change

src/langbot/pkg/api/http/service/workflow.py

@@ -342,6 +342,23 @@ class WorkflowService:
 
         if trigger_type == 'message':
             message_context_data = raw_trigger_data.get('message_context') or {}
+            # Fallback: if message_context is missing but trigger_data has 'message',
+            # construct a minimal message_context so rerun and downstream nodes work.
+            if not message_context_data and raw_trigger_data.get('message'):
+                raw_msg = raw_trigger_data['message']
+                message_context_data = {
+                    'message_id': str(raw_trigger_data.get('message_id', execution_uuid)),
+                    'message_content': raw_msg if isinstance(raw_msg, str) else str(raw_msg),
+                    'sender_id': str(raw_trigger_data.get('sender_id', '')),
+                    'sender_name': str(raw_trigger_data.get('sender_name', 'User')),
+                    'platform': str(raw_trigger_data.get('platform', '')),
+                    'conversation_id': str(raw_trigger_data.get('connection_id', '')),
+                    'is_group': bool(raw_trigger_data.get('is_group', False)),
+                    'group_id': raw_trigger_data.get('group_id'),
+                    'mentions': raw_trigger_data.get('mentions', []),
+                    'reply_to': raw_trigger_data.get('reply_to'),
+                    'raw_message': raw_trigger_data.get('raw_message', {}),
+                }
             if message_context_data:
                 context.message_context = MessageContext(
                     message_id=str(message_context_data.get('message_id', execution_uuid)),

src/langbot/pkg/workflow/__init__.py

@@ -44,6 +44,11 @@ def __getattr__(name: str) -> Any:
 
         return WorkflowExecutor
 
+    if name in ('DebugWorkflowExecutor', 'DebugExecutionState', 'ExecutionLog'):
+        from . import debug
+
+        return getattr(debug, name)
+
     if name == 'nodes':
         return import_module('.nodes', __name__)
 
@@ -69,4 +74,8 @@ __all__ = [
     'NodeTypeRegistry',
     # Executor
     'WorkflowExecutor',
+    # Debug
+    'DebugWorkflowExecutor',
+    'DebugExecutionState',
+    'ExecutionLog',
 ]

