QRCode_MCP

Instructions

Implementation Reference

• src/index.ts:55-78 (handler)

  The handler function for the 'qrcode' MCP tool. It receives input parameters, calls generateQRCode to produce a data URL, extracts the base64 part, and returns it as image content.

  async ({
    text,
    size,
    darkColor,
    lightColor,
    errorCorrectionLevel,
    margin,
  }) => {
    const qrcode = await generateQRCode(text, {
      width: size,
      color: {
        dark: darkColor,
        light: lightColor,
      },
      errorCorrectionLevel,
      margin,
    });
  
    const base64Image = qrcode.split(",")[1];
  
    return Promise.resolve({
      content: [{ type: "image", data: base64Image, mimeType: "image/png" }],
    });
  }

• src/index.ts:32-54 (schema)

  Zod schema defining the input parameters for the 'qrcode' tool, including text, size, colors, error correction level, and margin with defaults.

  {
    text: z.string().describe("The input string to generate qrcode"),
    size: z
      .number()
      .describe("The size of qrcode, default is 256")
      .default(256),
    darkColor: z
      .string()
      .describe("The dark color of qrcode, default is #000000")
      .default("#000000"),
    lightColor: z
      .string()
      .describe("The light color of qrcode, default is #ffffff")
      .default("#ffffff"),
    errorCorrectionLevel: z
      .enum(["L", "M", "Q", "H"])
      .describe("The error correction level of qrcode, default is M")
      .default("M"),
    margin: z
      .number()
      .describe("The margin of qrcode, default is 4")
      .default(4),
  },

• src/index.ts:29-79 (registration)

  Registration of the 'qrcode' tool on the MCP server using server.tool(), specifying name, description, input schema, and handler function.

  server.tool(
    "qrcode",
    "Generate a QR code image",
    {
      text: z.string().describe("The input string to generate qrcode"),
      size: z
        .number()
        .describe("The size of qrcode, default is 256")
        .default(256),
      darkColor: z
        .string()
        .describe("The dark color of qrcode, default is #000000")
        .default("#000000"),
      lightColor: z
        .string()
        .describe("The light color of qrcode, default is #ffffff")
        .default("#ffffff"),
      errorCorrectionLevel: z
        .enum(["L", "M", "Q", "H"])
        .describe("The error correction level of qrcode, default is M")
        .default("M"),
      margin: z
        .number()
        .describe("The margin of qrcode, default is 4")
        .default(4),
    },
    async ({
      text,
      size,
      darkColor,
      lightColor,
      errorCorrectionLevel,
      margin,
    }) => {
      const qrcode = await generateQRCode(text, {
        width: size,
        color: {
          dark: darkColor,
          light: lightColor,
        },
        errorCorrectionLevel,
        margin,
      });
  
      const base64Image = qrcode.split(",")[1];
  
      return Promise.resolve({
        content: [{ type: "image", data: base64Image, mimeType: "image/png" }],
      });
    }
  );

• src/service/qrcode.ts:19-44 (helper)

  Core helper function that generates QR code data URL using the 'qrcode' library, merging default and provided options.

  async function generateQRCode(
    text: string,
    options: QRCodeOptions = {}
  ): Promise<string> {
    try {
      const defaultOptions: QRCodeOptions = {
        width: 256,
        margin: 4,
        color: {
          dark: "#000000",
          light: "#ffffff",
        },
        errorCorrectionLevel: "M",
      };
  
      // 合并默认选项和用户选项
      const qrOptions = { ...defaultOptions, ...options };
  
      // 生成二维码（返回 base64 格式）
      const qrCodeImage = await QRCode.toDataURL(text, qrOptions);
      return qrCodeImage;
    } catch (error) {
      console.error("generateQRCode error:", error);
      throw error;
    }
  }

• src/service/qrcode.ts:3-11 (schema)

  TypeScript interface defining options for QR code generation, used internally by generateQRCode.

  interface QRCodeOptions {
    width?: number; // 二维码宽度
    margin?: number; // 二维码边距
    color?: {
      dark?: string; // 二维码颜色
      light?: string; // 背景颜色
    };
    errorCorrectionLevel?: "L" | "M" | "Q" | "H"; // 错误纠正级别
  }