Copilot · MCP testing
Test your MCP app's UI in Copilot.
Copilot renders MCP apps in inline and fullscreen mode, inside a up to 768px wide × up to 400px tall frame. Your app has to look right in that envelope. MCPJam renders it locally against Copilot's real context so you see it before your users do.
npx @mcpjam/inspector@latestCopilot's app envelope
Display modes
Copilot supports inline and fullscreen, defaulting to inline. Your app has to hold up in each one.
Viewport
Apps render in a up to 768px wide × up to 400px tall frame on desktop. Design and test to that box, not to your dev browser.
Media placement
No tool-result media placement in Copilot. Media returned by tools won't render in the app surface.
Theme
Copilot's context reports a dark theme, pointer input (no touch). Test your app's contrast there.
Local, no tunnel
MCPJam's App Builder emulates the app locally and previews across viewports, with no ChatGPT subscription and a built-in tunnel when you need to test in a real client.
How we know
Vendor docs: Based on the vendor's published documentation. Last reviewed 2026-07-08.
Walkthrough: Copilot
Run npx @mcpjam/inspector@latest, connect the MCP server config you already use, and select Copilot as the host. MCPJam emulates Copilot with openai/gpt-5.3-chat on desktop, so what you see is this host's behavior, not a generic client's.
Open your app in the App Builder preview: it renders in Copilot's up to 768px wide × up to 400px tall frame, in inline and fullscreen mode, with no subscription needed and a built-in tunnel when you need to test in a real client. Resize across the previews and confirm nothing clips.
Frequently asked questions
Run npx @mcpjam/inspector@latest, connect your server, and select Copilot. MCPJam emulates the host with openai/gpt-5.3-chat, so you can watch the real behavior locally, free and open source.
Copilot renders apps in a up to 768px wide × up to 400px tall frame, supporting inline and fullscreen display modes. (Catalog last reviewed 2026-07-08.)
MCPJam's host-compat catalog (the same data behind caniuse.dev). Vendor docs: Based on the vendor's published documentation. Last reviewed 2026-07-08.
See it in Copilot before your users do.
One command, your existing server config, Copilot's real behavior in the loop.
Open source · no credit card · ~2 min