Ignore background tasks that workflow agents start in the Claude bridge

plugins/provider-claude-code/src/delta-test-harness.ts

@@ -49,6 +49,74 @@ export function loadSessionFixture(name: string): Record<string, unknown>[] {
     });
 }
 
+/**
+ * The assistant `tool_use` block that spawns a background task. The CLI
+ * streams it before the task's `task_started`, and the translator only
+ * materializes a task whose spawning call it saw open.
+ */
+export function spawningToolUseMessage(args: {
+  toolUseId: string;
+  toolName: string;
+  input?: Record<string, unknown>;
+  parentToolUseId?: string;
+}): Record<string, unknown> {
+  return {
+    type: "assistant",
+    message: {
+      role: "assistant",
+      content: [
+        {
+          type: "tool_use",
+          id: args.toolUseId,
+          name: args.toolName,
+          input: args.input ?? {},
+        },
+      ],
+    },
+    parent_tool_use_id: args.parentToolUseId ?? null,
+    session_id: "sess-1",
+  };
+}
+
+/** The spawning `tool_use` for a `task_started` fixture or literal. */
+export function spawningToolUseFor(
+  taskStarted: Record<string, unknown>,
+): Record<string, unknown> {
+  const toolUseId = taskStarted.tool_use_id;
+  if (typeof toolUseId !== "string") {
+    throw new Error("task_started fixture has no tool_use_id");
+  }
+  const description =
+    typeof taskStarted.description === "string" ? taskStarted.description : "";
+  switch (taskStarted.task_type) {
+    case "local_workflow":
+      return spawningToolUseMessage({
+        toolUseId,
+        toolName: "Workflow",
+        input: { script: taskStarted.prompt ?? "" },
+      });
+    case "local_bash":
+      return spawningToolUseMessage({
+        toolUseId,
+        toolName: "Bash",
+        input: { command: description, run_in_background: true },
+      });
+    default:
+      return spawningToolUseMessage({
+        toolUseId,
+        toolName: "Agent",
+        input: {
+          description,
+          prompt: taskStarted.prompt ?? description,
+          run_in_background: true,
+          ...(typeof taskStarted.subagent_type === "string"
+            ? { subagent_type: taskStarted.subagent_type }
+            : {}),
+        },
+      });
+  }
+}
+
 const CLAUDE_TEST_ENTROPY = "cl-test";
 export const TURN_1 = "cl-test-t1";
 export const TURN_2 = "cl-test-t2";

plugins/provider-claude-code/src/delta-translation.test.ts

@@ -7,6 +7,7 @@ import {
   TURN_2,
   createClaudeDeltaHarness,
   loadFixture,
+  spawningToolUseFor,
 } from "./delta-test-harness.js";
 
 /**
@@ -435,6 +436,10 @@ describe("claude turn and checkpoint lifecycle", () => {
     const harness = createClaudeDeltaHarness();
     const context = { threadId: "bb-thread-rate-limited" };
     harness.acceptInput("creq_23456789af", context.threadId);
+    harness.translate(
+      spawningToolUseFor(loadFixture("task-started-subagent.json")),
+      context,
+    );
     harness.translate(loadFixture("task-started-subagent.json"), context);
     harness.translate(
       {
@@ -937,6 +942,10 @@ describe("claude synthetic no-response handling", () => {
   it("keeps an open turn for synthetic no-response messages while an agent is running", () => {
     const harness = createClaudeDeltaHarness();
     const context = { threadId: "bb-thread-1" };
+    harness.translate(
+      spawningToolUseFor(loadFixture("task-started-subagent.json")),
+      context,
+    );
     harness.translate(loadFixture("task-started-subagent.json"), context);
 
     const events = harness.translate(

plugins/provider-claude-code/src/delta-translation.ts

@@ -875,6 +875,7 @@ export function createClaudeDeltaTranslator(
       event,
       tasks: state.tasksById,
       turnStartSuppressed: isTurnStartSuppressed(state),
+      hasForwardedToolUse: (toolUseId) => state.startedTools.has(toolUseId),
     });
     if (taskDeltas !== null) {
       return withMirror(state, taskDeltas);

plugins/provider-claude-code/src/presentation.test.ts

@@ -7,7 +7,10 @@
  */
 import type { ThreadEvent } from "@bb/domain";
 import { describe, expect, it } from "vitest";
-import { createClaudeDeltaHarness } from "./delta-test-harness.js";
+import {
+  createClaudeDeltaHarness,
+  spawningToolUseFor,
+} from "./delta-test-harness.js";
 import { createClaudeDeltaTranslator } from "./delta-translation.js";
 
 function toolUse(
@@ -682,6 +685,7 @@ describe("claude background-task presentation", () => {
       ["local_bash", {}],
       ["local_agent", { subagent_type: "Explore" }],
     ] as const) {
+      harness.translate(spawningToolUseFor(taskStarted(taskType, extra)));
       const opened = harness.translate(taskStarted(taskType, extra));
       const started = startedItems(opened)[0];
       presentations.set(