🔌 Learn MCP the school way

The Model Context Protocol — the standard plug between AI apps and the world — taught with a difference: the protocol is IN the repo. A real MCP server and a real host/client, ~200 lines of pure Python, zero dependencies. You read every byte that moves.

🤝 the handshake🧰 tools/resources/prompts 🔬 real server code🔌 real client code 🌍 5 use cases🎼 sequence diagrams

📖 Part 1 — THE PROTOCOL (1–5)

  • the adapter drawer 🍝 → the standard socket 🔌
  • rooms, sockets, instruments — who talks to whom
  • three shelves; three verbs and a handshake 🤝
  • stdio vs HTTP + the three trust rules 🚧

🔧 Part 2 — BUILD & DEPLOY (6–8)

  • read a real server: 110 honest lines 🔬
  • read a real host — where the power lives 🔌
  • 5 production-shaped use cases, drawn twice 🌍
  • --drive mode: YOU play the model 🧠
# the 60-second wow — the ENTIRE protocol, live:
git clone https://github.com/BaluRaut/learn-mcp-school.git && cd learn-mcp-school
python3 client/mini_client.py          # watch every JSON-RPC message
python3 client/mini_client.py --drive  # YOU pick the tool calls

🗺️ The big picture — one diagram, both worlds

Click for the 4K version.

The big picture: the MCP protocol, then building servers and clients and deploying five real-world use cases

🎓 The 8 lessons

One git branch = one idea; branch 05 contains lessons 01–05. Deep-dive companion to the AI course's bonus lesson 13.

1

🍝 Why MCP

The adapter drawer (N×M) → the standard socket (N+M).lesson-01-why-mcpRead lesson →See the diagram ↗
2

🏫 Architecture

Room (host) · wall socket (client) · instrument (server).lesson-02-architectureRead lesson →See the diagram ↗
3

🧰 The three shelves

Tools, resources, prompts — model, app and user each decide one.lesson-03-primitivesRead lesson →See the diagram ↗
4

🤝 The wire

Three verbs and a handshake — the whole protocol, message by message.lesson-04-the-wireRead lesson →See the diagram ↗
5

🚧 Transports & trust

Direct plug vs extension cord — and the three rules of not getting burned.lesson-05-transports-securityRead lesson →See the diagram ↗
6

🔬 Build a server

110 honest lines: the wrapped thing, the shelf, the dispatcher, the plumbing.lesson-06-build-a-serverRead lesson →See the diagram ↗
7

🔌 Build a client

The side with the power — the model asks, the HOST does.lesson-07-build-a-clientRead lesson →See the diagram ↗
8

🌍 Real-world use cases

Coding, support, data, meetings, reports — with sequence diagrams.lesson-08-use-casesRead lesson →See the diagram ↗
🌍 The showcase: 5 real-world use cases — coding assistant, support desk, data analyst, meeting-prep butler, report robot — each with a numbered flow diagram AND a full sequence diagram.

📐 The lesson diagrams — follow the numbers

Purple = the protocol, orange = build & deploy. Lessons 02, 04 and 07 are drawn as sequence diagrams — the natural language of protocols. Also on a standalone page.

1 🍝 Why MCP

The adapter drawer (N×M) → the standard socket (N+M).

🍝 before: N×M adaptersIDE×GitHub · chatbot×GitHub ·agent×GitHub · every pair,hand-built, none reusable🏫 hosts - standard socketsIDE · chatbot · agent🔬 servers - standard plugsGitHub · files · your DB12🔌 N+Mwrite once,plug in everywhere3

Read full lesson 01 →

2 🏫 Architecture

Room (host) · wall socket (client) · instrument (server).

🧠 model🏫 host🔌 client🔬 serverthe model only ever ASKS · the host does · the server answers'I want lookup_grade(sita)' — in words1the host DECIDES — permission checks live here 🚧approved → forward2tools/call over the socket3result4→ lands on the model's desk 📄5

Read full lesson 02 →

3 🧰 The three shelves

Tools, resources, prompts — model, app and user each decide one.

🧰 TOOLSactions with inputs:lookup_grade · add_homeworkWHO decides: the MODEL(host permitting)📁 RESOURCESreadable context:file:// · db://students/3AWHO decides: the APP(what goes on the desk)📜 PROMPTSsuggested recipes:/summarize-ticketWHO decides: the USER(menus, slash-commands)123three shelves, three deciders — say it twice and you know more MCP than most 😄

Read full lesson 03 →

4 🤝 The wire

Three verbs and a handshake — the whole protocol, message by message.

🔌 client🔬 serverthree verbs and a handshake — run python3 client/mini_client.py and watch these exact linesinitialize {protocolVersion, clientInfo}1{protocolVersion, capabilities:{tools}, serverInfo}2notifications/initialized — no id, no reply3tools/list4{tools:[{name, description, inputSchema}…]}5tools/call {name:"lookup_grade", arguments:{student:"sita"}}6{content:[{type:"text", text:"Sita (3A) has grade A+."}]}7

Read full lesson 04 →

5 🚧 Transports & trust

Direct plug vs extension cord — and the three rules of not getting burned.

🔌 stdio - the direct plughost launches server as child process;JSON per line on stdin/stdout · local things1📡 HTTP - the extension cordsame messages over HTTP + auth (OAuth);remote/shared things · team DB, SaaS2🚧 rule 1: a server =installed software withYOUR permissions🚧 rule 2: tool results maycarry prompt injection —treat as data, not commands🚧 rule 3: WRITES get ahuman gate — reads may flow,add_homework waits for a click3

Read full lesson 05 →

6 🔬 Build a server

110 honest lines: the wrapped thing, the shelf, the dispatcher, the plumbing.

1 🗄️ the wrapped thingtoy DB here — YOUR Postgres/API in real life;MCP is just the plug on the front12 📋 the shelf: TOOLSname · description (FOR THE MODEL!) ·inputSchema — rich schemas steer behavior23 🔀 run_tool() dispatcherplain Python if-ladder — unit-testable,no protocol in sight34 🔧 main() plumbingline in → JSON-RPC → line out · flush=True!errors = polite isError content, never a crash4server/school_server.py — 110 lines, all four parts visible · the official SDKs automate exactly this

Read full lesson 06 →

7 🔌 Build a client

The side with the power — the model asks, the HOST does.

🧑 you (--drive)🏫 MiniHost🔬 school_serverclient/mini_client.py — swap the input() for a model API call and you have a real agent host"call lookup_grade {student: sita}"1⚡ the POWER moment: the host decides (real hosts: permission prompt here 🚧)tools/call {…, id:4}2{id:4, content:[…grade A+…]}3📄 lands on the desk4

Read full lesson 07 →

8 🌍 Real-world use cases

Coding, support, data, meetings, reports — with sequence diagrams.

🐙 coding assistantissue → code → tests → PR(PR waits for your click 🚧)1🎧 support deskorders DB (read-only!) + docs→ grounded answer + receipts2📊 data analystquery_db → make_chartSELECT-only via scoped account3📅 meeting-prep butlercalendar + CRM + email —3 servers, one desk (N+M!)4📁 report robotread folder → summarize →slack_post gated by a click 🚧5each drawn twice on the use-cases page: numbered flow + full sequence diagram →

Read full lesson 08 →

Start Lesson 01 → 🌍 The 5 use cases 📐 All 8 lesson diagrams 🧪 Quiz 🗓️ Study plan 🧠 The AI course