diff --git a/web/src/api/taskStream.test.ts b/web/src/api/taskStream.test.ts
new file mode 100644
index 00000000..8a992309
--- /dev/null
+++ b/web/src/api/taskStream.test.ts
@@ -0,0 +1,59 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import { buildTaskRequest, buildResumeRequest } from './taskStream';
+
+test('buildTaskRequest: maps five project fields + task_key + user identity', () => {
+  const req = buildTaskRequest({
+    taskKey: 'feasibility_reg',
+    projectName: '超声主机系统',
+    customerName: '北京水木东方',
+    deviceType: '超声吸引刀',
+    intendedUse: '外科手术导航',
+    targetMarket: '国内',
+    userId: 1,
+    projectId: 7,
+  });
+  assert.equal(req.task_key, 'feasibility_reg');
+  assert.equal(req.project_name, '超声主机系统');
+  assert.equal(req.customer_name, '北京水木东方');
+  assert.equal(req.device_type, '超声吸引刀');
+  assert.equal(req.intended_use, '外科手术导航');
+  assert.equal(req.target_market, '国内');
+  assert.equal(req.user_id, 1);
+  assert.equal(req.project_id, 7);
+  assert.equal('work_dir' in req, false);
+});
+
+test('buildTaskRequest: omits optional fields when absent', () => {
+  const req = buildTaskRequest({
+    taskKey: 'intake',
+    projectName: 'P',
+    customerName: 'C',
+    deviceType: 'D',
+  });
+  assert.equal('intended_use' in req, false);
+  assert.equal('target_market' in req, false);
+  assert.equal('user_id' in req, false);
+  assert.equal('project_id' in req, false);
+});
+
+test('buildResumeRequest: adds work_dir on top of task request', () => {
+  const req = buildResumeRequest(
+    { taskKey: 'feasibility_reg', projectName: 'P', customerName: 'C', deviceType: 'D', userId: 2 },
+    '/tmp/ws-x'
+  );
+  assert.equal(req.work_dir, '/tmp/ws-x');
+  assert.equal(req.task_key, 'feasibility_reg');
+  assert.equal(req.user_id, 2);
+  assert.equal('add_steps' in req, false);
+});
+
+test('buildResumeRequest: forwards add_steps when provided', () => {
+  const req = buildResumeRequest(
+    { taskKey: 'intake', projectName: 'P', customerName: 'C', deviceType: 'D' },
+    '/tmp/ws-y',
+    [{ id: 'step_dyn_1', role: 'regulatory', title: '补充条款' }]
+  );
+  assert.equal(req.work_dir, '/tmp/ws-y');
+  assert.deepEqual(req.add_steps, [{ id: 'step_dyn_1', role: 'regulatory', title: '补充条款' }]);
+});
\ No newline at end of file
diff --git a/web/src/api/taskStream.ts b/web/src/api/taskStream.ts
new file mode 100644
index 00000000..e361b867
--- /dev/null
+++ b/web/src/api/taskStream.ts
@@ -0,0 +1,85 @@
+import { parseSSEChunk, type StreamEvent } from './chatStream';
+
+/** 长任务运行上下文：触发 / 重试 / 重新开始时重发请求所需的最小参数集 */
+export type TaskRunContext = {
+  taskKey: string;
+  projectName: string;
+  customerName: string;
+  deviceType: string;
+  intendedUse?: string;
+  targetMarket?: string;
+  userId?: number;
+  projectId?: number;
+};
+
+/**
+ * streamTask 消费 POST /api/v1/tasks/run/stream 的 SSE 事件流。
+ * 复用 chatStream 的 parseSSEChunk 解析与中止语义。
+ */
+export async function streamTask(
+  body: Record<string, unknown>,
+  handlers: {
+    onEvent: (ev: StreamEvent) => void;
+    onRequestId?: (id: string) => void;
+  },
+  signal?: AbortSignal,
+): Promise<void> {
+  const resp = await fetch('/api/v1/tasks/run/stream', {
+    method: 'POST',
+    headers: { 'Content-Type': 'application/json', Accept: 'text/event-stream' },
+    body: JSON.stringify(body),
+    signal,
+  });
+  const rid = resp.headers.get('X-Request-Id') || resp.headers.get('x-request-id');
+  if (rid) handlers.onRequestId?.(rid);
+  if (!resp.ok || !resp.body) {
+    throw Object.assign(new Error(`HTTP ${resp.status}`), {
+      httpStatus: resp.status,
+      requestId: rid,
+    });
+  }
+  const reader = resp.body.getReader();
+  const decoder = new TextDecoder();
+  let buf = '';
+  while (true) {
+    const { done, value } = await reader.read();
+    if (done) break;
+    buf += decoder.decode(value, { stream: true });
+    const parsed = parseSSEChunk(buf);
+    buf = parsed.rest;
+    for (const ev of parsed.events) handlers.onEvent(ev);
+  }
+  if (buf) {
+    const flushed = parseSSEChunk(buf, { flush: true });
+    for (const ev of flushed.events) handlers.onEvent(ev);
+  }
