#!/usr/bin/env node
import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
import { z } from "zod";
import crypto from "crypto";
// 火山引擎即梦AI API配置
const ENDPOINT = "https://visual.volcengineapi.com";
const HOST = "visual.volcengineapi.com";
const REGION = "cn-north-1";
const SERVICE = "cv";
// 环境变量配置
const JIMENG_ACCESS_KEY = process.env.JIMENG_ACCESS_KEY;
const JIMENG_SECRET_KEY = process.env.JIMENG_SECRET_KEY;
if (!JIMENG_ACCESS_KEY || !JIMENG_SECRET_KEY) {
console.error("警告：未设置环境变量 JIMENG_ACCESS_KEY 和 JIMENG_SECRET_KEY");
console.error("服务将启动但无法调用API功能，仅供测试使用");
}
// 图片比例映射
const RATIO_MAPPING: Record<string, { width: number; height: number }> = {
"4:3": { width: 512, height: 384 },
"3:4": { width: 384, height: 512 },
"16:9": { width: 512, height: 288 },
"9:16": { width: 288, height: 512 }
};
// 辅助函数：生成签名密钥
function getSignatureKey(key: string, dateStamp: string, regionName: string, serviceName: string): Buffer {
const kDate = crypto.createHmac('sha256', key).update(dateStamp).digest();
const kRegion = crypto.createHmac('sha256', kDate).update(regionName).digest();
const kService = crypto.createHmac('sha256', kRegion).update(serviceName).digest();
const kSigning = crypto.createHmac('sha256', kService).update('request').digest();
return kSigning;
}
// 格式化查询参数
function formatQuery(parameters: Record<string, string>): string {
const sortedKeys = Object.keys(parameters).sort();
return sortedKeys.map(key => `${key}=${parameters[key]}`).join('&');
}
// 火山引擎V4签名算法
function signV4Request(
accessKey: string,
secretKey: string,
service: string,
reqQuery: string,
reqBody: string
): { headers: Record<string, string>; requestUrl: string } {
const t = new Date();
const currentDate = t.toISOString().replace(/[:\-]|\.\d{3}/g, '');
const datestamp = currentDate.substring(0, 8);
const method = 'POST';
const canonicalUri = '/';
const canonicalQuerystring = reqQuery;
const signedHeaders = 'content-type;host;x-content-sha256;x-date';
const payloadHash = crypto.createHash('sha256').update(reqBody).digest('hex');
const contentType = 'application/json';
const canonicalHeaders = [
`content-type:${contentType}`,
`host:${HOST}`,
`x-content-sha256:${payloadHash}`,
`x-date:${currentDate}`
].join('\n') + '\n';
const canonicalRequest = [
method,
canonicalUri,
canonicalQuerystring,
canonicalHeaders,
signedHeaders,
payloadHash
].join('\n');
const algorithm = 'HMAC-SHA256';
const credentialScope = `${datestamp}/${REGION}/${service}/request`;
const stringToSign = [
algorithm,
currentDate,
credentialScope,
crypto.createHash('sha256').update(canonicalRequest).digest('hex')
].join('\n');
const signingKey = getSignatureKey(secretKey, datestamp, REGION, service);
const signature = crypto.createHmac('sha256', signingKey).update(stringToSign).digest('hex');
const authorizationHeader = `${algorithm} Credential=${accessKey}/${credentialScope}, SignedHeaders=${signedHeaders}, Signature=${signature}`;
const headers = {
'X-Date': currentDate,
'Authorization': authorizationHeader,
'X-Content-Sha256': payloadHash,
'Content-Type': contentType
};
const requestUrl = `${ENDPOINT}?${canonicalQuerystring}`;
return { headers, requestUrl };
}
