dify/api/dify_graph/nodes/agent/agent_node.py

from __future__ import annotations

import json
from collections.abc import Generator, Mapping, Sequence
from typing import TYPE_CHECKING, Any, cast

from packaging.version import Version
from pydantic import ValidationError
from sqlalchemy import select
from sqlalchemy.orm import Session

from core.agent.entities import AgentToolEntity
from core.agent.plugin_entities import AgentStrategyParameter
from core.memory.token_buffer_memory import TokenBufferMemory
from core.model_manager import ModelInstance, ModelManager
from core.provider_manager import ProviderManager
from core.tools.entities.tool_entities import (
    ToolIdentity,
    ToolInvokeMessage,
    ToolParameter,
    ToolProviderType,
)
from core.tools.tool_manager import ToolManager
from core.tools.utils.message_transformer import ToolFileMessageTransformer
from dify_graph.enums import (
    NodeType,
    SystemVariableKey,
    WorkflowNodeExecutionMetadataKey,
    WorkflowNodeExecutionStatus,
)
from dify_graph.file import File, FileTransferMethod
from dify_graph.model_runtime.entities.llm_entities import LLMUsage, LLMUsageMetadata
from dify_graph.model_runtime.entities.model_entities import AIModelEntity, ModelType
from dify_graph.model_runtime.utils.encoders import jsonable_encoder
from dify_graph.node_events import (
    AgentLogEvent,
    NodeEventBase,
    NodeRunResult,
    StreamChunkEvent,
    StreamCompletedEvent,
)
from dify_graph.nodes.agent.entities import AgentNodeData, AgentOldVersionModelFeatures, ParamsAutoGenerated
from dify_graph.nodes.base.node import Node
from dify_graph.nodes.base.variable_template_parser import VariableTemplateParser
from dify_graph.runtime import VariablePool
from dify_graph.variables.segments import ArrayFileSegment, StringSegment
from extensions.ext_database import db
from factories import file_factory
from factories.agent_factory import get_plugin_agent_strategy
from models import ToolFile
from models.model import Conversation
from services.tools.builtin_tools_manage_service import BuiltinToolManageService

from .exc import (
    AgentInputTypeError,
    AgentInvocationError,
    AgentMessageTransformError,
    AgentNodeError,
    AgentVariableNotFoundError,
    AgentVariableTypeError,
    ToolFileNotFoundError,
)

if TYPE_CHECKING:
    from core.agent.strategy.plugin import PluginAgentStrategy
    from core.plugin.entities.request import InvokeCredentials


class AgentNode(Node[AgentNodeData]):
    """
    Agent Node
    """

    node_type = NodeType.AGENT

    @classmethod
    def version(cls) -> str:
        return "1"

    def _run(self) -> Generator[NodeEventBase, None, None]:
        from core.plugin.impl.exc import PluginDaemonClientSideError

        try:
            strategy = get_plugin_agent_strategy(
                tenant_id=self.tenant_id,
                agent_strategy_provider_name=self.node_data.agent_strategy_provider_name,
                agent_strategy_name=self.node_data.agent_strategy_name,
            )
        except Exception as e:
            yield StreamCompletedEvent(
                node_run_result=NodeRunResult(
                    status=WorkflowNodeExecutionStatus.FAILED,
                    inputs={},
                    error=f"Failed to get agent strategy: {str(e)}",
                ),
            )
            return

        agent_parameters = strategy.get_parameters()

        # get parameters
        parameters = self._generate_agent_parameters(
            agent_parameters=agent_parameters,
            variable_pool=self.graph_runtime_state.variable_pool,
            node_data=self.node_data,
            strategy=strategy,
        )
        parameters_for_log = self._generate_agent_parameters(
            agent_parameters=agent_parameters,
            variable_pool=self.graph_runtime_state.variable_pool,
            node_data=self.node_data,
            for_log=True,
            strategy=strategy,
        )
        credentials = self._generate_credentials(parameters=parameters)

