fix(cli): replace markdown headings with XML tags in thread read output

Changed uwf thread read to wrap role prompts and agent outputs in XML tags
(<prompt> and <output>) instead of markdown headings (### Prompt, ### Content).
This prevents Claude Code from treating step outputs as structural headings.

- Updated formatStepPrompt to use <prompt>...</prompt> tags
- Updated formatStepContent to use <output>...</output> tags
- Added comprehensive test suite in thread-read-xml-tags.test.ts
- Updated existing tests to verify XML tag behavior

Fixes #459

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/cli-workflow/src/__tests__/thread-read-xml-tags.test.ts

@@ -0,0 +1,683 @@
+import { mkdir, mkdtemp, rm } from "node:fs/promises";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { bootstrap, putSchema } from "@uncaged/json-cas";
+import { createFsStore } from "@uncaged/json-cas-fs";
+import type { CasRef, ThreadId } from "@uncaged/workflow-protocol";
+import { afterEach, beforeEach, describe, expect, test } from "vitest";
+import { cmdThreadRead, THREAD_READ_DEFAULT_QUOTA } from "../commands/thread.js";
+import { registerUwfSchemas } from "../schemas.js";
+import type { UwfStore } from "../store.js";
+import { saveThreadsIndex } from "../store.js";
+
+// ── schemas used in tests ────────────────────────────────────────────────────
+
+const TURN_SCHEMA = {
+  title: "hermes-turn",
+  type: "object" as const,
+  required: ["index", "role", "content"],
+  properties: {
+    index: { type: "integer" as const },
+    role: { type: "string" as const },
+    content: { type: "string" as const },
+    toolCalls: {
+      anyOf: [
+        { type: "array" as const, items: { type: "object" as const } },
+        { type: "null" as const },
+      ],
+    },
+    reasoning: { anyOf: [{ type: "string" as const }, { type: "null" as const }] },
+  },
+  additionalProperties: false,
+};
+
+const DETAIL_SCHEMA = {
+  title: "hermes-detail",
+  type: "object" as const,
+  required: ["sessionId", "model", "duration", "turnCount", "turns"],
+  properties: {
+    sessionId: { type: "string" as const },
+    model: { type: "string" as const },
+    duration: { type: "integer" as const },
+    turnCount: { type: "integer" as const },
+    turns: {
+      type: "array" as const,
+      items: { type: "string" as const, format: "cas_ref" },
+    },
+  },
+  additionalProperties: false,
+};
+
+// ── helpers ───────────────────────────────────────────────────────────────────
+
+async function makeUwfStore(storageRoot: string): Promise<UwfStore> {
+  const casDir = join(storageRoot, "cas");
+  await mkdir(casDir, { recursive: true });
+  const store = createFsStore(casDir);
+  const schemas = await registerUwfSchemas(store);
+  return { storageRoot, store, schemas };
+}
+
+async function registerDetailSchemas(store: ReturnType<typeof createFsStore>) {
+  await bootstrap(store);
+  const [turn, detail] = await Promise.all([
+    putSchema(store, TURN_SCHEMA),
+    putSchema(store, DETAIL_SCHEMA),
+  ]);
+  return { turn, detail };
+}
+
+// ── fixture ───────────────────────────────────────────────────────────────────
+
+let tmpDir: string;
+
+beforeEach(async () => {
+  tmpDir = await mkdtemp(join(tmpdir(), "cli-uwf-test-"));
+});
+
+afterEach(async () => {
+  await rm(tmpDir, { recursive: true, force: true });
+});
+
+// ── thread read XML tag isolation ─────────────────────────────────────────────
+
+describe("thread read XML tag isolation", () => {
+  test("scenario 1: wraps output in XML tags instead of heading", async () => {
+    const uwf = await makeUwfStore(tmpDir);
+    const detailSchemas = await registerDetailSchemas(uwf.store);
+
+    const workflowHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "test-wf",
+      description: "desc",
+      roles: {
+        planner: {
+          description: "Planner",
+          goal: "You are a planning agent. Your task is to...",
+          capabilities: [],
+          procedure: "Plan the work.",
+          output: "Summarize the plan.",
+          meta: "placeholder00" as CasRef,
+        },
+      },
+      conditions: {},
+      graph: {},