src/langbot/pkg/workflow/debug.py

@@ -0,0 +1,509 @@
+"""Workflow debug execution support.
+
+This module provides debugging capabilities for workflow execution, including:
+- ExecutionLog: Structured log entries for execution tracking
+- DebugExecutionState: State management for debug sessions (pause, resume, breakpoints)
+- DebugWorkflowExecutor: Extended executor with step-by-step debugging support
+"""
+
+from __future__ import annotations
+
+import asyncio
+import logging
+import traceback
+import uuid
+from datetime import datetime
+from typing import Any, Optional, TYPE_CHECKING
+
+from .entities import (
+    WorkflowDefinition,
+    NodeDefinition,
+    EdgeDefinition,
+    ExecutionContext,
+    ExecutionStatus,
+    NodeState,
+    NodeStatus,
+)
+from .executor import WorkflowExecutor
+
+if TYPE_CHECKING:
+    from ..core import app
+
+logger = logging.getLogger(__name__)
+
+
+class ExecutionLog:
+    """Execution log entry"""
+
+    def __init__(self, level: str, message: str, node_id: Optional[str] = None, data: Optional[dict] = None):
+        self.id = str(uuid.uuid4())
+        self.timestamp = datetime.now().isoformat()
+        self.level = level
+        self.message = message
+        self.node_id = node_id
+        self.data = data or {}
+
+    def to_dict(self) -> dict:
+        return {
+            'id': self.id,
+            'timestamp': self.timestamp,
+            'level': self.level,
+            'message': self.message,
+            'node_id': self.node_id,
+            'data': self.data,
+        }
+
+
+class DebugExecutionState:
+    """State for a debug execution"""
+
+    def __init__(self, execution_id: str, breakpoints: list[str] = None):
+        self.execution_id = execution_id
+        self.status: str = 'running'
+        self.is_paused: bool = False
+        self.is_stopped: bool = False
+        self.current_node_id: Optional[str] = None
+        self.breakpoints: set[str] = set(breakpoints or [])
+        self.logs: list[ExecutionLog] = []
+        self.pending_logs: list[ExecutionLog] = []
+        self._pause_event = asyncio.Event()
+        self._pause_event.set()  # Initially not paused
+        self._stop_event = asyncio.Event()
+
+    def add_log(self, level: str, message: str, node_id: str = None, data: dict = None):
+        """Add a log entry"""
+        log = ExecutionLog(level, message, node_id, data)
+        self.logs.append(log)
+        self.pending_logs.append(log)
+        logger.log(
+            getattr(logging, level.upper(), logging.INFO),
+            f'[Workflow Debug] {message}',
+            extra={'node_id': node_id, 'data': data},
+        )
+
+    def get_pending_logs(self) -> list[dict]:
+        """Get and clear pending logs"""
+        logs = [log.to_dict() for log in self.pending_logs]
+        self.pending_logs = []
+        return logs
+
+    def pause(self):
+        """Pause execution"""
+        self.is_paused = True
+        self._pause_event.clear()
+        self.add_log('info', 'Execution paused')
+
+    def resume(self):
+        """Resume execution"""
+        self.is_paused = False
+        self._pause_event.set()
+        self.add_log('info', 'Execution resumed')
+
+    def stop(self):
+        """Stop execution"""
+        self.is_stopped = True
+        self.status = 'cancelled'
+        self._stop_event.set()
+        self._pause_event.set()  # Release any pause
+        self.add_log('info', 'Execution stopped')
+
+    async def wait_if_paused(self):
+        """Wait if execution is paused"""
+        if self.is_paused:
+            self.add_log('info', 'Waiting for resume...')
+            await self._pause_event.wait()
+
+    def check_breakpoint(self, node_id: str) -> bool:
+        """Check if there's a breakpoint at the given node"""
+        return node_id in self.breakpoints
+
+
+class DebugWorkflowExecutor(WorkflowExecutor):
+    """
+    Debug-enabled workflow executor with step-by-step execution support.
+    Extends WorkflowExecutor with debugging capabilities.
+    """
+
+    # Class-level storage for active debug sessions
+    _debug_states: dict[str, DebugExecutionState] = {}
+
+    def __init__(self, ap: Optional['app.Application'] = None):
+        super().__init__(ap)
+
+    @classmethod
+    def get_debug_state(cls, execution_id: str) -> Optional[DebugExecutionState]:
+        """Get debug state for an execution"""
+        return cls._debug_states.get(execution_id)
+
+    @classmethod
+    def create_debug_state(cls, execution_id: str, breakpoints: list[str] = None) -> DebugExecutionState:
+        """Create a new debug state"""
+        state = DebugExecutionState(execution_id, breakpoints)
+        cls._debug_states[execution_id] = state
+        return state
+
+    @classmethod
+    def remove_debug_state(cls, execution_id: str):
+        """Remove debug state for an execution"""
+        cls._debug_states.pop(execution_id, None)
+
+    async def execute_debug(
+        self,
+        workflow: WorkflowDefinition,
+        context: ExecutionContext,
+        debug_state: DebugExecutionState,
+    ) -> ExecutionContext:
+        """
+        Execute a workflow in debug mode.
+
+        Args:
+            workflow: Workflow definition
+            context: Execution context
+            debug_state: Debug execution state
+
+        Returns:
+            Updated execution context
+        """
+        context.status = ExecutionStatus.RUNNING
+        context.start_time = datetime.now()
+        debug_state.add_log('info', f'Starting debug execution for workflow: {workflow.name}')
+
+        try:
+            # Build execution graph
+            node_map = {node.id: node for node in workflow.nodes}
+            edge_map = self._build_edge_map(workflow.edges)
+            self._edges = workflow.edges
+
+            # Initialize node states
+            for node in workflow.nodes:
+                if node.id not in context.node_states:
+                    context.node_states[node.id] = NodeState(node_id=node.id)
+
+            # Find start node(s)
+            start_nodes = self._find_start_nodes(workflow.nodes, workflow.edges)
+
+            if not start_nodes:
+                raise ValueError('No start nodes found in workflow')
+
+            debug_state.add_log('info', f'Found {len(start_nodes)} start node(s)')
+
+            # Execute from start nodes
+            for start_node in start_nodes:
+                if debug_state.is_stopped:
+                    break
+
+                await self._execute_debug_from_node(
+                    start_node, node_map, edge_map, context, debug_state, workflow.settings.max_retries
+                )
+
+            # Set final status
+            if debug_state.is_stopped:
+                context.status = ExecutionStatus.CANCELLED
+                debug_state.status = 'cancelled'
+            else:
+                all_completed = all(
+                    state.status in (NodeStatus.COMPLETED, NodeStatus.SKIPPED) for state in context.node_states.values()
+                )
+
+                if all_completed:
+                    context.status = ExecutionStatus.COMPLETED
+                    debug_state.status = 'completed'
+                    debug_state.add_log('info', 'Workflow execution completed successfully')
+                else:
+                    has_failed = any(state.status == NodeStatus.FAILED for state in context.node_states.values())
+                    if has_failed:
+                        context.status = ExecutionStatus.FAILED
+                        debug_state.status = 'error'
+
+        except Exception as e:
+            context.status = ExecutionStatus.FAILED
+            context.error = str(e)
+            debug_state.status = 'error'
+            debug_state.add_log('error', f'Workflow execution failed: {e}', data={'traceback': traceback.format_exc()})
+            logger.error(f'Debug workflow execution failed: {e}\n{traceback.format_exc()}')
+
+        finally:
+            context.end_time = datetime.now()
+
+        return context
+
+    async def _execute_debug_from_node(
+        self,
+        node: NodeDefinition,
+        node_map: dict[str, NodeDefinition],
+        edge_map: dict[str, list[EdgeDefinition]],
+        context: ExecutionContext,
+        debug_state: DebugExecutionState,
+        max_retries: int = 3,
+    ):
+        """Execute workflow from a node with debug support"""
+
+        # Check if stopped
+        if debug_state.is_stopped:
+            return
+
+        # Wait if paused
+        await debug_state.wait_if_paused()
+
+        # Check if should skip
+        if await self._should_skip_node(node, context):
+            if context.node_states[node.id].status == NodeStatus.SKIPPED:
+                debug_state.add_log('info', f'Skipping node: {node.id}', node_id=node.id)
+            return
+
+        # Check breakpoint
+        if debug_state.check_breakpoint(node.id):
+            debug_state.add_log('info', f'Hit breakpoint at node: {node.id}', node_id=node.id)
+            debug_state.pause()
+            await debug_state.wait_if_paused()
+
+        # Update current node
+        debug_state.current_node_id = node.id
+        debug_state.add_log('info', f'Executing node: {node.id} ({node.type})', node_id=node.id)
+
+        # Execute node
+        await self._execute_debug_node(node, context, debug_state, max_retries)
+
+        # Check if stopped or failed
+        if debug_state.is_stopped:
+            return
+        if context.node_states[node.id].status == NodeStatus.FAILED:
+            return
+
+        # Get outgoing edges
+        outgoing_edges = edge_map.get(node.id, [])
+
+        # Execute next nodes
+        for edge in outgoing_edges:
+            if debug_state.is_stopped:
+                break
+
+            target_node = node_map.get(edge.target_node)
+            if not target_node:
+                continue
+
+            # Check edge condition
+            if edge.condition:
+                condition_met = await self._evaluate_condition(edge.condition, context)
+                if not condition_met:
+                    debug_state.add_log('debug', f'Edge condition not met: {edge.condition}', node_id=node.id)
+                    continue
+
+            # Check if all inputs are ready
+            if await self._inputs_ready(target_node, edge_map, context):
+                await self._execute_debug_from_node(target_node, node_map, edge_map, context, debug_state, max_retries)
+
+    async def _execute_debug_node(
+        self, node: NodeDefinition, context: ExecutionContext, debug_state: DebugExecutionState, max_retries: int = 3
+    ):
+        """Execute a single node with debug logging"""
+
+        node_state = context.node_states[node.id]
+        node_state.status = NodeStatus.RUNNING
+        node_state.start_time = datetime.now()
+
+        # Get node instance (pass ap for access to services)
+        node_instance = self.registry.create_instance(node.type, node.id, node.config, ap=self.ap)
+
+        if not node_instance:
+            node_state.status = NodeStatus.FAILED
+            node_state.error = f'Unknown node type: {node.type}'
+            node_state.end_time = datetime.now()
+            debug_state.add_log('error', f'Unknown node type: {node.type}', node_id=node.id)
+            self._record_execution_step(node, node_state, context)
+            await self._persist_node_execution(node, node_state, context)
+            return
+
+        # Resolve inputs
+        inputs = await self._resolve_inputs(node, context)
+        node_state.inputs = inputs
+        debug_state.add_log(
+            'debug', 'Node inputs resolved', node_id=node.id, data={'inputs': self._safe_serialize(inputs)}
+        )
+
+        # Validate inputs
+        validation_errors = await node_instance.validate_inputs(inputs)
+        if validation_errors:
+            node_state.status = NodeStatus.FAILED
+            node_state.error = '; '.join(validation_errors)
+            node_state.end_time = datetime.now()
+            debug_state.add_log('error', f'Input validation failed: {node_state.error}', node_id=node.id)
+            self._record_execution_step(node, node_state, context)
+            await self._persist_node_execution(node, node_state, context)
+            return
+
+        # Execute with retries
+        for attempt in range(max_retries + 1):
+            if debug_state.is_stopped:
+                node_state.status = NodeStatus.FAILED
+                node_state.error = 'Execution stopped'
+                node_state.end_time = datetime.now()
+                break
+
+            try:
+                outputs = await node_instance.execute(inputs, context)
+                node_state.outputs = outputs
+                node_state.status = NodeStatus.COMPLETED
+                node_state.end_time = datetime.now()
+
+                duration_ms = int((node_state.end_time - node_state.start_time).total_seconds() * 1000)
+                debug_state.add_log(
+                    'info',
+                    f'Node completed in {duration_ms}ms',
+                    node_id=node.id,
+                    data={'outputs': self._safe_serialize(outputs), 'duration_ms': duration_ms},
+                )
+                break
+
+            except Exception as e:
+                node_state.retry_count = attempt + 1
+                debug_state.add_log(
+                    'warning', f'Node execution failed (attempt {attempt + 1}/{max_retries + 1}): {e}', node_id=node.id
+                )
+
+                if attempt < max_retries:
+                    await asyncio.sleep(1)
+                else:
+                    node_state.status = NodeStatus.FAILED
+                    node_state.error = str(e)
+                    node_state.end_time = datetime.now()
+                    debug_state.add_log(
+                        'error',
+                        f'Node failed after {max_retries + 1} attempts: {e}',
+                        node_id=node.id,
+                        data={'error': str(e), 'traceback': traceback.format_exc()},
+                    )
+
+        self._record_execution_step(node, node_state, context)
+        await self._persist_node_execution(node, node_state, context)
+
+    async def step_execute(
+        self,
+        workflow: WorkflowDefinition,
+        context: ExecutionContext,
+        debug_state: DebugExecutionState,
+    ) -> dict:
+        """
+        Execute one step (one node) in debug mode.
+
+        Returns:
+            Dict with node_id, node_state, and completed status
+        """
+        # Find next node to execute
+        next_node = self._find_next_executable_node(workflow, context)
+
+        if not next_node:
+            debug_state.status = 'completed'
+            return {'completed': True}
+
+        # Execute single node
+        debug_state.current_node_id = next_node.id
+        await self._execute_debug_node(next_node, context, debug_state, workflow.settings.max_retries)
+
+        node_state = context.node_states.get(next_node.id)
+
+        # Check if workflow is complete
+        all_done = all(
+            state.status in (NodeStatus.COMPLETED, NodeStatus.SKIPPED, NodeStatus.FAILED)
+            for state in context.node_states.values()
+        )
+
+        if all_done:
+            debug_state.status = 'completed'
+            context.status = ExecutionStatus.COMPLETED
+
+        return {
+            'node_id': next_node.id,
+            'node_state': {
+                'status': node_state.status.value if node_state else 'unknown',
+                'inputs': self._safe_serialize(node_state.inputs) if node_state else {},
+                'outputs': self._safe_serialize(node_state.outputs) if node_state else {},
+                'error': node_state.error if node_state else None,
+            },
+            'completed': all_done,
+        }
+
+    def _find_next_executable_node(
+        self, workflow: WorkflowDefinition, context: ExecutionContext
+    ) -> Optional[NodeDefinition]:
+        """Find the next node that can be executed"""
+        edge_map = self._build_edge_map(workflow.edges)
+
+        for node in workflow.nodes:
+            state = context.node_states.get(node.id)
+
+            # Skip completed, running, or failed nodes
+            if state and state.status in (
+                NodeStatus.COMPLETED,
+                NodeStatus.RUNNING,
+                NodeStatus.FAILED,
+                NodeStatus.SKIPPED,
+            ):
+                continue
+
+            # Check if this node's inputs are ready
+            incoming_nodes = set()
+            for source_id, edges in edge_map.items():
+                for edge in edges:
+                    if edge.target_node == node.id:
+                        incoming_nodes.add(source_id)
+
+            # If no incoming nodes, it's a start node
+            if not incoming_nodes:
+                return node
+
+            # Check if all incoming nodes are done
+            all_incoming_done = True
+            for source_id in incoming_nodes:
+                source_state = context.node_states.get(source_id)
+                if not source_state or source_state.status not in (NodeStatus.COMPLETED, NodeStatus.SKIPPED):
+                    all_incoming_done = False
+                    break
+
+            if all_incoming_done:
+                return node
+
+        return None
+
+    def _safe_serialize(self, data: Any) -> Any:
+        """Safely serialize data for logging"""
+        if data is None:
+            return None
+        if isinstance(data, (str, int, float, bool)):
+            return data
+        if isinstance(data, (list, tuple)):
+            return [self._safe_serialize(item) for item in data[:100]]  # Limit list size
+        if isinstance(data, dict):
+            result = {}
+            for key, value in list(data.items())[:50]:  # Limit dict size
+                result[str(key)] = self._safe_serialize(value)
+            return result
+        # For complex objects, try to convert to string
+        try:
+            return str(data)[:1000]  # Limit string length
+        except Exception:
+            return '<non-serializable>'
+
+    def get_execution_state(self, context: ExecutionContext, debug_state: DebugExecutionState) -> dict:
+        """Get current execution state for API response"""
+        node_states = {}
+        for node_id, state in context.node_states.items():
+            node_states[node_id] = {
+                'status': state.status.value,
+                'inputs': self._safe_serialize(state.inputs),
+                'outputs': self._safe_serialize(state.outputs),
+                'error': state.error,
+                'startTime': state.start_time.isoformat() if state.start_time else None,
+                'endTime': state.end_time.isoformat() if state.end_time else None,
+                'duration': int((state.end_time - state.start_time).total_seconds() * 1000)
+                if state.start_time and state.end_time
+                else None,
+            }
+
+        return {
+            'status': debug_state.status,
+            'current_node_id': debug_state.current_node_id,
+            'node_states': node_states,
+            'new_logs': debug_state.get_pending_logs(),
+            'error': context.error,
+        }

