diff --git a/src/main/runtime/rpc/methods/orchestration/worker/worker-launch-model-authority.test.ts b/src/main/runtime/rpc/methods/orchestration/worker/worker-launch-model-authority.test.ts
index 8a067e7b6f9..c7730259666 100644
--- a/src/main/runtime/rpc/methods/orchestration/worker/worker-launch-model-authority.test.ts
+++ b/src/main/runtime/rpc/methods/orchestration/worker/worker-launch-model-authority.test.ts
@@ -87,8 +87,11 @@ describe('worker launch model authority', () => {
 
     expect(authority).toEqual({
       source: 'live',
-      modelIds: ['opus[1m]', 'haiku', 'claude-opus-5[1m]', 'opus']
+      modelIds: ['opus[1m]', 'haiku', 'claude-opus-5[1m]', 'opus', 'default']
     })
+    expect(
+      resolveWorkerLaunchPreferences({ agent: 'claude', model: 'default', authority }).preferences
+    ).toEqual({ model: 'default' })
   })
 
   it('never asks an agent whose probe only extends the seed, and so refuses nothing', async () => {
@@ -309,6 +312,27 @@ describe('worker launch model authority', () => {
     expect(second.modelIds).toContain('opus[1m]')
   })
 
+  it('does not reuse a catalog from a different agent command', async () => {
+    const { runtime, discover } = probeRuntime(() => probeSuccess([liveModel('opus[1m]')]))
+    const base = {
+      catalog: CLAUDE_CATALOG,
+      agent: 'claude' as const,
+      runtime,
+      worktreeSelector: 'id:wt_local'
+    }
+
+    await resolveWorkerLaunchModelAuthority({ ...base, agentCommandOverride: 'claude-stable' })
+    await resolveWorkerLaunchModelAuthority({ ...base, agentCommandOverride: 'claude-preview' })
+
+    expect(discover).toHaveBeenCalledTimes(2)
+    expect(discover).toHaveBeenNthCalledWith(1, 'id:wt_local', 'claude', {
+      agentCmdOverrides: { claude: 'claude-stable' }
+    })
+    expect(discover).toHaveBeenNthCalledWith(2, 'id:wt_local', 'claude', {
+      agentCmdOverrides: { claude: 'claude-preview' }
+    })
+  })
+
   it('shares one in-flight probe across dispatches that race it', async () => {
     let release: (() => void) | undefined
     const started = new Promise<void>((resolve) => {
diff --git a/src/main/runtime/rpc/methods/orchestration/worker/worker-launch-model-authority.ts b/src/main/runtime/rpc/methods/orchestration/worker/worker-launch-model-authority.ts
index c995728427b..9ebf2678f84 100644
--- a/src/main/runtime/rpc/methods/orchestration/worker/worker-launch-model-authority.ts
+++ b/src/main/runtime/rpc/methods/orchestration/worker/worker-launch-model-authority.ts
@@ -7,11 +7,14 @@
  * worktree selector. Dynamic membership is combined with stable CLI aliases: a picker need not
  * display an alias such as `opus`, but the launch flag still accepts it.
  *
- * Two things answer `seed`, which claims no membership at all and so refuses nothing.
+ * Several conditions answer `seed`, which claims no membership at all and so refuses nothing.
  *
  * A host that could not be listed: loss of contact is never evidence that a model does not exist
  * there (`docs/reference/ssh-execution-boundary.md`).
  *
+ * A launch whose terminal-only arguments or environment are absent from the probe: that answer is
+ * not evidence about the CLI invocation that will actually run.
+ *
  * And an agent whose probe only EXTENDS the seed rather than replacing it — the Codex catalog is
  * explicit that its seed is short and that unknown ids must pass through, so a list that merges
  * into it cannot be read as complete. Only an agent whose discovery replaces the seed gets a
@@ -54,9 +57,9 @@ export const SEED_WORKER_LAUNCH_MODEL_AUTHORITY: WorkerLaunchModelAuthority = {
 
 type CachedModels = { expiresAt: number; models: readonly CommitMessageModelCapability[] }
 