+    });
+
+    const startHash = await uwf.store.put(uwf.schemas.startNode, {
+      workflow: workflowHash,
+      prompt: "Fix issue #459",
+    });
+
+    const outputHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "out",
+      description: "",
+      roles: {},
+      conditions: {},
+      graph: {},
+    });
+
+    const turnHash = await uwf.store.put(detailSchemas.turn, {
+      index: 0,
+      role: "assistant",
+      content:
+        "---\nstatus: ready\nplan: CMWGHQKT58RY4\n---\n\n# Analysis Complete\n## Issue Summary\nThe issue requires XML tag isolation.",
+      toolCalls: null,
+      reasoning: null,
+    });
+    const detailHash = await uwf.store.put(detailSchemas.detail, {
+      sessionId: "sx",
+      model: "mx",
+      duration: 500,
+      turnCount: 1,
+      turns: [turnHash],
+    });
+
+    const stepHash = await uwf.store.put(uwf.schemas.stepNode, {
+      start: startHash,
+      prev: null,
+      role: "planner",
+      output: outputHash,
+      detail: detailHash,
+      agent: "uwf-claude-code",
+    });
+
+    const threadId = "01JTEST0000000000000001" as ThreadId;
+    await saveThreadsIndex(tmpDir, { [threadId]: stepHash });
+
+    const markdown = await cmdThreadRead(tmpDir, threadId, THREAD_READ_DEFAULT_QUOTA, null, false);
+
+    // Should wrap output in XML tags
+    expect(markdown).toContain("<output>");
+    expect(markdown).toContain("</output>");
+
+    // Should not have ### Content heading
+    expect(markdown).not.toContain("### Content");
+
+    // Should preserve markdown headings inside output tags
+    expect(markdown).toContain("# Analysis Complete");
+    expect(markdown).toContain("## Issue Summary");
+  });
+
+  test("scenario 2: wraps prompt in XML tags", async () => {
+    const uwf = await makeUwfStore(tmpDir);
+    const detailSchemas = await registerDetailSchemas(uwf.store);
+
+    const workflowHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "test-wf",
+      description: "desc",
+      roles: {
+        planner: {
+          description: "Planner",
+          goal: "You are a planning agent. Your task is to analyze and plan.",
+          capabilities: [],
+          procedure: "Plan the work.",
+          output: "Summarize the plan.",
+          meta: "placeholder00" as CasRef,
+        },
+      },
+      conditions: {},
+      graph: {},
+    });
+
+    const startHash = await uwf.store.put(uwf.schemas.startNode, {
+      workflow: workflowHash,
+      prompt: "Fix issue",
+    });
+
+    const outputHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "out",
+      description: "",
+      roles: {},
+      conditions: {},
+      graph: {},
+    });
+
+    const turnHash = await uwf.store.put(detailSchemas.turn, {
+      index: 0,
+      role: "assistant",
+      content: "---\nstatus: ready\n---\n\nContent here...",
+      toolCalls: null,
+      reasoning: null,
+    });
+    const detailHash = await uwf.store.put(detailSchemas.detail, {
+      sessionId: "sx",
+      model: "mx",
+      duration: 500,
+      turnCount: 1,
+      turns: [turnHash],
+    });
+
+    const stepHash = await uwf.store.put(uwf.schemas.stepNode, {
+      start: startHash,
+      prev: null,
+      role: "planner",
+      output: outputHash,
+      detail: detailHash,
+      agent: "uwf-claude-code",
+    });
+
+    const threadId = "01JTEST0000000000000002" as ThreadId;
+    await saveThreadsIndex(tmpDir, { [threadId]: stepHash });
+
+    const markdown = await cmdThreadRead(tmpDir, threadId, THREAD_READ_DEFAULT_QUOTA, null, false);
+
+    // Should wrap prompt in XML tags
+    expect(markdown).toContain("<prompt>");
+    expect(markdown).toContain("</prompt>");
+    expect(markdown).toContain("You are a planning agent. Your task is to analyze and plan.");
+
+    // Should not have ### Prompt heading
+    expect(markdown).not.toContain("### Prompt");
+
+    // Should wrap output in XML tags
+    expect(markdown).toContain("<output>");
+    expect(markdown).toContain("</output>");
+  });
+
+  test("scenario 3: same role repeated does not show prompt twice", async () => {
+    const uwf = await makeUwfStore(tmpDir);