// 生成组合后的prompt
function generatePrompt(text: string, illustration: string, color: string): string {
return `字体设计："${text}"，黑色字体，斜体，带阴影。干净的背景，白色到${color}渐变。点缀浅灰色、半透明${illustration}等元素插图做配饰插画。`;
}
// 调用即梦AI API
async function callJimengAPI(prompt: string, ratio: { width: number; height: number }): Promise<string | null> {
// 查询参数
const queryParams = {
'Action': 'CVProcess',
'Version': '2022-08-31'
};
const formattedQuery = formatQuery(queryParams);
// 请求体参数
const bodyParams = {
req_key: "jimeng_high_aes_general_v21_L",
prompt: prompt,
return_url: true,
width: ratio.width,
height: ratio.height
};
const formattedBody = JSON.stringify(bodyParams);
try {
// 生成签名和请求头
const { headers, requestUrl } = signV4Request(
JIMENG_ACCESS_KEY!,
JIMENG_SECRET_KEY!,
SERVICE,
formattedQuery,
formattedBody
);
const response = await fetch(requestUrl, {
method: 'POST',
headers: headers,
body: formattedBody
});
if (!response.ok) {
throw new Error(`HTTP error! status: ${response.status}`);
}
const responseText = await response.text();
// 替换转义字符，与Python示例保持一致
const cleanedResponse = responseText.replace(/\\u0026/g, "&");
const result = JSON.parse(cleanedResponse);
// 根据火山引擎即梦AI API响应格式解析结果
if (result.ResponseMetadata && result.ResponseMetadata.Error) {
throw new Error(`API error: ${result.ResponseMetadata.Error.Message || 'Unknown error'}`);
}
// 返回生成的图片URL - 根据搜索结果，即梦AI返回的是data.image_urls数组
if (result.data && result.data.image_urls && result.data.image_urls.length > 0) {
return result.data.image_urls[0];
}
return null;
} catch (error) {
console.error("调用即梦AI API时出错:", error);
return null;
}
}
// 创建MCP服务器实例
const server = new McpServer({
name: "jimengpic",
version: "1.0.0",
});
// 注册图片生成工具
server.tool(
"generate-image",
"当用户需要生成图片时使用的工具",
{
text: z.string().describe("用户需要在图片上显示的文字"),
illustration: z.string().describe("根据用户要显示的文字，提取3-5个可以作为图片配饰的插画元素关键词"),
color: z.string().describe("图片的背景主色调"),
ratio: z.enum(["4:3", "3:4", "16:9", "9:16"]).describe("图片比例。支持: 4:3 (512*384), 3:4 (384*512), 16:9 (512*288), 9:16 (288*512)")
},
async ({ text, illustration, color, ratio }: { text: string; illustration: string; color: string; ratio: string }) => {
const imageSize = RATIO_MAPPING[ratio];
if (!imageSize) {
return {
content: [
{
type: "text",
text: `错误：不支持的图片比例 ${ratio}。支持的比例: 4:3, 3:4, 16:9, 9:16`
}
]
};
}
// 检查API密钥是否配置
if (!JIMENG_ACCESS_KEY || !JIMENG_SECRET_KEY) {
return {
content: [
{
type: "text",
text: "错误：未设置环境变量 JIMENG_ACCESS_KEY 和 JIMENG_SECRET_KEY，无法调用API。"
}
]
};
}
// 生成组合后的prompt
const prompt = generatePrompt(text, illustration, color);
const imageUrl = await callJimengAPI(prompt, imageSize);
if (!imageUrl) {
return {
content: [
{
type: "text",
text: "生成图片失败，请检查网络连接和API密钥配置。"
}
]
};
}
return {
content: [
{
type: "text",
text: `图片生成成功！\n\n显示文字: ${text}\n配饰元素: ${illustration}\n背景色调: ${color}\n图片比例: ${ratio} (${imageSize.width}×${imageSize.height})\n生成提示词: ${prompt}\n图片URL: ${imageUrl}`
}
]
};
}
);
// 启动服务器
async function main() {
const transport = new StdioServerTransport();
await server.connect(transport);
console.error("即梦AI图片生成MCP服务已启动");
}
main().catch((error) => {
console.error("启动服务时发生错误:", error);
process.exit(1);
});