        # get conversation id
        conversation_id = self.graph_runtime_state.variable_pool.get(["sys", SystemVariableKey.CONVERSATION_ID])

        try:
            message_stream = strategy.invoke(
                params=parameters,
                user_id=self.user_id,
                app_id=self.app_id,
                conversation_id=conversation_id.text if conversation_id else None,
                credentials=credentials,
            )
        except Exception as e:
            error = AgentInvocationError(f"Failed to invoke agent: {str(e)}", original_error=e)
            yield StreamCompletedEvent(
                node_run_result=NodeRunResult(
                    status=WorkflowNodeExecutionStatus.FAILED,
                    inputs=parameters_for_log,
                    error=str(error),
                )
            )
            return

        try:
            yield from self._transform_message(
                messages=message_stream,
                tool_info={
                    "icon": self.agent_strategy_icon,
                    "agent_strategy": self.node_data.agent_strategy_name,
                },
                parameters_for_log=parameters_for_log,
                user_id=self.user_id,
                tenant_id=self.tenant_id,
                node_type=self.node_type,
                node_id=self._node_id,
                node_execution_id=self.id,
            )
        except PluginDaemonClientSideError as e:
            transform_error = AgentMessageTransformError(
                f"Failed to transform agent message: {str(e)}", original_error=e
            )
            yield StreamCompletedEvent(
                node_run_result=NodeRunResult(
                    status=WorkflowNodeExecutionStatus.FAILED,
                    inputs=parameters_for_log,
                    error=str(transform_error),
                )
            )

    def _generate_agent_parameters(
        self,
        *,
        agent_parameters: Sequence[AgentStrategyParameter],
        variable_pool: VariablePool,
        node_data: AgentNodeData,
        for_log: bool = False,
        strategy: PluginAgentStrategy,
    ) -> dict[str, Any]:
        """
        Generate parameters based on the given tool parameters, variable pool, and node data.

        Args:
            agent_parameters (Sequence[AgentParameter]): The list of agent parameters.
            variable_pool (VariablePool): The variable pool containing the variables.
            node_data (AgentNodeData): The data associated with the agent node.

        Returns:
            Mapping[str, Any]: A dictionary containing the generated parameters.

        """
        agent_parameters_dictionary = {parameter.name: parameter for parameter in agent_parameters}

        result: dict[str, Any] = {}
        for parameter_name in node_data.agent_parameters:
            parameter = agent_parameters_dictionary.get(parameter_name)
            if not parameter:
                result[parameter_name] = None
                continue
            agent_input = node_data.agent_parameters[parameter_name]
            match agent_input.type:
                case "variable":
                    variable = variable_pool.get(agent_input.value)  # type: ignore
                    if variable is None:
                        raise AgentVariableNotFoundError(str(agent_input.value))
                    parameter_value = variable.value
                case "mixed" | "constant":
                    # variable_pool.convert_template expects a string template,
                    # but if passing a dict, convert to JSON string first before rendering
                    try:
                        if not isinstance(agent_input.value, str):
                            parameter_value = json.dumps(agent_input.value, ensure_ascii=False)
                        else:
                            parameter_value = str(agent_input.value)
                    except TypeError:
                        parameter_value = str(agent_input.value)
                    segment_group = variable_pool.convert_template(parameter_value)
                    parameter_value = segment_group.log if for_log else segment_group.text
                    # variable_pool.convert_template returns a string,
                    # so we need to convert it back to a dictionary
                    try:
                        if not isinstance(agent_input.value, str):
                            parameter_value = json.loads(parameter_value)
                    except json.JSONDecodeError:
                        parameter_value = parameter_value
                case _:
                    raise AgentInputTypeError(agent_input.type)
            value = parameter_value
            if parameter.type == "array[tools]":
                value = cast(list[dict[str, Any]], value)
                value = [tool for tool in value if tool.get("enabled", False)]
                value = self._filter_mcp_type_tool(strategy, value)
                for tool in value:
                    if "schemas" in tool:
                        tool.pop("schemas")
                    parameters = tool.get("parameters", {})
                    if all(isinstance(v, dict) for _, v in parameters.items()):
                        params = {}
                        for key, param in parameters.items():
                            if param.get("auto", ParamsAutoGenerated.OPEN) in (
                                ParamsAutoGenerated.CLOSE,
                                0,
                            ):
                                value_param = param.get("value", {})
                                if value_param and value_param.get("type", "") == "variable":
                                    variable_selector = value_param.get("value")
                                    if not variable_selector:
                                        raise ValueError("Variable selector is missing for a variable-type parameter.")

