feat: Human Input Node (#32060)

The frontend and backend implementation for the human input node.

Co-authored-by: twwu <twwu@dify.ai>
Co-authored-by: JzoNg <jzongcode@gmail.com>
Co-authored-by: yyh <92089059+lyzno1@users.noreply.github.com>
Co-authored-by: zhsama <torvalds@linux.do>

api/controllers/console/__init__.py

@@ -37,6 +37,7 @@ from . import (
     apikey,
     extension,
     feature,
+    human_input_form,
     init_validate,
     ping,
     setup,
@@ -171,6 +172,7 @@ __all__ = [
     "forgot_password",
     "generator",
     "hit_testing",
+    "human_input_form",
     "init_validate",
     "installed_app",
     "load_balancing_config",

api/controllers/console/app/conversation.py

@@ -89,6 +89,7 @@ status_count_model = console_ns.model(
         "success": fields.Integer,
         "failed": fields.Integer,
         "partial_success": fields.Integer,
+        "paused": fields.Integer,
     },
 )
 

api/controllers/console/app/message.py

@@ -33,7 +33,7 @@ from libs.login import current_account_with_tenant, login_required
 from models.model import AppMode, Conversation, Message, MessageAnnotation, MessageFeedback
 from services.errors.conversation import ConversationNotExistsError
 from services.errors.message import MessageNotExistsError, SuggestedQuestionsAfterAnswerDisabledError
-from services.message_service import MessageService
+from services.message_service import MessageService, attach_message_extra_contents
 
 logger = logging.getLogger(__name__)
 
@@ -207,6 +207,7 @@ message_detail_model = console_ns.model(
         "created_at": TimestampField,
         "agent_thoughts": fields.List(fields.Nested(agent_thought_model)),
         "message_files": fields.List(fields.Nested(message_file_model)),
+        "extra_contents": fields.List(fields.Raw),
         "metadata": fields.Raw(attribute="message_metadata_dict"),
         "status": fields.String,
         "error": fields.String,
@@ -299,6 +300,7 @@ class ChatMessageListApi(Resource):
             has_more = False
 
         history_messages = list(reversed(history_messages))
+        attach_message_extra_contents(history_messages)
 
         return InfiniteScrollPagination(data=history_messages, limit=args.limit, has_more=has_more)
 
@@ -481,4 +483,5 @@ class MessageApi(Resource):
         if not message:
             raise NotFound("Message Not Exists.")
 
+        attach_message_extra_contents([message])
         return message

api/controllers/console/app/workflow.py

@@ -507,6 +507,179 @@ class WorkflowDraftRunLoopNodeApi(Resource):
             raise InternalServerError()
 
