderMissing
       ),
+    agentCommandNotRunnable: (values) =>
+      translate(
+        'components.native-chat.failureWords.agentCommandNotRunnable',
+        COPY.agentCommandNotRunnable,
+        values
+      ),
     chooseClaudeAccount: () =>
       translate(
         'components.native-chat.failureWords.chooseClaudeAccount',
diff --git a/src/renderer/src/components/native-chat/native-chat-session-option-discovery.ts b/src/renderer/src/components/native-chat/native-chat-session-option-discovery.ts
index b4520a225c0..ac43cd4c74b 100644
--- a/src/renderer/src/components/native-chat/native-chat-session-option-discovery.ts
+++ b/src/renderer/src/components/native-chat/native-chat-session-option-discovery.ts
@@ -127,7 +127,7 @@ export async function discoverNativeChatCatalogModels(
   const hostCatalogAgent =
     agent === 'claude' ? ('claude' as const) : agent === 'codex' ? ('codex' as const) : null
   // Only `local` proves a native pane: a paired runtime's key also covers its SSH/WSL worktrees.
-  // A custom launch command runs a binary the structured catalog never lists; the CLI listing honors it.
+  // Terminal-backed chat runs the full custom command line, which only the CLI listing models.
   if (
     hostCatalogAgent &&
     hostKey === LOCAL_COMMIT_MESSAGE_HOST_KEY &&
diff --git a/src/renderer/src/i18n/en-runtime-required.json b/src/renderer/src/i18n/en-runtime-required.json
index a36edc792f1..2933c7538f5 100644
--- a/src/renderer/src/i18n/en-runtime-required.json
+++ b/src/renderer/src/i18n/en-runtime-required.json
@@ -2796,6 +2796,7 @@
         "managedAccountEnvOverride": "This Claude launch sets its own Anthropic sign-in variables. Remove them to use a managed Claude account.",
         "managedAccountUnsupported": "While a Claude account is added in WSL, Claude chats need a Windows Claude account.",
         "launchFolderMissing": "The folder this chat ran in no longer exists. Restore it to continue this chat.",
+        "agentCommandNotRunnable": "{{agent}}'s Command in Settings → Agents must be a program path or name Orca can find, with no arguments or variables. Change it or reset it.",
         "noTurnToStop": "{{agent}} had no turn running to stop.",
         "notDelivered": "This message was not delivered.",
         "notDeliveredSendAgain": "This message was not delivered. Send it again to continue.",
diff --git a/src/renderer/src/i18n/locales/en.json b/src/renderer/src/i18n/locales/en.json
index 8816b3a4dbc..a8320eb8c96 100644
--- a/src/renderer/src/i18n/locales/en.json
+++ b/src/renderer/src/i18n/locales/en.json
@@ -17798,6 +17798,7 @@
         "accountSwitchInProgress": "A Claude account switch is in progress. Try again after it finishes.",
         "managedAccountUnsupported": "While a Claude account is added in WSL, Claude chats need a Windows Claude account.",
         "launchFolderMissing": "The folder this chat ran in no longer exists. Restore it to continue this chat.",
+        "agentCommandNotRunnable": "{{agent}}'s Command in Settings → Agents must be a program path or name Orca can find, with no arguments or variables. Change it or reset it.",
         "chooseClaudeAccount": "Choose or add one in Claude Accounts settings.",
         "chooseClaudeAccountThenRunCommand": "Choose or add one in Claude Accounts settings, then run /{{command}} again.",
         "chooseClaudeAccountThenSend": "Choose or add one in Claude Accounts settings, then send your message again.",
diff --git a/src/renderer/src/i18n/locales/es.json b/src/renderer/src/i18n/locales/es.json
index 9d39b2425eb..5af0be4c76b 100644
--- a/src/renderer/src/i18n/locales/es.json