                                    variable = variable_pool.get(variable_selector)
                                    if variable is None:
                                        raise AgentVariableNotFoundError(str(variable_selector))

                                    params[key] = variable.value
                                else:
                                    params[key] = value_param.get("value", "") if value_param is not None else None
                            else:
                                params[key] = None
                        parameters = params
                    tool["settings"] = {k: v.get("value", None) for k, v in tool.get("settings", {}).items()}
                    tool["parameters"] = parameters

            if not for_log:
                if parameter.type == "array[tools]":
                    value = cast(list[dict[str, Any]], value)
                    tool_value = []
                    for tool in value:
                        provider_type = ToolProviderType(tool.get("type", ToolProviderType.BUILT_IN))
                        setting_params = tool.get("settings", {})
                        parameters = tool.get("parameters", {})
                        manual_input_params = [key for key, value in parameters.items() if value is not None]

                        parameters = {**parameters, **setting_params}
                        entity = AgentToolEntity(
                            provider_id=tool.get("provider_name", ""),
                            provider_type=provider_type,
                            tool_name=tool.get("tool_name", ""),
                            tool_parameters=parameters,
                            plugin_unique_identifier=tool.get("plugin_unique_identifier", None),
                            credential_id=tool.get("credential_id", None),
                        )

                        extra = tool.get("extra", {})

                        # This is an issue that caused problems before.
                        # Logically, we shouldn't use the node_data.version field for judgment
                        # But for backward compatibility with historical data
                        # this version field judgment is still preserved here.
                        runtime_variable_pool: VariablePool | None = None
                        if node_data.version != "1" or node_data.tool_node_version is not None:
                            runtime_variable_pool = variable_pool
                        tool_runtime = ToolManager.get_agent_tool_runtime(
                            self.tenant_id, self.app_id, entity, self.invoke_from, runtime_variable_pool
                        )
                        if tool_runtime.entity.description:
                            tool_runtime.entity.description.llm = (
                                extra.get("description", "") or tool_runtime.entity.description.llm
                            )
                        for tool_runtime_params in tool_runtime.entity.parameters:
                            tool_runtime_params.form = (
                                ToolParameter.ToolParameterForm.FORM
                                if tool_runtime_params.name in manual_input_params
                                else tool_runtime_params.form
                            )
                        manual_input_value = {}
                        if tool_runtime.entity.parameters:
                            manual_input_value = {
                                key: value for key, value in parameters.items() if key in manual_input_params
                            }
                        runtime_parameters = {
                            **tool_runtime.runtime.runtime_parameters,
                            **manual_input_value,
                        }
                        tool_value.append(
                            {
                                **tool_runtime.entity.model_dump(mode="json"),
                                "runtime_parameters": runtime_parameters,
                                "credential_id": tool.get("credential_id", None),
                                "provider_type": provider_type.value,
                            }
                        )
                    value = tool_value
                if parameter.type == AgentStrategyParameter.AgentStrategyParameterType.MODEL_SELECTOR:
                    value = cast(dict[str, Any], value)
                    model_instance, model_schema = self._fetch_model(value)
                    # memory config
                    history_prompt_messages = []
                    if node_data.memory:
                        memory = self._fetch_memory(model_instance)
                        if memory:
                            prompt_messages = memory.get_history_prompt_messages(
                                message_limit=node_data.memory.window.size or None
                            )
                            history_prompt_messages = [
                                prompt_message.model_dump(mode="json") for prompt_message in prompt_messages
                            ]
                    value["history_prompt_messages"] = history_prompt_messages
                    if model_schema:
                        # remove structured output feature to support old version agent plugin
                        model_schema = self._remove_unsupported_model_features_for_old_version(model_schema)
                        value["entity"] = model_schema.model_dump(mode="json")
                    else:
                        value["entity"] = None
            result[parameter_name] = value

        return result

    def _generate_credentials(
        self,
        parameters: dict[str, Any],
    ) -> InvokeCredentials:
        """
        Generate credentials based on the given agent parameters.
        """
        from core.plugin.entities.request import InvokeCredentials

        credentials = InvokeCredentials()

        # generate credentials for tools selector
        credentials.tool_credentials = {}
        for tool in parameters.get("tools", []):
            if tool.get("credential_id"):
                try:
                    identity = ToolIdentity.model_validate(tool.get("identity", {}))
                    credentials.tool_credentials[identity.provider] = tool.get("credential_id", None)
                except ValidationError:
                    continue
        return credentials