 
+class HumanInputFormPreviewPayload(BaseModel):
+    inputs: dict[str, Any] = Field(
+        default_factory=dict,
+        description="Values used to fill missing upstream variables referenced in form_content",
+    )
+
+
+class HumanInputFormSubmitPayload(BaseModel):
+    form_inputs: dict[str, Any] = Field(..., description="Values the user provides for the form's own fields")
+    inputs: dict[str, Any] = Field(
+        ...,
+        description="Values used to fill missing upstream variables referenced in form_content",
+    )
+    action: str = Field(..., description="Selected action ID")
+
+
+class HumanInputDeliveryTestPayload(BaseModel):
+    delivery_method_id: str = Field(..., description="Delivery method ID")
+    inputs: dict[str, Any] = Field(
+        default_factory=dict,
+        description="Values used to fill missing upstream variables referenced in form_content",
+    )
+
+
+reg(HumanInputFormPreviewPayload)
+reg(HumanInputFormSubmitPayload)
+reg(HumanInputDeliveryTestPayload)
+
+
+@console_ns.route("/apps/<uuid:app_id>/advanced-chat/workflows/draft/human-input/nodes/<string:node_id>/form/preview")
+class AdvancedChatDraftHumanInputFormPreviewApi(Resource):
+    @console_ns.doc("get_advanced_chat_draft_human_input_form")
+    @console_ns.doc(description="Get human input form preview for advanced chat workflow")
+    @console_ns.doc(params={"app_id": "Application ID", "node_id": "Node ID"})
+    @console_ns.expect(console_ns.models[HumanInputFormPreviewPayload.__name__])
+    @setup_required
+    @login_required
+    @account_initialization_required
+    @get_app_model(mode=[AppMode.ADVANCED_CHAT])
+    @edit_permission_required
+    def post(self, app_model: App, node_id: str):
+        """
+        Preview human input form content and placeholders
+        """
+        current_user, _ = current_account_with_tenant()
+        args = HumanInputFormPreviewPayload.model_validate(console_ns.payload or {})
+        inputs = args.inputs
+
+        workflow_service = WorkflowService()
+        preview = workflow_service.get_human_input_form_preview(
+            app_model=app_model,
+            account=current_user,
+            node_id=node_id,
+            inputs=inputs,
+        )
+        return jsonable_encoder(preview)
+
+
+@console_ns.route("/apps/<uuid:app_id>/advanced-chat/workflows/draft/human-input/nodes/<string:node_id>/form/run")
+class AdvancedChatDraftHumanInputFormRunApi(Resource):
+    @console_ns.doc("submit_advanced_chat_draft_human_input_form")
+    @console_ns.doc(description="Submit human input form preview for advanced chat workflow")
+    @console_ns.doc(params={"app_id": "Application ID", "node_id": "Node ID"})
+    @console_ns.expect(console_ns.models[HumanInputFormSubmitPayload.__name__])
+    @setup_required
+    @login_required
+    @account_initialization_required
+    @get_app_model(mode=[AppMode.ADVANCED_CHAT])
+    @edit_permission_required
+    def post(self, app_model: App, node_id: str):
+        """
+        Submit human input form preview
+        """
+        current_user, _ = current_account_with_tenant()
+        args = HumanInputFormSubmitPayload.model_validate(console_ns.payload or {})
+        workflow_service = WorkflowService()
+        result = workflow_service.submit_human_input_form_preview(
+            app_model=app_model,
+            account=current_user,
+            node_id=node_id,
+            form_inputs=args.form_inputs,
+            inputs=args.inputs,
+            action=args.action,
+        )
+        return jsonable_encoder(result)
+
+
+@console_ns.route("/apps/<uuid:app_id>/workflows/draft/human-input/nodes/<string:node_id>/form/preview")
+class WorkflowDraftHumanInputFormPreviewApi(Resource):
+    @console_ns.doc("get_workflow_draft_human_input_form")
+    @console_ns.doc(description="Get human input form preview for workflow")
+    @console_ns.doc(params={"app_id": "Application ID", "node_id": "Node ID"})
+    @console_ns.expect(console_ns.models[HumanInputFormPreviewPayload.__name__])
+    @setup_required
+    @login_required
+    @account_initialization_required
+    @get_app_model(mode=[AppMode.WORKFLOW])
+    @edit_permission_required
+    def post(self, app_model: App, node_id: str):
+        """
+        Preview human input form content and placeholders
+        """
+        current_user, _ = current_account_with_tenant()
+        args = HumanInputFormPreviewPayload.model_validate(console_ns.payload or {})
+        inputs = args.inputs
+
+        workflow_service = WorkflowService()
+        preview = workflow_service.get_human_input_form_preview(
+            app_model=app_model,
+            account=current_user,
+            node_id=node_id,
+            inputs=inputs,
+        )
+        return jsonable_encoder(preview)
+
+
+@console_ns.route("/apps/<uuid:app_id>/workflows/draft/human-input/nodes/<string:node_id>/form/run")
+class WorkflowDraftHumanInputFormRunApi(Resource):
+    @console_ns.doc("submit_workflow_draft_human_input_form")
+    @console_ns.doc(description="Submit human input form preview for workflow")
+    @console_ns.doc(params={"app_id": "Application ID", "node_id": "Node ID"})
+    @console_ns.expect(console_ns.models[HumanInputFormSubmitPayload.__name__])
+    @setup_required
+    @login_required
+    @account_initialization_required
+    @get_app_model(mode=[AppMode.WORKFLOW])
+    @edit_permission_required
+    def post(self, app_model: App, node_id: str):
+        """
+        Submit human input form preview
+        """
+        current_user, _ = current_account_with_tenant()
+        workflow_service = WorkflowService()
+        args = HumanInputFormSubmitPayload.model_validate(console_ns.payload or {})
+        result = workflow_service.submit_human_input_form_preview(
+            app_model=app_model,
+            account=current_user,
+            node_id=node_id,
+            form_inputs=args.form_inputs,
+            inputs=args.inputs,
+            action=args.action,
+        )
+        return jsonable_encoder(result)
+
+
+@console_ns.route("/apps/<uuid:app_id>/workflows/draft/human-input/nodes/<string:node_id>/delivery-test")
+class WorkflowDraftHumanInputDeliveryTestApi(Resource):
+    @console_ns.doc("test_workflow_draft_human_input_delivery")
+    @console_ns.doc(description="Test human input delivery for workflow")
+    @console_ns.doc(params={"app_id": "Application ID", "node_id": "Node ID"})
+    @console_ns.expect(console_ns.models[HumanInputDeliveryTestPayload.__name__])
+    @setup_required
+    @login_required
+    @account_initialization_required
+    @get_app_model(mode=[AppMode.WORKFLOW, AppMode.ADVANCED_CHAT])
+    @edit_permission_required
+    def post(self, app_model: App, node_id: str):
+        """
+        Test human input delivery
+        """
+        current_user, _ = current_account_with_tenant()
+        workflow_service = WorkflowService()
+        args = HumanInputDeliveryTestPayload.model_validate(console_ns.payload or {})
+        workflow_service.test_human_input_delivery(
+            app_model=app_model,
+            account=current_user,
+            node_id=node_id,
+            delivery_method_id=args.delivery_method_id,
+            inputs=args.inputs,
+        )
+        return jsonable_encoder({})
+
+
 @console_ns.route("/apps/<uuid:app_id>/workflows/draft/run")
 class DraftWorkflowRunApi(Resource):
     @console_ns.doc("run_draft_workflow")