+
+    const workflowHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "test-wf",
+      description: "desc",
+      roles: {
+        writer: {
+          description: "Writer",
+          goal: "You are a writer agent.",
+          capabilities: [],
+          procedure: "Write content.",
+          output: "Summarize writing.",
+          meta: "placeholder00" as CasRef,
+        },
+      },
+      conditions: {},
+      graph: {},
+    });
+
+    const startHash = await uwf.store.put(uwf.schemas.startNode, {
+      workflow: workflowHash,
+      prompt: "Write something",
+    });
+
+    const outputHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "out",
+      description: "",
+      roles: {},
+      conditions: {},
+      graph: {},
+    });
+
+    const step1 = await uwf.store.put(uwf.schemas.stepNode, {
+      start: startHash,
+      prev: null,
+      role: "writer",
+      output: outputHash,
+      detail: null,
+      agent: "uwf-test",
+    });
+
+    const step2 = await uwf.store.put(uwf.schemas.stepNode, {
+      start: startHash,
+      prev: step1 as CasRef,
+      role: "writer",
+      output: outputHash,
+      detail: null,
+      agent: "uwf-test",
+    });
+
+    const threadId = "01JTEST0000000000000003" as ThreadId;
+    await saveThreadsIndex(tmpDir, { [threadId]: step2 });
+
+    const markdown = await cmdThreadRead(tmpDir, threadId, THREAD_READ_DEFAULT_QUOTA, null, false);
+
+    // Should only show prompt tags once
+    const promptCount = (markdown.match(/<prompt>/g) ?? []).length;
+    expect(promptCount).toBe(1);
+  });
+
+  test("scenario 4: step with no detail shows no output tags", async () => {
+    const uwf = await makeUwfStore(tmpDir);
+
+    const workflowHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "test-wf",
+      description: "desc",
+      roles: {
+        worker: {
+          description: "Worker",
+          goal: "You are a worker agent.",
+          capabilities: [],
+          procedure: "Do work.",
+          output: "Summarize work.",
+          meta: "placeholder00" as CasRef,
+        },
+      },
+      conditions: {},
+      graph: {},
+    });
+
+    const startHash = await uwf.store.put(uwf.schemas.startNode, {
+      workflow: workflowHash,
+      prompt: "Do stuff",
+    });
+
+    const outputHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "out",
+      description: "",
+      roles: {},
+      conditions: {},
+      graph: {},
+    });
+
+    const stepHash = await uwf.store.put(uwf.schemas.stepNode, {
+      start: startHash,
+      prev: null,
+      role: "worker",
+      output: outputHash,
+      detail: null,
+      agent: "uwf-test",
+    });
+
+    const threadId = "01JTEST0000000000000004" as ThreadId;
+    await saveThreadsIndex(tmpDir, { [threadId]: stepHash });
+
+    const markdown = await cmdThreadRead(tmpDir, threadId, THREAD_READ_DEFAULT_QUOTA, null, false);
+
+    // Should not have output tags
+    expect(markdown).not.toContain("<output>");
+    expect(markdown).not.toContain("</output>");
+
+    // Step header should still be displayed
+    expect(markdown).toContain("## Step 1: worker");
+
+    // Prompt should still be shown
+    expect(markdown).toContain("<prompt>");
+  });
+
+  test("scenario 5: empty content shows no output tags", async () => {
+    const uwf = await makeUwfStore(tmpDir);
+
+    const workflowHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "test-wf",
+      description: "desc",
+      roles: {},
+      conditions: {},
+      graph: {},
+    });
+
+    const startHash = await uwf.store.put(uwf.schemas.startNode, {
+      workflow: workflowHash,
+      prompt: "Do stuff",
+    });
+
+    const outputHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "out",
+      description: "",
+      roles: {},
+      conditions: {},
+      graph: {},
+    });
+
+    // A detail ref that doesn't exist → extractLastAssistantContent returns null
+    const missingDetailRef = "missingdetail0" as CasRef;
+
+    const stepHash = await uwf.store.put(uwf.schemas.stepNode, {
+      start: startHash,
+      prev: null,
+      role: "worker",
