fix(native-chat): a Codex Stop that Codex refuses or never answers ends the Codex process

src/main/codex/codex-structured-conversation-stop.test.ts

@@ -52,7 +52,9 @@ describe('a Codex Stop that names no turn', () => {
         detail: {
           text: 'expected active turn id turn-journal but found turn-1',
           audience: 'person'
-        }
+        },
+        // An invalid-request refusal: the named turn is not the one Codex is running.
+        turnNotRunning: true
       }
     })
     expect(rig.interrupts().map((call) => call.params?.turnId)).toEqual(['turn-journal'])

src/main/codex/codex-structured-session-adapter-fixture.ts

@@ -13,6 +13,7 @@ import {
   type CodexStructuredLaunch,
   type CodexStructuredSessionEvent
 } from './codex-structured-session-adapter'
+import type { CodexStructuredSessionAdapterDeps } from './codex-structured-session-state'
 
 export const THREAD_ID = 'thread-abc'
 
@@ -104,7 +105,9 @@ export function answerWithOpenedTurn(
 export function adapterFor(
   codex: ReturnType<typeof fakeCodex>,
   launch: Partial<CodexStructuredLaunch> = {},
-  events: CodexStructuredSessionEvent[] = []
+  events: CodexStructuredSessionEvent[] = [],
+  /** Host wiring the runtime adds, such as the late dispatch settlement. */
+  deps: Partial<CodexStructuredSessionAdapterDeps> = {}
 ): CodexStructuredSessionAdapter {
   let acquisitionGeneration = 0
   return new CodexStructuredSessionAdapter({
@@ -120,7 +123,8 @@ export function adapterFor(
     openConnection: codex.openConnection,
     readProcessStartTime: async () => 1_700_000_000_000,
     now: () => 1_700_000_000_500,
-    mintAcquisitionGeneration: () => `generation-${++acquisitionGeneration}`
+    mintAcquisitionGeneration: () => `generation-${++acquisitionGeneration}`,
+    ...deps
   })
 }
 

src/main/codex/codex-structured-turn-cancellation.ts

@@ -5,10 +5,21 @@ import type { AgentSessionCancelOutcome } from '../native-chat/agent-session-wir
 import type { CodexSession } from './codex-structured-session-state'
 import type { CodexJournalTranslationAdmission } from './codex-structured-journal-contracts'
 
+/**
+ * Codex's interrupt handler answers -32600 when the named turn is not its running one (no turn,
+ * another turn, thread not loaded) and -32603 when it could not submit the interrupt. A request it
+ * could not parse, or one before initialize, also answers -32600: read as not running, it keeps the
+ * child, as before.
+ */
+function isCodexTurnNotRunningRefusal(error: unknown): boolean {
+  return isCodexAppServerRequestError(error) && error.code === -32600
+}
+
 /**
  * Codex answers a turn's interrupt only as that turn ends, so the answer is what confirms the
- * Stop. The interrupt is the whole Stop: Codex kills the turn's one-shot commands itself and keeps
- * its background terminals running until the thread ends.
+ * Stop. An answered interrupt is the whole Stop: Codex kills the turn's one-shot commands itself
+ * and keeps its background terminals running until the thread ends. One Codex could not carry out,
+ * or never answered, leaves the host to end the child (`performCancel`).
  */
 export async function interruptCodexTurn(input: {
   session: CodexSession
@@ -29,7 +40,13 @@ export async function interruptCodexTurn(input: {
       throw error
     }
     const detail = providerDiagnosticOf(error)
-    return { cancelled: false, refusal: detail ? { detail } : {} }
+    return {
+      cancelled: false,
+      refusal: {
+        ...(detail ? { detail } : {}),
+        ...(isCodexTurnNotRunningRefusal(error) ? { turnNotRunning: true } : {})
+      }
+    }
   }
   const promptAdmission = input.onConfirmed?.()
   if (promptAdmission && !promptAdmission.accepted) {

src/main/native-chat/agent-session-wire/structured-agent-session-adapter-stop.ts

@@ -1,19 +1,29 @@
 // How a provider's Stop, and a prompt card's own Cancel, end what they end. Every member is
-// optional: a provider that declares none keeps its child after a Stop, and its card's Cancel
-// interrupts the turn holding the card.
+// optional: a provider that declares none keeps its child after a Stop it took, and its card's
+// Cancel interrupts the turn holding the card.
 
