import express from 'express'; import fetch from 'node-fetch'; import dotenv from 'dotenv'; dotenv.config(); // ================= 配置读取区域 ================= const PORT = process.env.PORT || 3000; const PROXY_AUTH_KEY = process.env.PROXY_AUTH_KEY; const UPSTREAM_URL = process.env.UPSTREAM_URL || 'https://llm-gateway.assemblyai.com/v1/chat/completions'; // 读取并处理 Key 列表 const rawKeys = process.env.UPSTREAM_KEYS || ''; // 以逗号分割，去除首尾空格，并过滤空项 const UPSTREAM_KEYS = rawKeys.split(';').map(k => k.trim()).filter(k => k.length > 0); // 检查配置是否正确 if (!PROXY_AUTH_KEY) { console.error('Error: 请在环境变量中配置 PROXY_AUTH_KEY'); process.exit(1); } if (UPSTREAM_KEYS.length === 0) { console.error('Error: 请在环境变量 UPSTREAM_KEYS 中至少配置一个 Key'); process.exit(1); } // ============================================== // Key 轮询索引 let keyIndex = 0; /** * 获取下一个 Key (Round-Robin / 轮询) */ const getNextKey = () => { const key = UPSTREAM_KEYS[keyIndex]; keyIndex = (keyIndex + 1) % UPSTREAM_KEYS.length; return key; }; const app = express(); // 解析 JSON 请求体，调大限制以防止大文本报错 app.use(express.json({ limit: '50mb' })); /** * 中间件：鉴权校验 */ const authMiddleware = (req, res, next) => { const authHeader = req.headers['authorization']; if (!authHeader) { return res.status(401).json({ error: 'Missing Authorization header' }); } // 提取 Bearer token const token = authHeader.replace('Bearer ', '').trim(); if (token !== PROXY_AUTH_KEY) { return res.status(403).json({ error: 'Invalid Proxy Authorization Key' }); } next(); }; /** * 消息处理逻辑： * 1. system -> user * 2. 过滤图片 * 3. 合并相同 Role * 4. 格式化 content 为数组对象 */ const processMessages = (messages) => { if (!Array.isArray(messages)) return []; const processedMessages = []; let currentMessage = null; for (const msg of messages) { // 1. 转换 role: system -> user const role = msg.role === 'system' ? 'user' : msg.role; // 2. 提取纯文本内容 (过滤图片) let textContent = ''; if (typeof msg.content === 'string') { textContent = msg.content; } else if (Array.isArray(msg.content)) { // 过滤 content 数组，只保留 type='text'，并忽略 type='image_url' textContent = msg.content .filter(item => item.type === 'text') .map(item => item.text) .join('\n'); } // 如果该条消息没有文本内容，直接跳过 if (!textContent) continue; // 3. 合并逻辑 if (currentMessage && currentMessage.role === role) { // 相同角色，合并内容，使用 \n 拼接 currentMessage.textBuffer += '\n' + textContent; } else { // 不同角色，先保存上一个（如果有） if (currentMessage) { processedMessages.push({ role: currentMessage.role, content: currentMessage.textBuffer }); } // 开启新消息块 currentMessage = { role: role, textBuffer: textContent }; } } // 把最后一条暂存的消息推入数组 if (currentMessage) { processedMessages.push({ role: currentMessage.role, content: currentMessage.textBuffer }); } return processedMessages; }; /** * 路由：Chat Completions */ app.post('/v1/chat/completions', authMiddleware, async (req, res) => { try { const { model, messages, stream = false, ...restBody } = req.body; // 预处理消息 const newMessages = processMessages(messages); // 获取轮询 Key const currentKey = getNextKey(); console.log(`[Request] Model: ${model}, Using Key Index: ${keyIndex === 0 ? UPSTREAM_KEYS.length - 1 : keyIndex - 1}`); // 构建发往上游的请求体 const upstreamBody = { model: model, messages: newMessages, stream: stream, ...restBody }; // 发送请求 const response = await fetch(UPSTREAM_URL, { method: 'POST', headers: { 'Content-Type': 'application/json', 'Authorization': `Bearer ${currentKey}` }, body: JSON.stringify(upstreamBody) }); if (!response.ok) { const errText = await response.text(); console.error('[Upstream Error]', response.status, errText); return res.status(response.status).send(errText); } // 处理流式响应 (Stream) if (stream) { res.setHeader('Content-Type', 'text/event-stream'); res.setHeader('Cache-Control', 'no-cache'); res.setHeader('Connection', 'keep-alive'); if (response.body) { for await (const chunk of response.body) { res.write(chunk); } res.end(); } } else { // 处理普通响应 const data = await response.json(); res.json(data); } } catch (error) { console.error('[Server Error]', error); res.status(500).json({ error: 'Internal Server Error', details: error.message }); } }); /** * 路由：模型列表 */ app.get('/v1/models', authMiddleware, (req, res) => { const modelsData = { object: "list", data: [ { "id": "claude-3-haiku-20240307", "name": "claude-3-haiku-20240307", "description": "", "top_provider": { "is_moderated": false, "context_length": 200000, "max_completion_tokens": 4096 }, "context_length": 200000, "supported_parameters": [], "default_parameters": { "temperature": null, "top_p": null, "frequency_penalty": null } }, { "id": "claude-3-5-haiku-20241022", "name": "claude-3-5-haiku-20241022", "description": "", "top_provider": { "is_moderated": false, "context_length": 200000, "max_completion_tokens": 8192 }, "context_length": 200000, "supported_parameters": [], "default_parameters": { "temperature": null, "top_p": null, "frequency_penalty": null } }, { "id": "claude-sonnet-4-20250514", "name": "claude-sonnet-4-20250514", "description": "", "top_provider": { "is_moderated": false, "context_length": 