fix(workflow): unblock plugin model selector tools on 1.14.0

[sawyer-shi]

This fixes a severe 1.14 regression where plugin tools using model-selector params failed before invocation with 'The selector must be a dictionary', blocking LLM/TTS model selection in plugin workflows.

This blocks plugin tools that rely on Dify platform model selection from running at all.
This PR fixes the model selector parameter flow by:
• Preserving model/app selector dictionaries instead of flattening them as primitive tool configuration values.
• Moving legacy selector-shaped tool configurations into tool_parameters, where structured constant values are supported by graph validation.
• Merging tool_parameters into the workflow tool runtime spec so plugin runtime invocation still receives the selected model config.
• Adding regression tests for LLM and TTS model selector payloads.

Summary

resolves #35816

Fixes a severe regression introduced in 1.14 where plugin workflow tools using model-selector parameters fail before the plugin is invoked.

When a plugin tool defines a Dify model selector parameter, such as an LLM or TTS model field, workflow execution can fail with:

Failed to invoke tool: The selector must be a dictionary.

Screenshots

Checklist

• This change requires a documentation update, included: Dify Document
• I understand that this PR may be closed in case there was no previous discussion or issues. (This doesn't apply to typos!)
• I've added a test for each change that was introduced, and I tried as much as possible to make a single atomic change.
• I've updated the documentation accordingly.
• I ran make lint && make type-check (backend) and cd web && pnpm exec vp staged (frontend) to appease the lint gods

[github-actions]