-/** Keyed by executing host, not by caller: one machine's CLI list is one fact. */
-const cachedByHost = new Map<string, CachedModels>()
-const inFlightByHost = new Map<string, Promise<readonly CommitMessageModelCapability[] | null>>()
+/** Callers that share an agent, execution host, and resolved command share one CLI fact. */
+const cachedByScope = new Map<string, CachedModels>()
+const inFlightByScope = new Map<string, Promise<readonly CommitMessageModelCapability[] | null>>()
 
 function discoveredCatalogModel(model: CommitMessageModelCapability): CatalogModel {
   return {
@@ -89,7 +92,8 @@ function liveWorkerLaunchModelAuthority(args: {
       ...new Set([
         ...listedIds,
         ...args.models.flatMap(({ resolvedModel }) => (resolvedModel ? [resolvedModel] : [])),
-        ...listedAliases
+        ...listedAliases,
+        ...(args.catalog.launchModelAliases ?? [])
       ])
     ]
   }
@@ -98,10 +102,13 @@ function liveWorkerLaunchModelAuthority(args: {
 async function probeHostModels(
   runtime: WorkerLaunchModelDiscoveryRuntime,
   agent: TuiAgent,
-  target: WorkerLaunchModelDiscoveryTarget
+  target: WorkerLaunchModelDiscoveryTarget,
+  agentCommandOverride: string
 ): Promise<readonly CommitMessageModelCapability[] | null> {
   try {
-    const result = await runtime.discoverRuntimeCommitMessageModels(target, agent)
+    const result = await runtime.discoverRuntimeCommitMessageModels(target, agent, {
+      agentCmdOverrides: { [agent]: agentCommandOverride }
+    })
     // `catalogOrigin: 'spec'` is the probe falling back to Orca's own list, not a CLI answer.
     return result.success && result.catalogOrigin === 'probe' && result.models.length > 0
       ? result.models
@@ -136,12 +143,12 @@ function withDiscoveryDeadline<T>(
 
 function readCachedModels(scope: string): readonly CommitMessageModelCapability[] | null {
   const now = Date.now()
-  for (const [key, entry] of cachedByHost) {
+  for (const [key, entry] of cachedByScope) {
     if (entry.expiresAt <= now) {
-      cachedByHost.delete(key)
+      cachedByScope.delete(key)
     }
   }
-  return cachedByHost.get(scope)?.models ?? null
+  return cachedByScope.get(scope)?.models ?? null
 }
 
 /**
@@ -151,10 +158,12 @@ function readCachedModels(scope: string): readonly CommitMessageModelCapability[
 export async function resolveWorkerLaunchModelAuthority(args: {
   catalog: AgentSessionOptionCatalog
   agent: TuiAgent
+  agentCommandOverride?: string
   runtime: WorkerLaunchModelDiscoveryRuntime | null
   worktreeSelector: WorkerLaunchModelDiscoveryTarget | null
 }): Promise<WorkerLaunchModelAuthority> {
   const { catalog, agent, runtime, worktreeSelector: target } = args
+  const agentCommandOverride = args.agentCommandOverride?.trim() ?? ''
   // Why: for an agent whose probe only EXTENDS the seed, the host's list is known not to be
   // exhaustive, so it can refuse nothing — and there is correspondingly nothing to ask it.
   if (!discoveredModelsReplaceSeed(agent, catalog)) {
@@ -185,22 +194,22 @@ export async function resolveWorkerLaunchModelAuthority(args: {
     }
     return SEED_WORKER_LAUNCH_MODEL_AUTHORITY
   }
-  const scope = `${agent} ${hostKey}`
+  const scope = JSON.stringify([agent, hostKey, agentCommandOverride])
   const cached = readCachedModels(scope)
   if (cached) {
     return liveWorkerLaunchModelAuthority({ catalog, agent, models: cached })
   }
-  let pending = inFlightByHost.get(scope)
+  let pending = inFlightByScope.get(scope)
   if (!pending) {
     // Failures are never cached, so the next dispatch retries rather than inheriting a miss.
-    pending = probeHostModels(runtime, agent, target).then((models) => {
-      inFlightByHost.delete(scope)
+    pending = probeHostModels(runtime, agent, target, agentCommandOverride).then((models) => {
+      inFlightByScope.delete(scope)
       if (models) {
-        cachedByHost.set(scope, { expiresAt: Date.now() + DISCOVERY_TTL_MS, models })
+        cachedByScope.set(scope, { expiresAt: Date.now() + DISCOVERY_TTL_MS, models })
       }
       return models
     })
-    inFlightByHost.set(scope, pending)
+    inFlightByScope.set(scope, pending)
   }
   // A dispatch that gives up on the budget still leaves the probe running for the next one.
   const models = await withDiscoveryDeadline(pending, deadlineAt)
@@ -219,6 +228,6 @@ export function describeWorkerLaunchModelRejection(args: {
 }
 