 import type {
   AgentJournalApprovalItem,
   AgentJournalQuestionItem
 } from '../../../shared/agent-session-journal-types'
+import type { ProviderDiagnostic } from '../../../shared/agent-session-failure'
+
+/** `refusal`: the provider answered the Stop and declined it, in its own words when it gave any.
+ *  `turnNotRunning`: its refusal is the kind it gives for a turn not running there, so the Stop keeps
+ *  the child; absent, it could not interrupt that turn, which may run on. */
+export type AgentSessionCancelOutcome = {
+  cancelled: boolean
+  refusal?: { detail?: ProviderDiagnostic; turnNotRunning?: true }
+}
 
 /** Where a card's Cancel goes: a dismissal (`dismissPrompt`), or the chat's Stop. */
 export type AgentSessionPromptCancelRoute = { kind: 'dismiss' } | { kind: 'stop' }
 
 export type StructuredAgentSessionAdapterStop = {
   /** A Stop ends this provider's child after `cancelTurn`, whatever it answered, unless it named a
    *  turn that is no longer live and the cancel answered that it did not take it; the next send
-   *  resumes the conversation. Absent or false keeps the child after a Stop. */
+   *  resumes the conversation. Absent or false keeps the child after a Stop the provider took; a
+   *  failed interrupt still ends a child running the turn the Stop meant. */
   stopEndsSession?(sessionId: string): boolean
   /** What a Stop that ends the session waits on before it ends the child: resolves once the provider
    *  has nothing in flight, a send it has not answered included, or when its grace, counted from

src/main/native-chat/agent-session-wire/structured-agent-session-adapter.ts

@@ -32,12 +32,13 @@ import type {
   AgentSessionThreadGoalChange
 } from '../../../shared/agent-session-wire'
 import type { AgentSessionRefusalReason } from '../../../shared/agent-session-wire-refusals'
-import type {
-  ProviderDiagnostic,
-  SubmissionRejectionFact
-} from '../../../shared/agent-session-failure'
+import type { SubmissionRejectionFact } from '../../../shared/agent-session-failure'
 import type { StructuredAgentSessionStopCause } from './structured-agent-session-stop-cause'
-import type { StructuredAgentSessionAdapterStop } from './structured-agent-session-adapter-stop'
+import type {
+  AgentSessionCancelOutcome,
+  StructuredAgentSessionAdapterStop
+} from './structured-agent-session-adapter-stop'
+export type { AgentSessionCancelOutcome } from './structured-agent-session-adapter-stop'
 export type {
   StructuredAgentSessionChildEndCause,
   StructuredAgentSessionStopCause
@@ -242,12 +243,6 @@ export type StructuredAgentSessionSetOptionInput = {
   fence: number
 }
 
-/** `refusal`: the provider answered the Stop and declined it, in its own words when it gave any. */
-export type AgentSessionCancelOutcome = {
-  cancelled: boolean
-  refusal?: { detail?: ProviderDiagnostic }
-}
-
 export type StructuredAgentSessionAdapter = StructuredAgentSessionAdapterStop & {
   /** Provider-aware capability check for hosts that route more than one adapter. */
   supportsCreate?(location: AgentSessionExecutionLocation, agent: string): boolean

src/main/native-chat/agent-session-wire/structured-agent-session-chat-stop.ts

@@ -1,7 +1,9 @@
 // The chat's Stop, however a client reached it: the Stop button or a question card's Cancel. One
 // body and one order: withdraw what is queued, record where the Stop took effect, interrupt, then
-// end the child in the next step on the session's lane. The body is reachable only through
-// `mutateWithChatStop`, which queues that step in the same synchronous call as the mutation.
+// end the child: in this step when the interrupt failed with the turn still running, else in the
+// next step on the session's lane for a provider whose Stop ends its session. The body is
+// reachable only through `mutateWithChatStop`, which queues that step in the same synchronous call
+// as the mutation.
 
 import { agentSessionFailureWords } from '../../../shared/agent-session-failure-words'
 import { agentSessionFailureFact } from '../../../shared/agent-session-failure'
@@ -83,6 +85,9 @@ export function mutateWithChatStop<TValue>(
           clientOperationId: envelope.clientOperationId,
           ...named,
           stopChild: () => context.stopAgent(sessionId),
+          onStopChildError: (error) => context.deps.onEventSinkError?.({ sessionId, error }),
+          // The host drops its child only once the exit is proven, and nothing else runs meanwhile.
+          childReleased: () => context.sessions.get(sessionId)?.child !== child,
           endSession: (owed) => {
             windDown = owed
           },