    @classmethod
    def _extract_variable_selector_to_variable_mapping(
        cls,
        *,
        graph_config: Mapping[str, Any],
        node_id: str,
        node_data: Mapping[str, Any],
    ) -> Mapping[str, Sequence[str]]:
        # Create typed NodeData from dict
        typed_node_data = AgentNodeData.model_validate(node_data)

        result: dict[str, Any] = {}
        for parameter_name in typed_node_data.agent_parameters:
            input = typed_node_data.agent_parameters[parameter_name]
            match input.type:
                case "mixed" | "constant":
                    selectors = VariableTemplateParser(str(input.value)).extract_variable_selectors()
                    for selector in selectors:
                        result[selector.variable] = selector.value_selector
                case "variable":
                    result[parameter_name] = input.value

        result = {node_id + "." + key: value for key, value in result.items()}

        return result

    @property
    def agent_strategy_icon(self) -> str | None:
        """
        Get agent strategy icon
        :return:
        """
        from core.plugin.impl.plugin import PluginInstaller

        manager = PluginInstaller()
        plugins = manager.list_plugins(self.tenant_id)
        try:
            current_plugin = next(
                plugin
                for plugin in plugins
                if f"{plugin.plugin_id}/{plugin.name}" == self.node_data.agent_strategy_provider_name
            )
            icon = current_plugin.declaration.icon
        except StopIteration:
            icon = None
        return icon

    def _fetch_memory(self, model_instance: ModelInstance) -> TokenBufferMemory | None:
        # get conversation id
        conversation_id_variable = self.graph_runtime_state.variable_pool.get(
            ["sys", SystemVariableKey.CONVERSATION_ID]
        )
        if not isinstance(conversation_id_variable, StringSegment):
            return None
        conversation_id = conversation_id_variable.value

        with Session(db.engine, expire_on_commit=False) as session:
            stmt = select(Conversation).where(Conversation.app_id == self.app_id, Conversation.id == conversation_id)
            conversation = session.scalar(stmt)

            if not conversation:
                return None

        memory = TokenBufferMemory(conversation=conversation, model_instance=model_instance)

        return memory

    def _fetch_model(self, value: dict[str, Any]) -> tuple[ModelInstance, AIModelEntity | None]:
        provider_manager = ProviderManager()
        provider_model_bundle = provider_manager.get_provider_model_bundle(
            tenant_id=self.tenant_id, provider=value.get("provider", ""), model_type=ModelType.LLM
        )
        model_name = value.get("model", "")
        model_credentials = provider_model_bundle.configuration.get_current_credentials(
            model_type=ModelType.LLM, model=model_name
        )
        provider_name = provider_model_bundle.configuration.provider.provider
        model_type_instance = provider_model_bundle.model_type_instance
        model_instance = ModelManager().get_model_instance(
            tenant_id=self.tenant_id,
            provider=provider_name,
            model_type=ModelType(value.get("model_type", "")),
            model=model_name,
        )
        model_schema = model_type_instance.get_model_schema(model_name, model_credentials)
        return model_instance, model_schema

    def _remove_unsupported_model_features_for_old_version(self, model_schema: AIModelEntity) -> AIModelEntity:
        if model_schema.features:
            for feature in model_schema.features[:]:  # Create a copy to safely modify during iteration
                try:
                    AgentOldVersionModelFeatures(feature.value)  # Try to create enum member from value
                except ValueError:
                    model_schema.features.remove(feature)
        return model_schema

    def _filter_mcp_type_tool(self, strategy: PluginAgentStrategy, tools: list[dict[str, Any]]) -> list[dict[str, Any]]:
        """
        Filter MCP type tool
        :param strategy: plugin agent strategy
        :param tool: tool
        :return: filtered tool dict
        """
        meta_version = strategy.meta_version
        if meta_version and Version(meta_version) > Version("0.0.1"):
            return tools
        else:
            return [tool for tool in tools if tool.get("type") != ToolProviderType.MCP]

    def _transform_message(
        self,
        messages: Generator[ToolInvokeMessage, None, None],
        tool_info: Mapping[str, Any],
        parameters_for_log: dict[str, Any],
        user_id: str,
        tenant_id: str,
        node_type: NodeType,
        node_id: str,
        node_execution_id: str,
    ) -> Generator[NodeEventBase, None, None]:
        """
        Convert ToolInvokeMessages into tuple[plain_text, files]
        """
        # transform message and handle file storage
        from core.plugin.impl.plugin import PluginInstaller

        message_stream = ToolFileMessageTransformer.transform_tool_invoke_messages(
            messages=messages,
            user_id=user_id,
            tenant_id=tenant_id,
            conversation_id=None,
        )

        text = ""
        files: list[File] = []
        json_list: list[dict | list] = []