+      output: outputHash,
+      detail: missingDetailRef,
+      agent: "uwf-test",
+    });
+
+    const threadId = "01JTEST0000000000000005" as ThreadId;
+    await saveThreadsIndex(tmpDir, { [threadId]: stepHash });
+
+    const markdown = await cmdThreadRead(tmpDir, threadId, THREAD_READ_DEFAULT_QUOTA, null, false);
+
+    // Should not have output tags
+    expect(markdown).not.toContain("<output>");
+    expect(markdown).not.toContain("</output>");
+  });
+
+  test("scenario 6: thread read with --start flag shows task section", async () => {
+    const uwf = await makeUwfStore(tmpDir);
+
+    const workflowHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "test-wf",
+      description: "desc",
+      roles: {
+        roleA: {
+          description: "Role A",
+          goal: "Goal for roleA",
+          capabilities: [],
+          procedure: "Do stuff.",
+          output: "Output.",
+          meta: "placeholder00" as CasRef,
+        },
+      },
+      conditions: {},
+      graph: {},
+    });
+
+    const startHash = await uwf.store.put(uwf.schemas.startNode, {
+      workflow: workflowHash,
+      prompt: "Initial prompt",
+    });
+
+    const outputHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "out",
+      description: "",
+      roles: {},
+      conditions: {},
+      graph: {},
+    });
+
+    const stepHash = await uwf.store.put(uwf.schemas.stepNode, {
+      start: startHash,
+      prev: null,
+      role: "roleA",
+      output: outputHash,
+      detail: null,
+      agent: "uwf-test",
+    });
+
+    const threadId = "01JTEST0000000000000006" as ThreadId;
+    await saveThreadsIndex(tmpDir, { [threadId]: stepHash });
+
+    const markdown = await cmdThreadRead(tmpDir, threadId, THREAD_READ_DEFAULT_QUOTA, null, true);
+
+    // Should include task section
+    expect(markdown).toContain("# Thread");
+    expect(markdown).toContain("## Task");
+    expect(markdown).toContain("Initial prompt");
+
+    // Prompts should use XML tags
+    expect(markdown).toContain("<prompt>");
+  });
+
+  test("scenario 7: thread read with --before parameter", async () => {
+    const uwf = await makeUwfStore(tmpDir);
+
+    const workflowHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "test-wf",
+      description: "desc",
+      roles: {
+        roleA: {
+          description: "Role A",
+          goal: "Goal for roleA",
+          capabilities: [],
+          procedure: "Do stuff.",
+          output: "Output.",
+          meta: "placeholder00" as CasRef,
+        },
+        roleB: {
+          description: "Role B",
+          goal: "Goal for roleB",
+          capabilities: [],
+          procedure: "Do stuff.",
+          output: "Output.",
+          meta: "placeholder00" as CasRef,
+        },
+        roleC: {
+          description: "Role C",
+          goal: "Goal for roleC",
+          capabilities: [],
+          procedure: "Do stuff.",
+          output: "Output.",
+          meta: "placeholder00" as CasRef,
+        },
+      },
+      conditions: {},
+      graph: {},
+    });
+
+    const startHash = await uwf.store.put(uwf.schemas.startNode, {
+      workflow: workflowHash,
+      prompt: "Initial prompt",
+    });
+
+    const outputHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "out",
+      description: "",
+      roles: {},
+      conditions: {},
+      graph: {},
+    });
+
+    const step1 = await uwf.store.put(uwf.schemas.stepNode, {
+      start: startHash,
+      prev: null,
+      role: "roleA",
+      output: outputHash,
+      detail: null,
+      agent: "uwf-test",
+    });
+
+    const step2 = await uwf.store.put(uwf.schemas.stepNode, {
+      start: startHash,
+      prev: step1 as CasRef,
+      role: "roleB",
+      output: outputHash,
+      detail: null,
+      agent: "uwf-test",
+    });
+
+    const step3 = await uwf.store.put(uwf.schemas.stepNode, {
+      start: startHash,
+      prev: step2 as CasRef,
+      role: "roleC",
+      output: outputHash,
+      detail: null,
+      agent: "uwf-test",
+    });
+
+    const threadId = "01JTEST0000000000000007" as ThreadId;
+    await saveThreadsIndex(tmpDir, { [threadId]: step3 });