src/langbot/pkg/workflow/executor.py

@@ -1,4 +1,12 @@
-"""Workflow execution engine"""
+"""Workflow execution engine.
+
+This module contains the core workflow execution logic:
+- WorkflowExecutor: Main execution engine with control flow handling
+- ParallelExecutor: Parallel branch execution
+- LoopExecutor: Loop/iterator execution
+
+Debug execution support has been moved to the ``debug`` module.
+"""
 
 from __future__ import annotations
 
@@ -6,7 +14,6 @@ import ast
 import asyncio
 import logging
 import operator
-import traceback
 import uuid
 from datetime import datetime
 from typing import Any, Optional, TYPE_CHECKING
@@ -32,92 +39,6 @@ if TYPE_CHECKING:
 logger = logging.getLogger(__name__)
 
 
-class ExecutionLog:
-    """Execution log entry"""
-
-    def __init__(self, level: str, message: str, node_id: Optional[str] = None, data: Optional[dict] = None):
-        self.id = str(uuid.uuid4())
-        self.timestamp = datetime.now().isoformat()
-        self.level = level
-        self.message = message
-        self.node_id = node_id
-        self.data = data or {}
-
-    def to_dict(self) -> dict:
-        return {
-            'id': self.id,
-            'timestamp': self.timestamp,
-            'level': self.level,
-            'message': self.message,
-            'node_id': self.node_id,
-            'data': self.data,
-        }
-
-
-class DebugExecutionState:
-    """State for a debug execution"""
-
-    def __init__(self, execution_id: str, breakpoints: list[str] = None):
-        self.execution_id = execution_id
-        self.status: str = 'running'
-        self.is_paused: bool = False
-        self.is_stopped: bool = False
-        self.current_node_id: Optional[str] = None
-        self.breakpoints: set[str] = set(breakpoints or [])
-        self.logs: list[ExecutionLog] = []
-        self.pending_logs: list[ExecutionLog] = []
-        self._pause_event = asyncio.Event()
-        self._pause_event.set()  # Initially not paused
-        self._stop_event = asyncio.Event()
-
-    def add_log(self, level: str, message: str, node_id: str = None, data: dict = None):
-        """Add a log entry"""
-        log = ExecutionLog(level, message, node_id, data)
-        self.logs.append(log)
-        self.pending_logs.append(log)
-        logger.log(
-            getattr(logging, level.upper(), logging.INFO),
-            f'[Workflow Debug] {message}',
-            extra={'node_id': node_id, 'data': data},
-        )
-
-    def get_pending_logs(self) -> list[dict]:
-        """Get and clear pending logs"""
-        logs = [log.to_dict() for log in self.pending_logs]
-        self.pending_logs = []
-        return logs
-
-    def pause(self):
-        """Pause execution"""
-        self.is_paused = True
-        self._pause_event.clear()
-        self.add_log('info', 'Execution paused')
-
-    def resume(self):
-        """Resume execution"""
-        self.is_paused = False
-        self._pause_event.set()
-        self.add_log('info', 'Execution resumed')
-
-    def stop(self):
-        """Stop execution"""
-        self.is_stopped = True
-        self.status = 'cancelled'
-        self._stop_event.set()
-        self._pause_event.set()  # Release any pause
-        self.add_log('info', 'Execution stopped')
-
-    async def wait_if_paused(self):
-        """Wait if execution is paused"""
-        if self.is_paused:
-            self.add_log('info', 'Waiting for resume...')
-            await self._pause_event.wait()
-
-    def check_breakpoint(self, node_id: str) -> bool:
-        """Check if there's a breakpoint at the given node"""
-        return node_id in self.breakpoints
-
-
 # ─── Safe expression evaluator (replaces eval()) ─────────────────────
 # Uses Python's ast module to whitelist only comparison / boolean / arithmetic
 # operations.  No function calls, attribute access, or subscript injection.
@@ -465,9 +386,30 @@ class WorkflowExecutor:
             await self._persist_node_execution(node, node_state, context)
             return
 
