The todo_list widget now renders in hosts that follow the MCP Apps specification. The view performs the ui/initialize → ui/notifications/initialized handshake the specification requires before a host may send tool data, then renders ui/notifications/tool-result; it keeps reading window.openai.toolOutput for ChatGPT builds that still inject it. There is one resource, ui://widget/todos/v2 with text/html;profile=mcp-app and an explicit empty CSP; openai/outputTemplate is the ChatGPT alias of _meta.ui.resourceUri and points at the same URI, so the text/html+skybridge duplicate is gone. A jsdom harness plays the host side in the test suite.
The MCP server says what it is. initialize names it after the OAuth issuer host instead of the template, returns instructions that summarize the approval flow, and declares listChanged: false for tools, resources and prompts, since a server built per request never notifies. Every tool sets all four annotations (reads are read-only and idempotent; nothing is destructive or open-world) and write tools publish the approval envelope as their outputSchema.
Agents can follow an approval to its end. A write call returns an absolute approvalUrl, /integrations?approval=<id> on the deployment that served it, which opens Integrations on that record. The new read-only approval_status tool reports whether the user executed (with the stored result), denied or let the request expire; the catalog has sixteen tools. The OAuth provider offers the email scope so UserInfo returns email and email_verified, and /.well-known/openai-apps-challenge serves the OPENAI_APPS_CHALLENGE_TOKEN Worker var during an OpenAI plugin review (404 while unset).
The agent plugin package is installable again. The Cursor and Grok marketplaces pointed at a folder that had been renamed, every manifest used the workers.dev origin instead of the production domain, and plugin.json carried a top-level logo the Agent Plugins 1.0.0 schema rejects. Listing copy and logo moved under extensions["com.openai"].interface, mcp.json declares the OAuth client, and new .claude-plugin/marketplace.json and .agents/plugins/marketplace.json files make it installable from Claude Code, the ChatGPT desktop app and Codex. The connection guide describes ChatGPT's current path, chatgpt.com/plugins → + → Add custom MCP server.
Sources: widget and server, approval status, challenge route and email scope, plugin marketplaces.