feat(workflow): workflow as tool output schema (#26241)

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: crazywoola <100913391+crazywoola@users.noreply.github.com>
Co-authored-by: Novice <novice12185727@gmail.com>

api/core/tools/entities/tool_bundle.py

@@ -1,4 +1,6 @@
-from pydantic import BaseModel
+from collections.abc import Mapping
+
+from pydantic import BaseModel, Field
 
 from core.tools.entities.tool_entities import ToolParameter
 
@@ -25,3 +27,5 @@ class ApiToolBundle(BaseModel):
     icon: str | None = None
     # openapi operation
     openapi: dict
+    # output schema
+    output_schema: Mapping[str, object] = Field(default_factory=dict)

api/core/tools/utils/workflow_configuration_sync.py

@@ -3,6 +3,7 @@ from typing import Any
 
 from core.app.app_config.entities import VariableEntity
 from core.tools.entities.tool_entities import WorkflowToolParameterConfiguration
+from core.workflow.nodes.base.entities import OutputVariableEntity
 
 
 class WorkflowToolConfigurationUtils:
@@ -24,6 +25,31 @@ class WorkflowToolConfigurationUtils:
 
         return [VariableEntity.model_validate(variable) for variable in start_node.get("data", {}).get("variables", [])]
 
+    @classmethod
+    def get_workflow_graph_output(cls, graph: Mapping[str, Any]) -> Sequence[OutputVariableEntity]:
+        """
+        get workflow graph output
+        """
+        nodes = graph.get("nodes", [])
+        outputs_by_variable: dict[str, OutputVariableEntity] = {}
+        variable_order: list[str] = []
+
+        for node in nodes:
+            if node.get("data", {}).get("type") != "end":
+                continue
+
+            for output in node.get("data", {}).get("outputs", []):
+                entity = OutputVariableEntity.model_validate(output)
+                variable = entity.variable
+
+                if variable not in variable_order:
+                    variable_order.append(variable)
+
+                # Later end nodes override duplicated variable definitions.
+                outputs_by_variable[variable] = entity
+
+        return [outputs_by_variable[variable] for variable in variable_order]
+
     @classmethod
     def check_is_synced(
         cls, variables: list[VariableEntity], tool_configurations: list[WorkflowToolParameterConfiguration]

api/core/tools/workflow_as_tool/provider.py

@@ -162,6 +162,20 @@ class WorkflowToolProviderController(ToolProviderController):
             else:
                 raise ValueError("variable not found")
 
+        # get output schema from workflow
+        outputs = WorkflowToolConfigurationUtils.get_workflow_graph_output(graph)
+
+        reserved_keys = {"json", "text", "files"}
+
+        properties = {}
+        for output in outputs:
+            if output.variable not in reserved_keys:
+                properties[output.variable] = {
+                    "type": output.value_type,
+                    "description": "",
+                }
+        output_schema = {"type": "object", "properties": properties}
+
         return WorkflowTool(
             workflow_as_tool_id=db_provider.id,
             entity=ToolEntity(
@@ -177,6 +191,7 @@ class WorkflowToolProviderController(ToolProviderController):
                     llm=db_provider.description,
                 ),
                 parameters=workflow_tool_parameters,
+                output_schema=output_schema,
             ),
             runtime=ToolRuntime(
                 tenant_id=db_provider.tenant_id,

api/core/tools/workflow_as_tool/tool.py

@@ -114,6 +114,11 @@ class WorkflowTool(Tool):
             for file in files:
                 yield self.create_file_message(file)  # type: ignore
 
+        # traverse `outputs` field and create variable messages
+        for key, value in outputs.items():
+            if key not in {"text", "json", "files"}:
+                yield self.create_variable_message(variable_name=key, variable_value=value)
+
         self._latest_usage = self._derive_usage_from_result(data)
 
         yield self.create_text_message(json.dumps(outputs, ensure_ascii=False))

api/core/workflow/nodes/base/entities.py

@@ -5,7 +5,7 @@ from collections.abc import Sequence
 from enum import StrEnum
 from typing import Any, Union
 
-from pydantic import BaseModel, model_validator
+from pydantic import BaseModel, field_validator, model_validator
 
 from core.workflow.enums import ErrorStrategy
 
@@ -35,6 +35,45 @@ class VariableSelector(BaseModel):
     value_selector: Sequence[str]
 