+
+    const markdown = await cmdThreadRead(
+      tmpDir,
+      threadId,
+      THREAD_READ_DEFAULT_QUOTA,
+      step2 as CasRef,
+      false,
+    );
+
+    // Should only show roleA
+    expect(markdown).toContain("roleA");
+    expect(markdown).not.toContain("roleB");
+    expect(markdown).not.toContain("roleC");
+
+    // Should use XML tags
+    expect(markdown).toContain("<prompt>");
+  });
+
+  test("scenario 9: special characters in content are preserved", async () => {
+    const uwf = await makeUwfStore(tmpDir);
+    const detailSchemas = await registerDetailSchemas(uwf.store);
+
+    const workflowHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "test-wf",
+      description: "desc",
+      roles: {
+        writer: {
+          description: "Writer",
+          goal: "You are a writer.",
+          capabilities: [],
+          procedure: "Write content.",
+          output: "Summarize.",
+          meta: "placeholder00" as CasRef,
+        },
+      },
+      conditions: {},
+      graph: {},
+    });
+
+    const startHash = await uwf.store.put(uwf.schemas.startNode, {
+      workflow: workflowHash,
+      prompt: "Write something",
+    });
+
+    const outputHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "out",
+      description: "",
+      roles: {},
+      conditions: {},
+      graph: {},
+    });
+
+    const turnHash = await uwf.store.put(detailSchemas.turn, {
+      index: 0,
+      role: "assistant",
+      content: "Content with <special> & characters > like <this>",
+      toolCalls: null,
+      reasoning: null,
+    });
+    const detailHash = await uwf.store.put(detailSchemas.detail, {
+      sessionId: "sx",
+      model: "mx",
+      duration: 500,
+      turnCount: 1,
+      turns: [turnHash],
+    });
+
+    const stepHash = await uwf.store.put(uwf.schemas.stepNode, {
+      start: startHash,
+      prev: null,
+      role: "writer",
+      output: outputHash,
+      detail: detailHash,
+      agent: "uwf-test",
+    });
+
+    const threadId = "01JTEST0000000000000008" as ThreadId;
+    await saveThreadsIndex(tmpDir, { [threadId]: stepHash });
+
+    const markdown = await cmdThreadRead(tmpDir, threadId, THREAD_READ_DEFAULT_QUOTA, null, false);
+
+    // Special characters should be preserved as-is
+    expect(markdown).toContain("Content with <special> & characters > like <this>");
+  });
+
+  test("scenario 10: quota limit with XML tags", async () => {
+    const uwf = await makeUwfStore(tmpDir);
+
+    const workflowHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "test-wf",
+      description: "desc",
+      roles: {
+        roleA: {
+          description: "Role A",
+          goal: "Goal for roleA",
+          capabilities: [],
+          procedure: "Do stuff.",
+          output: "Output.",
+          meta: "placeholder00" as CasRef,
+        },
+      },
+      conditions: {},
+      graph: {},
+    });
+
+    const startHash = await uwf.store.put(uwf.schemas.startNode, {
+      workflow: workflowHash,
+      prompt: "Initial prompt",
+    });
+
+    const outputHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "out",
+      description: "",
+      roles: {},
+      conditions: {},
+      graph: {},
+    });
+
+    const steps: CasRef[] = [];
+    let prev: CasRef | null = null;
+    for (let i = 0; i < 5; i++) {
+      const step = (await uwf.store.put(uwf.schemas.stepNode, {
+        start: startHash,
+        prev,
+        role: "roleA",
+        output: outputHash,
+        detail: null,
+        agent: "uwf-test",
+      })) as CasRef;
+      steps.push(step);
+      prev = step;
+    }
+
+    const threadId = "01JTEST0000000000000009" as ThreadId;
+    await saveThreadsIndex(tmpDir, { [threadId]: steps[steps.length - 1]! });
+
+    // Use very small quota
+    const markdown = await cmdThreadRead(tmpDir, threadId, 1, null, false);
+
+    // Should have skip hint
+    expect(markdown).toContain("earlier step");
+
+    // Should have XML tags for displayed steps
+    if (markdown.includes("<prompt>")) {
+      expect(markdown).toContain("</prompt>");
+    }
+  });
+});

