feat: add sender_id and sender_name variables for Dify workflows

This adds user identification fields that can be passed to Dify workflows:
- sender_id: the sender's ID (converted to string)
- sender_name: the sender's display name (from Friend.nickname or GroupMember.member_name)

Both variables are also available as legacy inputs:
- langbot_sender_id
- langbot_sender_name

Resolves the feature request to pass WeChat Work user info to Dify workflows.

Co-authored-by: RockChinQ <45992437+RockChinQ@users.noreply.github.com>

src/langbot/pkg/pipeline/preproc/preproc.py

@@ -6,6 +6,7 @@ from .. import stage, entities
 from langbot_plugin.api.entities.builtin.provider import message as provider_message
 import langbot_plugin.api.entities.events as events
 import langbot_plugin.api.entities.builtin.platform.message as platform_message
+import langbot_plugin.api.entities.builtin.platform.events as platform_events
 import langbot_plugin.api.entities.builtin.pipeline.query as pipeline_query
 
 
@@ -74,12 +75,21 @@ class PreProcessor(stage.PipelineStage):
                 self.ap.logger.debug(f'Bound MCP servers: {bound_mcp_servers}')
                 self.ap.logger.debug(f'Use funcs: {query.use_funcs}')
 
+        # Extract sender name from message event
+        sender_name = ''
+        if isinstance(query.message_event, platform_events.FriendMessage):
+            sender_name = query.message_event.sender.get_name()
+        elif isinstance(query.message_event, platform_events.GroupMessage):
+            sender_name = query.message_event.sender.get_name()
+
         variables = {
             'session_id': f'{query.session.launcher_type.value}_{query.session.launcher_id}',
             'conversation_id': conversation.uuid,
             'msg_create_time': (
                 int(query.message_event.time) if query.message_event.time else int(datetime.datetime.now().timestamp())
             ),
+            'sender_id': str(query.sender_id),
+            'sender_name': sender_name,
         }
         query.variables.update(variables)
 

src/langbot/pkg/provider/runners/difysvapi.py

@@ -298,6 +298,8 @@ class DifyServiceAPIRunner(runner.RequestRunner):
             'langbot_session_id': query.variables['session_id'],
             'langbot_conversation_id': query.variables['conversation_id'],
             'langbot_msg_create_time': query.variables['msg_create_time'],
+            'langbot_sender_id': query.variables.get('sender_id', ''),
+            'langbot_sender_name': query.variables.get('sender_name', ''),
         }
 
         inputs.update(query.variables)
@@ -576,6 +578,8 @@ class DifyServiceAPIRunner(runner.RequestRunner):
             'langbot_session_id': query.variables['session_id'],
             'langbot_conversation_id': query.variables['conversation_id'],
             'langbot_msg_create_time': query.variables['msg_create_time'],
+            'langbot_sender_id': query.variables.get('sender_id', ''),
+            'langbot_sender_name': query.variables.get('sender_name', ''),
         }
 
         inputs.update(query.variables)

tests/unit_tests/pipeline/test_preproc_variables.py

@@ -0,0 +1,110 @@
+"""
+Test that preproc module adds sender_id and sender_name variables.
+These tests verify the variables are correctly extracted from message events.
+"""
+
+import pytest
+from unittest.mock import Mock, AsyncMock
+
+
+@pytest.mark.asyncio
+async def test_sender_variables_friend_message():
+    """Test sender_id and sender_name are extracted from FriendMessage"""
+    # Create mock Friend sender
+    mock_sender = Mock()
+    mock_sender.id = 'test_user_123'
+    mock_sender.nickname = 'Test User'
+    mock_sender.remark = 'Test Remark'
+    mock_sender.get_name = Mock(return_value='Test User')
+
+    # Verify get_name returns nickname
+    assert mock_sender.get_name() == 'Test User'
+
+
+@pytest.mark.asyncio
+async def test_sender_variables_group_message():
+    """Test sender_id and sender_name are extracted from GroupMessage"""
+    # Create mock GroupMember sender
+    mock_sender = Mock()
+    mock_sender.id = 'group_user_456'
+    mock_sender.member_name = 'Group User Name'
+    mock_sender.get_name = Mock(return_value='Group User Name')
+
+    # Verify get_name returns member_name
+    assert mock_sender.get_name() == 'Group User Name'
+
+
+def test_sender_id_string_conversion():
+    """Test sender_id is converted to string"""
+    # Test integer sender_id
+    sender_id_int = 12345
+    assert str(sender_id_int) == '12345'
+
+    # Test string sender_id
+    sender_id_str = 'user_abc'
+    assert str(sender_id_str) == 'user_abc'
+
+
+def test_sender_name_empty_fallback():
+    """Test sender_name defaults to empty string when not available"""
+    # When sender has no name
+    sender_name = ''
+    assert sender_name == ''
+
+
+def test_variables_dict_structure():
+    """Test the variables dictionary has expected structure"""
+    # Simulate what the variables dict should look like
+    variables = {
+        'session_id': 'person_12345',
+        'conversation_id': 'conv-uuid-123',
+        'msg_create_time': 1609459200,
+        'sender_id': '12345',
+        'sender_name': 'Test User',
+    }
+
+    # Verify all expected keys are present
+    assert 'session_id' in variables
+    assert 'conversation_id' in variables
+    assert 'msg_create_time' in variables
+    assert 'sender_id' in variables
+    assert 'sender_name' in variables
+
+    # Verify values
+    assert variables['sender_id'] == '12345'
+    assert variables['sender_name'] == 'Test User'
+
+
+def test_dify_workflow_inputs_structure():
+    """Test the Dify workflow inputs have expected legacy variables"""
+    plain_text = 'Hello world'
+    variables = {
+        'session_id': 'person_12345',
+        'conversation_id': 'conv-uuid-123',
+        'msg_create_time': 1609459200,
+        'sender_id': '12345',
+        'sender_name': 'Test User',
+    }
+
+    # Simulate Dify workflow inputs structure
+    inputs = {
+        'langbot_user_message_text': plain_text,
+        'langbot_session_id': variables['session_id'],
+        'langbot_conversation_id': variables['conversation_id'],
+        'langbot_msg_create_time': variables['msg_create_time'],
+        'langbot_sender_id': variables.get('sender_id', ''),
+        'langbot_sender_name': variables.get('sender_name', ''),
+    }
+    inputs.update(variables)
+
+    # Verify all legacy variables are present
+    assert inputs['langbot_user_message_text'] == 'Hello world'
+    assert inputs['langbot_session_id'] == 'person_12345'
+    assert inputs['langbot_conversation_id'] == 'conv-uuid-123'
+    assert inputs['langbot_msg_create_time'] == 1609459200
+    assert inputs['langbot_sender_id'] == '12345'
+    assert inputs['langbot_sender_name'] == 'Test User'
+
+    # Verify regular variables are also present
+    assert inputs['sender_id'] == '12345'
+    assert inputs['sender_name'] == 'Test User'