+        # Check if node supports streaming (has execute_stream method and stream config is enabled)
+        use_streaming = hasattr(node_instance, 'execute_stream') and node.config.get('stream', False)
+
         # Execute with retries
         for attempt in range(max_retries + 1):
             try:
+                if use_streaming:
+                    # Streaming execution with aggregation and timeout
+                    aggregated_response = ''
+                    try:
+                        async with asyncio.timeout(300):  # 5 minute timeout for streaming
+                            async for chunk in node_instance.execute_stream(inputs, context):
+                                if chunk:
+                                    aggregated_response += chunk
+                    except asyncio.TimeoutError:
+                        logger.warning(f'Node {node.id} ({node.type}) streaming timed out, falling back to non-streaming')
+                        use_streaming = False
+                        outputs = await node_instance.execute(inputs, context)
+                    else:
+                        # Get response from context if set by execute_stream, otherwise use aggregated
+                        final_response = context.variables.pop('_last_llm_response', aggregated_response)
+                        outputs = {'response': final_response, 'usage': {'prompt_tokens': 0, 'completion_tokens': 0, 'total_tokens': 0}}
+                        logger.info(f'Node {node.id} ({node.type}) streaming completed, response length: {len(final_response)}')
+                else:
                     outputs = await node_instance.execute(inputs, context)
                 node_state.outputs = outputs
                 node_state.status = NodeStatus.COMPLETED
@@ -516,9 +458,25 @@ class WorkflowExecutor:
 
         # Get inputs from message context
         if context.message_context:
+            inputs['message'] = context.message_context.message_content
             inputs['message_content'] = context.message_context.message_content
             inputs['sender_id'] = context.message_context.sender_id
             inputs['platform'] = context.message_context.platform
+        else:
+            logger.warning(
+                f'[_resolve_inputs] node={node.id} ({node.type}): message_context is None!',
+                extra={
+                    'node_id': node.id,
+                    'node_type': node.type,
+                    'execution_id': context.execution_id,
+                    'variables_keys': list(context.variables.keys()) if context.variables else [],
+                },
+            )
+
+        # Log current inputs state after message_context processing
+        logger.debug(
+            f'[_resolve_inputs] node={node.id} after message_context: {list(inputs.keys())}',
+        )
 
         # Get inputs from node config that reference other nodes
         for key, value in node.config.items():
@@ -549,6 +507,22 @@ class WorkflowExecutor:
                 # Last resort: use the first available output
                 inputs[target_port] = next(iter(source_state.outputs.values()))
 
+        # Smart input mapping: if a node needs 'message' but received a different
+        # port name (e.g., 'content' from llm_call), copy the value to 'message'.
+        # This handles edge connection mismatches where the sender uses a different
+        # port name than what the receiver expects.
+        if 'message' not in inputs or inputs.get('message') is None:
+            for fallback_key in ('content', 'response', 'input', 'output', 'result', 'text'):
+                if fallback_key in inputs and inputs[fallback_key] is not None:
+                    inputs['message'] = inputs[fallback_key]
+                    logger.debug(
+                        f'[_resolve_inputs] node={node.id}: mapped {fallback_key} -> message',
+                    )
+                    break
+
+        logger.debug(
+            f'[_resolve_inputs] node={node.id} final inputs keys: {list(inputs.keys())}, message={repr(inputs.get("message", "<missing>")[:100] if isinstance(inputs.get("message"), str) else inputs.get("message"))}',
+        )
         return inputs
 
     async def _resolve_expression(self, expression: str, context: ExecutionContext) -> Any:
@@ -851,392 +825,3 @@ class LoopExecutor:
         return results
 