 
+class OutputVariableType(StrEnum):
+    STRING = "string"
+    NUMBER = "number"
+    INTEGER = "integer"
+    SECRET = "secret"
+    BOOLEAN = "boolean"
+    OBJECT = "object"
+    FILE = "file"
+    ARRAY = "array"
+    ARRAY_STRING = "array[string]"
+    ARRAY_NUMBER = "array[number]"
+    ARRAY_OBJECT = "array[object]"
+    ARRAY_BOOLEAN = "array[boolean]"
+    ARRAY_FILE = "array[file]"
+    ANY = "any"
+    ARRAY_ANY = "array[any]"
+
+
+class OutputVariableEntity(BaseModel):
+    """
+    Output Variable Entity.
+    """
+
+    variable: str
+    value_type: OutputVariableType
+    value_selector: Sequence[str]
+
+    @field_validator("value_type", mode="before")
+    @classmethod
+    def normalize_value_type(cls, v: Any) -> Any:
+        """
+        Normalize value_type to handle case-insensitive array types.
+        Converts 'Array[...]' to 'array[...]' for backward compatibility.
+        """
+        if isinstance(v, str) and v.startswith("Array["):
+            return v.lower()
+        return v
+
+
 class DefaultValueType(StrEnum):
     STRING = "string"
     NUMBER = "number"

api/core/workflow/nodes/end/entities.py

@@ -1,7 +1,6 @@
 from pydantic import BaseModel, Field
 
-from core.workflow.nodes.base import BaseNodeData
+from core.workflow.nodes.base.entities import BaseNodeData, OutputVariableEntity
-from core.workflow.nodes.base.entities import VariableSelector
 
 
 class EndNodeData(BaseNodeData):
@@ -9,7 +8,7 @@ class EndNodeData(BaseNodeData):
     END Node Data.
     """
 
-    outputs: list[VariableSelector]
+    outputs: list[OutputVariableEntity]
 
 
 class EndStreamParam(BaseModel):

api/services/tools/tools_transform_service.py

@@ -405,6 +405,7 @@ class ToolTransformService:
                 name=tool.operation_id or "",
                 label=I18nObject(en_US=tool.operation_id, zh_Hans=tool.operation_id),
                 description=I18nObject(en_US=tool.summary or "", zh_Hans=tool.summary or ""),
+                output_schema=tool.output_schema,
                 parameters=tool.parameters,
                 labels=labels or [],
             )

api/services/tools/workflow_tools_manage_service.py

@@ -291,6 +291,10 @@ class WorkflowToolManageService:
         if len(workflow_tools) == 0:
             raise ValueError(f"Tool {db_tool.id} not found")
 
+        tool_entity = workflow_tools[0].entity
+        # get output schema from workflow tool entity
+        output_schema = tool_entity.output_schema
+
         return {
             "name": db_tool.name,
             "label": db_tool.label,
@@ -299,6 +303,7 @@ class WorkflowToolManageService:
             "icon": json.loads(db_tool.icon),
             "description": db_tool.description,
             "parameters": jsonable_encoder(db_tool.parameter_configurations),
+            "output_schema": output_schema,
             "tool": ToolTransformService.convert_tool_entity_to_api_entity(
                 tool=tool.get_tools(db_tool.tenant_id)[0],
                 labels=ToolLabelManager.get_tool_labels(tool),

api/tests/test_containers_integration_tests/services/tools/test_workflow_tools_manage_service.py

@@ -257,7 +257,6 @@ class TestWorkflowToolManageService:
 
         # Attempt to create second workflow tool with same name
         second_tool_parameters = self._create_test_workflow_tool_parameters()
-
         with pytest.raises(ValueError) as exc_info:
             WorkflowToolManageService.create_workflow_tool(
                 user_id=account.id,
@@ -309,7 +308,6 @@ class TestWorkflowToolManageService:
 
         # Attempt to create workflow tool with non-existent app
         tool_parameters = self._create_test_workflow_tool_parameters()
-
         with pytest.raises(ValueError) as exc_info:
             WorkflowToolManageService.create_workflow_tool(
                 user_id=account.id,
@@ -365,7 +363,6 @@ class TestWorkflowToolManageService:
                 "required": True,
             }
         ]
-
         # Attempt to create workflow tool with invalid parameters
         with pytest.raises(ValueError) as exc_info:
             WorkflowToolManageService.create_workflow_tool(
@@ -416,7 +413,6 @@ class TestWorkflowToolManageService:
         # Create first workflow tool
         first_tool_name = fake.word()
         first_tool_parameters = self._create_test_workflow_tool_parameters()
-
         WorkflowToolManageService.create_workflow_tool(
             user_id=account.id,
             tenant_id=account.current_tenant.id,
@@ -431,7 +427,6 @@ class TestWorkflowToolManageService:
         # Attempt to create second workflow tool with same app_id but different name
         second_tool_name = fake.word()
         second_tool_parameters = self._create_test_workflow_tool_parameters()
-
         with pytest.raises(ValueError) as exc_info:
             WorkflowToolManageService.create_workflow_tool(
                 user_id=account.id,
@@ -486,7 +481,6 @@ class TestWorkflowToolManageService:
 
