diff --git a/api/core/entities/parameter_entities.py b/api/core/entities/parameter_entities.py
index 36800bc263..b071bfa5b1 100644
--- a/api/core/entities/parameter_entities.py
+++ b/api/core/entities/parameter_entities.py
@@ -15,6 +15,11 @@ class CommonParameterType(StrEnum):
     MODEL_SELECTOR = "model-selector"
     TOOLS_SELECTOR = "array[tools]"
 
+    # Dynamic select parameter
+    # Once you are not sure about the available options until authorization is done
+    # eg: Select a Slack channel from a Slack workspace
+    DYNAMIC_SELECT = "dynamic-select"
+
     # TOOL_SELECTOR = "tool-selector"
 
 
diff --git a/api/core/plugin/entities/parameters.py b/api/core/plugin/entities/parameters.py
index 895dd0d0fc..a011801006 100644
--- a/api/core/plugin/entities/parameters.py
+++ b/api/core/plugin/entities/parameters.py
@@ -35,6 +35,7 @@ class PluginParameterType(enum.StrEnum):
     APP_SELECTOR = CommonParameterType.APP_SELECTOR.value
     MODEL_SELECTOR = CommonParameterType.MODEL_SELECTOR.value
     TOOLS_SELECTOR = CommonParameterType.TOOLS_SELECTOR.value
+    DYNAMIC_SELECT = CommonParameterType.DYNAMIC_SELECT.value
 
     # deprecated, should not use.
     SYSTEM_FILES = CommonParameterType.SYSTEM_FILES.value
diff --git a/api/core/tools/entities/tool_entities.py b/api/core/tools/entities/tool_entities.py
index 03047c0545..d2c28076ae 100644
--- a/api/core/tools/entities/tool_entities.py
+++ b/api/core/tools/entities/tool_entities.py
@@ -240,6 +240,7 @@ class ToolParameter(PluginParameter):
         FILES = PluginParameterType.FILES.value
         APP_SELECTOR = PluginParameterType.APP_SELECTOR.value
         MODEL_SELECTOR = PluginParameterType.MODEL_SELECTOR.value
+        DYNAMIC_SELECT = PluginParameterType.DYNAMIC_SELECT.value
 
         # deprecated, should not use.
         SYSTEM_FILES = PluginParameterType.SYSTEM_FILES.value
diff --git a/web/app/components/base/select/index.tsx b/web/app/components/base/select/index.tsx
index fa8730f698..44cb0522f6 100644
--- a/web/app/components/base/select/index.tsx
+++ b/web/app/components/base/select/index.tsx
@@ -1,10 +1,10 @@
 'use client'
 import type { FC } from 'react'
-import React, { useEffect, useState } from 'react'
+import React, { useEffect, useRef, useState } from 'react'
 import { Combobox, ComboboxButton, ComboboxInput, ComboboxOption, ComboboxOptions, Listbox, ListboxButton, ListboxOption, ListboxOptions } from '@headlessui/react'
 import { ChevronDownIcon, ChevronUpIcon, XMarkIcon } from '@heroicons/react/20/solid'
 import Badge from '../badge/index'
-import { RiCheckLine } from '@remixicon/react'
+import { RiCheckLine, RiLoader4Line } from '@remixicon/react'
 import { useTranslation } from 'react-i18next'
 import classNames from '@/utils/classnames'
 import {
@@ -51,6 +51,8 @@ export type ISelectProps = {
     item: Item
     selected: boolean
   }) => React.ReactNode
+  isLoading?: boolean
+  onOpenChange?: (open: boolean) => void
 }
 const Select: FC<ISelectProps> = ({
   className,
@@ -178,17 +180,20 @@ const SimpleSelect: FC<ISelectProps> = ({
   defaultValue = 1,
   disabled = false,
   onSelect,
+  onOpenChange,
   placeholder,
   optionWrapClassName,
   optionClassName,
   hideChecked,
   notClearable,
   renderOption,
+  isLoading = false,
 }) => {
   const { t } = useTranslation()
   const localPlaceholder = placeholder || t('common.placeholder.select')
 
   const [selectedItem, setSelectedItem] = useState<Item | null>(null)
+
   useEffect(() => {
     let defaultSelect = null
     const existed = items.find((item: Item) => item.value === defaultValue)
@@ -199,8 +204,10 @@ const SimpleSelect: FC<ISelectProps> = ({
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [defaultValue])
 