 
-class DebugWorkflowExecutor(WorkflowExecutor):
-    """
-    Debug-enabled workflow executor with step-by-step execution support.
-    Extends WorkflowExecutor with debugging capabilities.
-    """
-
-    # Class-level storage for active debug sessions
-    _debug_states: dict[str, DebugExecutionState] = {}
-
-    def __init__(self, ap: Optional['app.Application'] = None):
-        super().__init__(ap)
-
-    @classmethod
-    def get_debug_state(cls, execution_id: str) -> Optional[DebugExecutionState]:
-        """Get debug state for an execution"""
-        return cls._debug_states.get(execution_id)
-
-    @classmethod
-    def create_debug_state(cls, execution_id: str, breakpoints: list[str] = None) -> DebugExecutionState:
-        """Create a new debug state"""
-        state = DebugExecutionState(execution_id, breakpoints)
-        cls._debug_states[execution_id] = state
-        return state
-
-    @classmethod
-    def remove_debug_state(cls, execution_id: str):
-        """Remove debug state for an execution"""
-        cls._debug_states.pop(execution_id, None)
-
-    async def execute_debug(
-        self,
-        workflow: WorkflowDefinition,
-        context: ExecutionContext,
-        debug_state: DebugExecutionState,
-    ) -> ExecutionContext:
-        """
-        Execute a workflow in debug mode.
-
-        Args:
-            workflow: Workflow definition
-            context: Execution context
-            debug_state: Debug execution state
-
-        Returns:
-            Updated execution context
-        """
-        context.status = ExecutionStatus.RUNNING
-        context.start_time = datetime.now()
-        debug_state.add_log('info', f'Starting debug execution for workflow: {workflow.name}')
-
-        try:
-            # Build execution graph
-            node_map = {node.id: node for node in workflow.nodes}
-            edge_map = self._build_edge_map(workflow.edges)
-            self._edges = workflow.edges
-
-            # Initialize node states
-            for node in workflow.nodes:
-                if node.id not in context.node_states:
-                    context.node_states[node.id] = NodeState(node_id=node.id)
-
-            # Find start node(s)
-            start_nodes = self._find_start_nodes(workflow.nodes, workflow.edges)
-
-            if not start_nodes:
-                raise ValueError('No start nodes found in workflow')
-
-            debug_state.add_log('info', f'Found {len(start_nodes)} start node(s)')
-
-            # Execute from start nodes
-            for start_node in start_nodes:
-                if debug_state.is_stopped:
-                    break
-
-                await self._execute_debug_from_node(
-                    start_node, node_map, edge_map, context, debug_state, workflow.settings.max_retries
-                )
-
-            # Set final status
-            if debug_state.is_stopped:
-                context.status = ExecutionStatus.CANCELLED
-                debug_state.status = 'cancelled'
-            else:
-                all_completed = all(
-                    state.status in (NodeStatus.COMPLETED, NodeStatus.SKIPPED) for state in context.node_states.values()
-                )
-
-                if all_completed:
-                    context.status = ExecutionStatus.COMPLETED
-                    debug_state.status = 'completed'
-                    debug_state.add_log('info', 'Workflow execution completed successfully')
-                else:
-                    has_failed = any(state.status == NodeStatus.FAILED for state in context.node_states.values())
-                    if has_failed:
-                        context.status = ExecutionStatus.FAILED
-                        debug_state.status = 'error'
-
-        except Exception as e:
-            context.status = ExecutionStatus.FAILED
-            context.error = str(e)
-            debug_state.status = 'error'
-            debug_state.add_log('error', f'Workflow execution failed: {e}', data={'traceback': traceback.format_exc()})
-            logger.error(f'Debug workflow execution failed: {e}\n{traceback.format_exc()}')
-
-        finally:
-            context.end_time = datetime.now()
-
-        return context
-
-    async def _execute_debug_from_node(
-        self,
-        node: NodeDefinition,
-        node_map: dict[str, NodeDefinition],
-        edge_map: dict[str, list[EdgeDefinition]],
-        context: ExecutionContext,
-        debug_state: DebugExecutionState,
-        max_retries: int = 3,
-    ):
-        """Execute workflow from a node with debug support"""
-
-        # Check if stopped
-        if debug_state.is_stopped:
-            return
-
-        # Wait if paused
-        await debug_state.wait_if_paused()
-
-        # Check if should skip
-        if await self._should_skip_node(node, context):
-            if context.node_states[node.id].status == NodeStatus.SKIPPED:
-                debug_state.add_log('info', f'Skipping node: {node.id}', node_id=node.id)
-            return
-
-        # Check breakpoint
-        if debug_state.check_breakpoint(node.id):
-            debug_state.add_log('info', f'Hit breakpoint at node: {node.id}', node_id=node.id)
-            debug_state.pause()
-            await debug_state.wait_if_paused()
-
-        # Update current node
-        debug_state.current_node_id = node.id
-        debug_state.add_log('info', f'Executing node: {node.id} ({node.type})', node_id=node.id)
-
-        # Execute node
-        await self._execute_debug_node(node, context, debug_state, max_retries)
-
-        # Check if stopped or failed
-        if debug_state.is_stopped:
-            return
-        if context.node_states[node.id].status == NodeStatus.FAILED:
-            return
-
-        # Get outgoing edges
-        outgoing_edges = edge_map.get(node.id, [])
-
-        # Execute next nodes
-        for edge in outgoing_edges:
-            if debug_state.is_stopped:
-                break
-
-            target_node = node_map.get(edge.target_node)
-            if not target_node:
-                continue
-
-            # Check edge condition
-            if edge.condition:
-                condition_met = await self._evaluate_condition(edge.condition, context)
-                if not condition_met:
-                    debug_state.add_log('debug', f'Edge condition not met: {edge.condition}', node_id=node.id)
-                    continue
-
-            # Check if all inputs are ready
-            if await self._inputs_ready(target_node, edge_map, context):
-                await self._execute_debug_from_node(target_node, node_map, edge_map, context, debug_state, max_retries)
-
-    async def _execute_debug_node(
-        self, node: NodeDefinition, context: ExecutionContext, debug_state: DebugExecutionState, max_retries: int = 3
-    ):
-        """Execute a single node with debug logging"""
-
-        node_state = context.node_states[node.id]
-        node_state.status = NodeStatus.RUNNING
-        node_state.start_time = datetime.now()
-
-        # Get node instance (pass ap for access to services)
-        node_instance = self.registry.create_instance(node.type, node.id, node.config, ap=self.ap)
-
-        if not node_instance:
-            node_state.status = NodeStatus.FAILED
-            node_state.error = f'Unknown node type: {node.type}'
-            node_state.end_time = datetime.now()
-            debug_state.add_log('error', f'Unknown node type: {node.type}', node_id=node.id)
-            self._record_execution_step(node, node_state, context)
-            await self._persist_node_execution(node, node_state, context)
-            return
-
-        # Resolve inputs
-        inputs = await self._resolve_inputs(node, context)
-        node_state.inputs = inputs
-        debug_state.add_log(
-            'debug', 'Node inputs resolved', node_id=node.id, data={'inputs': self._safe_serialize(inputs)}
-        )
-
-        # Validate inputs
-        validation_errors = await node_instance.validate_inputs(inputs)
-        if validation_errors:
-            node_state.status = NodeStatus.FAILED
-            node_state.error = '; '.join(validation_errors)
-            node_state.end_time = datetime.now()
-            debug_state.add_log('error', f'Input validation failed: {node_state.error}', node_id=node.id)
-            self._record_execution_step(node, node_state, context)
-            await self._persist_node_execution(node, node_state, context)
-            return
-
-        # Execute with retries
-        for attempt in range(max_retries + 1):
-            if debug_state.is_stopped:
-                node_state.status = NodeStatus.FAILED
-                node_state.error = 'Execution stopped'
-                node_state.end_time = datetime.now()
-                break
-
-            try:
-                outputs = await node_instance.execute(inputs, context)
-                node_state.outputs = outputs
-                node_state.status = NodeStatus.COMPLETED
-                node_state.end_time = datetime.now()
-
-                duration_ms = int((node_state.end_time - node_state.start_time).total_seconds() * 1000)
-                debug_state.add_log(
-                    'info',
-                    f'Node completed in {duration_ms}ms',
-                    node_id=node.id,
-                    data={'outputs': self._safe_serialize(outputs), 'duration_ms': duration_ms},
-                )
-                break
-
-            except Exception as e:
-                node_state.retry_count = attempt + 1
-                debug_state.add_log(
-                    'warning', f'Node execution failed (attempt {attempt + 1}/{max_retries + 1}): {e}', node_id=node.id
-                )
-
-                if attempt < max_retries:
-                    await asyncio.sleep(1)
-                else:
-                    node_state.status = NodeStatus.FAILED
-                    node_state.error = str(e)
-                    node_state.end_time = datetime.now()
-                    debug_state.add_log(
-                        'error',
-                        f'Node failed after {max_retries + 1} attempts: {e}',
-                        node_id=node.id,
-                        data={'error': str(e), 'traceback': traceback.format_exc()},
-                    )
-
-        self._record_execution_step(node, node_state, context)
-        await self._persist_node_execution(node, node_state, context)
-
-    async def step_execute(
-        self,
-        workflow: WorkflowDefinition,
-        context: ExecutionContext,
-        debug_state: DebugExecutionState,
-    ) -> dict:
-        """
-        Execute one step (one node) in debug mode.
-
-        Returns:
-            Dict with node_id, node_state, and completed status
-        """
-        # Find next node to execute
-        next_node = self._find_next_executable_node(workflow, context)
-
-        if not next_node:
-            debug_state.status = 'completed'
-            return {'completed': True}
-
-        # Execute single node
-        debug_state.current_node_id = next_node.id
-        await self._execute_debug_node(next_node, context, debug_state, workflow.settings.max_retries)
-
-        node_state = context.node_states.get(next_node.id)
-
-        # Check if workflow is complete
-        all_done = all(
-            state.status in (NodeStatus.COMPLETED, NodeStatus.SKIPPED, NodeStatus.FAILED)
-            for state in context.node_states.values()
-        )
-
-        if all_done:
-            debug_state.status = 'completed'
-            context.status = ExecutionStatus.COMPLETED
-
-        return {
-            'node_id': next_node.id,
-            'node_state': {
-                'status': node_state.status.value if node_state else 'unknown',
-                'inputs': self._safe_serialize(node_state.inputs) if node_state else {},
-                'outputs': self._safe_serialize(node_state.outputs) if node_state else {},
-                'error': node_state.error if node_state else None,
-            },
-            'completed': all_done,
-        }
-
-    def _find_next_executable_node(
-        self, workflow: WorkflowDefinition, context: ExecutionContext
-    ) -> Optional[NodeDefinition]:
-        """Find the next node that can be executed"""
-        edge_map = self._build_edge_map(workflow.edges)
-
-        for node in workflow.nodes:
-            state = context.node_states.get(node.id)
-
-            # Skip completed, running, or failed nodes
-            if state and state.status in (
-                NodeStatus.COMPLETED,
-                NodeStatus.RUNNING,
-                NodeStatus.FAILED,
-                NodeStatus.SKIPPED,
-            ):
-                continue
-
-            # Check if this node's inputs are ready
-            incoming_nodes = set()
-            for source_id, edges in edge_map.items():
-                for edge in edges:
-                    if edge.target_node == node.id:
-                        incoming_nodes.add(source_id)
-
-            # If no incoming nodes, it's a start node
-            if not incoming_nodes:
-                return node
-
-            # Check if all incoming nodes are done
-            all_incoming_done = True
-            for source_id in incoming_nodes:
-                source_state = context.node_states.get(source_id)
-                if not source_state or source_state.status not in (NodeStatus.COMPLETED, NodeStatus.SKIPPED):
-                    all_incoming_done = False
-                    break
-
-            if all_incoming_done:
-                return node
-
-        return None
-
-    def _safe_serialize(self, data: Any) -> Any:
-        """Safely serialize data for logging"""
-        if data is None:
-            return None
-        if isinstance(data, (str, int, float, bool)):
-            return data
-        if isinstance(data, (list, tuple)):
-            return [self._safe_serialize(item) for item in data[:100]]  # Limit list size
-        if isinstance(data, dict):
-            result = {}
-            for key, value in list(data.items())[:50]:  # Limit dict size
-                result[str(key)] = self._safe_serialize(value)
-            return result
-        # For complex objects, try to convert to string
-        try:
-            return str(data)[:1000]  # Limit string length
-        except Exception:
-            return '<non-serializable>'
-
-    def get_execution_state(self, context: ExecutionContext, debug_state: DebugExecutionState) -> dict:
-        """Get current execution state for API response"""
-        node_states = {}
-        for node_id, state in context.node_states.items():
-            node_states[node_id] = {
-                'status': state.status.value,
-                'inputs': self._safe_serialize(state.inputs),
-                'outputs': self._safe_serialize(state.outputs),
-                'error': state.error,
-                'startTime': state.start_time.isoformat() if state.start_time else None,
-                'endTime': state.end_time.isoformat() if state.end_time else None,
-                'duration': int((state.end_time - state.start_time).total_seconds() * 1000)
-                if state.start_time and state.end_time
-                else None,
-            }
-
-        return {
-            'status': debug_state.status,
-            'current_node_id': debug_state.current_node_id,
-            'node_states': node_states,
-            'new_logs': debug_state.get_pending_logs(),
-            'error': context.error,
-        }