         # Attempt to create workflow tool for app without workflow
         tool_parameters = self._create_test_workflow_tool_parameters()
-
         with pytest.raises(ValueError) as exc_info:
             WorkflowToolManageService.create_workflow_tool(
                 user_id=account.id,
@@ -534,7 +528,6 @@ class TestWorkflowToolManageService:
         # Create initial workflow tool
         initial_tool_name = fake.word()
         initial_tool_parameters = self._create_test_workflow_tool_parameters()
-
         WorkflowToolManageService.create_workflow_tool(
             user_id=account.id,
             tenant_id=account.current_tenant.id,
@@ -621,7 +614,6 @@ class TestWorkflowToolManageService:
 
         # Attempt to update non-existent workflow tool
         tool_parameters = self._create_test_workflow_tool_parameters()
-
         with pytest.raises(ValueError) as exc_info:
             WorkflowToolManageService.update_workflow_tool(
                 user_id=account.id,
@@ -671,7 +663,6 @@ class TestWorkflowToolManageService:
         # Create first workflow tool
         first_tool_name = fake.word()
         first_tool_parameters = self._create_test_workflow_tool_parameters()
-
         WorkflowToolManageService.create_workflow_tool(
             user_id=account.id,
             tenant_id=account.current_tenant.id,

api/tests/unit_tests/core/tools/workflow_as_tool/test_tool.py

@@ -3,7 +3,7 @@ import pytest
 from core.app.entities.app_invoke_entities import InvokeFrom
 from core.tools.__base.tool_runtime import ToolRuntime
 from core.tools.entities.common_entities import I18nObject
-from core.tools.entities.tool_entities import ToolEntity, ToolIdentity
+from core.tools.entities.tool_entities import ToolEntity, ToolIdentity, ToolInvokeMessage
 from core.tools.errors import ToolInvokeError
 from core.tools.workflow_as_tool.tool import WorkflowTool
 
