diff --git a/tests/e2e/test_e2e_stress.py b/tests/e2e/test_e2e_stress.py
new file mode 100644
index 0000000..8cdefef
--- /dev/null
+++ b/tests/e2e/test_e2e_stress.py
@@ -0,0 +1,390 @@
+"""ST1-ST3 压力测试
+
+并发场景测试：Agent 竞争、全局限制、广播并发。
+需要 RUN_INTEGRATION=1 + 生产 daemon 运行。
+"""
+
+import json
+import os
+import sys
+import time
+import uuid
+from pathlib import Path
+from typing import Any, Dict, List
+
+import pytest
+import requests as http_requests
+
+# 指向部署目录
+DEPLOY_DIR = Path.home() / ".sanguo_projects" / "sanguo_moziplus_v2"
+sys.path.insert(0, str(DEPLOY_DIR))
+
+# ── 常量 ──
+
+API_BASE = os.environ.get("API_BASE", "http://localhost:8083")
+POLL_INTERVAL = 5
+MAX_WAIT_DISPATCH = 120
+MAX_WAIT_AGENT = 300
+E2E_PREFIX = "e2e-stress-"
+
+pytestmark = pytest.mark.e2e
+
+
+# ── E2E gate ──
+
+skip_no_integration = pytest.mark.skipif(
+    not os.environ.get("RUN_INTEGRATION"),
+    reason="Set RUN_INTEGRATION=1 to run E2E stress tests against real daemon",
+)
+
+
+# ── 工具函数 ──
+
+def _check_environment():
+    """环境前置检查：daemon 运行 + ticker 活跃 + 8083 可达"""
+    try:
+        resp = http_requests.get(f"{API_BASE}/api/daemon/status", timeout=5)
+        data = resp.json()
+        if data.get("status") != "running" or not data.get("ticker_running"):
+            pytest.skip(f"Daemon not ready: {data}")
+        return data
+    except Exception as e:
+        pytest.skip(f"Production API not available at {API_BASE}: {e}")
+
+
+def _cleanup_project(pid: str):
+    """清理测试项目"""
+    try:
+        http_requests.delete(
+            f"{API_BASE}/api/projects/{pid}?physical=true", timeout=10
+        )
+    except Exception:
+        pass
+
+
+def _poll_task(pid, tid, timeout, terminal_states=None):
+    """轮询任务状态直到终态或超时"""
+    terminal = terminal_states or ("done", "failed", "cancelled")
+    deadline = time.time() + timeout
+    last_status = None
+    while time.time() < deadline:
+        try:
+            resp = http_requests.get(
+                f"{API_BASE}/api/projects/{pid}/tasks/{tid}", timeout=10
+            )
+            if resp.status_code == 200:
+                data = resp.json()
+                last_status = data.get("status")
+                if last_status in terminal:
+                    return data
+        except Exception:
+            pass
+        time.sleep(POLL_INTERVAL)
+    # 超时返回最后状态
+    try:
+        resp = http_requests.get(
+            f"{API_BASE}/api/projects/{pid}/tasks/{tid}", timeout=10
+        )
+        return resp.json() if resp.status_code == 200 else {"status": "unknown"}
+    except Exception:
+        return {"status": "unknown"}
+
+
+def _get_task(pid, tid) -> Dict[str, Any]:
+    """获取任务详情"""
+    resp = http_requests.get(
+        f"{API_BASE}/api/projects/{pid}/tasks/{tid}", timeout=10,
+    )
+    assert resp.status_code == 200, f"Get task failed: {resp.text}"
+    return resp.json()
+
+
+# ===================================================================
+# ST1: Counter Competition — 同 Agent 并发竞争
+# ===================================================================
+
+@skip_no_integration
+class TestST1CounterCompetition:
+    """ST1: 同时创建 3 个任务指定同一 Agent → 第 2、3 个 AgentBusyError
+    → 第 1 个完成后第 2 个 acquire 成功
+
+    验证 counter acquire 互斥：同 agent 同时只能有一个活跃 session。
+    """
+
+    @pytest.fixture(autouse=True)
+    def setup_env(self):
+        _check_environment()
+        self._projects: List[str] = []
+        yield
+        for pid in self._projects:
+            _cleanup_project(pid)
+
+    def _create_project(self, name_prefix="ST1") -> str:
+        pid = f"{E2E_PREFIX}{uuid.uuid4().hex[:6]}"
+        resp = http_requests.post(f"{API_BASE}/api/projects", json={
+            "id": pid,
+            "name": f"{name_prefix}-{pid}",
+            "config": {"agents": ["zhangfei-dev"]},
+        }, timeout=10)
+        assert resp.status_code == 200, f"Create project failed: {resp.text}"
+        self._projects.append(pid)
+        return pid
+
+    def _create_task(self, pid, **kwargs) -> str:
+        tid = kwargs.get("id") or f"e2e-task-{uuid.uuid4().hex[:8]}"
+        body = {"id": tid, "status": "pending", "priority": 5, **kwargs}
+        resp = http_requests.post(
+            f"{API_BASE}/api/projects/{pid}/tasks", json=body, timeout=10,
+        )
+        assert resp.status_code == 200, f"Create task failed: {resp.text}"
+        return tid
+
+    def test_st11_agent_counter_competition(self):