        agent_logs: list[AgentLogEvent] = []
        agent_execution_metadata: Mapping[WorkflowNodeExecutionMetadataKey, Any] = {}
        llm_usage = LLMUsage.empty_usage()
        variables: dict[str, Any] = {}

        for message in message_stream:
            if message.type in {
                ToolInvokeMessage.MessageType.IMAGE_LINK,
                ToolInvokeMessage.MessageType.BINARY_LINK,
                ToolInvokeMessage.MessageType.IMAGE,
            }:
                assert isinstance(message.message, ToolInvokeMessage.TextMessage)

                url = message.message.text
                if message.meta:
                    transfer_method = message.meta.get("transfer_method", FileTransferMethod.TOOL_FILE)
                else:
                    transfer_method = FileTransferMethod.TOOL_FILE

                tool_file_id = str(url).split("/")[-1].split(".")[0]

                with Session(db.engine) as session:
                    stmt = select(ToolFile).where(ToolFile.id == tool_file_id)
                    tool_file = session.scalar(stmt)
                    if tool_file is None:
                        raise ToolFileNotFoundError(tool_file_id)

                mapping = {
                    "tool_file_id": tool_file_id,
                    "type": file_factory.get_file_type_by_mime_type(tool_file.mimetype),
                    "transfer_method": transfer_method,
                    "url": url,
                }
                file = file_factory.build_from_mapping(
                    mapping=mapping,
                    tenant_id=tenant_id,
                )
                files.append(file)
            elif message.type == ToolInvokeMessage.MessageType.BLOB:
                # get tool file id
                assert isinstance(message.message, ToolInvokeMessage.TextMessage)
                assert message.meta

                tool_file_id = message.message.text.split("/")[-1].split(".")[0]
                with Session(db.engine) as session:
                    stmt = select(ToolFile).where(ToolFile.id == tool_file_id)
                    tool_file = session.scalar(stmt)
                    if tool_file is None:
                        raise ToolFileNotFoundError(tool_file_id)

                mapping = {
                    "tool_file_id": tool_file_id,
                    "transfer_method": FileTransferMethod.TOOL_FILE,
                }

                files.append(
                    file_factory.build_from_mapping(
                        mapping=mapping,
                        tenant_id=tenant_id,
                    )
                )
            elif message.type == ToolInvokeMessage.MessageType.TEXT:
                assert isinstance(message.message, ToolInvokeMessage.TextMessage)
                text += message.message.text
                yield StreamChunkEvent(
                    selector=[node_id, "text"],
                    chunk=message.message.text,
                    is_final=False,
                )
            elif message.type == ToolInvokeMessage.MessageType.JSON:
                assert isinstance(message.message, ToolInvokeMessage.JsonMessage)
                if node_type == NodeType.AGENT:
                    if isinstance(message.message.json_object, dict):
                        msg_metadata: dict[str, Any] = message.message.json_object.pop("execution_metadata", {})
                        llm_usage = LLMUsage.from_metadata(cast(LLMUsageMetadata, msg_metadata))
                        agent_execution_metadata = {
                            WorkflowNodeExecutionMetadataKey(key): value
                            for key, value in msg_metadata.items()
                            if key in WorkflowNodeExecutionMetadataKey.__members__.values()
                        }
                    else:
                        msg_metadata = {}
                        llm_usage = LLMUsage.empty_usage()
                        agent_execution_metadata = {}
                if message.message.json_object:
                    json_list.append(message.message.json_object)
            elif message.type == ToolInvokeMessage.MessageType.LINK:
                assert isinstance(message.message, ToolInvokeMessage.TextMessage)
                stream_text = f"Link: {message.message.text}\n"
                text += stream_text
                yield StreamChunkEvent(
                    selector=[node_id, "text"],
                    chunk=stream_text,
                    is_final=False,
                )
            elif message.type == ToolInvokeMessage.MessageType.VARIABLE:
                assert isinstance(message.message, ToolInvokeMessage.VariableMessage)
                variable_name = message.message.variable_name
                variable_value = message.message.variable_value
                if message.message.stream:
                    if not isinstance(variable_value, str):
                        raise AgentVariableTypeError(
                            "When 'stream' is True, 'variable_value' must be a string.",
                            variable_name=variable_name,
                            expected_type="str",
                            actual_type=type(variable_value).__name__,
                        )
                    if variable_name not in variables:
                        variables[variable_name] = ""
                    variables[variable_name] += variable_value

                    yield StreamChunkEvent(
                        selector=[node_id, variable_name],
                        chunk=variable_value,
                        is_final=False,
                    )
                else:
                    variables[variable_name] = variable_value
            elif message.type == ToolInvokeMessage.MessageType.FILE:
                assert message.meta is not None
                assert isinstance(message.meta, dict)
                # Validate that meta contains a 'file' key
                if "file" not in message.meta:
                    raise AgentNodeError("File message is missing 'file' key in meta")