@@ -51,3 +51,166 @@ def test_workflow_tool_should_raise_tool_invoke_error_when_result_has_error_fiel
         # actually `run` the tool.
         list(tool.invoke("test_user", {}))
     assert exc_info.value.args == ("oops",)
+
+
+def test_workflow_tool_should_generate_variable_messages_for_outputs(monkeypatch: pytest.MonkeyPatch):
+    """Test that WorkflowTool should generate variable messages when there are outputs"""
+    entity = ToolEntity(
+        identity=ToolIdentity(author="test", name="test tool", label=I18nObject(en_US="test tool"), provider="test"),
+        parameters=[],
+        description=None,
+        has_runtime_parameters=False,
+    )
+    runtime = ToolRuntime(tenant_id="test_tool", invoke_from=InvokeFrom.EXPLORE)
+    tool = WorkflowTool(
+        workflow_app_id="",
+        workflow_as_tool_id="",
+        version="1",
+        workflow_entities={},
+        workflow_call_depth=1,
+        entity=entity,
+        runtime=runtime,
+    )
+
+    # Mock workflow outputs
+    mock_outputs = {"result": "success", "count": 42, "data": {"key": "value"}}
+
+    # needs to patch those methods to avoid database access.
+    monkeypatch.setattr(tool, "_get_app", lambda *args, **kwargs: None)
+    monkeypatch.setattr(tool, "_get_workflow", lambda *args, **kwargs: None)
+
+    # Mock user resolution to avoid database access
+    from unittest.mock import Mock
+
+    mock_user = Mock()
+    monkeypatch.setattr(tool, "_resolve_user", lambda *args, **kwargs: mock_user)
+
+    # replace `WorkflowAppGenerator.generate` 's return value.
+    monkeypatch.setattr(
+        "core.app.apps.workflow.app_generator.WorkflowAppGenerator.generate",
+        lambda *args, **kwargs: {"data": {"outputs": mock_outputs}},
+    )
+    monkeypatch.setattr("libs.login.current_user", lambda *args, **kwargs: None)
+
+    # Execute tool invocation
+    messages = list(tool.invoke("test_user", {}))
+
+    # Verify generated messages
+    # Should contain: 3 variable messages + 1 text message + 1 JSON message = 5 messages
+    assert len(messages) == 5
+
+    # Verify variable messages
+    variable_messages = [msg for msg in messages if msg.type == ToolInvokeMessage.MessageType.VARIABLE]
+    assert len(variable_messages) == 3
+
+    # Verify content of each variable message
+    variable_dict = {msg.message.variable_name: msg.message.variable_value for msg in variable_messages}
+    assert variable_dict["result"] == "success"
+    assert variable_dict["count"] == 42
+    assert variable_dict["data"] == {"key": "value"}
+
+    # Verify text message
+    text_messages = [msg for msg in messages if msg.type == ToolInvokeMessage.MessageType.TEXT]
+    assert len(text_messages) == 1
+    assert '{"result": "success", "count": 42, "data": {"key": "value"}}' in text_messages[0].message.text
+
+    # Verify JSON message
+    json_messages = [msg for msg in messages if msg.type == ToolInvokeMessage.MessageType.JSON]
+    assert len(json_messages) == 1
+    assert json_messages[0].message.json_object == mock_outputs
+
+
+def test_workflow_tool_should_handle_empty_outputs(monkeypatch: pytest.MonkeyPatch):
+    """Test that WorkflowTool should handle empty outputs correctly"""
+    entity = ToolEntity(
+        identity=ToolIdentity(author="test", name="test tool", label=I18nObject(en_US="test tool"), provider="test"),
+        parameters=[],
+        description=None,
+        has_runtime_parameters=False,
+    )
+    runtime = ToolRuntime(tenant_id="test_tool", invoke_from=InvokeFrom.EXPLORE)
+    tool = WorkflowTool(
+        workflow_app_id="",
+        workflow_as_tool_id="",
+        version="1",
+        workflow_entities={},
+        workflow_call_depth=1,
+        entity=entity,
+        runtime=runtime,
+    )
+
+    # needs to patch those methods to avoid database access.
+    monkeypatch.setattr(tool, "_get_app", lambda *args, **kwargs: None)
+    monkeypatch.setattr(tool, "_get_workflow", lambda *args, **kwargs: None)
+
+    # Mock user resolution to avoid database access
+    from unittest.mock import Mock
+
+    mock_user = Mock()
+    monkeypatch.setattr(tool, "_resolve_user", lambda *args, **kwargs: mock_user)
+
+    # replace `WorkflowAppGenerator.generate` 's return value.
+    monkeypatch.setattr(
+        "core.app.apps.workflow.app_generator.WorkflowAppGenerator.generate",
+        lambda *args, **kwargs: {"data": {}},
+    )
+    monkeypatch.setattr("libs.login.current_user", lambda *args, **kwargs: None)
+
+    # Execute tool invocation
+    messages = list(tool.invoke("test_user", {}))
+
+    # Verify generated messages
+    # Should contain: 0 variable messages + 1 text message + 1 JSON message = 2 messages
+    assert len(messages) == 2
+
+    # Verify no variable messages
+    variable_messages = [msg for msg in messages if msg.type == ToolInvokeMessage.MessageType.VARIABLE]
+    assert len(variable_messages) == 0
+
+    # Verify text message
+    text_messages = [msg for msg in messages if msg.type == ToolInvokeMessage.MessageType.TEXT]
+    assert len(text_messages) == 1
+    assert text_messages[0].message.text == "{}"
+
+    # Verify JSON message
+    json_messages = [msg for msg in messages if msg.type == ToolInvokeMessage.MessageType.JSON]
+    assert len(json_messages) == 1
+    assert json_messages[0].message.json_object == {}
+
+
+def test_create_variable_message():
+    """Test the functionality of creating variable messages"""
+    entity = ToolEntity(
+        identity=ToolIdentity(author="test", name="test tool", label=I18nObject(en_US="test tool"), provider="test"),
+        parameters=[],
+        description=None,
+        has_runtime_parameters=False,
+    )
+    runtime = ToolRuntime(tenant_id="test_tool", invoke_from=InvokeFrom.EXPLORE)
+    tool = WorkflowTool(
+        workflow_app_id="",
+        workflow_as_tool_id="",
+        version="1",
+        workflow_entities={},
+        workflow_call_depth=1,
+        entity=entity,
+        runtime=runtime,
+    )
+
+    # Test different types of variable values
+    test_cases = [
+        ("string_var", "test string"),
+        ("int_var", 42),
+        ("float_var", 3.14),
+        ("bool_var", True),
+        ("list_var", [1, 2, 3]),
+        ("dict_var", {"key": "value"}),
+    ]
+
+    for var_name, var_value in test_cases:
+        message = tool.create_variable_message(var_name, var_value)
+
+        assert message.type == ToolInvokeMessage.MessageType.VARIABLE
+        assert message.message.variable_name == var_name
+        assert message.message.variable_value == var_value
+        assert message.message.stream is False

api/tests/unit_tests/core/workflow/graph_engine/test_human_input_pause_multi_branch.py

