MCP app or server: how to choose

Do not start MCP adoption by asking whether a framework is powerful enough. Start by asking what the user must see, approve, and recover from.

Start With The Surface

A plain MCP server is enough when the product only needs to expose a tool, resource, or prompt to an existing client. It is easier to test, inspect, and replace.

An MCP App is more defensible when the workflow needs a visible widget: a chart, map, file browser, progress panel, or other state the user must inspect before the next action.

• Use a server when tool access is the main product.
• Use an app when the user needs a visible decision surface.
• Use a client or agent wrapper when your product must orchestrate other MCP servers.

Use mcp-use As A Reference Stack

mcp-use is useful because the official docs and README show several MCP surfaces together: TypeScript and Python server SDKs, MCP Apps with React widgets, an Inspector, deploy tooling, and agent/client libraries.

That makes it a good comparison object, not an automatic default. The full stack is only worth adopting when your workflow needs those surfaces together.

Checklist Before Building

1. Name the host: ChatGPT, Claude, an internal tool, or your own product.
2. Name the user action that must be visible before the next step.
3. Name the data or account boundary the workflow can touch.
4. Name where errors, logs, reconnect state, and auth failures will be inspected.
5. Try the server path first, then add a widget only if the workflow loses clarity without it.

When To Skip The App Layer

Skip the app layer for a private automation, a one-off internal script, or a workflow that only returns structured data. A widget can make auth, state, and support harder if it does not change the decision.