+++ b/src/renderer/src/i18n/locales/es.json
@@ -17573,6 +17573,7 @@
         "accountSwitchInProgress": "Hay un cambio de cuenta de Claude en curso. Vuelva a intentarlo cuando termine.",
         "managedAccountUnsupported": "Mientras haya una cuenta de Claude agregada en WSL, los chats de Claude necesitan una cuenta de Claude de Windows.",
         "launchFolderMissing": "La carpeta en la que se ejecutaba este chat ya no existe. Restáurela para continuar este chat.",
+        "agentCommandNotRunnable": "{{agent}}: el Comando en Ajustes → Agentes debe ser la ruta o el nombre de un programa que Orca pueda encontrar, sin argumentos ni variables. Cámbielo o restablézcalo con Reiniciar.",
         "chooseClaudeAccount": "Elija o agregue una en la configuración de Cuentas de Claude.",
         "chooseClaudeAccountThenRunCommand": "Elija o agregue una en la configuración de Cuentas de Claude y vuelva a ejecutar /{{command}}.",
         "chooseClaudeAccountThenSend": "Elija o agregue una en la configuración de Cuentas de Claude y vuelva a enviar su mensaje.",
diff --git a/src/renderer/src/i18n/locales/fr.json b/src/renderer/src/i18n/locales/fr.json
index 9df7cf8896d..93954938d4c 100644
--- a/src/renderer/src/i18n/locales/fr.json
+++ b/src/renderer/src/i18n/locales/fr.json
@@ -17674,6 +17674,7 @@
         "accountSwitchInProgress": "Un changement de compte Claude est en cours. Réessayez une fois qu'il sera terminé.",
         "managedAccountUnsupported": "Tant qu'un compte Claude est ajouté dans WSL, les chats Claude nécessitent un compte Claude Windows.",
         "launchFolderMissing": "Le dossier dans lequel ce chat s'exécutait n'existe plus. Restaurez-le pour poursuivre ce chat.",
+        "agentCommandNotRunnable": "{{agent}} : la Commande dans Paramètres → Agents doit être le chemin ou le nom d'un programme qu'Orca peut trouver, sans arguments ni variables. Modifiez-la ou réinitialisez-la.",
         "chooseClaudeAccount": "Choisissez-en un ou ajoutez-en un dans les paramètres Comptes Claude.",
         "chooseClaudeAccountThenRunCommand": "Choisissez-en un ou ajoutez-en un dans les paramètres Comptes Claude, puis relancez /{{command}}.",
         "chooseClaudeAccountThenSend": "Choisissez-en un ou ajoutez-en un dans les paramètres Comptes Claude, puis renvoyez votre message.",
diff --git a/src/renderer/src/i18n/locales/ja.json b/src/renderer/src/i18n/locales/ja.json
index 22c7c495c2d..676b1d728d9 100644
--- a/src/renderer/src/i18n/locales/ja.json
+++ b/src/renderer/src/i18n/locales/ja.json
@@ -17608,6 +17608,7 @@
         "accountSwitchInProgress": "Claude アカウントの切り替え中です。完了してからもう一度お試しください。",
         "managedAccountUnsupported": "WSL に Claude アカウントが追加されている間、Claude チャットには Windows の Claude アカウントが必要です。",
         "launchFolderMissing": "このチャットが実行されていたフォルダーは存在しなくなりました。このチャットを続けるには、フォルダーを復元してください。",
+        "agentCommandNotRunnable": "[設定] → [Agent] にある {{agent}} の [コマンド] には、Orca が見つけられるプログラムのパスまたは名前を、引数や変数なしで指定する必要があります。変更するか、[リセット] してください。",
         "chooseClaudeAccount": "Claude アカウントの設定で選択または追加してください。",
         "chooseClaudeAccountThenRunCommand": "Claude アカウントの設定で選択または追加してから、/{{command}} をもう一度実行してください。",
         "chooseClaudeAccountThenSend": "Claude アカウントの設定で選択または追加してから、メッセージをもう一度送信してください。",
diff --git a/src/renderer/src/i18n/locales/ko.json b/src/renderer/src/i18n/locales/ko.json
index a101803edc1..829fa949ea6 100644
--- a/src/renderer/src/i18n/locales/ko.json
+++ b/src/renderer/src/i18n/locales/ko.json
@@ -17608,6 +17608,7 @@
         "accountSwitchInProgress": "Claude 계정 전환이 진행 중입니다. 완료된 후 다시 시도하세요.",