@@ -14,7 +14,7 @@ from core.workflow.graph_events import (
     NodeRunStreamChunkEvent,
     NodeRunSucceededEvent,
 )
-from core.workflow.nodes.base.entities import VariableSelector
+from core.workflow.nodes.base.entities import OutputVariableEntity, OutputVariableType
 from core.workflow.nodes.end.end_node import EndNode
 from core.workflow.nodes.end.entities import EndNodeData
 from core.workflow.nodes.human_input import HumanInputNode
@@ -110,8 +110,12 @@ def _build_branching_graph(mock_config: MockConfig) -> tuple[Graph, GraphRuntime
     end_primary_data = EndNodeData(
         title="End Primary",
         outputs=[
-            VariableSelector(variable="initial_text", value_selector=["llm_initial", "text"]),
+            OutputVariableEntity(
-            VariableSelector(variable="primary_text", value_selector=["llm_primary", "text"]),
+                variable="initial_text", value_type=OutputVariableType.STRING, value_selector=["llm_initial", "text"]
+            ),
+            OutputVariableEntity(
+                variable="primary_text", value_type=OutputVariableType.STRING, value_selector=["llm_primary", "text"]
+            ),
         ],
         desc=None,
     )
@@ -126,8 +130,14 @@ def _build_branching_graph(mock_config: MockConfig) -> tuple[Graph, GraphRuntime
     end_secondary_data = EndNodeData(
         title="End Secondary",
         outputs=[
-            VariableSelector(variable="initial_text", value_selector=["llm_initial", "text"]),
+            OutputVariableEntity(
-            VariableSelector(variable="secondary_text", value_selector=["llm_secondary", "text"]),
+                variable="initial_text", value_type=OutputVariableType.STRING, value_selector=["llm_initial", "text"]
+            ),
+            OutputVariableEntity(
+                variable="secondary_text",
+                value_type=OutputVariableType.STRING,
+                value_selector=["llm_secondary", "text"],
+            ),
         ],
         desc=None,
     )

api/tests/unit_tests/core/workflow/graph_engine/test_human_input_pause_single_branch.py

@@ -13,7 +13,7 @@ from core.workflow.graph_events import (
     NodeRunStreamChunkEvent,
     NodeRunSucceededEvent,
 )
-from core.workflow.nodes.base.entities import VariableSelector
+from core.workflow.nodes.base.entities import OutputVariableEntity, OutputVariableType
 from core.workflow.nodes.end.end_node import EndNode
 from core.workflow.nodes.end.entities import EndNodeData
 from core.workflow.nodes.human_input import HumanInputNode
@@ -108,8 +108,12 @@ def _build_llm_human_llm_graph(mock_config: MockConfig) -> tuple[Graph, GraphRun
     end_data = EndNodeData(
         title="End",
         outputs=[
-            VariableSelector(variable="initial_text", value_selector=["llm_initial", "text"]),
+            OutputVariableEntity(
-            VariableSelector(variable="resume_text", value_selector=["llm_resume", "text"]),
+                variable="initial_text", value_type=OutputVariableType.STRING, value_selector=["llm_initial", "text"]
+            ),
+            OutputVariableEntity(
+                variable="resume_text", value_type=OutputVariableType.STRING, value_selector=["llm_resume", "text"]
+            ),
         ],
         desc=None,
     )

api/tests/unit_tests/core/workflow/graph_engine/test_if_else_streaming.py

@@ -11,7 +11,7 @@ from core.workflow.graph_events import (
     NodeRunStreamChunkEvent,
     NodeRunSucceededEvent,
 )
-from core.workflow.nodes.base.entities import VariableSelector
+from core.workflow.nodes.base.entities import OutputVariableEntity, OutputVariableType
 from core.workflow.nodes.end.end_node import EndNode
 from core.workflow.nodes.end.entities import EndNodeData
 from core.workflow.nodes.if_else.entities import IfElseNodeData
@@ -123,8 +123,12 @@ def _build_if_else_graph(branch_value: str, mock_config: MockConfig) -> tuple[Gr
     end_primary_data = EndNodeData(
         title="End Primary",
         outputs=[
-            VariableSelector(variable="initial_text", value_selector=["llm_initial", "text"]),
+            OutputVariableEntity(
-            VariableSelector(variable="primary_text", value_selector=["llm_primary", "text"]),
+                variable="initial_text", value_type=OutputVariableType.STRING, value_selector=["llm_initial", "text"]
+            ),
+            OutputVariableEntity(
+                variable="primary_text", value_type=OutputVariableType.STRING, value_selector=["llm_primary", "text"]
+            ),
         ],
         desc=None,
     )
@@ -139,8 +143,14 @@ def _build_if_else_graph(branch_value: str, mock_config: MockConfig) -> tuple[Gr
     end_secondary_data = EndNodeData(
         title="End Secondary",
         outputs=[
-            VariableSelector(variable="initial_text", value_selector=["llm_initial", "text"]),
+            OutputVariableEntity(
-            VariableSelector(variable="secondary_text", value_selector=["llm_secondary", "text"]),
+                variable="initial_text", value_type=OutputVariableType.STRING, value_selector=["llm_initial", "text"]
+            ),
+            OutputVariableEntity(
+                variable="secondary_text",
+                value_type=OutputVariableType.STRING,
+                value_selector=["llm_secondary", "text"],
+            ),
         ],
         desc=None,
     )