api/controllers/console/app/workflow_run.py

@@ -5,10 +5,15 @@ from flask import request
 from flask_restx import Resource, fields, marshal_with
 from pydantic import BaseModel, Field, field_validator
 from sqlalchemy import select
+from sqlalchemy.orm import sessionmaker
 
+from configs import dify_config
 from controllers.console import console_ns
 from controllers.console.app.wraps import get_app_model
 from controllers.console.wraps import account_initialization_required, setup_required
+from controllers.web.error import NotFoundError
+from core.workflow.entities.pause_reason import HumanInputRequired
+from core.workflow.enums import WorkflowExecutionStatus
 from extensions.ext_database import db
 from fields.end_user_fields import simple_end_user_fields
 from fields.member_fields import simple_account_fields
@@ -27,9 +32,21 @@ from libs.custom_inputs import time_duration
 from libs.helper import uuid_value
 from libs.login import current_user, login_required
 from models import Account, App, AppMode, EndUser, WorkflowArchiveLog, WorkflowRunTriggeredFrom
+from models.workflow import WorkflowRun
+from repositories.factory import DifyAPIRepositoryFactory
 from services.retention.workflow_run.constants import ARCHIVE_BUNDLE_NAME
 from services.workflow_run_service import WorkflowRunService
 
+
+def _build_backstage_input_url(form_token: str | None) -> str | None:
+    if not form_token:
+        return None
+    base_url = dify_config.APP_WEB_URL
+    if not base_url:
+        return None
+    return f"{base_url.rstrip('/')}/form/{form_token}"
+
+
 # Workflow run status choices for filtering
 WORKFLOW_RUN_STATUS_CHOICES = ["running", "succeeded", "failed", "stopped", "partial-succeeded"]
 EXPORT_SIGNED_URL_EXPIRE_SECONDS = 3600
@@ -440,3 +457,68 @@ class WorkflowRunNodeExecutionListApi(Resource):
         )
 
         return {"data": node_executions}
+
+
+@console_ns.route("/workflow/<string:workflow_run_id>/pause-details")
+class ConsoleWorkflowPauseDetailsApi(Resource):
+    """Console API for getting workflow pause details."""
+
+    @setup_required
+    @login_required
+    @account_initialization_required
+    def get(self, workflow_run_id: str):
+        """
+        Get workflow pause details.
+
+        GET /console/api/workflow/<workflow_run_id>/pause-details
+
+        Returns information about why and where the workflow is paused.
+        """
+
+        # Query WorkflowRun to determine if workflow is suspended
+        session_maker = sessionmaker(bind=db.engine)
+        workflow_run_repo = DifyAPIRepositoryFactory.create_api_workflow_run_repository(session_maker=session_maker)
+
+        workflow_run = db.session.get(WorkflowRun, workflow_run_id)
+        if not workflow_run:
+            raise NotFoundError("Workflow run not found")
+
+        if workflow_run.tenant_id != current_user.current_tenant_id:
+            raise NotFoundError("Workflow run not found")
+
+        # Check if workflow is suspended
+        is_paused = workflow_run.status == WorkflowExecutionStatus.PAUSED
+        if not is_paused:
+            return {
+                "paused_at": None,
+                "paused_nodes": [],
+            }, 200
+
+        pause_entity = workflow_run_repo.get_workflow_pause(workflow_run_id)
+        pause_reasons = pause_entity.get_pause_reasons() if pause_entity else []
+
+        # Build response
+        paused_at = pause_entity.paused_at if pause_entity else None
+        paused_nodes = []
+        response = {
+            "paused_at": paused_at.isoformat() + "Z" if paused_at else None,
+            "paused_nodes": paused_nodes,
+        }
+
+        for reason in pause_reasons:
+            if isinstance(reason, HumanInputRequired):
+                paused_nodes.append(
+                    {
+                        "node_id": reason.node_id,
+                        "node_title": reason.node_title,
+                        "pause_type": {
+                            "type": "human_input",
+                            "form_id": reason.form_id,
+                            "backstage_input_url": _build_backstage_input_url(reason.form_token),
+                        },
+                    }
+                )
+            else:
+                raise AssertionError("unimplemented.")
+
+        return response, 200