                # Validate that the file is an instance of File
                if not isinstance(message.meta["file"], File):
                    raise AgentNodeError(f"Expected File object but got {type(message.meta['file']).__name__}")
                files.append(message.meta["file"])
            elif message.type == ToolInvokeMessage.MessageType.LOG:
                assert isinstance(message.message, ToolInvokeMessage.LogMessage)
                if message.message.metadata:
                    icon = tool_info.get("icon", "")
                    dict_metadata = dict(message.message.metadata)
                    if dict_metadata.get("provider"):
                        manager = PluginInstaller()
                        plugins = manager.list_plugins(tenant_id)
                        try:
                            current_plugin = next(
                                plugin
                                for plugin in plugins
                                if f"{plugin.plugin_id}/{plugin.name}" == dict_metadata["provider"]
                            )
                            icon = current_plugin.declaration.icon
                        except StopIteration:
                            pass
                        icon_dark = None
                        try:
                            builtin_tool = next(
                                provider
                                for provider in BuiltinToolManageService.list_builtin_tools(
                                    user_id,
                                    tenant_id,
                                )
                                if provider.name == dict_metadata["provider"]
                            )
                            icon = builtin_tool.icon
                            icon_dark = builtin_tool.icon_dark
                        except StopIteration:
                            pass

                        dict_metadata["icon"] = icon
                        dict_metadata["icon_dark"] = icon_dark
                        message.message.metadata = dict_metadata
                agent_log = AgentLogEvent(
                    message_id=message.message.id,
                    node_execution_id=node_execution_id,
                    parent_id=message.message.parent_id,
                    error=message.message.error,
                    status=message.message.status.value,
                    data=message.message.data,
                    label=message.message.label,
                    metadata=message.message.metadata,
                    node_id=node_id,
                )

                # check if the agent log is already in the list
                for log in agent_logs:
                    if log.message_id == agent_log.message_id:
                        # update the log
                        log.data = agent_log.data
                        log.status = agent_log.status
                        log.error = agent_log.error
                        log.label = agent_log.label
                        log.metadata = agent_log.metadata
                        break
                else:
                    agent_logs.append(agent_log)

                yield agent_log

        # Add agent_logs to outputs['json'] to ensure frontend can access thinking process
        json_output: list[dict[str, Any] | list[Any]] = []

        # Step 1: append each agent log as its own dict.
        if agent_logs:
            for log in agent_logs:
                json_output.append(
                    {
                        "id": log.message_id,
                        "parent_id": log.parent_id,
                        "error": log.error,
                        "status": log.status,
                        "data": log.data,
                        "label": log.label,
                        "metadata": log.metadata,
                        "node_id": log.node_id,
                    }
                )
        # Step 2: normalize JSON into {"data": [...]}.change json to list[dict]
        if json_list:
            json_output.extend(json_list)
        else:
            json_output.append({"data": []})

        # Send final chunk events for all streamed outputs
        # Final chunk for text stream
        yield StreamChunkEvent(
            selector=[node_id, "text"],
            chunk="",
            is_final=True,
        )

        # Final chunks for any streamed variables
        for var_name in variables:
            yield StreamChunkEvent(
                selector=[node_id, var_name],
                chunk="",
                is_final=True,
            )

        yield StreamCompletedEvent(
            node_run_result=NodeRunResult(
                status=WorkflowNodeExecutionStatus.SUCCEEDED,
                outputs={
                    "text": text,
                    "usage": jsonable_encoder(llm_usage),
                    "files": ArrayFileSegment(value=files),
                    "json": json_output,
                    **variables,
                },
                metadata={
                    **agent_execution_metadata,
                    WorkflowNodeExecutionMetadataKey.TOOL_INFO: tool_info,
                    WorkflowNodeExecutionMetadataKey.AGENT_LOG: agent_logs,
                },
                inputs=parameters_for_log,
                llm_usage=llm_usage,
            )
        )