web/app/components/app/app-publisher/index.tsx

@@ -38,7 +38,7 @@ import {
   PortalToFollowElemTrigger,
 } from '@/app/components/base/portal-to-follow-elem'
 import WorkflowToolConfigureButton from '@/app/components/tools/workflow-tool/configure-button'
-import type { InputVar } from '@/app/components/workflow/types'
+import type { InputVar, Variable } from '@/app/components/workflow/types'
 import { appDefaultIconBackground } from '@/config'
 import { useGlobalPublicStore } from '@/context/global-public-context'
 import { useFormatTimeFromNow } from '@/hooks/use-format-time-from-now'
@@ -103,6 +103,7 @@ export type AppPublisherProps = {
   crossAxisOffset?: number
   toolPublished?: boolean
   inputs?: InputVar[]
+  outputs?: Variable[]
   onRefreshData?: () => void
   workflowToolAvailable?: boolean
   missingStartNode?: boolean
@@ -125,6 +126,7 @@ const AppPublisher = ({
   crossAxisOffset = 0,
   toolPublished,
   inputs,
+  outputs,
   onRefreshData,
   workflowToolAvailable = true,
   missingStartNode = false,
@@ -457,6 +459,7 @@ const AppPublisher = ({
                           name={appDetail?.name}
                           description={appDetail?.description}
                           inputs={inputs}
+                          outputs={outputs}
                           handlePublish={handlePublish}
                           onRefreshData={onRefreshData}
                           disabledReason={workflowToolMessage}

web/app/components/tools/types.ts

@@ -1,4 +1,5 @@
 import type { TypeWithI18N } from '../header/account-setting/model-provider-page/declarations'
+import type { VarType } from '../workflow/types'
 
 export enum LOC {
   tools = 'tools',
@@ -194,6 +195,21 @@ export type WorkflowToolProviderParameter = {
   type?: string
 }
 
+export type WorkflowToolProviderOutputParameter = {
+  name: string
+  description: string
+  type?: VarType
+  reserved?: boolean
+}
+
+export type WorkflowToolProviderOutputSchema = {
+  type: string
+  properties: Record<string, {
+    type: string
+    description: string
+  }>
+}
+
 export type WorkflowToolProviderRequest = {
   name: string
   icon: Emoji
@@ -218,6 +234,7 @@ export type WorkflowToolProviderResponse = {
     description: TypeWithI18N
     labels: string[]
     parameters: ParamItem[]
+    output_schema: WorkflowToolProviderOutputSchema
   }
   privacy_policy: string
 }

web/app/components/tools/workflow-tool/configure-button.tsx

@@ -11,8 +11,8 @@ import WorkflowToolModal from '@/app/components/tools/workflow-tool'
 import Loading from '@/app/components/base/loading'
 import Toast from '@/app/components/base/toast'
 import { createWorkflowToolProvider, fetchWorkflowToolDetailByAppID, saveWorkflowToolProvider } from '@/service/tools'
-import type { Emoji, WorkflowToolProviderParameter, WorkflowToolProviderRequest, WorkflowToolProviderResponse } from '@/app/components/tools/types'
+import type { Emoji, WorkflowToolProviderOutputParameter, WorkflowToolProviderParameter, WorkflowToolProviderRequest, WorkflowToolProviderResponse } from '@/app/components/tools/types'
-import type { InputVar } from '@/app/components/workflow/types'
+import type { InputVar, Variable } from '@/app/components/workflow/types'
 import type { PublishWorkflowParams } from '@/types/workflow'
 import { useAppContext } from '@/context/app-context'
 import { useInvalidateAllWorkflowTools } from '@/service/use-tools'
@@ -26,6 +26,7 @@ type Props = {
   name: string
   description: string
   inputs?: InputVar[]
+  outputs?: Variable[]
   handlePublish: (params?: PublishWorkflowParams) => Promise<void>
   onRefreshData?: () => void
   disabledReason?: string
@@ -40,6 +41,7 @@ const WorkflowToolConfigureButton = ({
   name,
   description,
   inputs,
+  outputs,
   handlePublish,
   onRefreshData,
   disabledReason,
@@ -80,6 +82,8 @@ const WorkflowToolConfigureButton = ({
 
   const payload = useMemo(() => {
     let parameters: WorkflowToolProviderParameter[] = []
+    let outputParameters: WorkflowToolProviderOutputParameter[] = []
+
     if (!published) {
       parameters = (inputs || []).map((item) => {
         return {
@@ -90,6 +94,13 @@ const WorkflowToolConfigureButton = ({
           type: item.type,
         }
       })
+      outputParameters = (outputs || []).map((item) => {
+        return {
+          name: item.variable,
+          description: '',
+          type: item.value_type,
+        }
+      })
     }
     else if (detail && detail.tool) {
       parameters = (inputs || []).map((item) => {
@@ -101,6 +112,14 @@ const WorkflowToolConfigureButton = ({
           form: detail.tool.parameters.find(param => param.name === item.variable)?.form || 'llm',
         }
       })
+      outputParameters = (outputs || []).map((item) => {
+        const found = detail.tool.output_schema?.properties?.[item.variable]
+        return {
+          name: item.variable,
+          description: found ? found.description : '',
+          type: item.value_type,
+        }
+      })
     }
     return {
       icon: detail?.icon || icon,
@@ -108,6 +127,7 @@ const WorkflowToolConfigureButton = ({
       name: detail?.name || '',
       description: detail?.description || description,
       parameters,
+      outputParameters,
       labels: detail?.tool?.labels || [],
       privacy_policy: detail?.privacy_policy || '',
       ...(published