api/controllers/console/human_input_form.py

@@ -0,0 +1,217 @@
+"""
+Console/Studio Human Input Form APIs.
+"""
+
+import json
+import logging
+from collections.abc import Generator
+
+from flask import Response, jsonify, request
+from flask_restx import Resource, reqparse
+from sqlalchemy import select
+from sqlalchemy.orm import Session, sessionmaker
+
+from controllers.console import console_ns
+from controllers.console.wraps import account_initialization_required, setup_required
+from controllers.web.error import InvalidArgumentError, NotFoundError
+from core.app.apps.advanced_chat.app_generator import AdvancedChatAppGenerator
+from core.app.apps.common.workflow_response_converter import WorkflowResponseConverter
+from core.app.apps.message_generator import MessageGenerator
+from core.app.apps.workflow.app_generator import WorkflowAppGenerator
+from extensions.ext_database import db
+from libs.login import current_account_with_tenant, login_required
+from models import App
+from models.enums import CreatorUserRole
+from models.human_input import RecipientType
+from models.model import AppMode
+from models.workflow import WorkflowRun
+from repositories.factory import DifyAPIRepositoryFactory
+from services.human_input_service import Form, HumanInputService
+from services.workflow_event_snapshot_service import build_workflow_event_stream
+
+logger = logging.getLogger(__name__)
+
+
+def _jsonify_form_definition(form: Form) -> Response:
+    payload = form.get_definition().model_dump()
+    payload["expiration_time"] = int(form.expiration_time.timestamp())
+    return Response(json.dumps(payload, ensure_ascii=False), mimetype="application/json")
+
+
+@console_ns.route("/form/human_input/<string:form_token>")
+class ConsoleHumanInputFormApi(Resource):
+    """Console API for getting human input form definition."""
+
+    @staticmethod
+    def _ensure_console_access(form: Form):
+        _, current_tenant_id = current_account_with_tenant()
+
+        if form.tenant_id != current_tenant_id:
+            raise NotFoundError("App not found")
+
+    @setup_required
+    @login_required
+    @account_initialization_required
+    def get(self, form_token: str):
+        """
+        Get human input form definition by form token.
+
+        GET /console/api/form/human_input/<form_token>
+        """
+        service = HumanInputService(db.engine)
+        form = service.get_form_definition_by_token_for_console(form_token)
+        if form is None:
+            raise NotFoundError(f"form not found, token={form_token}")
+
+        self._ensure_console_access(form)
+
+        return _jsonify_form_definition(form)
+
+    @account_initialization_required
+    @login_required
+    def post(self, form_token: str):
+        """
+        Submit human input form by form token.
+
+        POST /console/api/form/human_input/<form_token>
+
+        Request body:
+        {
+            "inputs": {
+                "content": "User input content"
+            },
+            "action": "Approve"
+        }
+        """
+        parser = reqparse.RequestParser()
+        parser.add_argument("inputs", type=dict, required=True, location="json")
+        parser.add_argument("action", type=str, required=True, location="json")
+        args = parser.parse_args()
+        current_user, _ = current_account_with_tenant()
+
+        service = HumanInputService(db.engine)
+        form = service.get_form_by_token(form_token)
+        if form is None:
+            raise NotFoundError(f"form not found, token={form_token}")
+
+        self._ensure_console_access(form)
+
+        recipient_type = form.recipient_type
+        if recipient_type not in {RecipientType.CONSOLE, RecipientType.BACKSTAGE}:
+            raise NotFoundError(f"form not found, token={form_token}")
+        # The type checker is not smart enought to validate the following invariant.
+        # So we need to assert it manually.
+        assert recipient_type is not None, "recipient_type cannot be None here."
+
+        service.submit_form_by_token(
+            recipient_type=recipient_type,
+            form_token=form_token,
+            selected_action_id=args["action"],
+            form_data=args["inputs"],