200000, "max_completion_tokens": 64000 }, "context_length": 200000, "supported_parameters": [], "default_parameters": { "temperature": null, "top_p": null, "frequency_penalty": null } }, { "id": "claude-sonnet-4-5-20250929", "name": "claude-sonnet-4-5-20250929", "description": "", "top_provider": { "is_moderated": false, "context_length": 200000, "max_completion_tokens": 64000 }, "context_length": 200000, "supported_parameters": [], "default_parameters": { "temperature": null, "top_p": null, "frequency_penalty": null } }, { "id": "claude-haiku-4-5-20251001", "name": "claude-haiku-4-5-20251001", "description": "", "top_provider": { "is_moderated": false, "context_length": 200000, "max_completion_tokens": 64000 }, "context_length": 200000, "supported_parameters": [], "default_parameters": { "temperature": null, "top_p": null, "frequency_penalty": null } }, { "id": "claude-opus-4-20250514", "name": "claude-opus-4-20250514", "description": "", "top_provider": { "is_moderated": false, "context_length": 200000, "max_completion_tokens": 32768 }, "context_length": 200000, "supported_parameters": [], "default_parameters": { "temperature": null, "top_p": null, "frequency_penalty": null } }, { "id": "gpt-oss-20b", "name": "gpt-oss-20b", "description": "", "top_provider": { "is_moderated": false, "context_length": 131072, "max_completion_tokens": 131072 }, "context_length": 131072, "supported_parameters": [], "default_parameters": { "temperature": null, "top_p": null, "frequency_penalty": null } }, { "id": "gpt-oss-120b", "name": "gpt-oss-120b", "description": "", "top_provider": { "is_moderated": false, "context_length": 131072, "max_completion_tokens": 131072 }, "context_length": 131072, "supported_parameters": [], "default_parameters": { "temperature": null, "top_p": null, "frequency_penalty": null } }, { "id": "gpt-5", "name": "gpt-5", "description": "", "top_provider": { "is_moderated": false, "context_length": 400000, "max_completion_tokens": 128000 }, "context_length": 400000, "supported_parameters": [], "default_parameters": { "temperature": null, "top_p": null, "frequency_penalty": null } }, { "id": "gpt-5-nano", "name": "gpt-5-nano", "description": "", "top_provider": { "is_moderated": false, "context_length": 400000, "max_completion_tokens": 128000 }, "context_length": 400000, "supported_parameters": [], "default_parameters": { "temperature": null, "top_p": null, "frequency_penalty": null } }, { "id": "gpt-5-mini", "name": "gpt-5-mini", "description": "", "top_provider": { "is_moderated": false, "context_length": 400000, "max_completion_tokens": 128000 }, "context_length": 400000, "supported_parameters": [], "default_parameters": { "temperature": null, "top_p": null, "frequency_penalty": null } }, { "id": "gpt-4.1", "name": "gpt-4.1", "description": "", "top_provider": { "is_moderated": false, "context_length": 1047576, "max_completion_tokens": 32768 }, "context_length": 1047576, "supported_parameters": [], "default_parameters": { "temperature": null, "top_p": null, "frequency_penalty": null } }, { "id": "chatgpt-4o-latest", "name": "chatgpt-4o-latest", "description": "", "top_provider": { "is_moderated": false, "context_length": 128000, "max_completion_tokens": 16384 }, "context_length": 128000, "supported_parameters": [], "default_parameters": { "temperature": null, "top_p": null, "frequency_penalty": null } }, { "id": "gemini-2.5-flash-lite", "name": "gemini-2.5-flash-lite", "description": "", "top_provider": { "is_moderated": false, "context_length": 1048576, "max_completion_tokens": 65535 }, "context_length": 1048576, "supported_parameters": [], "default_parameters": { "temperature": null, "top_p": null, "frequency_penalty": null } }, { "id": "gemini-2.5-flash", "name": "gemini-2.5-flash", "description": "", "top_provider": { "is_moderated": false, "context_length": 1048576, "max_completion_tokens": 65535 }, "context_length": 1048576, "supported_parameters": [], "default_parameters": { "temperature": null, "top_p": null, "frequency_penalty": null } }, { "id": "gemini-2.5-pro", "name": "gemini-2.5-pro", "description": "", "top_provider": { "is_moderated": false, "context_length": 200000, "max_completion_tokens": 65535 }, "context_length": 200000, "supported_parameters": [], "default_parameters": { "temperature": null, "top_p": null, "frequency_penalty": null } }, { "id": "gemini-3-pro-preview", "name": "gemini-3-pro-preview", "description": "", "top_provider": { "is_moderated": false, "context_length": 1048575, "max_completion_tokens": 65535 }, "context_length": 1048575, "supported_parameters": [], "default_parameters": { "temperature": null, "top_p": null, "frequency_penalty": null } } ] }; res.json(modelsData); }); // 启动服务器 app.listen(PORT, () => { console.log(`Proxy Server running on port ${PORT}`); console.log(`Loaded ${UPSTREAM_KEYS.length} upstream keys.`); });