web/app/components/tools/workflow-tool/index.tsx

@@ -1,9 +1,9 @@
 'use client'
 import type { FC } from 'react'
-import React, { useState } from 'react'
+import React, { useMemo, useState } from 'react'
 import { useTranslation } from 'react-i18next'
 import { produce } from 'immer'
-import type { Emoji, WorkflowToolProviderParameter, WorkflowToolProviderRequest } from '../types'
+import type { Emoji, WorkflowToolProviderOutputParameter, WorkflowToolProviderParameter, WorkflowToolProviderRequest } from '../types'
 import cn from '@/utils/classnames'
 import Drawer from '@/app/components/base/drawer-plus'
 import Input from '@/app/components/base/input'
@@ -16,6 +16,8 @@ import MethodSelector from '@/app/components/tools/workflow-tool/method-selector
 import LabelSelector from '@/app/components/tools/labels/selector'
 import ConfirmModal from '@/app/components/tools/workflow-tool/confirm-modal'
 import Tooltip from '@/app/components/base/tooltip'
+import { VarType } from '@/app/components/workflow/types'
+import { RiErrorWarningLine } from '@remixicon/react'
 
 type Props = {
   isAdd?: boolean
@@ -45,7 +47,29 @@ const WorkflowToolAsModal: FC<Props> = ({
   const [name, setName] = useState(payload.name)
   const [description, setDescription] = useState(payload.description)
   const [parameters, setParameters] = useState<WorkflowToolProviderParameter[]>(payload.parameters)
-  const handleParameterChange = (key: string, value: string, index: number) => {
+  const outputParameters = useMemo<WorkflowToolProviderOutputParameter[]>(() => payload.outputParameters, [payload.outputParameters])
+  const reservedOutputParameters: WorkflowToolProviderOutputParameter[] = [
+    {
+      name: 'text',
+      description: t('workflow.nodes.tool.outputVars.text'),
+      type: VarType.string,
+      reserved: true,
+    },
+    {
+      name: 'files',
+      description: t('workflow.nodes.tool.outputVars.files.title'),
+      type: VarType.arrayFile,
+      reserved: true,
+    },
+    {
+      name: 'json',
+      description: t('workflow.nodes.tool.outputVars.json'),
+      type: VarType.arrayObject,
+      reserved: true,
+    },
+  ]
+
+  const handleParameterChange = (key: string, value: any, index: number) => {
     const newData = produce(parameters, (draft: WorkflowToolProviderParameter[]) => {
       if (key === 'description')
         draft[index].description = value
@@ -69,6 +93,10 @@ const WorkflowToolAsModal: FC<Props> = ({
     return /^\w+$/.test(name)
   }
 
+  const isOutputParameterReserved = (name: string) => {
+    return reservedOutputParameters.find(p => p.name === name)
+  }
+
   const onConfirm = () => {
     let errorMessage = ''
     if (!label)
@@ -225,6 +253,51 @@ const WorkflowToolAsModal: FC<Props> = ({
                   </table>
                 </div>
               </div>
+              {/* Tool Output  */}
+              <div>
+                <div className='system-sm-medium py-2 text-text-primary'>{t('tools.createTool.toolOutput.title')}</div>
+                <div className='w-full overflow-x-auto rounded-lg border border-divider-regular'>
+                  <table className='w-full text-xs font-normal leading-[18px] text-text-secondary'>
+                    <thead className='uppercase text-text-tertiary'>
+                      <tr className='border-b border-divider-regular'>
+                        <th className="w-[156px] p-2 pl-3 font-medium">{t('tools.createTool.name')}</th>
+                        <th className="p-2 pl-3 font-medium">{t('tools.createTool.toolOutput.description')}</th>
+                      </tr>
+                    </thead>
+                    <tbody>
+                      {[...reservedOutputParameters, ...outputParameters].map((item, index) => (
+                        <tr key={index} className='border-b border-divider-regular last:border-0'>
+                          <td className="max-w-[156px] p-2 pl-3">
+                            <div className='text-[13px] leading-[18px]'>
+                              <div title={item.name} className='flex items-center'>
+                                <span className='truncate font-medium text-text-primary'>{item.name}</span>
+                                <span className='shrink-0 pl-1 text-xs leading-[18px] text-[#ec4a0a]'>{item.reserved ? t('tools.createTool.toolOutput.reserved') : ''}</span>
+                                {
+                                  !item.reserved && isOutputParameterReserved(item.name) ? (
+                                    <Tooltip
+                                      popupContent={
+                                        <div className='w-[180px]'>
+                                          {t('tools.createTool.toolOutput.reservedParameterDuplicateTip')}
+                                        </div>
+                                      }
+                                    >
+                                      <RiErrorWarningLine className='h-3 w-3 text-text-warning-secondary' />
+                                    </Tooltip>
+                                  ) : null
+                                }
+                              </div>
+                              <div className='text-text-tertiary'>{item.type}</div>
+                            </div>
+                          </td>
+                          <td className="w-[236px] p-2 pl-3 text-text-tertiary">
+                            <span className='text-[13px] font-normal leading-[18px] text-text-secondary'>{item.description}</span>
+                          </td>
+                        </tr>
+                      ))}
+                    </tbody>
+                  </table>
+                </div>
+              </div>
               {/* Tags */}
               <div>
                 <div className='system-sm-medium py-2 text-text-primary'>{t('tools.createTool.toolInput.label')}</div>

