FastMCP working

Author: danlapid

.github/workflows/python-ci.yml

@@ -0,0 +1,29 @@
+name: Python CI
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  lint-and-format:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      
+      - name: Set up Python 3.12
+        uses: actions/setup-python@v4
+        with:
+          python-version: '3.12'
+          
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install ruff
+          
+      - name: Lint with Ruff
+        run: |
+          ruff check .
+          ruff format --check .
+          

.github/workflows/test.yml

@@ -0,0 +1,62 @@
+name: Test Deploy CI
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+
+jobs:
+  vendoring:
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macos-latest] # , windows-latest
+    runs-on: ${{ matrix.os }}
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v4
+        with:
+          python-version: '3.12'
+
+      - name: Install Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: 22
+
+      - name: Install Wrangler
+        run: npm install -g wrangler
+
+      - name: Run vendoring (Linux/macOS)
+        if: runner.os != 'Windows'
+        run: |
+          python3.12 -m venv .venv
+          source .venv/bin/activate
+          .venv/bin/pip install pyodide-build
+          .venv/bin/pyodide venv .venv-pyodide
+          .venv-pyodide/bin/pip install -t src/vendor -r vendor.txt
+
+      # Windows is not supported by pyodide.
+      # - name: Run vendoring (Windows)
+      #   if: runner.os == 'Windows'
+      #   run: |
+      #     python -m venv .venv
+      #     .\.venv\Scripts\Activate.ps1
+      #     .venv\Scripts\pip install pyodide-build
+      #     .venv\Scripts\pyodide venv .venv-pyodide
+      #     .venv-pyodide\Scripts\pip install -t src/vendor -r vendor.txt
+
+      - name: Test worker deployment
+        run: wrangler deploy --dry-run
+      
+      - name: Run tests (Linux/macOS)
+        if: runner.os != 'Windows'
+        run: |
+            source .venv/bin/activate
+            pip install -r requirements-test.txt
+            pytest tests

.gitignore

@@ -1,4 +1,8 @@
 .venv/
+.venv-pyodide/
+.pytest_cache/
 node_modules/
+__pycache__/
 src/vendor/
-.vscode/
+.vscode/
+.wrangler/

README.md

@@ -1,19 +1,18 @@
-# Vendoring Packages: FastAPI + Jinja2 Example
+# Python Workers: FastMCP Example
 
-*Note: You must have Python Packages enabled on your account for built-in packages to work. Request Access to our Closed Beta using [This Form](https://forms.gle/FcjjhV3YtPyjRPaL8)*
+This is an example of a Python Worker that uses the FastMCP package.
 
-This is an example of a Python Worker that uses a built-in package (FastAPI) with a vendored package (Jinja2).
+[![Deploy to Workers](https://deploy.workers.cloudflare.com/button)](https://deploy.workers.cloudflare.com/?url=https://github.com/cloudflare/ai/tree/main/demos/python-workers-mcp)
 
-## Adding Packages
+>[!NOTE]
+>Due to the [size](https://developers.cloudflare.com/workers/platform/limits/#worker-size) of the Worker, this example can only be deployed if you're using the Workers Paid plan. Free plan users will encounter deployment errors because this Worker exceeds the 3MB size limit.
 
-Built-in packages can be selected from [this list](https://developers.cloudflare.com/workers/languages/python/packages/#supported-packages) and added to your `requirements.txt` file. These can be used with no other explicit install step.
+## Adding Packages
 
 Vendored packages are added to your source files and need to be installed in a special manner. The Python Workers team plans to make this process automatic in the future, but for now, manual steps need to be taken.
 
 ### Vendoring Packages
 
-[//]: # (NOTE: when updating the instructions below, be sure to also update the vendoring.yml CI workflow)
-
 First, install Python3.12 and pip for Python 3.12.
 
