diff --git a/src/agentkit/core/orchestrator.py b/src/agentkit/core/orchestrator.py
index bff418b..2abe8d0 100644
--- a/src/agentkit/core/orchestrator.py
+++ b/src/agentkit/core/orchestrator.py
@@ -293,6 +293,7 @@ class Orchestrator:
             for i, defn in enumerate(subtask_defs):
                 depends_on = [
                     f"task-{i}" for i in defn.get("depends_on", [])
+                    if isinstance(i, int) and 0 <= i < len(subtask_defs)
                 ]
                 subtasks.append(SubTask(
                     task_id=f"task-{i}",
@@ -799,7 +800,7 @@ class Orchestrator:
         aggregated = await self._aggregate_results(retry_plan, merged_results, task)
 
         failed_count = sum(
-            1 for r in merged_results.values() if r.get("status") != "completed"
+            1 for r in merged_results.values() if r.get("status") == "failed"
         )
         if failed_count == len(merged_results):
             status = TaskStatus.FAILED
diff --git a/src/agentkit/core/plan_executor.py b/src/agentkit/core/plan_executor.py
index adb7aaa..6d76680 100644
--- a/src/agentkit/core/plan_executor.py
+++ b/src/agentkit/core/plan_executor.py
@@ -494,7 +494,9 @@ class PlanExecutor:
         if failed > 0:
             return TaskStatus.PARTIALLY_COMPLETED  # 部分成功
         if completed + skipped == total:
-            # 所有步骤要么完成要么跳过
-            return TaskStatus.COMPLETED
+            # 所有步骤要么完成要么跳过 — 至少需要一个完成才算成功
+            if completed > 0:
+                return TaskStatus.COMPLETED
+            return TaskStatus.FAILED  # 全部跳过 = 没有实际完成
 
-        return TaskStatus.COMPLETED
+        return TaskStatus.PARTIALLY_COMPLETED
diff --git a/src/agentkit/server/app.py b/src/agentkit/server/app.py
index 587e8d4..03b82ed 100644
--- a/src/agentkit/server/app.py
+++ b/src/agentkit/server/app.py
@@ -203,6 +203,11 @@ async def lifespan(app: FastAPI):
     if mcp_manager is not None:
         await mcp_manager.stop_all()
 
+    # Close Redis client for working memory
+    working_redis = getattr(app.state, "working_redis_client", None)
+    if working_redis is not None:
+        await working_redis.aclose()
+
     if server_config is not None:
         server_config.stop_watching()
 
@@ -493,6 +498,7 @@ def create_app(
                 redis_url = server_config.memory["working"].get("redis_url", "redis://localhost:6379")
                 redis_client = aioredis.from_url(redis_url, decode_responses=True)
                 working = WorkingMemory(redis=redis_client)
+                app.state.working_redis_client = redis_client
 
             if server_config.memory.get("semantic", {}).get("enabled"):
                 sem_conf = server_config.memory["semantic"]
diff --git a/src/agentkit/server/routes/workflows.py b/src/agentkit/server/routes/workflows.py
index efdd046..b292233 100644
--- a/src/agentkit/server/routes/workflows.py
+++ b/src/agentkit/server/routes/workflows.py
@@ -414,7 +414,11 @@ def _evaluate_condition(expression: str, variables: dict[str, Any]) -> bool:
             if left and not _SAFE_VAR_PATTERN.match(left):
                 raise ValueError(f"Invalid variable name in condition: {left}")
 
-            left_val = variables.get(left, left)
+            if left and left not in variables:
+                # Missing variable: treat as None/empty — condition evaluates to False
+                left_val = None
+            else:
+                left_val = variables.get(left, left)
             # Strip quotes from right side if present
             if right.startswith('"') and right.endswith('"'):
                 right_val = right[1:-1]
@@ -469,7 +473,7 @@ async def _broadcast_ws(message: dict[str, Any]) -> None:
 
