Support for Google's Vertex AI

package.json

@@ -53,7 +53,7 @@
     "prettier": "3.2.5",
     "rollup": "^4.9.1",
     "tsx": "^4.7.0",
-    "wrangler": "^3.0.1"
+    "wrangler": "^3.48.0"
   },
   "bin": "build/start-server.js",
   "type": "module"

src/globals.ts

@@ -30,6 +30,7 @@ export const ANYSCALE: string = 'anyscale';
 export const PALM: string = 'palm';
 export const TOGETHER_AI: string = 'together-ai';
 export const GOOGLE: string = 'google';
+export const GOOGLE_VERTEX_AI: string = 'vertex-ai';
 export const PERPLEXITY_AI: string = 'perplexity-ai';
 export const MISTRAL_AI: string = 'mistral-ai';
 export const DEEPINFRA: string = 'deepinfra';
@@ -50,6 +51,7 @@ export const VALID_PROVIDERS = [
   AZURE_OPEN_AI,
   COHERE,
   GOOGLE,
+  GOOGLE_VERTEX_AI,
   MISTRAL_AI,
   OPEN_AI,
   PALM,

src/handlers/handlerUtils.ts

@@ -191,6 +191,10 @@ export const fetchProviderOptionsFromConfig = (
       providerOptions[0].deploymentId = camelCaseConfig.deploymentId;
     if (camelCaseConfig.apiVersion)
       providerOptions[0].apiVersion = camelCaseConfig.apiVersion;
+    if (camelCaseConfig.apiVersion)
+      providerOptions[0].vertexProjectId = camelCaseConfig.vertexProjectId;
+    if (camelCaseConfig.apiVersion)
+      providerOptions[0].vertexRegion = camelCaseConfig.vertexRegion;
     if (camelCaseConfig.workersAiAccountId)
       providerOptions[0].workersAiAccountId =
         camelCaseConfig.workersAiAccountId;
@@ -395,7 +399,11 @@ export async function tryPostProxy(
   c.set('requestOptions', [
     ...requestOptions,
     {
-      providerOptions: { ...providerOption, requestURL: url, rubeusURL: fn },
+      providerOptions: {
+        ...providerOption,
+        requestURL: url,
+        rubeusURL: fn,
+      },
       requestParams: params,
       response: mappedResponse.clone(),
       cacheStatus: cacheStatus,
@@ -589,7 +597,11 @@ export async function tryPost(
   c.set('requestOptions', [
     ...requestOptions,
     {
-      providerOptions: { ...providerOption, requestURL: url, rubeusURL: fn },
+      providerOptions: {
+        ...providerOption,
+        requestURL: url,
+        rubeusURL: fn,
+      },
       requestParams: transformedRequestBody,
       response: mappedResponse.clone(),
       cacheStatus: cacheStatus,

src/handlers/streamHandler.ts

@@ -8,7 +8,7 @@ import {
 } from '../globals';
 import { OpenAIChatCompleteResponse } from '../providers/openai/chatComplete';
 import { OpenAICompleteResponse } from '../providers/openai/complete';
-import { getStreamModeSplitPattern } from '../utils';
+import { getStreamModeSplitPattern, type SplitPatternType } from '../utils';
 
 function readUInt32BE(buffer: Uint8Array, offset: number) {
   return (
@@ -114,7 +114,7 @@ export async function* readAWSStream(
 
 export async function* readStream(
   reader: ReadableStreamDefaultReader,
-  splitPattern: string,
+  splitPattern: SplitPatternType,
   transformFunction: Function | undefined,
   isSleepTimeRequired: boolean,
   fallbackChunkId: string
@@ -235,7 +235,9 @@ export async function handleStreamingMode(
   requestURL: string
 ): Promise<Response> {
   const splitPattern = getStreamModeSplitPattern(proxyProvider, requestURL);
-  const fallbackChunkId = Date.now().toString();
+  // If the provider doesn't supply completion id,
+  // we generate a fallback id using the provider name + timestamp.
+  const fallbackChunkId = `${proxyProvider}-${Date.now().toString()}`;
 
   if (!response.body) {
     throw new Error('Response format is invalid. Body not found');
@@ -274,7 +276,12 @@ export async function handleStreamingMode(
 