+            submission_user_id=current_user.id,
+        )
+
+        return jsonify({})
+
+
+@console_ns.route("/workflow/<string:workflow_run_id>/events")
+class ConsoleWorkflowEventsApi(Resource):
+    """Console API for getting workflow execution events after resume."""
+
+    @account_initialization_required
+    @login_required
+    def get(self, workflow_run_id: str):
+        """
+        Get workflow execution events stream after resume.
+
+        GET /console/api/workflow/<workflow_run_id>/events
+
+        Returns Server-Sent Events stream.
+        """
+
+        user, tenant_id = current_account_with_tenant()
+        session_maker = sessionmaker(db.engine)
+        repo = DifyAPIRepositoryFactory.create_api_workflow_run_repository(session_maker)
+        workflow_run = repo.get_workflow_run_by_id_and_tenant_id(
+            tenant_id=tenant_id,
+            run_id=workflow_run_id,
+        )
+        if workflow_run is None:
+            raise NotFoundError(f"WorkflowRun not found, id={workflow_run_id}")
+
+        if workflow_run.created_by_role != CreatorUserRole.ACCOUNT:
+            raise NotFoundError(f"WorkflowRun not created by account, id={workflow_run_id}")
+
+        if workflow_run.created_by != user.id:
+            raise NotFoundError(f"WorkflowRun not created by the current account, id={workflow_run_id}")
+
+        with Session(expire_on_commit=False, bind=db.engine) as session:
+            app = _retrieve_app_for_workflow_run(session, workflow_run)
+
+        if workflow_run.finished_at is not None:
+            # TODO(QuantumGhost): should we modify the handling for finished workflow run here?
+            response = WorkflowResponseConverter.workflow_run_result_to_finish_response(
+                task_id=workflow_run.id,
+                workflow_run=workflow_run,
+                creator_user=user,
+            )
+
+            payload = response.model_dump(mode="json")
+            payload["event"] = response.event.value
+
+            def _generate_finished_events() -> Generator[str, None, None]:
+                yield f"data: {json.dumps(payload)}\n\n"
+
+            event_generator = _generate_finished_events
+
+        else:
+            msg_generator = MessageGenerator()
+            if app.mode == AppMode.ADVANCED_CHAT:
+                generator = AdvancedChatAppGenerator()
+            elif app.mode == AppMode.WORKFLOW:
+                generator = WorkflowAppGenerator()
+            else:
+                raise InvalidArgumentError(f"cannot subscribe to workflow run, workflow_run_id={workflow_run.id}")
+
+            include_state_snapshot = request.args.get("include_state_snapshot", "false").lower() == "true"
+
+            def _generate_stream_events():
+                if include_state_snapshot:
+                    return generator.convert_to_event_stream(
+                        build_workflow_event_stream(
+                            app_mode=AppMode(app.mode),
+                            workflow_run=workflow_run,
+                            tenant_id=workflow_run.tenant_id,
+                            app_id=workflow_run.app_id,
+                            session_maker=session_maker,
+                        )
+                    )
+                return generator.convert_to_event_stream(
+                    msg_generator.retrieve_events(AppMode(app.mode), workflow_run.id),
+                )
+
+            event_generator = _generate_stream_events
+
+        return Response(
+            event_generator(),
+            mimetype="text/event-stream",
+            headers={
+                "Cache-Control": "no-cache",
+                "Connection": "keep-alive",
+            },
+        )
+
+
+def _retrieve_app_for_workflow_run(session: Session, workflow_run: WorkflowRun):
+    query = select(App).where(
+        App.id == workflow_run.app_id,
+        App.tenant_id == workflow_run.tenant_id,
+    )
+    app = session.scalars(query).first()
+    if app is None:
+        raise AssertionError(
+            f"App not found for WorkflowRun, workflow_run_id={workflow_run.id}, "
+            f"app_id={workflow_run.app_id}, tenant_id={workflow_run.tenant_id}"
+        )
+
+    return app