Pyrefly Diff

base → PR

--- /tmp/pyrefly_base.txt	2026-05-06 03:10:30.965640898 +0000
+++ /tmp/pyrefly_pr.txt	2026-05-06 03:10:17.273530065 +0000
@@ -1,7 +1,7 @@
 ERROR Object of class `Server` has no attribute `app` [missing-attribute]
    --> app_factory.py:132:5
 ERROR Object of class `App` has no attribute `access_mode` [missing-attribute]
-   --> controllers/console/app/app.py:573:13
+   --> controllers/console/app/app.py:553:13
 ERROR Argument `str | None` is not assignable to parameter `language` with type `str` in function `services.account_service.AccountService.send_email_register_email` [bad-argument-type]
   --> controllers/console/auth/email_register.py:75:108
 ERROR Object of class `MissingRouter` has no attribute `get` [missing-attribute]
@@ -764,8 +764,6 @@
    --> tests/test_containers_integration_tests/core/workflow/test_human_input_resume_node_execution.py:270:29
 ERROR Argument `Literal['owner']` is not assignable to parameter `role` with type `SQLCoreOperations[TenantAccountRole] | TenantAccountRole` in function `models.account.TenantAccountJoin.__init__` [bad-argument-type]
   --> tests/test_containers_integration_tests/helpers/execution_extra_content.py:48:14
-ERROR Returned type `int | str` is not assignable to declared return type `str` [bad-return]
-   --> tests/test_containers_integration_tests/libs/broadcast_channel/redis/test_sharded_channel.py:363:16
 ERROR Object of class `TypeEngine` has no attribute `length` [missing-attribute]
    --> tests/test_containers_integration_tests/models/test_types_enum_text.py:104:16
 ERROR Object of class `NoneType` has no attribute `user_type` [missing-attribute]
@@ -1807,29 +1805,27 @@
 ERROR Object of class `int` has no attribute `lower` [missing-attribute]
    --> tests/unit_tests/controllers/console/app/test_annotation_security.py:256:35
 ERROR Object of class `ModuleType` has no attribute `console_ns` [missing-attribute]
-  --> tests/unit_tests/controllers/console/app/test_app_response_models.py:72:5
+  --> tests/unit_tests/controllers/console/app/test_app_response_models.py:70:5
 ERROR Object of class `ModuleType` has no attribute `api` [missing-attribute]
-  --> tests/unit_tests/controllers/console/app/test_app_response_models.py:73:5
+  --> tests/unit_tests/controllers/console/app/test_app_response_models.py:71:5
 ERROR Object of class `ModuleType` has no attribute `bp` [missing-attribute]
-  --> tests/unit_tests/controllers/console/app/test_app_response_models.py:74:5
+  --> tests/unit_tests/controllers/console/app/test_app_response_models.py:72:5
 ERROR Object of class `ModuleType` has no attribute `app` [missing-attribute]
-  --> tests/unit_tests/controllers/console/app/test_app_response_models.py:80:5
+  --> tests/unit_tests/controllers/console/app/test_app_response_models.py:78:5
 ERROR Argument `ModuleSpec | None` is not assignable to parameter `spec` with type `ModuleSpec` in function `_frozen_importlib.module_from_spec` [bad-argument-type]
-   --> tests/unit_tests/controllers/console/app/test_app_response_models.py:109:36
+   --> tests/unit_tests/controllers/console/app/test_app_response_models.py:107:36
 ERROR Object of class `NoneType` has no attribute `loader` [missing-attribute]
-   --> tests/unit_tests/controllers/console/app/test_app_response_models.py:112:12
+   --> tests/unit_tests/controllers/console/app/test_app_response_models.py:110:12
 ERROR Object of class `object` has no attribute `exec_module` [missing-attribute]