web/app/components/workflow-app/components/workflow-header/features-trigger.tsx

@@ -39,6 +39,7 @@ import useTheme from '@/hooks/use-theme'
 import cn from '@/utils/classnames'
 import { useIsChatMode } from '@/app/components/workflow/hooks'
 import type { StartNodeType } from '@/app/components/workflow/nodes/start/types'
+import type { EndNodeType } from '@/app/components/workflow/nodes/end/types'
 import { useProviderContext } from '@/context/provider-context'
 import { Plan } from '@/app/components/billing/type'
 import useNodes from '@/app/components/workflow/store/workflow/use-nodes'
@@ -61,6 +62,7 @@ const FeaturesTrigger = () => {
   const nodes = useNodes()
   const hasWorkflowNodes = nodes.length > 0
   const startNode = nodes.find(node => node.data.type === BlockEnum.Start)
+  const endNode = nodes.find(node => node.data.type === BlockEnum.End)
   const startVariables = (startNode as Node<StartNodeType>)?.data?.variables
   const edges = useEdges<CommonEdgeType>()
 
@@ -81,6 +83,7 @@ const FeaturesTrigger = () => {
 
     return data
   }, [fileSettings?.image?.enabled, startVariables])
+  const endVariables = useMemo(() => (endNode as Node<EndNodeType>)?.data?.outputs || [], [endNode])
 
   const { handleCheckBeforePublish } = useChecklistBeforePublish()
   const { handleSyncWorkflowDraft } = useNodesSyncDraft()
@@ -201,6 +204,7 @@ const FeaturesTrigger = () => {
           disabled: nodesReadOnly || !hasWorkflowNodes,
           toolPublished,
           inputs: variables,
+          outputs: endVariables,
           onRefreshData: handleToolConfigureUpdate,
           onPublish,
           onToggle: onPublisherToggle,

web/app/components/workflow/nodes/tool/panel.tsx

@@ -121,6 +121,7 @@ const Panel: FC<NodePanelProps<ToolNodeType>> = ({
             />
             {outputSchema.map((outputItem) => {
               const schemaType = getMatchedSchemaType(outputItem.value, schemaTypeDefinitions)
+              // TODO empty object type always match `qa_structured` schema type
               return (
                 <div key={outputItem.name}>
                   {outputItem.value?.type === 'object' ? (

web/i18n/en-US/tools.ts

@@ -113,6 +113,13 @@ const translation = {
       description: 'Description',
       descriptionPlaceholder: 'Description of the parameter\'s meaning',
     },
+    toolOutput: {
+      title: 'Tool Output',
+      name: 'Name',
+      reserved: 'Reserved',
+      reservedParameterDuplicateTip: 'text, json, and files are reserved variables. Variables with these names cannot appear in the output schema.',
+      description: 'Description',
+    },
     customDisclaimer: 'Custom disclaimer',
     customDisclaimerPlaceholder: 'Please enter custom disclaimer',
     confirmTitle: 'Confirm to save ?',

web/i18n/zh-Hans/tools.ts

@@ -113,6 +113,13 @@ const translation = {
       description: '描述',
       descriptionPlaceholder: '参数意义的描述',
     },
+    toolOutput: {
+      title: '工具出参',
+      name: '名称',
+      reserved: '预留',
+      reservedParameterDuplicateTip: 'text、json、files 是预留变量，这些名称的变量不能出现在 output_schema 中。',
+      description: '描述',
+    },
     customDisclaimer: '自定义免责声明',
     customDisclaimerPlaceholder: '请输入自定义免责声明',
     confirmTitle: '确认保存？',