api/controllers/service_api/app/workflow.py

@@ -33,8 +33,9 @@ from core.workflow.graph_engine.manager import GraphEngineManager
 from extensions.ext_database import db
 from fields.workflow_app_log_fields import build_workflow_app_log_pagination_model
 from libs import helper
-from libs.helper import TimestampField
+from libs.helper import OptionalTimestampField, TimestampField
 from models.model import App, AppMode, EndUser
+from models.workflow import WorkflowRun
 from repositories.factory import DifyAPIRepositoryFactory
 from services.app_generate_service import AppGenerateService
 from services.errors.app import IsDraftWorkflowError, WorkflowIdFormatError, WorkflowNotFoundError
@@ -63,17 +64,32 @@ class WorkflowLogQuery(BaseModel):
 
 register_schema_models(service_api_ns, WorkflowRunPayload, WorkflowLogQuery)
 
+
+class WorkflowRunStatusField(fields.Raw):
+    def output(self, key, obj: WorkflowRun, **kwargs):
+        return obj.status.value
+
+
+class WorkflowRunOutputsField(fields.Raw):
+    def output(self, key, obj: WorkflowRun, **kwargs):
+        if obj.status == WorkflowExecutionStatus.PAUSED:
+            return {}
+
+        outputs = obj.outputs_dict
+        return outputs or {}
+
+
 workflow_run_fields = {
     "id": fields.String,
     "workflow_id": fields.String,
-    "status": fields.String,
+    "status": WorkflowRunStatusField,
     "inputs": fields.Raw,
-    "outputs": fields.Raw,
+    "outputs": WorkflowRunOutputsField,
     "error": fields.String,
     "total_steps": fields.Integer,
     "total_tokens": fields.Integer,
     "created_at": TimestampField,
-    "finished_at": TimestampField,
+    "finished_at": OptionalTimestampField,
     "elapsed_time": fields.Float,
 }
 

api/controllers/web/__init__.py

@@ -23,6 +23,7 @@ from . import (
     feature,
     files,
     forgot_password,
+    human_input_form,
     login,
     message,
     passport,
@@ -30,6 +31,7 @@ from . import (
     saved_message,
     site,
     workflow,
+    workflow_events,
 )
 
 api.add_namespace(web_ns)
@@ -44,6 +46,7 @@ __all__ = [
     "feature",
     "files",
     "forgot_password",
+    "human_input_form",
     "login",
     "message",
     "passport",
@@ -52,4 +55,5 @@ __all__ = [
     "site",
     "web_ns",
     "workflow",
+    "workflow_events",
 ]

api/controllers/web/error.py

@@ -117,6 +117,12 @@ class InvokeRateLimitError(BaseHTTPException):
     code = 429
 
 
+class WebFormRateLimitExceededError(BaseHTTPException):
+    error_code = "web_form_rate_limit_exceeded"
+    description = "Too many form requests. Please try again later."
+    code = 429
+
+
 class NotFoundError(BaseHTTPException):
     error_code = "not_found"
     code = 404