-   --> tests/unit_tests/controllers/console/app/test_app_response_models.py:113:5
+   --> tests/unit_tests/controllers/console/app/test_app_response_models.py:111:5
 ERROR Argument `SimpleNamespace` is not assignable to parameter `workflow` with type `Workflow` in function `controllers.console.app.workflow._parse_file` [bad-argument-type]
   --> tests/unit_tests/controllers/console/app/test_workflow.py:26:40
 ERROR Argument `SimpleNamespace` is not assignable to parameter `workflow` with type `Workflow` in function `controllers.console.app.workflow._parse_file` [bad-argument-type]
   --> tests/unit_tests/controllers/console/app/test_workflow.py:44:42
 ERROR Object of class `FunctionType` has no attribute `assert_called_once_with` [missing-attribute]
-   --> tests/unit_tests/controllers/console/app/test_workflow.py:406:5
-ERROR Object of class `FunctionType` has no attribute `call_count` [missing-attribute]
-   --> tests/unit_tests/controllers/console/app/test_workflow.py:438:12
+   --> tests/unit_tests/controllers/console/app/test_workflow.py:405:5
 ERROR `in` is not supported between `Literal['Maximum']` and `None` [not-iterable]
-   --> tests/unit_tests/controllers/console/app/test_workflow.py:466:12
+   --> tests/unit_tests/controllers/console/app/test_workflow.py:433:12
 ERROR Argument `dict[str, float | list[Unknown] | str]` is not assignable to parameter `payload` with type `dict[str, object] | None` in function `_patch_payload` [bad-argument-type]
    --> tests/unit_tests/controllers/console/app/test_workflow_comment_api.py:157:29
 ERROR Argument `dict[str, float | str]` is not assignable to parameter `payload` with type `dict[str, object] | None` in function `_patch_payload` [bad-argument-type]
@@ -5425,11 +5421,11 @@
 ERROR Object of class `_InteractiveSurfaceDeliveryConfig` has no attribute `recipients` [missing-attribute]
   --> tests/unit_tests/core/workflow/test_human_input_adapter.py:87:12
 ERROR Argument `Literal[123]` is not assignable to parameter `node_data` with type `BaseModel | Mapping[str, Any]` in function `core.workflow.human_input_adapter.adapt_human_input_node_data_for_graph` [bad-argument-type]
-   --> tests/unit_tests/core/workflow/test_human_input_adapter.py:214:47
+   --> tests/unit_tests/core/workflow/test_human_input_adapter.py:279:47
 ERROR Argument `Literal[123]` is not assignable to parameter `node_data` with type `BaseModel | Mapping[str, Any]` in function `core.workflow.human_input_adapter.adapt_node_data_for_graph` [bad-argument-type]
-   --> tests/unit_tests/core/workflow/test_human_input_adapter.py:300:35
+   --> tests/unit_tests/core/workflow/test_human_input_adapter.py:365:35
 ERROR Argument `Literal[123]` is not assignable to parameter `node_config` with type `BaseModel | Mapping[str, Any]` in function `core.workflow.human_input_adapter.adapt_node_config_for_graph` [bad-argument-type]
-   --> tests/unit_tests/core/workflow/test_human_input_adapter.py:305:37
+   --> tests/unit_tests/core/workflow/test_human_input_adapter.py:370:37
 ERROR Argument `_FakeSession` is not assignable to parameter `session` with type `Session | None` in function `core.workflow.human_input_forms.load_form_tokens_by_form_id` [bad-argument-type]
   --> tests/unit_tests/core/workflow/test_human_input_forms.py:37:60
 ERROR Argument `_FakeSession` is not assignable to parameter `session` with type `Session | None` in function `core.workflow.human_input_forms.load_form_tokens_by_form_id` [bad-argument-type]
@@ -5455,23 +5451,23 @@