 *Currently, other versions of Python will not work - use 3.12!*
@@ -30,36 +29,42 @@ Within our virtual environment, install the pyodide CLI:
 .venv/bin/pyodide venv .venv-pyodide
 ```
 
-Next, add packages to your vendor.txt file. Here we'll add jinja2
-```
-jinja2
-```
-
-Lastly, add these packages to your source files at `src/vendor`. For any additional packages, re-run this command.
+Lastly, download the vendored packages. For any additional packages, re-run this command.
 ```console
 .venv-pyodide/bin/pip install -t src/vendor -r vendor.txt
 ```
 
-### Using Vendored packages
+### Developing and Deploying
+
+To develop your Worker, run `npx wrangler@latest dev`.
+
+To deploy your Worker, run `npx wrangler@latest deploy`.
 
-In your wrangler.toml, make the vendor directory available:
+### Testing
 
-```toml
-[[rules]]
-globs = ["vendor/**"]
-type = "Data"
-fallthrough = true
+To test run:
+```console
+source .venv/bin/activate
+pip install -r requirements-test.txt
+pytest tests
 ```
 
-Now, you can import and use the packages:
+### Linting and Formatting
+
+This project uses Ruff for linting and formatting:
 
-```python
-import jinja2
-# ... etc ...
+```console
+pip install ruff
+ruff check .  # Run linting
+ruff format .  # Format code
 ```
 
-### Developing and Deploying
+### IDE Integration
 
-To develop your Worker, run `npx wrangler@latest dev`.
+To have good autocompletions in your IDE simply select .venv-pyodide/bin/python as your IDE's interpreter.
 
-To deploy your Worker, run `npx wrangler@latest deploy`.
+You should also install your dependencies for type hints.
+
+```console
+.venv-pyodide/bin/pip install -r requirements-dev.txt
+```

build.sh

@@ -0,0 +1,30 @@
+#!/bin/bash
+set -e
+
+# Check if Python 3.12 is installed
+if ! command -v python3.12 &> /dev/null; then
+    echo "Error: Python 3.12 is required but not installed."
+    exit 1
+fi
+
+# Install pyodide CLI if needed
+if ! pip show pyodide-build &> /dev/null; then
+    echo "Installing pyodide-build..."
+    pip install pyodide-build
+else
+    echo "pyodide-build already installed."
+fi
+
+# Create pyodide virtual environment if it doesn't exist
+if [ ! -d ".venv-pyodide" ]; then
+    echo "Creating pyodide virtual environment (.venv-pyodide)..."
+    pyodide venv .venv-pyodide
+else
+    echo "Using existing pyodide virtual environment (.venv-pyodide)..."
+fi
+
+# Download vendored packages
+echo "Installing vendored packages from vendor.txt..."
+.venv-pyodide/bin/pip install -t src/vendor -r vendor.txt
+
+echo "Build completed successfully!"

package.json

@@ -0,0 +1,14 @@
+{
+    "name": "python-workers-mcp",
+    "version": "1.0.0",
+    "private": true,
+    "description": "Python Workers MCP Demo",
+    "scripts": {
+      "build": "./build.sh",
+      "dev": "wrangler dev",
+      "deploy": "wrangler deploy"
+    },
+    "devDependencies": {
+      "wrangler": "^4.14.0"
+    }
+  }

pyproject.toml

@@ -0,0 +1,24 @@
+[tool.ruff]
+target-version = "py312"
+line-length = 100
+[tool.ruff.lint]
+select = [
+    "E",  # pycodestyle errors
+    "F",  # pyflakes
+    "B",  # flake8-bugbear
+    "I",  # isort
+    "C4",  # flake8-comprehensions
+    "UP",  # pyupgrade
+    "N",  # pep8-naming
+    "RUF",  # ruff-specific rules
+]
+ignore = []
+
+[tool.ruff.lint.isort]
+known-first-party = ["src"]
+
+[tool.ruff.format]
+quote-style = "double"
+indent-style = "space"
+line-ending = "auto"
+skip-magic-trailing-comma = false

requirements-dev.txt

@@ -0,0 +1,9 @@
+pytest
+requests
+mcp
+pytest-asyncio
+ruff
+mcp
+structlog
+webtypy
+pyodide-py

requirements-test.txt

@@ -0,0 +1,5 @@
+pytest
+requests
+mcp
+pytest-asyncio
+ruff