api/controllers/web/human_input_form.py

@@ -0,0 +1,161 @@
+"""
+Web App Human Input Form APIs.
+"""
+
+import json
+import logging
+from datetime import datetime
+
+from flask import Response, request
+from flask_restx import Resource, reqparse
+from werkzeug.exceptions import Forbidden
+
+from configs import dify_config
+from controllers.web import web_ns
+from controllers.web.error import NotFoundError, WebFormRateLimitExceededError
+from controllers.web.site import serialize_app_site_payload
+from extensions.ext_database import db
+from libs.helper import RateLimiter, extract_remote_ip
+from models.account import TenantStatus
+from models.model import App, Site
+from services.human_input_service import Form, FormNotFoundError, HumanInputService
+
+logger = logging.getLogger(__name__)
+
+_FORM_SUBMIT_RATE_LIMITER = RateLimiter(
+    prefix="web_form_submit_rate_limit",
+    max_attempts=dify_config.WEB_FORM_SUBMIT_RATE_LIMIT_MAX_ATTEMPTS,
+    time_window=dify_config.WEB_FORM_SUBMIT_RATE_LIMIT_WINDOW_SECONDS,
+)
+_FORM_ACCESS_RATE_LIMITER = RateLimiter(
+    prefix="web_form_access_rate_limit",
+    max_attempts=dify_config.WEB_FORM_SUBMIT_RATE_LIMIT_MAX_ATTEMPTS,
+    time_window=dify_config.WEB_FORM_SUBMIT_RATE_LIMIT_WINDOW_SECONDS,
+)
+
+
+def _stringify_default_values(values: dict[str, object]) -> dict[str, str]:
+    result: dict[str, str] = {}
+    for key, value in values.items():
+        if value is None:
+            result[key] = ""
+        elif isinstance(value, (dict, list)):
+            result[key] = json.dumps(value, ensure_ascii=False)
+        else:
+            result[key] = str(value)
+    return result
+
+
+def _to_timestamp(value: datetime) -> int:
+    return int(value.timestamp())
+
+
+def _jsonify_form_definition(form: Form, site_payload: dict | None = None) -> Response:
+    """Return the form payload (optionally with site) as a JSON response."""
+    definition_payload = form.get_definition().model_dump()
+    payload = {
+        "form_content": definition_payload["rendered_content"],
+        "inputs": definition_payload["inputs"],
+        "resolved_default_values": _stringify_default_values(definition_payload["default_values"]),
+        "user_actions": definition_payload["user_actions"],
+        "expiration_time": _to_timestamp(form.expiration_time),
+    }
+    if site_payload is not None:
+        payload["site"] = site_payload
+    return Response(json.dumps(payload, ensure_ascii=False), mimetype="application/json")
+
+
+@web_ns.route("/form/human_input/<string:form_token>")
+class HumanInputFormApi(Resource):
+    """API for getting and submitting human input forms via the web app."""
+
+    # NOTE(QuantumGhost): this endpoint is unauthenticated on purpose for now.
+
+    # def get(self, _app_model: App, _end_user: EndUser, form_token: str):
+    def get(self, form_token: str):
+        """
+        Get human input form definition by token.
+
+        GET /api/form/human_input/<form_token>
+        """
+        ip_address = extract_remote_ip(request)
+        if _FORM_ACCESS_RATE_LIMITER.is_rate_limited(ip_address):
+            raise WebFormRateLimitExceededError()
+        _FORM_ACCESS_RATE_LIMITER.increment_rate_limit(ip_address)
+
+        service = HumanInputService(db.engine)
+        # TODO(QuantumGhost): forbid submision for form tokens
+        # that are only for console.
+        form = service.get_form_by_token(form_token)
+
+        if form is None:
+            raise NotFoundError("Form not found")
+
+        service.ensure_form_active(form)
+        app_model, site = _get_app_site_from_form(form)
+
+        return _jsonify_form_definition(form, site_payload=serialize_app_site_payload(app_model, site, None))
+
+    # def post(self, _app_model: App, _end_user: EndUser, form_token: str):
+    def post(self, form_token: str):
+        """
+        Submit human input form by token.
+
+        POST /api/form/human_input/<form_token>
+
+        Request body:
+        {
+            "inputs": {
+                "content": "User input content"
+            },
+            "action": "Approve"
+        }
+        """
+        parser = reqparse.RequestParser()
+        parser.add_argument("inputs", type=dict, required=True, location="json")
+        parser.add_argument("action", type=str, required=True, location="json")
+        args = parser.parse_args()
+
+        ip_address = extract_remote_ip(request)
+        if _FORM_SUBMIT_RATE_LIMITER.is_rate_limited(ip_address):
+            raise WebFormRateLimitExceededError()
+        _FORM_SUBMIT_RATE_LIMITER.increment_rate_limit(ip_address)
+
+        service = HumanInputService(db.engine)
+        form = service.get_form_by_token(form_token)
+        if form is None:
+            raise NotFoundError("Form not found")
+
+        if (recipient_type := form.recipient_type) is None:
+            logger.warning("Recipient type is None for form, form_id=%", form.id)
+            raise AssertionError("Recipient type is None")
+
+        try:
+            service.submit_form_by_token(
+                recipient_type=recipient_type,
+                form_token=form_token,
+                selected_action_id=args["action"],
+                form_data=args["inputs"],
+                submission_end_user_id=None,
+                # submission_end_user_id=_end_user.id,
+            )
+        except FormNotFoundError:
+            raise NotFoundError("Form not found")
+
+        return {}, 200
+
+
+def _get_app_site_from_form(form: Form) -> tuple[App, Site]:
+    """Resolve App/Site for the form's app and validate tenant status."""
+    app_model = db.session.query(App).where(App.id == form.app_id).first()
+    if app_model is None or app_model.tenant_id != form.tenant_id:
+        raise NotFoundError("Form not found")
+
+    site = db.session.query(Site).where(Site.app_id == app_model.id).first()
+    if site is None:
+        raise Forbidden()
+
+    if app_model.tenant and app_model.tenant.status == TenantStatus.ARCHIVE:
+        raise Forbidden()
+
+    return app_model, site

api/controllers/web/site.py

@@ -1,4 +1,6 @@
-from flask_restx import fields, marshal_with
+from typing import cast
+
+from flask_restx import fields, marshal, marshal_with
 from werkzeug.exceptions import Forbidden
 
 from configs import dify_config
@@ -7,7 +9,7 @@ from controllers.web.wraps import WebApiResource
 from extensions.ext_database import db
 from libs.helper import AppIconUrlField
 from models.account import TenantStatus
-from models.model import Site
+from models.model import App, Site
 from services.feature_service import FeatureService
 