 
 @router.get("/workflows")
-async def list_workflows(request: Request, limit: int = 50):
+async def list_workflows(request: Request, limit: int = 50, _auth: None = Depends(_verify_api_key)):
     """List all workflows."""
     store = _get_store(request)
     summaries = store.list(limit=limit)
@@ -477,7 +481,7 @@ async def list_workflows(request: Request, limit: int = 50):
 
 
 @router.post("/workflows", status_code=201)
-async def create_workflow(request: Request, body: CreateWorkflowRequest):
+async def create_workflow(request: Request, body: CreateWorkflowRequest, _auth: None = Depends(_verify_api_key)):
     """Create a new workflow."""
     store = _get_store(request)
     _validate_workflow_stages(body.stages)
@@ -495,7 +499,7 @@ async def create_workflow(request: Request, body: CreateWorkflowRequest):
 
 
 @router.get("/workflows/{workflow_id}")
-async def get_workflow(request: Request, workflow_id: str):
+async def get_workflow(request: Request, workflow_id: str, _auth: None = Depends(_verify_api_key)):
     """Get a workflow by ID."""
     store = _get_store(request)
     workflow = store.get(workflow_id)
@@ -506,7 +510,8 @@ async def get_workflow(request: Request, workflow_id: str):
 
 @router.put("/workflows/{workflow_id}")
 async def update_workflow(
-    request: Request, workflow_id: str, body: CreateWorkflowRequest
+    request: Request, workflow_id: str, body: CreateWorkflowRequest,
+    _auth: None = Depends(_verify_api_key),
 ):
     """Update an existing workflow."""
     store = _get_store(request)
@@ -527,7 +532,7 @@ async def update_workflow(
 
 
 @router.delete("/workflows/{workflow_id}")
-async def delete_workflow(request: Request, workflow_id: str):
+async def delete_workflow(request: Request, workflow_id: str, _auth: None = Depends(_verify_api_key)):
     """Delete a workflow."""
     store = _get_store(request)
     deleted = store.delete(workflow_id)
@@ -638,7 +643,7 @@ async def approve_execution(
 
 
 @router.post("/workflows/executions/{execution_id}/cancel")
-async def cancel_execution(request: Request, execution_id: str):
+async def cancel_execution(request: Request, execution_id: str, _auth: None = Depends(_verify_api_key)):
     """Cancel a running execution."""
     store = _get_store(request)
     execution = store.get_execution(execution_id)
diff --git a/src/agentkit/tools/computer_use.py b/src/agentkit/tools/computer_use.py
index 1afbede..2a08878 100644
--- a/src/agentkit/tools/computer_use.py
+++ b/src/agentkit/tools/computer_use.py
@@ -8,10 +8,8 @@
 from __future__ import annotations
 
 import base64
-import ipaddress
 import logging
 from typing import Any, Callable, Awaitable
-from urllib.parse import urlparse
 
 import httpx
 
@@ -43,26 +41,7 @@ _FALLBACK_SHELL_SUGGESTIONS: dict[str, list[str]] = {
 }
 
 
-def _is_safe_url(url: str) -> bool:
-    """Check if URL is safe (not pointing to private/internal networks)."""
-    try:
-        parsed = urlparse(url)
-        if parsed.scheme not in ("http", "https"):
-            return False
-        hostname = parsed.hostname
-        if not hostname:
-            return False
-        if hostname in ("localhost", "metadata.google.internal", "metadata.internal"):
-            return False
-        try:
-            ip = ipaddress.ip_address(hostname)
-            if ip.is_private or ip.is_loopback or ip.is_reserved or ip.is_link_local:
-                return False
-        except ValueError:
-            pass
-        return True
-    except Exception:
-        return False
+from agentkit.utils.security import is_safe_url as _is_safe_url
 
 
 class ComputerUseTool(Tool):
diff --git a/src/agentkit/tools/shell.py b/src/agentkit/tools/shell.py
index 435b77f..0d9a970 100644
--- a/src/agentkit/tools/shell.py
+++ b/src/agentkit/tools/shell.py
@@ -102,7 +102,7 @@ _DANGEROUS_PATTERNS: tuple[str, ...] = (
 )
 
