fix(runner): preserve validated native assistant delta channels

Co-Authored-By: Paperclip <noreply@paperclip.ing>

packages/paperclip-runner/src/drivers/codex/codex-app-server-driver.events.test.ts

@@ -42,8 +42,32 @@ import {
   type PrpEvent,
   type PrpStructuredRunResult,
 } from "./codex-app-server-driver.test-support.js";
+import { rehydrateRunnerdDeltaNotification } from "../../live/runnerd-codex-transport.js";
 
 describe("Codex app-server Codex driver", () => {
+  it.each(["progress", "final"] as const)("preserves the trusted canonical %s delta channel without a preceding item start", async channel => {
+    const transport = new FakeCodexTransport();
+    const session = await makeDriver([transport]).openSession({
+      runId: "run-canonical-delta-channel", normalizedSessionId: "session-canonical-delta-channel", workingDirectory: WORKSPACE,
+    });
+    const { turnId } = await session.startTurn({ message: { role: "user", text: "Stream native commentary." } });
+    transport.push("turn/started", { threadId: "thread-1", turn: { id: turnId, status: "inProgress" } });
+    transport.push("item/agentMessage/delta", rehydrateRunnerdDeltaNotification({
+      itemId: "native-message-1", kind: "agentMessage", channel, text: "Native message before steering.",
+    }, "thread-1", turnId));
+    transport.push("item/agentMessage/delta", {
+      threadId: "thread-1", turnId, itemId: "unmarked-message-1", kind: "agentMessage", channel,
+      delta: "Unmarked provider channel.", canonicalItem: true,
+    });
+    transport.push("turn/completed", { threadId: "thread-1", turn: { id: turnId, status: "interrupted", items: [] } });
+    const events = await collectUntilTerminal(session.events());
+    expect(events.find(event => event.eventType === "item.delta" && event.itemId === "native-message-1")?.payload)
+      .toMatchObject({ text: "Native message before steering.", channel });
+    expect(events.find(event => event.eventType === "item.delta" && event.itemId === "unmarked-message-1")?.payload)
+      .toMatchObject({ text: "Unmarked provider channel.", channel: "unknown" });
+    await session.close({ reason: "canonical delta channel verified" });
+  });
+
   it("admits a strictly bound semantic result from the durable runner", async () => {
     const transport = new FakeCodexTransport();
     const session = await makeDriver([transport]).openSession({

packages/paperclip-runner/src/drivers/codex/codex-session-notifications.ts

@@ -29,6 +29,7 @@ import {
 } from "./codex-session-workspace.js";
 import {
   boundedText,
+  RUNNERD_CANONICAL_ITEM,
   differingJsonPaths,
   itemFromParams,
   itemText,
@@ -506,7 +507,7 @@ async function mapNotificationBody(state: CodexSessionState, notification: Codex
     const deltaKind = deltaKinds[notification.method];
     if (deltaKind !== undefined) {
       if (!state.notificationNamesActiveTurn(turnId, "item update")) return;
-      const methodChannel = channelForDelta(state, notification.method);
+      const methodChannel = channelForDelta(state, notification.method, params);
       const channel =
         methodChannel !== "unknown"
           ? methodChannel
@@ -581,8 +582,16 @@ function channelForStartedItem(
 function channelForDelta(
   state: CodexSessionState,
     method: string,
+    params: Record<string, unknown>,
   ): "progress" | "final" | "summary" | "detail" | "unknown" {
     if (method === "item/reasoning/summaryTextDelta") return "summary";
     if (method === "item/reasoning/textDelta") return "detail";
+    // Native ACPX may emit a delta without an item-start notification. Preserve
+    // its validated PRP channel through this compatibility facade. The local
+    // symbol cannot be forged by a provider's JSON message.
+    if (method === "item/agentMessage/delta"
+      && Reflect.get(params, RUNNERD_CANONICAL_ITEM) === true
+      && params.kind === "agentMessage"
+      && (params.channel === "progress" || params.channel === "final")) return params.channel;
     return "unknown";
   }

packages/paperclip-runner/src/live/runnerd-codex-transport.test.ts

@@ -2046,8 +2046,9 @@ it("classifies each coalesced canonical delta without mixing reasoning into assi
 });
 
 it("restores provider identity and streamed text from a canonical delta", () => {
-  expect(rehydrateRunnerdDeltaNotification({ text: "Reading Gmail", itemId: "message-1", turnId: "controller-turn" }, "root-thread", "provider-turn"))
-    .toMatchObject({ threadId: "root-thread", turnId: "provider-turn", delta: "Reading Gmail", itemId: "message-1" });
+  const params = rehydrateRunnerdDeltaNotification({ kind: "agentMessage", channel: "progress", text: "Reading Gmail", itemId: "message-1", turnId: "controller-turn" }, "root-thread", "provider-turn");
+  expect(params).toMatchObject({ threadId: "root-thread", turnId: "provider-turn", delta: "Reading Gmail", itemId: "message-1", channel: "progress" });
+  expect(Reflect.get(params, RUNNERD_CANONICAL_ITEM)).toBe(true);
 });
 
 it("rehydrates a canonical agent item for the strict Codex facade", () => {

packages/paperclip-runner/src/live/runnerd-codex-transport.ts

@@ -1873,6 +1873,7 @@ export function rehydrateRunnerdDeltaNotification(
   // turn is deliberately different from the provider's turn ID.
   return {
     ...rawParams,
+    [RUNNERD_CANONICAL_ITEM]: true,
     threadId: openedThreadId,
     turnId: activeTurnId,
     delta: rawParams.delta ?? rawParams.text,