   // Convert GEMINI/COHERE json stream to text/event-stream for non-proxy calls
   if (
-    [GOOGLE, COHERE, BEDROCK].includes(proxyProvider) &&
+    [
+      //
+      GOOGLE,
+      COHERE,
+      BEDROCK,
+    ].includes(proxyProvider) &&
     responseTransformer
   ) {
     return new Response(readable, {

src/middlewares/requestValidator/schema/config.ts

@@ -1,5 +1,5 @@
 import { z } from 'zod';
-import { OLLAMA, VALID_PROVIDERS } from '../../../globals';
+import { OLLAMA, VALID_PROVIDERS, GOOGLE_VERTEX_AI } from '../../../globals';
 
 export const configSchema: any = z
   .object({
@@ -20,7 +20,9 @@ export const configSchema: any = z
     provider: z
       .string()
       .refine((value) => VALID_PROVIDERS.includes(value), {
-        message: `Invalid 'provider' value. Must be one of: ${VALID_PROVIDERS.join(', ')}`,
+        message: `Invalid 'provider' value. Must be one of: ${VALID_PROVIDERS.join(
+          ', '
+        )}`,
       })
       .optional(),
     api_key: z.string().optional(),
@@ -57,6 +59,9 @@ export const configSchema: any = z
     request_timeout: z.number().optional(),
     custom_host: z.string().optional(),
     forward_headers: z.array(z.string()).optional(),
+    // Google Vertex AI specific
+    vertex_project_id: z.string().optional(),
+    vertex_region: z.string().optional(),
   })
   .refine(
     (value) => {
@@ -94,4 +99,16 @@ export const configSchema: any = z
     {
       message: 'Invalid custom host',
     }
+  )
+  // Validate Google Vertex AI specific fields
+  .refine(
+    (value) => {
+      const isGoogleVertexAIProvider = value.provider === GOOGLE_VERTEX_AI;
+      const hasGoogleVertexAIFields =
+        value.vertex_project_id && value.vertex_region;
+      return !(isGoogleVertexAIProvider && !hasGoogleVertexAIFields);
+    },
+    {
+      message: `Invalid configuration. 'vertex_project_id' and 'vertex_region' are required for '${GOOGLE_VERTEX_AI}' provider. Example: { 'provider': 'vertex-ai', 'vertex_project_id': 'my-project-id', 'vertex_region': 'us-central1', api_key: 'ya29...' }`,
+    }
   );

src/providers/google-vertex-ai/api.ts

@@ -0,0 +1,42 @@
+import { ProviderAPIConfig } from '../types';
+
+// Good reference for using REST: https://cloud.google.com/vertex-ai/generative-ai/docs/start/quickstarts/quickstart-multimodal#gemini-beginner-samples-drest
+// Difference versus Studio AI: https://cloud.google.com/vertex-ai/docs/start/ai-platform-users
+export const GoogleApiConfig: ProviderAPIConfig = {
+  getBaseURL: ({ providerOptions }) => {
+    const { vertexProjectId, vertexRegion } = providerOptions;
+
+    return `https://${vertexRegion}-aiplatform.googleapis.com/v1/projects/${vertexProjectId}/locations/${vertexRegion}/publishers/google`;
+  },
+  headers: ({ providerOptions }) => {
+    const { apiKey } = providerOptions;
+
+    return {
+      'Content-Type': 'application/json',
+      Authorization: `Bearer ${apiKey}`,
+    };
+  },
+  getEndpoint: ({ fn, gatewayRequestBody }) => {
+    let mappedFn = fn;
+    const { model, stream } = gatewayRequestBody;
+    if (stream) {
+      mappedFn = `stream-${fn}`;
+    }
+    switch (mappedFn) {
+      case 'chatComplete': {
+        return `/models/${model}:generateContent`;
+      }
+      case 'stream-chatComplete': {
+        return `/models/${model}:streamGenerateContent?alt=sse`;
+      }
+
+      // Embed API is not yet implemented in the gateway
+      // This may be as easy as copy-paste from Google provider, but needs to be tested
+
+      default:
+        return '';
+    }
+  },
+};
+
+export default GoogleApiConfig;