 
-_SHELL_OPERATORS = re.compile(r'[|;&]|&&|\|\||\$\(|`')
+_SHELL_OPERATORS = re.compile(r'[|;&]|&&|\|\||\$\(|\$\{|`|\$<|>|<|\n')
 
 
 class ShellTool(Tool):
diff --git a/src/agentkit/utils/security.py b/src/agentkit/utils/security.py
index c81bd0f..c832859 100644
--- a/src/agentkit/utils/security.py
+++ b/src/agentkit/utils/security.py
@@ -5,7 +5,14 @@ from urllib.parse import urlparse
 
 
 def is_safe_url(url: str) -> bool:
-    """Check if URL is safe (not pointing to private/internal networks)."""
+    """Check if URL is safe (not pointing to private/internal networks).
+
+    Validates against:
+    - Private/loopback/reserved/link-local/unspecified IPs
+    - IPv6-mapped IPv4 addresses (e.g. ::ffff:127.0.0.1)
+    - Common metadata/internal hostnames
+    - Non-HTTP schemes
+    """
     try:
         parsed = urlparse(url)
         if parsed.scheme not in ("http", "https"):
@@ -13,14 +20,41 @@ def is_safe_url(url: str) -> bool:
         hostname = parsed.hostname
         if not hostname:
             return False
-        if hostname in ("localhost", "metadata.google.internal", "metadata.internal"):
+        # Block known internal/metadata hostnames
+        _blocked_hostnames = {
+            "localhost",
+            "metadata.google.internal",
+            "metadata.internal",
+            "metadata.azure.com",
+        }
+        hostname_lower = hostname.lower()
+        if hostname_lower in _blocked_hostnames:
+            return False
+        if hostname_lower.endswith((".internal", ".local", ".localhost")):
             return False
         try:
             ip = ipaddress.ip_address(hostname)
-            if ip.is_private or ip.is_loopback or ip.is_reserved or ip.is_link_local:
+            if _is_unsafe_ip(ip):
                 return False
         except ValueError:
+            # hostname is a domain, not a literal IP — DNS rebinding risk remains
+            # (would need DNS resolution to fully mitigate)
             pass
         return True
     except Exception:
         return False
+
+
+def _is_unsafe_ip(ip: ipaddress.IPv4Address | ipaddress.IPv6Address) -> bool:
+    """Check if an IP address is unsafe (private, loopback, etc.).
+
+    Handles IPv6-mapped IPv4 addresses by checking the embedded IPv4.
+    """
+    if ip.is_private or ip.is_loopback or ip.is_reserved or ip.is_link_local or ip.is_unspecified:
+        return True
+    # Check IPv6-mapped IPv4 (e.g. ::ffff:127.0.0.1)
+    if isinstance(ip, ipaddress.IPv6Address) and ip.ipv4_mapped is not None:
+        mapped = ip.ipv4_mapped
+        if mapped.is_private or mapped.is_loopback or mapped.is_reserved or mapped.is_link_local:
+            return True
+    return False
diff --git a/tests/unit/core/test_plan_executor.py b/tests/unit/core/test_plan_executor.py
index 1582907..223bd70 100644
--- a/tests/unit/core/test_plan_executor.py
+++ b/tests/unit/core/test_plan_executor.py
@@ -662,8 +662,8 @@ class TestPlanExecutorOverallStatus:
         executor = PlanExecutor(agent_pool=pool, max_retries=0)
         result = await executor.execute(plan, make_task())
 
-        # 默认策略 SKIP → 全部跳过 → COMPLETED
-        assert result.status == TaskStatus.COMPLETED
+        # 默认策略 SKIP → 全部跳过 → FAILED（没有实际完成的步骤）
+        assert result.status == TaskStatus.FAILED
 
     @pytest.mark.asyncio
     async def test_empty_plan(self):