openai-apps-sdk
Installation
SKILL.md
OpenAI Apps SDK
ChatGPT implements MCP Apps. The Apps SDK is MCP Apps plus ChatGPT-only
extensions. Build on the standard first; reach for window.openai only for
capabilities the standard does not cover.
Prefer the shared field, every time
| Goal | MCP Apps standard (use this) | ChatGPT alias (legacy) |
|---|---|---|
| Link tool → UI resource | _meta.ui.resourceUri |
_meta["openai/outputTemplate"] |
| Receive tool input | ui/initialize + ui/notifications/tool-input |
window.openai.toolInput |
| Receive tool result | ui/notifications/tool-result |
window.openai.toolOutput |
| Call a tool from the UI | tools/call |
window.openai.callTool |
| Send a follow-up message | ui/message |
window.openai.sendFollowUpMessage |
| Update model-visible context | ui/update-model-context |
(no alias — use the standard) |
The aliases still work for existing integrations. New code uses the middle column, which also runs in Claude and M365 Copilot unchanged.