packages/cli-workflow/src/__tests__/thread.test.ts

@@ -198,10 +198,10 @@ describe("extractLastAssistantContent", () => {
   });
 });
 
-// ── cmdThreadRead: ### Content section ───────────────────────────────────────
+// ── cmdThreadRead: <output> section ──────────────────────────────────────────
 
-describe("cmdThreadRead ### Content section", () => {
+describe("cmdThreadRead <output> section", () => {
-  test("includes ### Content before ### Output when detail has assistant turns", async () => {
+  test("includes <output> tags when detail has assistant turns", async () => {
     const uwf = await makeUwfStore(tmpDir);
     const detailSchemas = await registerDetailSchemas(uwf.store);
 
@@ -264,12 +264,13 @@ describe("cmdThreadRead ### Content section", () => {
 
     const markdown = await cmdThreadRead(tmpDir, threadId, THREAD_READ_DEFAULT_QUOTA, null, false);
 
-    expect(markdown).toContain("### Content");
+    expect(markdown).toContain("<output>");
+    expect(markdown).toContain("</output>");
     expect(markdown).toContain("The assistant response text");
-    expect(markdown).not.toContain("### Output");
+    expect(markdown).not.toContain("### Content");
   });
 
-  test("omits ### Content when detail has no matching assistant turns", async () => {
+  test("omits <output> tags when detail has no matching assistant turns", async () => {
     const uwf = await makeUwfStore(tmpDir);
 
     const workflowHash = await uwf.store.put(uwf.schemas.workflow, {
@@ -308,8 +309,9 @@ describe("cmdThreadRead ### Content section", () => {
 
     const markdown = await cmdThreadRead(tmpDir, threadId, THREAD_READ_DEFAULT_QUOTA, null, false);
 
+    expect(markdown).not.toContain("<output>");
+    expect(markdown).not.toContain("</output>");
     expect(markdown).not.toContain("### Content");
-    expect(markdown).not.toContain("### Output");
   });
 });
 
@@ -384,9 +386,9 @@ describe("cmdThreadStepDetails", () => {
   });
 });
 
-// ── cmdThreadRead: ### Prompt deduplication ───────────────────────────────────
+// ── cmdThreadRead: <prompt> deduplication ────────────────────────────────────
 
-describe("cmdThreadRead ### Prompt deduplication", () => {
+describe("cmdThreadRead <prompt> deduplication", () => {
   async function makeThreadWithRoles(uwf: UwfStore, roles: string[]): Promise<string> {
     const roleMap: Record<string, unknown> = {};
     for (const r of [...new Set(roles)]) {
@@ -434,36 +436,36 @@ describe("cmdThreadRead ### Prompt deduplication", () => {
     return stepHash;
   }
 
-  test("same consecutive role shows ### Prompt once", async () => {
+  test("same consecutive role shows <prompt> once", async () => {
     const uwf = await makeUwfStore(tmpDir);
     const headHash = await makeThreadWithRoles(uwf, ["writer", "writer"]);
     const threadId = "01JTEST0000000000000003" as ThreadId;
     await saveThreadsIndex(tmpDir, { [threadId]: headHash });
 
     const markdown = await cmdThreadRead(tmpDir, threadId, THREAD_READ_DEFAULT_QUOTA, null, false);
-    const count = (markdown.match(/### Prompt/g) ?? []).length;
+    const count = (markdown.match(/<prompt>/g) ?? []).length;
     expect(count).toBe(1);
   });
 
-  test("different consecutive roles each show ### Prompt", async () => {
+  test("different consecutive roles each show <prompt>", async () => {
     const uwf = await makeUwfStore(tmpDir);
     const headHash = await makeThreadWithRoles(uwf, ["planner", "coder"]);
     const threadId = "01JTEST0000000000000004" as ThreadId;
     await saveThreadsIndex(tmpDir, { [threadId]: headHash });
 
     const markdown = await cmdThreadRead(tmpDir, threadId, THREAD_READ_DEFAULT_QUOTA, null, false);
-    const count = (markdown.match(/### Prompt/g) ?? []).length;
+    const count = (markdown.match(/<prompt>/g) ?? []).length;
     expect(count).toBe(2);
   });
 
-  test("non-consecutive same role shows ### Prompt twice", async () => {
+  test("non-consecutive same role shows <prompt> twice", async () => {
     const uwf = await makeUwfStore(tmpDir);
     const headHash = await makeThreadWithRoles(uwf, ["roleA", "roleB", "roleA"]);
     const threadId = "01JTEST0000000000000005" as ThreadId;
     await saveThreadsIndex(tmpDir, { [threadId]: headHash });
 
     const markdown = await cmdThreadRead(tmpDir, threadId, THREAD_READ_DEFAULT_QUOTA, null, false);
-    const count = (markdown.match(/### Prompt/g) ?? []).length;
+    const count = (markdown.match(/<prompt>/g) ?? []).length;
     expect(count).toBe(2);
   });
 });

packages/cli-workflow/src/commands/thread.ts

@@ -665,14 +665,14 @@ function formatStepPrompt(
 ): string {
   if (!roleDef || shownPromptRoles.has(role)) return "";
   shownPromptRoles.add(role);
-  return ["", "", "### Prompt", "", roleDef.goal].join("\n");
+  return ["", "", "<prompt>", roleDef.goal, "</prompt>"].join("\n");
 }
 
 function formatStepContent(uwf: UwfStore, item: OrderedStepItem): string {
   if (!item.payload.detail) return "";
   const content = extractLastAssistantContent(uwf, item.payload.detail);
   if (content === null) return "";
-  return ["", "", "### Content", "", content].join("\n");
+  return ["", "", "<output>", content, "</output>"].join("\n");
 }
 
 function formatStartSection(options: {