Feat/add litellm provider

app/api/[provider]/[...path]/route.ts

@@ -16,6 +16,7 @@ import { handle as xaiHandler } from "../../xai";
 import { handle as chatglmHandler } from "../../glm";
 import { handle as proxyHandler } from "../../proxy";
 import { handle as ai302Handler } from "../../302ai";
+import { handle as litellmHandler } from "../../litellm";
 
 async function handle(
   req: NextRequest,
@@ -55,6 +56,8 @@ async function handle(
       return openaiHandler(req, { params });
     case ApiPath["302.AI"]:
       return ai302Handler(req, { params });
+    case ApiPath.LiteLLM:
+      return litellmHandler(req, { params });
     default:
       return proxyHandler(req, { params });
   }

app/api/auth.ts

@@ -104,6 +104,9 @@ export function auth(req: NextRequest, modelProvider: ModelProvider) {
       case ModelProvider.SiliconFlow:
         systemApiKey = serverConfig.siliconFlowApiKey;
         break;
+      case ModelProvider.LiteLLM:
+        systemApiKey = serverConfig.litellmApiKey;
+        break;
       case ModelProvider.GPT:
       default:
         if (req.nextUrl.pathname.includes("azure/deployments")) {

app/api/litellm.ts

@@ -0,0 +1,123 @@
+import { getServerSideConfig } from "@/app/config/server";
+import {
+  LITELLM_BASE_URL,
+  ApiPath,
+  ModelProvider,
+  ServiceProvider,
+} from "@/app/constant";
+import { prettyObject } from "@/app/utils/format";
+import { NextRequest, NextResponse } from "next/server";
+import { auth } from "@/app/api/auth";
+import { isModelNotavailableInServer } from "@/app/utils/model";
+
+const serverConfig = getServerSideConfig();
+
+export async function handle(
+  req: NextRequest,
+  { params }: { params: { path: string[] } },
+) {
+  console.log("[LiteLLM Route] params ", params);
+
+  if (req.method === "OPTIONS") {
+    return NextResponse.json({ body: "OK" }, { status: 200 });
+  }
+
+  const authResult = auth(req, ModelProvider.LiteLLM);
+  if (authResult.error) {
+    return NextResponse.json(authResult, {
+      status: 401,
+    });
+  }
+
+  try {
+    const response = await request(req);
+    return response;
+  } catch (e) {
+    console.error("[LiteLLM] ", e);
+    return NextResponse.json(prettyObject(e));
+  }
+}
+
+async function request(req: NextRequest) {
+  const controller = new AbortController();
+
+  let path = `${req.nextUrl.pathname}`.replaceAll(ApiPath.LiteLLM, "");
+
+  let baseUrl = serverConfig.litellmUrl || LITELLM_BASE_URL;
+
+  if (!baseUrl.startsWith("http")) {
+    baseUrl = `https://${baseUrl}`;
+  }
+
+  if (baseUrl.endsWith("/")) {
+    baseUrl = baseUrl.slice(0, -1);
+  }
+
+  console.log("[Proxy] ", path);
+  console.log("[Base Url]", baseUrl);
+
+  const timeoutId = setTimeout(
+    () => {
+      controller.abort();
+    },
+    10 * 60 * 1000,
+  );
+
+  const fetchUrl = `${baseUrl}${path}`;
+  const fetchOptions: RequestInit = {
+    headers: {
+      "Content-Type": "application/json",
+      Authorization: req.headers.get("Authorization") ?? "",
+    },
+    method: req.method,
+    body: req.body,
+    redirect: "manual",
+    // @ts-ignore
+    duplex: "half",
+    signal: controller.signal,
+  };
+
+  if (serverConfig.customModels && req.body) {
+    try {
+      const clonedBody = await req.text();
+      fetchOptions.body = clonedBody;
+
+      const jsonBody = JSON.parse(clonedBody) as { model?: string };
+
+      if (
+        isModelNotavailableInServer(
+          serverConfig.customModels,
+          jsonBody?.model as string,
+          ServiceProvider.LiteLLM as string,
+        )
+      ) {
+        return NextResponse.json(
+          {
+            error: true,
+            message: `you are not allowed to use ${jsonBody?.model} model`,
+          },
+          {
+            status: 403,
+          },
+        );
+      }
+    } catch (e) {
+      console.error(`[LiteLLM] filter`, e);
+    }
+  }
+  try {
+    const res = await fetch(fetchUrl, fetchOptions);
+
+    const newHeaders = new Headers(res.headers);
+    newHeaders.delete("www-authenticate");
+    newHeaders.set("X-Accel-Buffering", "no");
+
+    return new Response(res.body, {
+      status: res.status,
+      statusText: res.statusText,
+      headers: newHeaders,
+    });
+  } finally {
+    clearTimeout(timeoutId);
+  }
+}

app/client/api.ts

@@ -25,6 +25,7 @@ import { XAIApi } from "./platforms/xai";
 import { ChatGLMApi } from "./platforms/glm";
 import { SiliconflowApi } from "./platforms/siliconflow";
 import { Ai302Api } from "./platforms/ai302";
+import { LiteLLMApi } from "./platforms/litellm";
 
 export const ROLES = ["system", "user", "assistant"] as const;
 export type MessageRole = (typeof ROLES)[number];
@@ -177,6 +178,9 @@ export class ClientApi {
       case ModelProvider["302.AI"]:
         this.llm = new Ai302Api();
         break;
+      case ModelProvider.LiteLLM:
+        this.llm = new LiteLLMApi();
+        break;
       default:
         this.llm = new ChatGPTApi();
     }
@@ -393,6 +397,8 @@ export function getClientApi(provider: ServiceProvider): ClientApi {
       return new ClientApi(ModelProvider.SiliconFlow);
     case ServiceProvider["302.AI"]:
       return new ClientApi(ModelProvider["302.AI"]);
+    case ServiceProvider.LiteLLM:
+      return new ClientApi(ModelProvider.LiteLLM);
     default:
       return new ClientApi(ModelProvider.GPT);
   }