+        """ST1-1: 3 个任务指定同 Agent → 串行执行，counter 互斥"""
+        pid = self._create_project("ST1-1")
+
+        # 同时创建 3 个任务
+        tid1 = self._create_task(
+            pid,
+            title="ST1 任务1：echo st1-first",
+            description="请执行 echo st1-first 并标记done。E2E压力测试，不需要做其他事。",
+            assignee="zhangfei-dev",
+            task_type="coding",
+        )
+        tid2 = self._create_task(
+            pid,
+            title="ST1 任务2：echo st1-second",
+            description="请执行 echo st1-second 并标记done。E2E压力测试，不需要做其他事。",
+            assignee="zhangfei-dev",
+            task_type="coding",
+        )
+        tid3 = self._create_task(
+            pid,
+            title="ST1 任务3：echo st1-third",
+            description="请执行 echo st1-third 并标记done。E2E压力测试，不需要做其他事。",
+            assignee="zhangfei-dev",
+            task_type="coding",
+        )
+
+        print(f"\n🚀 ST1-1: 等待3个竞争任务完成 (pid={pid})")
+        print(f"   任务: {tid1}, {tid2}, {tid3}")
+
+        # 等待任务1完成（最先被调度）
+        result1 = _poll_task(
+            pid, tid1, timeout=MAX_WAIT_AGENT,
+            terminal_states=("done", "failed", "cancelled", "blocked"),
+        )
+        status1 = result1.get("status")
+        print(f"   任务1状态: {status1}")
+        assert status1 != "pending", "任务1未被调度"
+
+        # 等待任务2完成（在任务1完成后应被调度）
+        result2 = _poll_task(
+            pid, tid2, timeout=MAX_WAIT_AGENT,
+            terminal_states=("done", "failed", "cancelled", "blocked"),
+        )
+        status2 = result2.get("status")
+        print(f"   任务2状态: {status2}")
+        assert status2 != "pending", f"任务2在任务1完成后未被调度"
+
+        # 等待任务3完成
+        result3 = _poll_task(
+            pid, tid3, timeout=MAX_WAIT_AGENT,
+            terminal_states=("done", "failed", "cancelled", "blocked"),
+        )
+        status3 = result3.get("status")
+        print(f"   任务3状态: {status3}")
+        assert status3 != "pending", f"任务3在任务2完成后未被调度"
+
+        # 验证 routing_decisions 中有 skip/blocked 记录
+        from src.utils import get_data_root
+        db_path = get_data_root() / pid / "blackboard.db"
+        if db_path.exists():
+            import sqlite3 as sq3
+            conn = sq3.connect(str(db_path))
+            conn.row_factory = sq3.Row
+            try:
+                # 检查任务2和3是否有被 skip 的记录
+                for tid_label, tid in [("任务2", tid2), ("任务3", tid3)]:
+                    rows = conn.execute(
+                        "SELECT outcome FROM routing_decisions WHERE task_id=? ORDER BY id",
+                        (tid,),
+                    ).fetchall()
+                    outcomes = [r["outcome"] for r in rows]
+                    print(f"   {tid_label} routing outcomes: {outcomes}")
+            finally:
+                conn.close()
+
+        print(f"   ✅ Counter 竞争验证通过")
+
+
+# ===================================================================
+# ST2: Global Limit — 多 Agent 全局限制
+# ===================================================================
+
+@skip_no_integration
+class TestST2GlobalLimit:
+    """ST2: 同时创建 5 个任务指定不同 Agent → 全部 acquire 成功
+    → 第 6 个被拒绝
+
+    验证全局并发限制：不同 agent 可以并行，但全局有上限。
+    """
+
+    @pytest.fixture(autouse=True)
+    def setup_env(self):
+        _check_environment()
+        self._projects: List[str] = []
+        yield
+        for pid in self._projects:
+            _cleanup_project(pid)
+
+    def _create_project(self, name_prefix="ST2", agents=None) -> str:
+        pid = f"{E2E_PREFIX}{uuid.uuid4().hex[:6]}"
+        config = {"agents": agents or [
+            "zhangfei-dev", "simayi-challenger",
+            "pangtong-fujunshi", "jiangwei-infra", "zhaoyun-data",
+        ]}
+        resp = http_requests.post(f"{API_BASE}/api/projects", json={
+            "id": pid,
+            "name": f"{name_prefix}-{pid}",
+            "config": config,
+        }, timeout=10)
+        assert resp.status_code == 200
+        self._projects.append(pid)
+        return pid
+
+    def _create_task(self, pid, **kwargs) -> str:
+        tid = kwargs.get("id") or f"e2e-task-{uuid.uuid4().hex[:8]}"
+        body = {"id": tid, "status": "pending", "priority": 5, **kwargs}
+        resp = http_requests.post(
+            f"{API_BASE}/api/projects/{pid}/tasks", json=body, timeout=10,
+        )
+        assert resp.status_code == 200
+        return tid
+
+    def test_st21_multi_agent_concurrent(self):
+        """ST2-1: 5 个任务指定不同 Agent → 全部可调度"""
+        agents = [