+  const listboxRef = useRef<HTMLDivElement>(null)
+
   return (
-    <Listbox
+    <Listbox ref={listboxRef}
       value={selectedItem}
       onChange={(value: Item) => {
         if (!disabled) {
@@ -212,10 +219,17 @@ const SimpleSelect: FC<ISelectProps> = ({
       <div className={classNames('group/simple-select relative h-9', wrapperClassName)}>
         {renderTrigger && <ListboxButton className='w-full'>{renderTrigger(selectedItem)}</ListboxButton>}
         {!renderTrigger && (
-          <ListboxButton className={classNames(`flex items-center w-full h-full rounded-lg border-0 bg-components-input-bg-normal pl-3 pr-10 sm:text-sm sm:leading-6 focus-visible:outline-none focus-visible:bg-state-base-hover-alt group-hover/simple-select:bg-state-base-hover-alt ${disabled ? 'cursor-not-allowed' : 'cursor-pointer'}`, className)}>
+          <ListboxButton onClick={() => {
+              // get data-open, use setTimeout to ensure the attribute is set
+              setTimeout(() => {
+                if (listboxRef.current)
+                  onOpenChange?.(listboxRef.current.getAttribute('data-open') !== null)
+              })
+          }} className={classNames(`flex items-center w-full h-full rounded-lg border-0 bg-components-input-bg-normal pl-3 pr-10 sm:text-sm sm:leading-6 focus-visible:outline-none focus-visible:bg-state-base-hover-alt group-hover/simple-select:bg-state-base-hover-alt ${disabled ? 'cursor-not-allowed' : 'cursor-pointer'}`, className)}>
             <span className={classNames('block truncate text-left system-sm-regular text-components-input-text-filled', !selectedItem?.name && 'text-components-input-text-placeholder')}>{selectedItem?.name ?? localPlaceholder}</span>
             <span className="absolute inset-y-0 right-0 flex items-center pr-2">
-              {(selectedItem && !notClearable)
+              {isLoading ? <RiLoader4Line className='h-3.5 w-3.5 animate-spin text-text-secondary' />
+              : (selectedItem && !notClearable)
                 ? (
                   <XMarkIcon
                     onClick={(e) => {
@@ -237,7 +251,7 @@ const SimpleSelect: FC<ISelectProps> = ({
           </ListboxButton>
         )}
 
-        {!disabled && (
+        {(!disabled) && (
           <ListboxOptions className={classNames('absolute z-10 mt-1 px-1 max-h-60 w-full overflow-auto rounded-xl bg-components-panel-bg-blur backdrop-blur-sm py-1 text-base shadow-lg border-components-panel-border border-[0.5px] focus:outline-none sm:text-sm', optionWrapClassName)}>
             {items.map((item: Item) => (
               <ListboxOption
diff --git a/web/app/components/header/account-setting/model-provider-page/declarations.ts b/web/app/components/header/account-setting/model-provider-page/declarations.ts
index 12dd9b3b5b..0ee7b26114 100644
--- a/web/app/components/header/account-setting/model-provider-page/declarations.ts
+++ b/web/app/components/header/account-setting/model-provider-page/declarations.ts
@@ -19,12 +19,14 @@ export enum FormTypeEnum {
   toolSelector = 'tool-selector',
   multiToolSelector = 'array[tools]',
   appSelector = 'app-selector',
+  dynamicSelect = 'dynamic-select',
 }
 
 export type FormOption = {
   label: TypeWithI18N
   value: string
   show_on: FormShowOnObject[]
+  icon?: string
 }
 
 export enum ModelTypeEnum {
diff --git a/web/app/components/workflow/nodes/_base/components/variable/constant-field.tsx b/web/app/components/workflow/nodes/_base/components/variable/constant-field.tsx
index 0adfa3c9fb..0d965e2d22 100644
--- a/web/app/components/workflow/nodes/_base/components/variable/constant-field.tsx
+++ b/web/app/components/workflow/nodes/_base/components/variable/constant-field.tsx
@@ -13,6 +13,8 @@ type Props = {
   readonly: boolean
   value: string
   onChange: (value: string | number, varKindType: VarKindType, varInfo?: Var) => void
+  onOpenChange?: (open: boolean) => void
+  isLoading?: boolean
 }
 
 const DEFAULT_SCHEMA = {} as CredentialFormSchema
@@ -22,6 +24,8 @@ const ConstantField: FC<Props> = ({
   readonly,
   value,
   onChange,
+  onOpenChange,
+  isLoading,
 }) => {
   const language = useLanguage()
   const placeholder = (schema as CredentialFormSchemaSelect).placeholder
@@ -36,7 +40,7 @@ const ConstantField: FC<Props> = ({
 
