#!/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.server.transport_security import TransportSecuritySettings from mcp import types from starlette.middleware.cors import CORSMiddleware VIEW_URI = "ui://qr-server/view.html" HOST = os.environ.get("HOST", "0.0.0.0") # 0.0.0.0 for Docker compatibility PORT = int(os.environ.get("PORT", "3001")) mcp = FastMCP("QR Code Server") # Embedded View HTML for self-contained usage (uv run or unbundled) EMBEDDED_VIEW_HTML = """

""" @mcp.tool(meta={ "ui":{"resourceUri": VIEW_URI}, "ui/resourceUri": VIEW_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( VIEW_URI, mime_type="text/html;profile=mcp-app", meta={"ui": {"csp": {"resourceDomains": ["https://unpkg.com"]}}}, ) def view() -> str: """View HTML resource with CSP metadata for external dependencies.""" return EMBEDDED_VIEW_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 # Allow Docker bridge IP for container-to-host communication security = TransportSecuritySettings( allowed_hosts=["127.0.0.1:*", "localhost:*", "[::1]:*", "172.17.0.1:*"] ) app = mcp.streamable_http_app(stateless_http=True, transport_security=security) 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)