When will inline MCP Apps (SEP-1865) be available outside the Dev ring?

[bertrandgressier]

I build an MCP server that exposes an MCP App (a ui:// resource, text/html;profile=mcp-app). It renders inline in VS Code but not in the GitHub Copilot app 1.3.0 (macOS).

What I observe

• The agent host (copilot-cli 1.0.106-8) advertises io.modelcontextprotocol/ui, calls the tool, then reads the ui:// resource successfully (HTTP 200).
• No panel is rendered, and the app logs show mcp_apps_enabled: false.
• The binary describes an "Inline MCP Apps" experiment, but I can't find it in Settings.
• Issue MCP Apps: declared frameDomains are received, but native guest still enforces a denying frame policy #5145 mentions that MCP Apps are currently a Dev-ring experiment (github/github-app#26726).

Questions

1. Is there a target release or timeline for MCP Apps in the stable ring?
2. Until then, is there a supported way for a non-staff user to opt in to the experiment (or the Dev ring)?

Environment: Copilot app 1.3.0, macOS, local Streamable HTTP MCP server, @modelcontextprotocol/ext-apps 2.0.4.

[bertrandgressier]

Related feature request: #1913 asks for MCP Apps support in the app (it predates the experiment). Linking so both threads can be followed together.