 ERROR `SimpleNamespace` is not assignable to attribute `graph_runtime_state` with type `GraphRuntimeState` [bad-assignment]
    --> tests/unit_tests/core/workflow/test_node_factory.py:771:39
 ERROR Object of class `ExternalRecipient` has no attribute `reference_id` [missing-attribute]
-  --> tests/unit_tests/core/workflow/test_node_runtime.py:88:12
+  --> tests/unit_tests/core/workflow/test_node_runtime.py:90:12
 ERROR Argument `object` is not assignable to parameter `method` with type `EmailDeliveryMethod | InteractiveSurfaceDeliveryMethod` in function `core.workflow.node_runtime.apply_dify_debug_email_recipient` [bad-argument-type]
-   --> tests/unit_tests/core/workflow/test_node_runtime.py:103:45
+   --> tests/unit_tests/core/workflow/test_node_runtime.py:105:45
 ERROR Argument `SimpleNamespace` is not assignable to parameter `model_instance` with type `ModelInstance` in function `core.workflow.node_runtime.DifyPreparedLLM.__init__` [bad-argument-type]
-   --> tests/unit_tests/core/workflow/test_node_runtime.py:135:32
+   --> tests/unit_tests/core/workflow/test_node_runtime.py:137:32
 ERROR Argument `SimpleNamespace` is not assignable to parameter `model_instance` with type `ModelInstance` in function `core.workflow.node_runtime.DifyPreparedLLM.__init__` [bad-argument-type]
-   --> tests/unit_tests/core/workflow/test_node_runtime.py:170:32
+   --> tests/unit_tests/core/workflow/test_node_runtime.py:172:32
 ERROR Argument `SimpleNamespace` is not assignable to parameter `model_instance` with type `ModelInstance` in function `core.workflow.node_runtime.DifyPreparedLLM.__init__` [bad-argument-type]
-   --> tests/unit_tests/core/workflow/test_node_runtime.py:183:32
+   --> tests/unit_tests/core/workflow/test_node_runtime.py:185:32
 ERROR Argument `SimpleNamespace` is not assignable to parameter `model_instance` with type `ModelInstance` in function `core.workflow.node_runtime.DifyPreparedLLM.__init__` [bad-argument-type]
-   --> tests/unit_tests/core/workflow/test_node_runtime.py:209:32
+   --> tests/unit_tests/core/workflow/test_node_runtime.py:211:32
 ERROR Argument `Literal['chat']` is not assignable to parameter `model_mode` with type `LLMMode` in function `core.workflow.node_runtime.DifyPromptMessageSerializer.serialize` [bad-argument-type]
-   --> tests/unit_tests/core/workflow/test_node_runtime.py:220:20
+   --> tests/unit_tests/core/workflow/test_node_runtime.py:222:20
 ERROR Argument `SimpleNamespace` is not assignable to parameter `file_reference_factory` with type `FileReferenceFactoryProtocol` in function `core.workflow.node_runtime.DifyRetrieverAttachmentLoader.__init__` [bad-argument-type]
-   --> tests/unit_tests/core/workflow/test_node_runtime.py:255:32
+   --> tests/unit_tests/core/workflow/test_node_runtime.py:257:32
 ERROR Object of class `NoneType` has no attribute `storage_key` [missing-attribute]
-   --> tests/unit_tests/core/workflow/test_node_runtime.py:266:12
+   --> tests/unit_tests/core/workflow/test_node_runtime.py:268:12
 ERROR Argument `list[VariableBase]` is not assignable to parameter `variables` with type `Sequence[Variable]` in function `core.workflow.variable_pool_initializer.add_variables_to_pool` [bad-argument-type]
    --> tests/unit_tests/core/workflow/test_variable_pool.py:94:13
 ERROR Argument `TestWorkflowEntry.test_single_step_run_injects_code_limits.StubWorkflow` is not assignable to parameter `workflow` with type `Workflow` in function `core.workflow.workflow_entry.WorkflowEntry.single_step_run` [bad-argument-type]

