Lesson 13: Set Up Your Development Environment

In this lesson you will set up a machine for building MCP servers. You will install a supported Python and Node.js and create one Python and one TypeScript project with the official v2 SDKs. Then you will run the MCP Inspector without installing anything globally.

This is the first lesson of the Building module. Lessons 14 to 23 assume the setup from this page. If you skipped the earlier modules, read how MCP works first so terms like host, client and server are familiar.

All commands here come from the official SDK docs and the MCP Inspector docs, checked on 28 October 2026.

Step 1: Check what you already have

Open a terminal and check your versions:

python3 --version
node --version
npm --version

Compare them with these minimums, taken from the package registries on 28 October 2026:

The two Python numbers disagree. The SDK's installation page also says 3.11+, so treat 3.11 as the safe floor.

A real-world note: on a Mac whose only Python was 3.9, pip install "mcp[cli]" failed with "No matching distribution found." That message usually means your Python is too old, not that the package is missing.

Step 2: Install uv for Python projects

The official Build an MCP server tutorial uses uv, a fast Python package and project manager. It can also download a newer Python for you, which solves the version problem above.

On macOS and Linux, the tutorial's install command is:

curl -LsSf https://astral.sh/uv/install.sh | sh

Windows users get a PowerShell one-liner on the same tutorial page. Restart your terminal after installing so uv is on your PATH.

Step 3: Create the Python project

Create a project, pin a modern Python, and add the SDK with its command-line extra:

uv init bookshop --python 3.12
cd bookshop
uv add "mcp[cli]"
uv run mcp version

The last command should print MCP version 2.3.0 or newer. The [cli] extra adds the mcp command, which includes mcp dev (opens your server in the Inspector), mcp run and mcp install, per the SDK's running guide.

If you prefer plain pip, create a virtual environment with Python 3.11+ and run pip install "mcp[cli]". The SDK docs show both.

One import detail matters. In v2 the high-level server class is MCPServer, imported with from mcp.server import MCPServer. Older tutorials use FastMCP from mcp.server.fastmcp, which v2 removed. Our build guide covers that change.

Step 4: Create the TypeScript project

The TypeScript SDK's first-server guide uses these commands:

mkdir bookshop-ts && cd bookshop-ts
npm init -y
npm pkg set type=module
npm install @modelcontextprotocol/server zod tsx
mkdir src

Three details from that guide:

• type=module is required, because the SDK ships ES modules only.
• tsx runs TypeScript directly, so you can skip a build step while learning.
• The package name changed in v2. Use @modelcontextprotocol/server, not @modelcontextprotocol/sdk, which is the v1 line.

If you want a compiled build instead, add TypeScript and a tsconfig.json that targets ES2022 with Node16 modules. The official tutorial shows that setup. Lesson 15 uses tsx and then compiles once.

Step 5: Run the MCP Inspector with npx

The MCP Inspector is the official test client. Version 2 ships one package with three faces: a web UI, a CLI and a terminal UI. You never need to install it globally:

npx @modelcontextprotocol/inspector            # web UI
npx @modelcontextprotocol/inspector --cli      # scriptable CLI
npx @modelcontextprotocol/inspector --tui      # terminal UI

The CLI is the fastest way to check a setup. Point it at any command that starts a stdio server and ask for the handshake only:

npx @modelcontextprotocol/inspector --cli \
  uv --directory /ABSOLUTE/PATH/TO/bookshop run server.py \
  --method initialize --format json

You will write server.py in the next lesson. Until then, the command fails with a missing-file error, which still proves npx can fetch and start the Inspector.

For CI, the Inspector's smoke-testing guide says to pin an exact version, such as npx --yes @modelcontextprotocol/inspector@2.13.0. A bare npx call resolves the latest release each time.

Step 6: Learn the two protocol eras now

The 2026-07-28 spec changed how a connection starts. Old clients send an initialize handshake; new ones send server/discover. The SDKs call these the "legacy" and "modern" eras, and both v2 SDKs serve both from the same code.

The Inspector CLI picks the era with --protocol-era. Its configuration reference says the default is legacy. So a plain Inspector run tests the old handshake, not the new one.

Make a habit of running both:

npx @modelcontextprotocol/inspector --cli <your server command> --protocol-era modern --method initialize
npx @modelcontextprotocol/inspector --cli <your server command> --protocol-era legacy --method initialize

The protocolVersion field in the output tells you which one you got: 2026-07-28 or 2025-11-25. Our spec reference on MCP stdio transport explains what travels over the pipe in each case.

Step 7: Pick a host for later lessons

You will connect your server to a real AI app at the end of lesson 14. Any MCP host works. The Python SDK's host guide covers Claude Desktop, Claude Code, Cursor and VS Code. It notes that VS Code needs version 1.99 or later with GitHub Copilot in Agent mode.

You do not need a host to finish the Building module. The Inspector covers everything.

Try it

Run these four checks and save the output somewhere:

1. uv run mcp version inside bookshop prints 2.3.0 or newer.
2. npm ls @modelcontextprotocol/server inside bookshop-ts prints 2.4.0 or newer.
3. node --version prints v22.19.0 or newer.
4. npx @modelcontextprotocol/inspector --cli --help prints the CLI flag list.

The commands in this lesson ran on 28 October 2026. Versions: mcp 2.3.0 on Python 3.12 (installed by uv 0.13.6), @modelcontextprotocol/server 2.4.0 on Node.js 24, and @modelcontextprotocol/inspector 2.13.0. If all four checks pass, you are ready for lesson 14.

Recap

• Use Python 3.11+ and Node.js 22.19+ to cover the SDKs and the Inspector together.
• Create Python projects with uv init and uv add "mcp[cli]".
• Create TypeScript projects with npm pkg set type=module and @modelcontextprotocol/server.
• Run the Inspector through npx, and pin its version in CI.
• Test both protocol eras, because the Inspector defaults to legacy.

Next step

When a server moves from a laptop to a team or a customer, the setup grows: secrets management, CI, hosting and review. If you would rather have that built for you, see eSEOspace MCP development. Otherwise, keep going with the Learn MCP course.

Course navigation

Previous lesson: Lesson 12: Remote vs Local Servers in Practice.

Next lesson: Lesson 14: Build Your First Tool in Python.

Back to the Learn MCP course outline.

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