 export function clearWorkerLaunchModelAuthorityCacheForTests(): void {
-  cachedByHost.clear()
-  inFlightByHost.clear()
+  cachedByScope.clear()
+  inFlightByScope.clear()
 }
diff --git a/src/main/runtime/rpc/methods/orchestration/worker/worker-start-validation.test.ts b/src/main/runtime/rpc/methods/orchestration/worker/worker-start-validation.test.ts
index 3bd43e64e4b..ac433af997b 100644
--- a/src/main/runtime/rpc/methods/orchestration/worker/worker-start-validation.test.ts
+++ b/src/main/runtime/rpc/methods/orchestration/worker/worker-start-validation.test.ts
@@ -13,7 +13,13 @@ import type { WorkerStartInput } from './worker-start-schema'
  * placement → selector mapping. A refactor that probed the worker's target worktree
  * instead of the coordinator's would still dispatch, and still pass every RPC-level test.
  */
-function validationRuntime(): {
+function validationRuntime(
+  settings: {
+    agentCmdOverrides?: Record<string, string>
+    agentDefaultArgs?: Record<string, string>
+    agentDefaultEnv?: Record<string, Record<string, string>>
+  } = {}
+): {
   runtime: OrcaRuntimeService
   discover: ReturnType<typeof vi.fn>
   resolveHostKey: ReturnType<typeof vi.fn>
@@ -22,6 +28,7 @@ function validationRuntime(): {
   const discover = vi.fn(async () => ({ success: false, error: 'no CLI' }))
   const runtime = {
     validateOrchestrationAgentLauncher: vi.fn(),
+    getClientSettings: vi.fn(() => settings),
     showTerminal: vi.fn(async () => ({ worktreeId: 'wt_coordinator' })),
     getOrchestrationDispatchAuthority: vi.fn(() => null),
     resolveRuntimeCommitMessageDiscoveryHostKey: resolveHostKey,
@@ -166,6 +173,43 @@ describe('worker start placement to probe selector', () => {
     expect(discover).not.toHaveBeenCalled()
   })
 
+  it.each([
+    { label: 'default arguments', settings: { agentDefaultArgs: { claude: '--settings corp' } } },
+    {
+      label: 'default environment',
+      settings: { agentDefaultEnv: { claude: { ANTHROPIC_BASE_URL: 'https://corp.invalid' } } }
+    }
+  ])('does not reject against a probe that omits the launch $label', async ({ settings }) => {
+    const { runtime, discover, resolveHostKey } = validationRuntime(settings)
+
+    const plan = await prepareLocalWorkerStart({
+      params: localParams({ model: 'gateway-only-model' }),
+      createsWorktree: false,
+      runtime
+    })
+
+    expect(plan.launch.preferences).toEqual({ model: 'gateway-only-model' })
+    expect(resolveHostKey).not.toHaveBeenCalled()
+    expect(discover).not.toHaveBeenCalled()
+  })
+
+  it('still probes through a configured command override, which discovery applies', async () => {
+    const { runtime, discover, resolveHostKey } = validationRuntime({
+      agentCmdOverrides: { claude: 'corp-claude' }
+    })
+
+    await prepareLocalWorkerStart({
+      params: localParams({}),
+      createsWorktree: false,
+      runtime
+    })
+
+    expect(resolveHostKey).toHaveBeenCalledWith('id:wt_coordinator')
+    expect(discover).toHaveBeenCalledWith('id:wt_coordinator', 'claude', {
+      agentCmdOverrides: { claude: 'corp-claude' }
+    })
+  })
+
   it('probes the remote worktree a federated attachment names', async () => {
     const { runtime, resolveHostKey } = validationRuntime()
 
