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ChatGPT supports MCP Apps. That means a widget built with the MCP Apps bridge can run in ChatGPT and in other MCP Apps-compatible hosts. mcp-use handles the compatibility details for you. Build the widget with the standard mcp-use server and React APIs; mcp-use emits the metadata ChatGPT needs and maps host behavior through the same hooks you use everywhere else.

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How ChatGPT fits in

OpenAI’s Apps SDK remains supported, and ChatGPT also implements the MCP Apps UI standard. mcp-use generates MCP Apps metadata and ChatGPT compatibility metadata from the same widget definitions. In practice:
  • Use widget: { name } and widget({ props, output }) on the server.
  • Use useWidget() and useCallTool() in React widgets.
  • Let mcp-use translate compatibility metadata for ChatGPT.
  • Reach for Apps SDK extensions only when a ChatGPT-specific capability has no shared MCP Apps equivalent yet.

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What mcp-use abstracts

The same widget code should work across supported hosts:
Widget behaviormcp-use API
Read tool input, result props, metadata, host context, and stateuseWidget()
Call MCP tools from the widgetuseCallTool()
Update model-visible widget stateuseWidget().setState or ModelContext
Send a follow-up user messageuseWidget().sendFollowUpMessage
Request inline, fullscreen, or picture-in-picture displayuseWidget().requestDisplayMode
These APIs keep widget code focused on behavior instead of host-specific bridge details.

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Next steps

  • Use Build widgets for the normal MCP Apps workflow.
  • Use Model context to decide what the model and widget should see.
  • Use Interactivity for tool calls, state, follow-up messages, and display controls.