         "managedAccountUnsupported": "WSL에 Claude 계정이 추가되어 있는 동안에는 Claude 채팅에 Windows Claude 계정이 필요합니다.",
         "launchFolderMissing": "이 채팅이 실행되던 폴더가 더 이상 존재하지 않습니다. 이 채팅을 계속하려면 폴더를 복원하세요.",
+        "agentCommandNotRunnable": "{{agent}}의 설정 → 에이전트 → 명령은 Orca가 찾을 수 있는 프로그램 경로나 이름이어야 하며, 인수나 변수를 포함할 수 없습니다. 변경하거나 재설정하세요.",
         "chooseClaudeAccount": "Claude 계정 설정에서 선택하거나 추가하세요.",
         "chooseClaudeAccountThenRunCommand": "Claude 계정 설정에서 선택하거나 추가한 다음 /{{command}}을(를) 다시 실행하세요.",
         "chooseClaudeAccountThenSend": "Claude 계정 설정에서 선택하거나 추가한 다음 메시지를 다시 보내세요.",
diff --git a/src/renderer/src/i18n/locales/zh.json b/src/renderer/src/i18n/locales/zh.json
index b76846075ad..48e88654708 100644
--- a/src/renderer/src/i18n/locales/zh.json
+++ b/src/renderer/src/i18n/locales/zh.json
@@ -17573,6 +17573,7 @@
         "accountSwitchInProgress": "正在切换 Claude 账户。请在切换完成后重试。",
         "managedAccountUnsupported": "当 WSL 中添加了 Claude 账户时，Claude 聊天需要 Windows Claude 账户。",
         "launchFolderMissing": "此聊天运行所在的文件夹已不存在。请恢复该文件夹以继续此聊天。",
+        "agentCommandNotRunnable": "{{agent}} 在设置 → 智能体中的命令必须是 Orca 能找到的程序路径或名称，且不能包含参数或变量。请修改或重置。",
         "chooseClaudeAccount": "请在 Claude 账户设置中选择或添加一个。",
         "chooseClaudeAccountThenRunCommand": "请在 Claude 账户设置中选择或添加一个，然后重新运行 /{{command}}。",
         "chooseClaudeAccountThenSend": "请在 Claude 账户设置中选择或添加一个，然后重新发送您的消息。",
diff --git a/src/renderer/src/lib/agent-launch-route-input.test.ts b/src/renderer/src/lib/agent-launch-route-input.test.ts
index 47738bde69b..8a1ac92a224 100644
--- a/src/renderer/src/lib/agent-launch-route-input.test.ts
+++ b/src/renderer/src/lib/agent-launch-route-input.test.ts
@@ -415,7 +415,7 @@ describe('buildAgentLaunchRouteInput', () => {
       }
     })
 
-    // A launch command override applies to terminal launches only, here or on the server.
+    // A launch command override never decides the surface, here or on the server.
     it("does not route on this machine's launch command override for the server", () => {
       const settings = { ...STRUCTURED_SETTINGS, agentCmdOverrides: { claude: 'claude-wrapper' } }
       expect(
diff --git a/src/shared/agent-session-failure-copy.ts b/src/shared/agent-session-failure-copy.ts
index a55978aea29..4575485b456 100644
--- a/src/shared/agent-session-failure-copy.ts
+++ b/src/shared/agent-session-failure-copy.ts
@@ -37,6 +37,8 @@ export const AGENT_SESSION_FAILURE_COPY = {
     'While a Claude account is added in WSL, Claude chats need a Windows Claude account.',
   launchFolderMissing:
     'The folder this chat ran in no longer exists. Restore it to continue this chat.',
+  agentCommandNotRunnable:
+    "{{agent}}'s Command in Settings → Agents must be a program path or name Orca can find, with no arguments or variables. Change it or reset it.",
   chooseClaudeAccount: 'Choose or add one in Claude Accounts settings.',
   chooseClaudeAccountThenRunCommand:
     'Choose or add one in Claude Accounts settings, then run /{{command}} again.',
diff --git a/src/shared/agent-session-failure-words.ts b/src/shared/agent-session-failure-words.ts
index abb601ff1b9..b8dacdfd813 100644
--- a/src/shared/agent-session-failure-words.ts
+++ b/src/shared/agent-session-failure-words.ts
@@ -220,6 +220,8 @@ const FAILURE_SENTENCES = {
   managedAccountEnvOverride: (_context, _fact, _surface, say) => say('managedAccountEnvOverride'),
   accountSwitchInProgress: (_context, _fact, _surface, say) => say('accountSwitchInProgress'),
   launchFolderMissing: (_context, _fact, _surface, say) => say('launchFolderMissing'),
+  agentCommandNotRunnable: (context, _fact, _surface, say) =>
+    say('agentCommandNotRunnable', agent(say, context)),