diff --git a/src/main/runtime/rpc/methods/orchestration/worker/worker-start-validation.ts b/src/main/runtime/rpc/methods/orchestration/worker/worker-start-validation.ts
index 8bcc2c3621e..71edc45d7e6 100644
--- a/src/main/runtime/rpc/methods/orchestration/worker/worker-start-validation.ts
+++ b/src/main/runtime/rpc/methods/orchestration/worker/worker-start-validation.ts
@@ -6,6 +6,7 @@ import {
   discoveredModelsReplaceSeed,
   getAgentSessionOptionCatalog
 } from '../../../../../../shared/agent-session-option-catalog'
+import { hasExplicitTuiLaunchCustomization } from '../../../../../../shared/tui-agent-launch-customization'
 import type { FederationAttachStartInput } from '../federation/federation-start-schema'
 import { resolveDispatchCallerWorktreeId } from '../../orchestration-caller-workspace'
 import {
@@ -30,6 +31,27 @@ type WorkerStartAgentPlan = {
 
 const COORDINATOR_HOSTED_PLACEMENTS = new Set(['current', 'new-child', 'new-top-level'])
 
+function modelProbeMissesLaunchCustomization(
+  settings: ReturnType<OrcaRuntimeService['getClientSettings']>,
+  agent: TuiAgent
+): boolean {
+  const { agentDefaultArgs, agentDefaultEnv } = settings
+  // Command overrides are part of model discovery. Terminal-only args and env are not, so their
+  // catalog cannot safely reject a value the actual launch may accept.
+  return hasExplicitTuiLaunchCustomization({ agentDefaultArgs, agentDefaultEnv }, agent)
+}
+
+function readWorkerLaunchSettings(
+  runtime: OrcaRuntimeService
+): ReturnType<OrcaRuntimeService['getClientSettings']> | null {
+  try {
+    return runtime.getClientSettings()
+  } catch {
+    // Missing settings cannot prove that discovery matches the eventual launch command.
+    return null
+  }
+}
+
 function canResolveWorkerLaunchModelAuthority(
   agent: string | undefined,
   model: string | undefined
@@ -221,6 +243,10 @@ async function resolveWorkerStartAgent(args: {
     if (!catalog || !discoveredModelsReplaceSeed(agent, catalog)) {
       return { agent, launch }
     }
+    const settings = readWorkerLaunchSettings(args.runtime)
+    if (!settings || modelProbeMissesLaunchCustomization(settings, agent)) {
+      return { agent, launch }
+    }
     return {
       agent,
       launch: resolveWorkerLaunchPreferences({
@@ -230,6 +256,7 @@ async function resolveWorkerStartAgent(args: {
         authority: await resolveWorkerLaunchModelAuthority({
           catalog,
           agent,
+          agentCommandOverride: settings.agentCmdOverrides?.[agent],
           runtime: args.runtime,
           worktreeSelector: args.worktreeSelector
         })
diff --git a/src/shared/agent-session-option-catalog-claude-codex.ts b/src/shared/agent-session-option-catalog-claude-codex.ts
index a3e25242e14..b6a9c00d66a 100644
--- a/src/shared/agent-session-option-catalog-claude-codex.ts
+++ b/src/shared/agent-session-option-catalog-claude-codex.ts
@@ -128,6 +128,8 @@ const CLAUDE_FAST_MODE: CatalogOption = {
 
 export const CLAUDE_SESSION_OPTION_CATALOG: AgentSessionOptionCatalog = {
   supportsWorkerLaunchPreferences: true,
+  // Why: list_models publishes `default`, but picker discovery drops that mirror row.
+  launchModelAliases: ['default'],
   // Why: these ids are Claude CLI aliases that resolve to the newest model of
   // each family on the host's CLI (`opus` is Opus 5 on current CLIs, older
   // Opus on older CLIs), so pinned version labels lie on part of the fleet.
diff --git a/src/shared/agent-session-option-catalog-types.ts b/src/shared/agent-session-option-catalog-types.ts
index 826b1edb162..b2c032bdb66 100644
--- a/src/shared/agent-session-option-catalog-types.ts
+++ b/src/shared/agent-session-option-catalog-types.ts
@@ -58,6 +58,8 @@ export type CatalogModel = {
 export type AgentSessionOptionCatalog = {
   models: CatalogModel[]
   modelApply: CatalogOptionApply
+  /** Stable launch values intentionally omitted from picker membership. */
+  launchModelAliases?: readonly string[]
   /** Opts this agent into structured per-worker launch overrides. */
   supportsWorkerLaunchPreferences?: true
   /** Launch-safe options for opaque model ids that are absent from the static catalog. */