+}
+
+/** 构造新任务运行请求（五要素 + task_key + 用户/项目标识） */
+export function buildTaskRequest(task: TaskRunContext): Record<string, unknown> {
+  const body: Record<string, unknown> = {
+    task_key: task.taskKey,
+    project_name: task.projectName,
+    customer_name: task.customerName,
+    device_type: task.deviceType,
+  };
+  if (task.intendedUse) body.intended_use = task.intendedUse;
+  if (task.targetMarket) body.target_market = task.targetMarket;
+  if (task.userId) body.user_id = task.userId;
+  if (task.projectId) body.project_id = task.projectId;
+  return body;
+}
+
+/** 构造 resume 请求：在任务请求基础上追加 work_dir（可选动态步骤），交由后端续跑既有工作区 */
+export function buildResumeRequest(
+  task: TaskRunContext,
+  workDir: string,
+  addSteps?: Array<Record<string, unknown>>,
+): Record<string, unknown> {
+  const body = buildTaskRequest(task);
+  body.work_dir = workDir;
+  if (addSteps && addSteps.length > 0) {
+    body.add_steps = addSteps;
+  }
+  return body;
+}
\ No newline at end of file
diff --git a/web/src/engine/phaseEventMapper.test.ts b/web/src/engine/phaseEventMapper.test.ts
new file mode 100644
index 00000000..e46e897b
--- /dev/null
+++ b/web/src/engine/phaseEventMapper.test.ts
@@ -0,0 +1,90 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import { applyPhaseEvent } from './phaseEventMapper';
+
+test('applyPhaseEvent: appends first phase as running node', () => {
+  const strip = applyPhaseEvent([], { phase_id: 'squad_assembly', message: '组建小队' });
+  assert.equal(strip.length, 1);
+  assert.equal(strip[0].step, 'squad_assembly');
+  assert.equal(strip[0].icon, '👥');
+  assert.equal(strip[0].status, 'running');
+});
+
+test('applyPhaseEvent: completes predecessors when a new phase arrives', () => {
+  let strip = applyPhaseEvent([], { phase_id: 'squad_assembly', message: 'a' });
+  strip = applyPhaseEvent(strip, { phase_id: 'knowledge_retrieval', message: 'b' });
+  assert.equal(strip.length, 2);
+  assert.equal(strip[0].status, 'completed');
+  assert.equal(strip[1].status, 'running');
+});
+
+test('applyPhaseEvent: same phase refreshes label in place (no duplicate node)', () => {
+  let strip = applyPhaseEvent([], { phase_id: 'quality_gate', message: 'x', progress: 85 });
+  strip = applyPhaseEvent(strip, { phase_id: 'quality_gate', message: 'y', progress: 95 });
+  assert.equal(strip.length, 1);
+  assert.match(strip[0].label, /95%/);
+});
+
+test('applyPhaseEvent: unknown phase falls back to hourglass meta', () => {
+  const strip = applyPhaseEvent([], { phase_id: 'mystery_phase' });
+  assert.equal(strip[0].icon, '⏳');
+  assert.equal(strip[0].label, '任务推进');
+});
+
+test('applyPhaseEvent: prefers backend message over short label', () => {
+  const strip = applyPhaseEvent([], { phase_id: 'squad_assembly', message: '正在组建真实小队...' });
+  assert.equal(strip[0].icon, '👥');
+  assert.equal(strip[0].label, '正在组建真实小队...');
+});
+
+test('applyPhaseEvent: step_completed closes running entry without appending', () => {
+  let strip = applyPhaseEvent([], { phase_id: 'squad_assembly', message: 'a' });
+  strip = applyPhaseEvent(strip, { phase_id: 'step_executing', message: '撰写中' });
+  strip = applyPhaseEvent(strip, { phase_id: 'step_completed', message: '完成' });
+  assert.equal(strip.length, 2);
+  assert.equal(strip[0].status, 'completed');
+  assert.equal(strip[1].status, 'completed');
+  assert.match(strip[1].label, /撰写中/);
+});
+
+test('applyPhaseEvent: stage_completed closes entries', () => {
+  let strip = applyPhaseEvent([], { phase_id: 'stage_started', message: 's' });
+  strip = applyPhaseEvent(strip, { phase_id: 'stage_completed', message: 'done' });
+  assert.equal(strip.length, 1);
+  assert.equal(strip[0].status, 'completed');
+});
+
+test('applyPhaseEvent: task_failed appends warning node', () => {
+  let strip = applyPhaseEvent([], { phase_id: 'step_executing', message: 'e' });
+  strip = applyPhaseEvent(strip, { phase_id: 'task_failed', message: 'boom' });
+  assert.equal(strip.length, 2);
+  assert.equal(strip[0].status, 'completed');
+  assert.equal(strip[1].step, 'task_failed');
+  assert.equal(strip[1].icon, '⚠️');
+  assert.equal(strip[1].status, 'running');