 
@@ -108,3 +110,14 @@ class AppSiteInfo:
                 "remove_webapp_brand": remove_webapp_brand,
                 "replace_webapp_logo": replace_webapp_logo,
             }
+
+
+def serialize_site(site: Site) -> dict:
+    """Serialize Site model using the same schema as AppSiteApi."""
+    return cast(dict, marshal(site, AppSiteApi.site_fields))
+
+
+def serialize_app_site_payload(app_model: App, site: Site, end_user_id: str | None) -> dict:
+    can_replace_logo = FeatureService.get_features(app_model.tenant_id).can_replace_logo
+    app_site_info = AppSiteInfo(app_model.tenant, app_model, site, end_user_id, can_replace_logo)
+    return cast(dict, marshal(app_site_info, AppSiteApi.app_fields))

api/controllers/web/workflow_events.py

@@ -0,0 +1,112 @@
+"""
+Web App Workflow Resume APIs.
+"""
+
+import json
+from collections.abc import Generator
+
+from flask import Response, request
+from sqlalchemy.orm import sessionmaker
+
+from controllers.web import api
+from controllers.web.error import InvalidArgumentError, NotFoundError
+from controllers.web.wraps import WebApiResource
+from core.app.apps.advanced_chat.app_generator import AdvancedChatAppGenerator
+from core.app.apps.base_app_generator import BaseAppGenerator
+from core.app.apps.common.workflow_response_converter import WorkflowResponseConverter
+from core.app.apps.message_generator import MessageGenerator
+from core.app.apps.workflow.app_generator import WorkflowAppGenerator
+from extensions.ext_database import db
+from models.enums import CreatorUserRole
+from models.model import App, AppMode, EndUser
+from repositories.factory import DifyAPIRepositoryFactory
+from services.workflow_event_snapshot_service import build_workflow_event_stream
+
+
+class WorkflowEventsApi(WebApiResource):
+    """API for getting workflow execution events after resume."""
+
+    def get(self, app_model: App, end_user: EndUser, task_id: str):
+        """
+        Get workflow execution events stream after resume.
+
+        GET /api/workflow/<task_id>/events
+
+        Returns Server-Sent Events stream.
+        """
+        workflow_run_id = task_id
+        session_maker = sessionmaker(db.engine)
+        repo = DifyAPIRepositoryFactory.create_api_workflow_run_repository(session_maker)
+        workflow_run = repo.get_workflow_run_by_id_and_tenant_id(
+            tenant_id=app_model.tenant_id,
+            run_id=workflow_run_id,
+        )
+
+        if workflow_run is None:
+            raise NotFoundError(f"WorkflowRun not found, id={workflow_run_id}")
+
+        if workflow_run.app_id != app_model.id:
+            raise NotFoundError(f"WorkflowRun not found, id={workflow_run_id}")
+
+        if workflow_run.created_by_role != CreatorUserRole.END_USER:
+            raise NotFoundError(f"WorkflowRun not created by end user, id={workflow_run_id}")
+
+        if workflow_run.created_by != end_user.id:
+            raise NotFoundError(f"WorkflowRun not created by the current end user, id={workflow_run_id}")
+
+        if workflow_run.finished_at is not None:
+            response = WorkflowResponseConverter.workflow_run_result_to_finish_response(
+                task_id=workflow_run.id,
+                workflow_run=workflow_run,
+                creator_user=end_user,
+            )
+
+            payload = response.model_dump(mode="json")
+            payload["event"] = response.event.value
+
+            def _generate_finished_events() -> Generator[str, None, None]:
+                yield f"data: {json.dumps(payload)}\n\n"
+
+            event_generator = _generate_finished_events
+        else:
+            app_mode = AppMode.value_of(app_model.mode)
+            msg_generator = MessageGenerator()
+            generator: BaseAppGenerator
+            if app_mode == AppMode.ADVANCED_CHAT:
+                generator = AdvancedChatAppGenerator()
+            elif app_mode == AppMode.WORKFLOW:
+                generator = WorkflowAppGenerator()
+            else:
+                raise InvalidArgumentError(f"cannot subscribe to workflow run, workflow_run_id={workflow_run.id}")
+
+            include_state_snapshot = request.args.get("include_state_snapshot", "false").lower() == "true"
+
+            def _generate_stream_events():
+                if include_state_snapshot:
+                    return generator.convert_to_event_stream(
+                        build_workflow_event_stream(
+                            app_mode=app_mode,
+                            workflow_run=workflow_run,
+                            tenant_id=app_model.tenant_id,
+                            app_id=app_model.id,
+                            session_maker=session_maker,
+                        )
+                    )
+                return generator.convert_to_event_stream(
+                    msg_generator.retrieve_events(app_mode, workflow_run.id),
+                )
+
+            event_generator = _generate_stream_events
+
+        return Response(
+            event_generator(),
+            mimetype="text/event-stream",
+            headers={
+                "Cache-Control": "no-cache",
+                "Connection": "keep-alive",
+            },
+        )
+
+
+# Register the APIs
+api.add_resource(WorkflowEventsApi, "/workflow/<string:task_id>/events")