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Skybridge exports hooks and utilities from skybridge/web that work across multiple runtimes. See the compatibility matrix below for platform-specific availability.

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State Management

useToolInfo

Get initial tool input, output and metadata

useWidgetState

Persist state across widget renders

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Context Sync

data-llm

Sync widget UI state with the model for contextual responses

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Utilities

createStore

Create a Zustand store that automatically syncs with widget state

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User Interface

useLayout

Get layout and visual environment (theme, safe area)

useUser

Get user information (locale, device type)

useDisplayMode

Get and request widget display mode changes

useRequestModal

Open a modal portaled outside of the widget iframe

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Actions

useCallTool

Call tools from within a widget

useOpenExternal

Open external links

useSendFollowUpMessage

Send a follow-up message in the conversation

useFiles

Upload and download files

useSetOpenInAppUrl

Set URL for “open in app” button in fullscreen mode in ChatGPT

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Advanced

useAppsSdkContext

Low-level hook to subscribe to window.openai state values (Apps SDK)

useMcpAppContext

Low-level hook to subscribe to MCP App host context (MCP Apps)

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Import

All hooks and utilities are exported from skybridge/web: 
import {
  createStore,
  useCallTool,
  useDisplayMode,
  useFiles,
  useLayout,
  useSetOpenInAppUrl,
  useAppsSdkContext,
  useMcpAppContext,
  useOpenExternal,
  useRequestModal,
  useSendFollowUpMessage,
  useToolInfo,
  useUser,
  useWidgetState,
} from "skybridge/web";

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Runtime Compatibility

Skybridge supports two runtime environments: Apps SDK (ChatGPT) and MCP Apps (open specification). Most hooks work in both, but some features are platform-specific.
Hook / FeatureApps SDKMCP AppsNotes
useToolInfo✅✅
useWidgetState✅⚠️MCP Apps: polyfilled; state doesn’t persist across widget renders
data-llm✅⚠️MCP Apps: polyfilled (same limitation as useWidgetState)
useCallTool✅✅
useSendFollowUpMessage✅✅
useOpenExternal✅✅
useLayout✅✅
useUser✅✅
useDisplayMode✅✅
useFiles✅❌Apps SDK only
useSetOpenInAppUrl✅❌Apps SDK only
useRequestModal✅⚠️MCP Apps: polyfilled; renders in iframe instead of host modal
useAppsSdkContext✅❌Apps SDK only
useMcpAppContext❌✅MCP Apps only
Learn more about runtime differences in Write Once, Run Everywhere.