+});
+
+test('applyPhaseEvent: decorates label with step index / total steps', () => {
+  const strip = applyPhaseEvent([], {
+    phase_id: 'step_executing',
+    message: 'm',
+    step_index: 2,
+    total_steps: 3,
+  });
+  assert.match(strip[0].label, /第 2\/3 步/);
+});
+
+test('applyPhaseEvent: repeated step_executing with step_index gets separate nodes', () => {
+  let strip = applyPhaseEvent([], { phase_id: 'step_executing', message: '一', step_index: 1, total_steps: 3 });
+  strip = applyPhaseEvent(strip, { phase_id: 'step_executing', message: '二', step_index: 2, total_steps: 3 });
+  assert.equal(strip.length, 2);
+  assert.equal(strip[0].status, 'completed');
+  assert.match(strip[0].label, /第 1\/3 步/);
+  assert.equal(strip[1].status, 'running');
+  assert.match(strip[1].label, /第 2\/3 步/);
+});
+
+test('applyPhaseEvent: ignores event without phase payload', () => {
+  const strip = applyPhaseEvent([], undefined);
+  assert.equal(strip.length, 0);
+});
\ No newline at end of file
diff --git a/web/src/engine/phaseEventMapper.ts b/web/src/engine/phaseEventMapper.ts
new file mode 100644
index 00000000..f81d8715
--- /dev/null
+++ b/web/src/engine/phaseEventMapper.ts
@@ -0,0 +1,80 @@
+import type { PhaseEvent } from '../types/workbench';
+
+/** 后端 phase 事件载荷（与 StreamEvent['phase'] 结构兼容，保持 mapper 独立可测） */
+export type PhaseEventPayload = {
+  phase_id?: string;
+  message?: string;
+  role?: string;
+  step_index?: number;
+  total_steps?: number;
+  progress?: number;
+};
+
+/** phase_id → 图标/短标签映射（与 bizdev-cli/main.go 的 CLI 映射保持一致） */
+const PHASE_META: Record<string, { icon: string; label: string }> = {
+  squad_assembly: { icon: '👥', label: '组建小队' },
+  knowledge_retrieval: { icon: '📚', label: '知识检索' },
+  knowledge_retrieved: { icon: '📚', label: '知识命中' },
+  step_executing: { icon: '⚙️', label: '专员执行' },
+  step_completed: { icon: '✅', label: '步骤完成' },
+  quality_gate: { icon: '🛡️', label: '质量门禁' },
+  advisor_briefing: { icon: '💡', label: '参谋简报' },
+  stage_transition: { icon: '🚀', label: '阶段跃迁' },
+  stage_started: { icon: '🚀', label: '阶段启动' },
+  stage_completed: { icon: '🎉', label: '阶段完成' },
+  task_failed: { icon: '⚠️', label: '任务异常' },
+};
+
+/** 收口型 phase：不追加新节点，仅把当前 running 条目置为 completed */
+const CLOSE_PHASES = new Set(['step_completed', 'stage_completed']);
+
+function decorateLabel(base: string, phase: PhaseEventPayload): string {
+  const { step_index, total_steps, progress } = phase;
+  if (step_index && step_index > 0 && total_steps && total_steps > 0) {
+    return `${base}（第 ${step_index}/${total_steps} 步）`;
+  }
+  if (progress && progress > 0) {
+    return `${base}（${progress}%）`;
+  }
+  return base;
+}
+
+/** 条目 key：同 phase 且无有效 step_index 时刷新文案；带 step_index 的重复 phase 各占一节点 */
+function stepKeyOf(phase: PhaseEventPayload): string {
+  const idx = phase.step_index ?? 0;
+  return idx > 0 ? `${phase.phase_id}#${idx}` : `${phase.phase_id}`;
+}
+
+/**
+ * applyPhaseEvent 把一条后端 phase 事件折叠进 PhaseEventStrip 序列（纯函数）。
+ * 进度求真：仅由真实 phase 事件驱动，无任何人为进度推演。
+ */
+export function applyPhaseEvent(strip: PhaseEvent[], phase?: PhaseEventPayload): PhaseEvent[] {
+  if (!phase?.phase_id) return strip;
+
+  const meta = PHASE_META[phase.phase_id] ?? { icon: '⏳', label: '任务推进' };
+  // 进度求真：优先展示后端下发的真实进度文案，短标签仅作缺省
+  const base = phase.message?.trim() || meta.label;
+  const label = decorateLabel(base, phase);
+  const key = stepKeyOf(phase);
+
+  // 已存在的条目：仅刷新文案（同阶段/同步骤进度更新）
+  const existingIdx = strip.findIndex((e) => e.step === key);
+  if (existingIdx >= 0) {
+    return strip.map((e, i) => (i === existingIdx ? { ...e, label } : e));
+  }
+
+  // 收口型 phase：running 条目置 completed，不追加新节点
+  if (CLOSE_PHASES.has(phase.phase_id)) {
+    return strip.map((e) => (e.status === 'running' ? { ...e, status: 'completed' as const } : e));
+  }
+
+  // 新 phase：先行条目全部置 completed，追加当前节点为 running
+  const settled = strip.map((e) =>
+    e.status === 'running' ? { ...e, status: 'completed' as const } : e
+  );
+  return [
+    ...settled,
+    { step: key, icon: meta.icon, label, status: 'running' as const },
+  ];
+}
\ No newline at end of file