[fatelei]

style check failed

[sawyer-shi]

style check failed

fixed，please help to recheck

[sawyer-shi]

style check failed

@fatelei fixed，please help to recheck

[github-actions]

Pyrefly Diff

base → PR

--- /tmp/pyrefly_base.txt	2026-05-06 04:24:44.008366591 +0000
+++ /tmp/pyrefly_pr.txt	2026-05-06 04:24:30.456293337 +0000
@@ -5425,11 +5425,11 @@
 ERROR Object of class `_InteractiveSurfaceDeliveryConfig` has no attribute `recipients` [missing-attribute]
   --> tests/unit_tests/core/workflow/test_human_input_adapter.py:87:12
 ERROR Argument `Literal[123]` is not assignable to parameter `node_data` with type `BaseModel | Mapping[str, Any]` in function `core.workflow.human_input_adapter.adapt_human_input_node_data_for_graph` [bad-argument-type]
-   --> tests/unit_tests/core/workflow/test_human_input_adapter.py:214:47
+   --> tests/unit_tests/core/workflow/test_human_input_adapter.py:279:47
 ERROR Argument `Literal[123]` is not assignable to parameter `node_data` with type `BaseModel | Mapping[str, Any]` in function `core.workflow.human_input_adapter.adapt_node_data_for_graph` [bad-argument-type]
-   --> tests/unit_tests/core/workflow/test_human_input_adapter.py:300:35
+   --> tests/unit_tests/core/workflow/test_human_input_adapter.py:365:35
 ERROR Argument `Literal[123]` is not assignable to parameter `node_config` with type `BaseModel | Mapping[str, Any]` in function `core.workflow.human_input_adapter.adapt_node_config_for_graph` [bad-argument-type]
-   --> tests/unit_tests/core/workflow/test_human_input_adapter.py:305:37
+   --> tests/unit_tests/core/workflow/test_human_input_adapter.py:370:37
 ERROR Argument `_FakeSession` is not assignable to parameter `session` with type `Session | None` in function `core.workflow.human_input_forms.load_form_tokens_by_form_id` [bad-argument-type]
   --> tests/unit_tests/core/workflow/test_human_input_forms.py:37:60
 ERROR Argument `_FakeSession` is not assignable to parameter `session` with type `Session | None` in function `core.workflow.human_input_forms.load_form_tokens_by_form_id` [bad-argument-type]
@@ -5455,23 +5455,23 @@
 ERROR `SimpleNamespace` is not assignable to attribute `graph_runtime_state` with type `GraphRuntimeState` [bad-assignment]
    --> tests/unit_tests/core/workflow/test_node_factory.py:771:39
 ERROR Object of class `ExternalRecipient` has no attribute `reference_id` [missing-attribute]
-  --> tests/unit_tests/core/workflow/test_node_runtime.py:88:12
+  --> tests/unit_tests/core/workflow/test_node_runtime.py:90:12
 ERROR Argument `object` is not assignable to parameter `method` with type `EmailDeliveryMethod | InteractiveSurfaceDeliveryMethod` in function `core.workflow.node_runtime.apply_dify_debug_email_recipient` [bad-argument-type]
-   --> tests/unit_tests/core/workflow/test_node_runtime.py:103:45
+   --> tests/unit_tests/core/workflow/test_node_runtime.py:105:45
 ERROR Argument `SimpleNamespace` is not assignable to parameter `model_instance` with type `ModelInstance` in function `core.workflow.node_runtime.DifyPreparedLLM.__init__` [bad-argument-type]
-   --> tests/unit_tests/core/workflow/test_node_runtime.py:135:32
+   --> tests/unit_tests/core/workflow/test_node_runtime.py:137:32
 ERROR Argument `SimpleNamespace` is not assignable to parameter `model_instance` with type `ModelInstance` in function `core.workflow.node_runtime.DifyPreparedLLM.__init__` [bad-argument-type]
-   --> tests/unit_tests/core/workflow/test_node_runtime.py:170:32
+   --> tests/unit_tests/core/workflow/test_node_runtime.py:172:32
 ERROR Argument `SimpleNamespace` is not assignable to parameter `model_instance` with type `ModelInstance` in function `core.workflow.node_runtime.DifyPreparedLLM.__init__` [bad-argument-type]
-   --> tests/unit_tests/core/workflow/test_node_runtime.py:183:32
+   --> tests/unit_tests/core/workflow/test_node_runtime.py:185:32
 ERROR Argument `SimpleNamespace` is not assignable to parameter `model_instance` with type `ModelInstance` in function `core.workflow.node_runtime.DifyPreparedLLM.__init__` [bad-argument-type]
-   --> tests/unit_tests/core/workflow/test_node_runtime.py:209:32
+   --> tests/unit_tests/core/workflow/test_node_runtime.py:211:32
 ERROR Argument `Literal['chat']` is not assignable to parameter `model_mode` with type `LLMMode` in function `core.workflow.node_runtime.DifyPromptMessageSerializer.serialize` [bad-argument-type]
-   --> tests/unit_tests/core/workflow/test_node_runtime.py:220:20
+   --> tests/unit_tests/core/workflow/test_node_runtime.py:222:20
 ERROR Argument `SimpleNamespace` is not assignable to parameter `file_reference_factory` with type `FileReferenceFactoryProtocol` in function `core.workflow.node_runtime.DifyRetrieverAttachmentLoader.__init__` [bad-argument-type]
-   --> tests/unit_tests/core/workflow/test_node_runtime.py:255:32
+   --> tests/unit_tests/core/workflow/test_node_runtime.py:257:32
 ERROR Object of class `NoneType` has no attribute `storage_key` [missing-attribute]
-   --> tests/unit_tests/core/workflow/test_node_runtime.py:266:12
+   --> tests/unit_tests/core/workflow/test_node_runtime.py:268:12
 ERROR Argument `list[VariableBase]` is not assignable to parameter `variables` with type `Sequence[Variable]` in function `core.workflow.variable_pool_initializer.add_variables_to_pool` [bad-argument-type]
    --> tests/unit_tests/core/workflow/test_variable_pool.py:94:13
 ERROR Argument `TestWorkflowEntry.test_single_step_run_injects_code_limits.StubWorkflow` is not assignable to parameter `workflow` with type `Workflow` in function `core.workflow.workflow_entry.WorkflowEntry.single_step_run` [bad-argument-type]