Topic 1: Module 4 at a glance, and the setup

By the end of this module, you'll have:

• A prototype notes server (examples/m04_server.py) that exposes the notes://index resource, the notes://{note_id} resource template, and the summarise_topic prompt next to Module 3's two tools, with hostile URIs rejected by three separate layers.
• A live change feed: a client that opens a subscriptions/listen stream and refetches notes when another client creates one or a colleague edits a file on disk, seen both through the SDK and as raw frames on the wire.
• A tiny host that turns server prompts into slash commands, so typing /summarise_topic sleep renders the prompt and runs the agent loop.
• A create_note that asks the user to confirm (form-mode elicitation) only when similar notes already exist, and an import_zotero tool that sends the user to a web page for their API key (URL-mode elicitation), both answered by a client elicitation_callback.
• A working understanding of Multi Round-Trip Requests, driven by hand round by round, including a resumed call in a second client and a rejected, tampered request_state.
• A clear picture of why sampling and roots are deprecated, what replaces them, and why a secret must never travel through a form field.

Prerequisites: Modules 1 to 3 (host, client and server roles; JSON-RPC and the 2026-07-28 stateless lifecycle; defining tools with MCPServer). Comfort with async/await and anyio.

Where we are: Module 3 gave the notes server its two tools, search_notes and create_note, and showed how a model picks between them. Tools are only one of the three server primitives. In this module we add the other two (resources and prompts), then look at the moments when a server needs something only the user can give: a confirmation, a click, a credential.