   return (
     <>
-      {schema.type === FormTypeEnum.select && (
+      {(schema.type === FormTypeEnum.select || schema.type === FormTypeEnum.dynamicSelect) && (
         <SimpleSelect
           wrapperClassName='w-full !h-8'
           className='flex items-center'
@@ -45,6 +49,8 @@ const ConstantField: FC<Props> = ({
           items={(schema as CredentialFormSchemaSelect).options.map(option => ({ value: option.value, name: option.label[language] || option.label.en_US }))}
           onSelect={item => handleSelectChange(item.value)}
           placeholder={placeholder?.[language] || placeholder?.en_US}
+          onOpenChange={onOpenChange}
+          isLoading={isLoading}
         />
       )}
       {schema.type === FormTypeEnum.textNumber && (
diff --git a/web/app/components/workflow/nodes/_base/components/variable/var-reference-picker.tsx b/web/app/components/workflow/nodes/_base/components/variable/var-reference-picker.tsx
index e9825cd44a..9f54128548 100644
--- a/web/app/components/workflow/nodes/_base/components/variable/var-reference-picker.tsx
+++ b/web/app/components/workflow/nodes/_base/components/variable/var-reference-picker.tsx
@@ -6,6 +6,7 @@ import {
   RiArrowDownSLine,
   RiCloseLine,
   RiErrorWarningFill,
+  RiLoader4Line,
   RiMoreLine,
 } from '@remixicon/react'
 import produce from 'immer'
@@ -17,7 +18,7 @@ import { getNodeInfoById, isConversationVar, isENV, isSystemVar, varTypeToStruct
 import ConstantField from './constant-field'
 import cn from '@/utils/classnames'
 import type { Node, NodeOutPutVar, ValueSelector, Var } from '@/app/components/workflow/types'
-import type { CredentialFormSchema } from '@/app/components/header/account-setting/model-provider-page/declarations'
+import { type CredentialFormSchema, type FormOption, FormTypeEnum } from '@/app/components/header/account-setting/model-provider-page/declarations'
 import { BlockEnum } from '@/app/components/workflow/types'
 import { VarBlockIcon } from '@/app/components/workflow/block-icon'
 import { Line3 } from '@/app/components/base/icons/src/public/common'
@@ -68,6 +69,7 @@ type Props = {
   minWidth?: number
   popupFor?: 'assigned' | 'toAssigned'
   zIndex?: number
+  isLoading?: boolean
 }
 
 const DEFAULT_VALUE_SELECTOR: Props['value'] = []
@@ -316,6 +318,50 @@ const VarReferencePicker: FC<Props> = ({
 