src/langbot/pkg/workflow/nodes/llm_call.py

@@ -2,17 +2,32 @@
 
 from __future__ import annotations
 
+import json
 import logging
 import re
-from typing import Any
+from typing import Any, AsyncGenerator
 
 import langbot_plugin.api.entities.builtin.provider.message as provider_message
+import langbot_plugin.api.entities.builtin.resource.tool as resource_tool
 
 from ..entities import ExecutionContext
 from ..node import WorkflowNode, workflow_node
 
 logger = logging.getLogger(__name__)
 
+# Pre-compiled regex patterns for CoT content removal (performance optimization)
+_THINK_PATTERNS = [
+    re.compile(r'<think>.*?</think>', re.DOTALL | re.IGNORECASE),
+    re.compile(r'<thought>.*?</thought>', re.DOTALL | re.IGNORECASE),
+    re.compile(r'<reasoning>.*?</reasoning>', re.DOTALL | re.IGNORECASE),
+    re.compile(r'<\u601d\u8003>.*?</\u601d\u8003>', re.DOTALL | re.IGNORECASE),
+    re.compile(r'<\u63a8\u7406>.*?</\u63a8\u7406>', re.DOTALL | re.IGNORECASE),
+]
+
+# Template variable regex
+_TEMPLATE_VAR_RE = re.compile(r'\{\{([^}]+)\}\}')
+
+
 @workflow_node('llm_call')
 class LLMCallNode(WorkflowNode):
     """LLM call node - invoke large language model"""
@@ -21,6 +36,10 @@ class LLMCallNode(WorkflowNode):
 
     def _resolve_template(self, template: str, inputs: dict[str, Any], context: ExecutionContext) -> str:
         """Resolve {{variable}} placeholders in a template string."""
+        if not template:
+            return ''
+
+        unresolved_vars = []
 
         def replacer(match: re.Match) -> str:
             expr = match.group(1).strip()
@@ -35,9 +54,121 @@ class LLMCallNode(WorkflowNode):
             if expr.startswith('message.') and context.message_context:
                 attr = expr[len('message.'):]
                 return str(getattr(context.message_context, attr, ''))
+            unresolved_vars.append(expr)
             return match.group(0)  # leave unresolved
 
-        return re.sub(r'\{\{([^}]+)\}\}', replacer, template)
+        result = _TEMPLATE_VAR_RE.sub(replacer, template)
+
+        # Log warning for unresolved variables
+        if unresolved_vars:
+            logger.warning(
+                f'LLM call node {self.node_id}: unresolved template variables: {unresolved_vars}'
+            )
+
+        return result
+
+    def _remove_think_content(self, text: str) -> str:
+        """Remove CoT (Chain of Thought) thinking content from response."""
+        if not text:
+            return text
+
+        result = text
+        for pattern in _THINK_PATTERNS:
+            result = pattern.sub('', result)
+
+        return result.strip()
+
+    def _apply_content_filter(self, text: str) -> tuple[str, bool, str]:
+        """Apply content safety filter to text.
+
+        Returns:
+            (filtered_text, is_blocked, user_notice)
+        """
+        if not text or not self.ap:
+            return text, False, ''
+
+        # Check if content filter is enabled
+        safety_config = getattr(self.ap, 'pipeline_cfg', None)
+        if not safety_config:
+            return text, False, ''
+
+        # Check sensitive words
+        sensitive_words = []
+        try:
+            if hasattr(self.ap, 'sensitive_meta') and hasattr(self.ap.sensitive_meta, 'data'):
+                sensitive_words = self.ap.sensitive_meta.data.get('words', [])
+        except Exception:
+            pass
+
+        if not sensitive_words:
+            return text, False, ''
+
+        found = False
+        filtered_text = text
+        for word in sensitive_words:
+            try:
+                matches = re.findall(word, filtered_text, re.IGNORECASE)
+                if matches:
+                    found = True
+                    mask_word = ''
+                    mask = '*'
+                    try:
+                        if hasattr(self.ap, 'sensitive_meta') and hasattr(self.ap.sensitive_meta, 'data'):
+                            mask_word = self.ap.sensitive_meta.data.get('mask_word', '')
+                            mask = self.ap.sensitive_meta.data.get('mask', '*')
+                    except Exception:
+                        pass
+
+                    for m in matches:
+                        if mask_word:
+                            filtered_text = filtered_text.replace(m, mask_word)
+                        else:
+                            filtered_text = filtered_text.replace(m, mask * len(m))
+            except re.error:
+                # Invalid regex pattern, skip
+                continue
+
+        if found:
+            return filtered_text, False, '消息中存在不合适的内容, 请修改'
+
+        return text, False, ''
+
+    def _parse_tools_config(self, tools_config: Any) -> list[dict]:
+        """Parse tools configuration from YAML config format."""
+        if not tools_config:
+            return []
+
+        # If it's already a list, return as-is
+        if isinstance(tools_config, list):
+            return tools_config
+
+        # If it's a string, try to parse as JSON
+        if isinstance(tools_config, str):
+            tools_config = tools_config.strip()
+            if not tools_config:
+                return []
+            try:
+                parsed = json.loads(tools_config)
+                if isinstance(parsed, list):
+                    return parsed
+            except json.JSONDecodeError:
+                logger.warning(f'Failed to parse tools config as JSON: {tools_config}')
+                return []
+
+        return []
+
+    def _build_system_prompt_with_format(self, base_prompt: str, output_format: str, json_schema: str) -> str:
+        """Build system prompt with output format instructions."""
+        prompt = base_prompt
+
+        if output_format == 'json':
+            prompt += '\n\nPlease respond in valid JSON format.'
+            if json_schema:
+                prompt += f'\nFollow this JSON schema:\n{json_schema}'
+        elif output_format == 'markdown':
+            prompt += '\n\nPlease respond in Markdown format.'
+
+        return prompt
 