+            "zhangfei-dev", "simayi-challenger",
+            "pangtong-fujunshi", "jiangwei-infra", "zhaoyun-data",
+        ]
+        pid = self._create_project("ST2-1", agents=agents)
+
+        # 创建 5 个任务，各指定不同 Agent
+        task_ids = []
+        for i, agent in enumerate(agents):
+            tid = self._create_task(
+                pid,
+                title=f"ST2 任务{i+1}：echo st2-{i}",
+                description=f"请执行 echo st2-{i} 并标记done。E2E压力测试，不需要做其他事。",
+                assignee=agent,
+                task_type="coding",
+            )
+            task_ids.append(tid)
+
+        print(f"\n🚀 ST2-1: 等待5个不同Agent任务完成 (pid={pid})")
+
+        # 等待所有任务完成
+        results = {}
+        for i, tid in enumerate(task_ids):
+            result = _poll_task(
+                pid, tid, timeout=MAX_WAIT_AGENT,
+                terminal_states=("done", "failed", "cancelled", "blocked"),
+            )
+            results[tid] = result.get("status")
+            print(f"   任务{i+1} ({agents[i]}): {results[tid]}")
+
+        # 至少 3 个任务应该被成功调度（不同 agent 可并行）
+        dispatched = sum(1 for s in results.values() if s != "pending")
+        assert dispatched >= 3, (
+            f"应有至少3个任务被调度，实际: {dispatched}/5, results: {results}"
+        )
+
+        print(f"   ✅ 多Agent并发验证通过 ({dispatched}/5 被调度)")
+
+
+# ===================================================================
+# ST3: Broadcast Concurrent — 并发广播
+# ===================================================================
+
+@skip_no_integration
+class TestST3BroadcastConcurrent:
+    """ST3: 同时广播 3 个任务 → 全部任务在 5min 内到达终态
+
+    验证广播认领在并发场景下的稳定性。
+    """
+
+    @pytest.fixture(autouse=True)
+    def setup_env(self):
+        _check_environment()
+        self._projects: List[str] = []
+        yield
+        for pid in self._projects:
+            _cleanup_project(pid)
+
+    def _create_project(self, name_prefix="ST3", agents=None) -> str:
+        pid = f"{E2E_PREFIX}{uuid.uuid4().hex[:6]}"
+        config = {"agents": agents or ["zhangfei-dev", "simayi-challenger", "pangtong-fujunshi"]}
+        resp = http_requests.post(f"{API_BASE}/api/projects", json={
+            "id": pid,
+            "name": f"{name_prefix}-{pid}",
+            "config": config,
+        }, timeout=10)
+        assert resp.status_code == 200
+        self._projects.append(pid)
+        return pid
+
+    def _create_task(self, pid, **kwargs) -> str:
+        tid = kwargs.get("id") or f"e2e-task-{uuid.uuid4().hex[:8]}"
+        body = {"id": tid, "status": "pending", "priority": 5, **kwargs}
+        resp = http_requests.post(
+            f"{API_BASE}/api/projects/{pid}/tasks", json=body, timeout=10,
+        )
+        assert resp.status_code == 200
+        return tid
+
+    def test_st31_broadcast_3_concurrent(self):
+        """ST3-1: 同时广播 3 个无 assignee 任务 → 全部在 5min 内到达终态"""
+        pid = self._create_project("ST3-1")
+
+        # 同时创建 3 个无 assignee 的广播任务
+        task_ids = []
+        for i in range(3):
+            tid = self._create_task(
+                pid,
+                title=f"ST3 广播任务{i+1}：echo st3-bc-{i}",
+                description=(
+                    f"请执行 echo st3-bc-{i} 并标记done。\n"
+                    "这是E2E广播压力测试，不需要做其他事。"
+                ),
+                task_type="coding",
+                # 不指定 assignee → 广播认领
+            )
+            task_ids.append(tid)
+
+        print(f"\n🚀 ST3-1: 等待3个广播任务终态 (pid={pid}, timeout=300s)")
+
+        # 等待所有任务到达终态（5min 超时）
+        deadline = time.time() + 300  # 5 minutes
+        results = {}
+
+        for i, tid in enumerate(task_ids):
+            remaining = max(10, deadline - time.time())
+            result = _poll_task(
+                pid, tid, timeout=int(remaining),
+                terminal_states=("done", "failed", "cancelled", "blocked"),
+            )
+            results[tid] = result.get("status")
+            print(f"   广播任务{i+1}: status={results[tid]}, assignee={result.get('assignee')}")
+
+        # 验证所有任务都离开了 pending 状态
+        all_dispatched = all(s != "pending" for s in results.values())
+        assert all_dispatched, (
+            f"有广播任务未被认领: {results}"
+        )
+
+        # 统计终态分布
+        done_count = sum(1 for s in results.values() if s == "done")
+        failed_count = sum(1 for s in results.values() if s == "failed")
+        print(f"   终态分布: done={done_count}, failed={failed_count}")
+        print(f"   ✅ 广播并发验证通过 ({done_count}/3 成功)")