     return null
   }, [isValidVar, isShowAPart, hasValue, t, outputVarNode?.title, outputVarNode?.type, value, type])
+
+  const [dynamicOptions, setDynamicOptions] = useState<FormOption[] | null>(null)
+  const [isLoading, setIsLoading] = useState(false)
+  const handleOpenDynamicSelect = useCallback((open: boolean) => {
+    if (schema?.type !== FormTypeEnum.dynamicSelect || !open || isLoading)
+      return
+    if (dynamicOptions)
+      return
+
+    setIsLoading(true)
+    // load options
+    setTimeout(() => {
+      setIsLoading(false)
+      setDynamicOptions([{
+        label: {
+          en_US: 'Option 1',
+          zh_Hans: '选项1',
+        },
+        value: 'option1',
+        show_on: [],
+      }, {
+        label: {
+          en_US: 'Option 2',
+          zh_Hans: '选项2',
+        },
+        value: 'option2',
+        show_on: [],
+      }])
+    }, 1000)
+  }, [isLoading])
+
+  const schemaWithDynamicSelect = useMemo(() => {
+    if (schema?.type !== FormTypeEnum.dynamicSelect)
+      return schema
+    // rewrite schema.options with dynamicOptions
+    if (dynamicOptions) {
+      return {
+        ...schema,
+        options: dynamicOptions,
+      }
+    }
+    return schema
+  }, [dynamicOptions])
+
   return (
     <div className={cn(className, !readonly && 'cursor-pointer')}>
       <PortalToFollowElem
@@ -366,8 +412,10 @@ const VarReferencePicker: FC<Props> = ({
                     <ConstantField
                       value={value as string}
                       onChange={onChange as ((value: string | number, varKindType: VarKindType, varInfo?: Var) => void)}
-                      schema={schema as CredentialFormSchema}
+                      schema={schemaWithDynamicSelect as CredentialFormSchema}
                       readonly={readonly}
+                      onOpenChange={handleOpenDynamicSelect}
+                      isLoading={isLoading}
                     />
                   )
                   : (
@@ -412,6 +460,7 @@ const VarReferencePicker: FC<Props> = ({
                                   )}
                                   <div className='flex items-center text-text-accent'>
                                     {!hasValue && <Variable02 className='h-3.5 w-3.5' />}
+                                    {isLoading && <RiLoader4Line className='h-3.5 w-3.5 animate-spin text-text-secondary' />}
                                     {isEnv && <Env className='h-3.5 w-3.5 text-util-colors-violet-violet-600' />}
                                     {isChatVar && <BubbleX className='h-3.5 w-3.5 text-util-colors-teal-teal-700' />}
                                     <div className={cn('ml-0.5 truncate text-xs font-medium', isEnv && '!text-text-secondary', isChatVar && 'text-util-colors-teal-teal-700', isException && 'text-text-warning')} title={varName} style={{
@@ -424,7 +473,16 @@ const VarReferencePicker: FC<Props> = ({
                                   {!isValidVar && <RiErrorWarningFill className='ml-0.5 h-3 w-3 text-text-destructive' />}
                                 </>
                               )
-                              : <div className={`overflow-hidden ${readonly ? 'text-components-input-text-disabled' : 'text-components-input-text-placeholder'} system-sm-regular text-ellipsis`}>{placeholder ?? t('workflow.common.setVarValuePlaceholder')}</div>}
+                              : <div className={`overflow-hidden ${readonly ? 'text-components-input-text-disabled' : 'text-components-input-text-placeholder'} system-sm-regular text-ellipsis`}>
+                                {isLoading ? (
+                                  <div className='flex items-center'>
+                                    <RiLoader4Line className='mr-1 h-3.5 w-3.5 animate-spin text-text-secondary' />
+                                    <span>{placeholder ?? t('workflow.common.setVarValuePlaceholder')}</span>
+                                  </div>
+                                ) : (
+                                  placeholder ?? t('workflow.common.setVarValuePlaceholder')
+                                )}
+                              </div>}
                           </div>
                         </Tooltip>
                       </div>
diff --git a/web/app/components/workflow/nodes/tool/components/input-var-list.tsx b/web/app/components/workflow/nodes/tool/components/input-var-list.tsx
index 1a609c58f5..b56c5c1318 100644
--- a/web/app/components/workflow/nodes/tool/components/input-var-list.tsx
+++ b/web/app/components/workflow/nodes/tool/components/input-var-list.tsx
@@ -58,6 +58,8 @@ const InputVarList: FC<Props> = ({
       return 'ModelSelector'
     else if (type === FormTypeEnum.toolSelector)
       return 'ToolSelector'
+    else if (type === FormTypeEnum.dynamicSelect)
+      return 'DynamicSelect'
     else
       return 'String'
   }
@@ -149,6 +151,7 @@ const InputVarList: FC<Props> = ({
   const handleOpen = useCallback((index: number) => {
     return () => onOpen(index)
   }, [onOpen])
+
   return (
     <div className='space-y-3'>
       {
@@ -163,7 +166,8 @@ const InputVarList: FC<Props> = ({
           } = schema
           const varInput = value[variable]
           const isNumber = type === FormTypeEnum.textNumber
-          const isSelect = type === FormTypeEnum.select
+          const isDynamicSelect = type === FormTypeEnum.dynamicSelect
+          const isSelect = type === FormTypeEnum.select || type === FormTypeEnum.dynamicSelect
           const isFile = type === FormTypeEnum.file || type === FormTypeEnum.files
           const isAppSelector = type === FormTypeEnum.appSelector
           const isModelSelector = type === FormTypeEnum.modelSelector
@@ -198,7 +202,7 @@ const InputVarList: FC<Props> = ({
                   value={varInput?.type === VarKindType.constant ? (varInput?.value ?? '') : (varInput?.value ?? [])}
                   onChange={handleNotMixedTypeChange(variable)}
                   onOpen={handleOpen(index)}
-                  defaultVarKindType={varInput?.type || (isNumber ? VarKindType.constant : VarKindType.variable)}
+                  defaultVarKindType={varInput?.type || ((isNumber || isDynamicSelect) ? VarKindType.constant : VarKindType.variable)}
                   isSupportConstantValue={isSupportConstantValue}
                   filterVar={isNumber ? filterVar : undefined}
                   availableVars={isSelect ? availableVars : undefined}