     async def execute(self, inputs: dict[str, Any], context: ExecutionContext) -> dict[str, Any]:
         model_uuid = self.get_config('model', '')
@@ -45,11 +176,32 @@ class LLMCallNode(WorkflowNode):
             raise ValueError('No model configured for LLM call node')
 
         if not self.ap:
-            raise RuntimeError('Application instance not available — cannot call LLM')
+            raise RuntimeError('Application instance not available - cannot call LLM')
 
-        # Resolve prompts
-        system_prompt = self._resolve_template(self.get_config('system_prompt', ''), inputs, context)
-        user_prompt = self._resolve_template(self.get_config('user_prompt_template', '{{input}}'), inputs, context)
+        # Get error handling config
+        exception_handling = self.get_config('exception_handling', 'show-error')
+        failure_hint = self.get_config('failure_hint', 'Request failed.')
+        remove_think = self.get_config('remove_think', False)
+        track_function_calls = self.get_config('track_function_calls', False)
+
+        # Get output format and json_schema config
+        output_format = self.get_config('output_format', 'text')
+        json_schema = self.get_config('json_schema', '')
+
+        # Get tools config
+        enable_tools = self.get_config('enable_tools', False)
+        tools_config = self.get_config('tools', [])
+
+        # Resolve prompts - handle null user_prompt_template
+        system_prompt = self._resolve_template(self.get_config('system_prompt') or '', inputs, context)
+        user_prompt_template = self.get_config('user_prompt_template')
+        if user_prompt_template is None:
+            # Default to input if not set
+            user_prompt_template = '{{input}}'
+        user_prompt = self._resolve_template(user_prompt_template, inputs, context)
+
+        # Build system prompt with format instructions
+        system_prompt = self._build_system_prompt_with_format(system_prompt, output_format, json_schema)
 
         # Build messages
         messages: list[provider_message.Message] = []
@@ -69,30 +221,89 @@ class LLMCallNode(WorkflowNode):
         if max_tokens and int(max_tokens) > 0:
             extra_args['max_tokens'] = int(max_tokens)
 
-        # Invoke LLM
+        # Build tools list if enabled
+        funcs: list[resource_tool.LLMTool] | None = None
+        if enable_tools and tools_config:
+            try:
+                tool_names = self._parse_tools_config(tools_config)
+                if tool_names:
+                    all_tools = await self.ap.tool_mgr.get_tools()
+                    funcs = [t for t in all_tools if t.name in tool_names]
+                    if funcs:
+                        logger.info(f'LLM call node {self.node_id}: using tools: {[t.name for t in funcs]}')
+            except Exception as e:
+                logger.warning(f'LLM call node {self.node_id}: failed to load tools - {e}')
+                funcs = None
+
+        # Invoke LLM with error handling
         logger.info(f'LLM call node {self.node_id}: invoking model {model_uuid}')
+        try:
             result_message = await runtime_model.provider.invoke_llm(
                 query=None,
                 model=runtime_model,
                 messages=messages,
-            funcs=None,
+                funcs=funcs,
                 extra_args=extra_args,
             )
+        except Exception as e:
+            logger.warning(f'LLM call node {self.node_id}: request failed - {e}')
+
+            # Handle based on exception handling strategy
+            if exception_handling == 'show-error':
+                raise
+            elif exception_handling == 'show-hint':
+                return {
+                    'response': failure_hint,
+                    'usage': {
+                        'prompt_tokens': 0,
+                        'completion_tokens': 0,
+                        'total_tokens': 0,
+                    },
+                    'error': str(e),
+                    'error_hint_shown': True,
+                }
+            else:  # hide
+                return {
+                    'response': '',
+                    'usage': {
+                        'prompt_tokens': 0,
+                        'completion_tokens': 0,
+                        'total_tokens': 0,
+                    },
+                    'error': str(e),
+                }
 
         # Extract response text
         response_text = ''
         if isinstance(result_message.content, str):
             response_text = result_message.content
         elif isinstance(result_message.content, list):
-            # ContentElement list — concatenate text elements
             for elem in result_message.content:
                 if hasattr(elem, 'text') and elem.text:
                     response_text += elem.text
                 elif isinstance(elem, str):
                     response_text += elem
 
+        # Remove CoT (Chain of Thought) content if configured
+        if remove_think:
+            response_text = self._remove_think_content(response_text)
+
+        # Apply content safety filter
+        response_text, is_blocked, filter_notice = self._apply_content_filter(response_text)
+        if is_blocked:
+            logger.warning(f'LLM call node {self.node_id}: response blocked by content filter - {filter_notice}')
+            return {
+                'response': filter_notice,
+                'usage': usage,
+                'blocked_by_filter': True,
+            }
+
         # Extract usage info if available
-        usage = {'prompt_tokens': 0, 'completion_tokens': 0, 'total_tokens': 0}
+        usage = {
+            'prompt_tokens': 0,
+            'completion_tokens': 0,
+            'total_tokens': 0,
+        }
         if hasattr(result_message, 'usage') and result_message.usage:
             u = result_message.usage
             usage = {
@@ -108,7 +319,136 @@ class LLMCallNode(WorkflowNode):
                 'total_tokens': getattr(u, 'total_tokens', 0) or 0,
             }
 
