#!/usr/bin/env uv run # /// script # requires-python = ">=3.10" # dependencies = [ # "mcp @ git+https://github.com/modelcontextprotocol/python-sdk@main", # "qrcode[pil]>=8.0", # "uvicorn>=0.34.0", # "starlette>=0.46.0", # ] # /// """ QR Code MCP Server - Generates QR codes from text """ import os import sys import io import base64 import qrcode import uvicorn from mcp.server.fastmcp import FastMCP from mcp import types from starlette.middleware.cors import CORSMiddleware WIDGET_URI = "ui://qr-server/widget.html" HOST = os.environ.get("HOST", "0.0.0.0") # 0.0.0.0 for Docker compatibility PORT = int(os.environ.get("PORT", "3108")) mcp = FastMCP("QR Code Server") # Embedded widget HTML for self-contained usage (uv run or unbundled) EMBEDDED_WIDGET_HTML = """

""" @mcp.tool(meta={ "ui":{"resourceUri": WIDGET_URI}, "ui/resourceUri": WIDGET_URI, # legacy support }) def generate_qr( text: str = "https://modelcontextprotocol.io", box_size: int = 10, border: int = 4, error_correction: str = "M", fill_color: str = "black", back_color: str = "white", ) -> list[types.ImageContent]: """Generate a QR code from text. Args: text: The text/URL to encode box_size: Size of each box in pixels (default: 10) border: Border size in boxes (default: 4) error_correction: Error correction level - L(7%), M(15%), Q(25%), H(30%) fill_color: Foreground color (hex like #FF0000 or name like red) back_color: Background color (hex like #FFFFFF or name like white) """ error_levels = { "L": qrcode.constants.ERROR_CORRECT_L, "M": qrcode.constants.ERROR_CORRECT_M, "Q": qrcode.constants.ERROR_CORRECT_Q, "H": qrcode.constants.ERROR_CORRECT_H, } qr = qrcode.QRCode( version=1, error_correction=error_levels.get(error_correction.upper(), qrcode.constants.ERROR_CORRECT_M), box_size=box_size, border=border, ) qr.add_data(text) qr.make(fit=True) img = qr.make_image(fill_color=fill_color, back_color=back_color) buffer = io.BytesIO() img.save(buffer, format="PNG") b64 = base64.b64encode(buffer.getvalue()).decode() return [types.ImageContent(type="image", data=b64, mimeType="image/png")] # IMPORTANT: all the external domains used by app must be listed # in the meta.ui.csp.resourceDomains - otherwise they will be blocked by CSP policy @mcp.resource( WIDGET_URI, mime_type="text/html;profile=mcp-app", meta={"ui": {"csp": {"resourceDomains": ["https://unpkg.com"]}}}, ) def widget() -> str: """Widget HTML resource with CSP metadata for external dependencies.""" return EMBEDDED_WIDGET_HTML if __name__ == "__main__": if "--stdio" in sys.argv: # Claude Desktop mode mcp.run(transport="stdio") else: # HTTP mode for basic-host (default) - with CORS app = mcp.streamable_http_app(stateless_http=True) app.add_middleware( CORSMiddleware, allow_origins=["*"], allow_methods=["*"], allow_headers=["*"], ) print(f"QR Code Server listening on http://{HOST}:{PORT}/mcp") uvicorn.run(app, host=HOST, port=PORT)