   managedAccountUnsupported: (context, _fact, _surface, say) =>
     joinSentences([
       say('managedAccountUnsupported'),
diff --git a/src/shared/agent-session-failure.ts b/src/shared/agent-session-failure.ts
index fe3180be6c8..fe69dd2243e 100644
--- a/src/shared/agent-session-failure.ts
+++ b/src/shared/agent-session-failure.ts
@@ -30,6 +30,7 @@ export const AGENT_SESSION_FAILURE_KINDS = [
   'accountSwitchInProgress',
   'managedAccountUnsupported',
   'launchFolderMissing',
+  'agentCommandNotRunnable',
   'providerExited',
   'restartFailed',
   'providerRejected',
diff --git a/src/shared/agent-session-refusal-details.ts b/src/shared/agent-session-refusal-details.ts
index f296e42df35..b9ef64f2c47 100644
--- a/src/shared/agent-session-refusal-details.ts
+++ b/src/shared/agent-session-refusal-details.ts
@@ -57,6 +57,8 @@ export const AGENT_SESSION_REFUSAL_REASONS = {
     'managedAccountUnsupported',
     /** A floating chat resumes only in the folder it ran in, and that folder is gone. */
     'launchFolderMissing',
+    /** Settings → Agents → Command names no program this host can run. */
+    'agentCommandNotRunnable',
     /** The agent started, then Orca could not open the chat's conversation for it. */
     'attachFailed'
   ],
diff --git a/src/shared/agent-session-refusal-reason-words.ts b/src/shared/agent-session-refusal-reason-words.ts
index d8756a3c9ec..d6c1b0354fb 100644
--- a/src/shared/agent-session-refusal-reason-words.ts
+++ b/src/shared/agent-session-refusal-reason-words.ts
@@ -97,6 +97,7 @@ const REASON_WORDS = {
     accountSwitchInProgress: { fact: 'accountSwitchInProgress', action: 'wait' },
     managedAccountUnsupported: { fact: 'managedAccountUnsupported', action: 'actFirst' },
     launchFolderMissing: { fact: 'launchFolderMissing', action: 'actFirst' },
+    agentCommandNotRunnable: { fact: 'agentCommandNotRunnable', action: 'actFirst' },
     attachFailed: codeWords('retry')
   },
   agent_session_ownership_unknown: {
diff --git a/src/shared/structured-agent-session-dispatch-rejection.ts b/src/shared/structured-agent-session-dispatch-rejection.ts
index a67b76cd3b8..69bd7760aea 100644
--- a/src/shared/structured-agent-session-dispatch-rejection.ts
+++ b/src/shared/structured-agent-session-dispatch-rejection.ts
@@ -91,6 +91,7 @@ const KIND_CATEGORY = {
   accountSwitchInProgress: 'startFailed',
   managedAccountUnsupported: 'startFailed',
   launchFolderMissing: 'startFailed',
+  agentCommandNotRunnable: 'startFailed',
   restartFailed: 'startFailed',
   providerRejected: 'content',
   attachmentInvalid: 'content',
@@ -117,6 +118,7 @@ const KIND_VERDICT = {
   accountSwitchInProgress: 'failure',
   managedAccountUnsupported: 'failure',
   launchFolderMissing: 'failure',
+  agentCommandNotRunnable: 'failure',
   restartFailed: 'failure',
   providerRejected: 'failure',
   attachmentInvalid: 'failure',
diff --git a/src/shared/structured-native-chat-launch-route.ts b/src/shared/structured-native-chat-launch-route.ts
index e1627c305dc..f92bac17e84 100644
--- a/src/shared/structured-native-chat-launch-route.ts
+++ b/src/shared/structured-native-chat-launch-route.ts
@@ -30,7 +30,7 @@ export type StructuredNativeChatBlocker =
   | 'reused-terminal'
   | 'agent-without-structured-session'
   /** The launch names a start directory outside its workspace, which only a PTY can apply. The
-   *  configured launch command and arguments are not read: they apply to terminal launches only. */
+   *  configured launch command and arguments never decide the surface. */
   | 'custom-start-directory'
   | 'remote-execution-host'
   | 'project-runtime'