-        return {
+        result: dict[str, Any] = {
             'response': response_text,
             'usage': usage,
         }
+
+        # Parse JSON output if format is json
+        if output_format == 'json' and response_text:
+            try:
+                result['parsed'] = json.loads(response_text)
+            except json.JSONDecodeError as e:
+                logger.warning(f'LLM call node {self.node_id}: failed to parse JSON response - {e}')
+                result['parsed'] = None
+                result['parse_error'] = str(e)
+
+        # Add function call tracking info if configured
+        if track_function_calls:
+            result['function_calls'] = []
+
+        return result
+
+    async def execute_stream(
+        self, inputs: dict[str, Any], context: ExecutionContext
+    ) -> AsyncGenerator[str, None]:
+        """Execute the LLM call with streaming output.
+
+        Yields chunks of response text as they arrive.
+        Falls back to non-streaming if streaming is not available.
+        """
+        model_uuid = self.get_config('model', '')
+        if not model_uuid:
+            raise ValueError('No model configured for LLM call node')
+
+        if not self.ap:
+            raise RuntimeError('Application instance not available - cannot call LLM')
+
+        remove_think = self.get_config('remove_think', False)
+        exception_handling = self.get_config('exception_handling', 'show-error')
+        failure_hint = self.get_config('failure_hint', 'Request failed.')
+
+        # Resolve prompts
+        system_prompt = self._resolve_template(self.get_config('system_prompt') or '', inputs, context)
+        user_prompt_template = self.get_config('user_prompt_template')
+        if user_prompt_template is None:
+            user_prompt_template = '{{input}}'
+        user_prompt = self._resolve_template(user_prompt_template, inputs, context)
+
+        # Build messages
+        messages: list[provider_message.Message] = []
+        if system_prompt:
+            messages.append(provider_message.Message(role='system', content=system_prompt))
+        messages.append(provider_message.Message(role='user', content=user_prompt))
+
+        # Get model
+        runtime_model = await self.ap.model_mgr.get_model_by_uuid(model_uuid)
+
+        # Build extra args
+        extra_args: dict[str, Any] = {}
+        temperature = self.get_config('temperature')
+        if temperature is not None:
+            extra_args['temperature'] = float(temperature)
+        max_tokens = self.get_config('max_tokens', 0)
+        if max_tokens and int(max_tokens) > 0:
+            extra_args['max_tokens'] = int(max_tokens)
+
+        logger.info(f'LLM call node {self.node_id}: streaming model {model_uuid}')
+
+        try:
+            # Try streaming first
+            stream = runtime_model.provider.invoke_llm_stream(
+                query=None,
+                model=runtime_model,
+                messages=messages,
+                funcs=None,
+                extra_args=extra_args,
+            )
+
+            full_response = ''
+            async for chunk in stream:
+                chunk_text = ''
+                if hasattr(chunk, 'content'):
+                    if isinstance(chunk.content, str):
+                        chunk_text = chunk.content
+                    elif isinstance(chunk.content, list):
+                        for elem in chunk.content:
+                            if hasattr(elem, 'text') and elem.text:
+                                chunk_text += elem.text
+                            elif isinstance(elem, str):
+                                chunk_text += elem
+
+                if chunk_text:
+                    if remove_think:
+                        chunk_text = self._remove_think_content(chunk_text)
+                    full_response += chunk_text
+                    yield chunk_text
+
+            # Store in context for downstream nodes
+            context.variables['_last_llm_response'] = full_response
+
+        except Exception as e:
+            logger.warning(f'LLM call node {self.node_id}: streaming failed, falling back - {e}')
+            # Fallback to non-streaming
+            try:
+                result_message = await runtime_model.provider.invoke_llm(
+                    query=None,
+                    model=runtime_model,
+                    messages=messages,
+                    funcs=None,
+                    extra_args=extra_args,
+                )
+                response_text = self._extract_response_text(result_message)
+                if remove_think:
+                    response_text = self._remove_think_content(response_text)
+                yield response_text
+                context.variables['_last_llm_response'] = response_text
+            except Exception as e2:
+                logger.error(f'LLM call node {self.node_id}: fallback also failed - {e2}')
+                if exception_handling == 'show-hint':
+                    yield failure_hint
+                elif exception_handling != 'hide':
+                    raise
+
+    def _extract_response_text(self, result_message: provider_message.Message) -> str:
+        """Extract response text from LLM result message."""
+        response_text = ''
+        if isinstance(result_message.content, str):
+            response_text = result_message.content
+        elif isinstance(result_message.content, list):
+            for elem in result_message.content:
+                if hasattr(elem, 'text') and elem.text:
+                    response_text += elem.text
+                elif isinstance(elem, str):
+                    response_text += elem
+        return response_text

src/langbot/templates/metadata/nodes/llm_call.yaml

@@ -153,3 +153,58 @@ config:
     description:
       en_US: Select tools that the model can use
       zh_Hans: 选择模型可以使用的工具
+
+  - name: exception_handling
+    type: select
+    required: true
+    default: show-hint
+    options:
+      - name: show-error
+        label:
+          en_US: Show Full Error
+          zh_Hans: 显示完整报错信息
+      - name: show-hint
+        label:
+          en_US: Show Failure Hint
+          zh_Hans: 仅文字提示
+      - name: hide
+        label:
+          en_US: Hide All
+          zh_Hans: 不显示任何异常信息
+    label:
+      en_US: Exception Handling Strategy
+      zh_Hans: 异常处理策略
+    description:
+      en_US: Controls how error messages are displayed to the user when an AI request fails
+      zh_Hans: 控制 AI 请求失败时向用户展示错误信息的方式
+
+  - name: failure_hint
+    type: string
+    required: false
+    default: 'Request failed.'
+    label:
+      en_US: Failure Hint Text
+      zh_Hans: 失败提示文本
+    description:
+      en_US: The text to display when a request fails. Only effective when Exception Handling Strategy is set to "Show Failure Hint"
+      zh_Hans: 请求失败时显示的提示文本，仅在异常处理策略设置为"仅文字提示"时生效
+
+  - name: remove_think
+    type: boolean
+    default: false
+    label:
+      en_US: Remove CoT
+      zh_Hans: 删除思维链
+    description:
+      en_US: 'If enabled, the model thinking content in the response will be automatically removed. Note: When using streaming response, removing CoT may cause the first token to wait for a long time.'
+      zh_Hans: '如果启用，将自动删除大模型回复中的模型思考内容。注意：当您使用流式响应时，删除思维链可能会导致首个 Token 的等待时间过长'
+
+  - name: track_function_calls
+    type: boolean
+    default: false
+    label:
+      en_US: Track Function Calls
+      zh_Hans: 跟踪函数调用
+    description:
+      en_US: If enabled, the Agent will output a hint to the user each time a tool is called
+      zh_Hans: 启用后，Agent 每次调用工具时都会输出一个提示给用户

src/langbot/templates/metadata/nodes/reply_message.yaml

@@ -13,6 +13,7 @@ description:
 inputs:
   - name: message
     type: string
+    required: false
     label:
       en_US: Message
       zh_Hans: 消息

web/src/app/home/workflows/components/workflow-editor/WorkflowEditorComponent.tsx

@@ -447,7 +447,7 @@ function WorkflowEditorInner() {
             panOnDrag={[1, 2]} // Middle click and right click to pan
             selectNodesOnDrag={false}
             defaultEdgeOptions={{
-              type: 'bezier',
+              type: 'default',
               animated: true,
               markerEnd: {
                 type: MarkerType.ArrowClosed,

web/src/app/home/workflows/store/useWorkflowStore.ts

@@ -257,7 +257,7 @@ export const useWorkflowStore = create<WorkflowState>((set, get) => ({
     const newEdge: WorkflowEdge = {
       ...connection,
       id: generateEdgeId(),
-      type: 'bezier',
+      type: 'default',
     } as WorkflowEdge;
 
     set((state) => ({
@@ -464,7 +464,7 @@ export const useWorkflowStore = create<WorkflowState>((set, get) => ({
       target: edge.target,
       sourceHandle: edge.source_port,
       targetHandle: edge.target_port,
-      type: 'bezier',
+      type: 'default',
       data: {
         label: edge.label,
         condition: edge.condition,