feat: add support for multiple AI providers (OpenAI, Google, OpenRouter) with configurable models

Author: DarkPhoenix2704

.env.example

@@ -1,2 +1,15 @@
+# AI Model Configuration
+# Choose your provider: 'openai', 'google', or 'openrouter'
+AI_PROVIDER=openai
+
+# Specify the model ID for your chosen provider
+# Examples:
+# - OpenAI: gpt-4-turbo, gpt-4, gpt-3.5-turbo
+# - Google: gemini-1.5-pro, gemini-1.5-flash
+# - OpenRouter: openai/gpt-4-turbo, anthropic/claude-3.5-sonnet
+AI_MODEL=gpt-4.1-2025-04-14
+
+# API Keys for each provider (only set the one you're using)
 OPENAI_API_KEY=
-OPENAI_MODEL=gpt-4.1-2025-04-14
+GOOGLE_GENERATIVE_AI_API_KEY=
+OPENROUTER_API_KEY=

app/api/chat/route.ts

@@ -1,13 +1,10 @@
 import { ProvideLinksToolSchema } from '@/lib/ai-tools/inkeep-qa-schema';
 import { SearchDocsToolSchema, searchAndFetchDocs } from '@/lib/ai-tools/search-and-fetch';
-import { createOpenAI } from '@ai-sdk/openai';
 import { convertToModelMessages, stepCountIs, streamText } from 'ai';
 import { systemPrompt } from '@/lib/searchPrompt';
-import {validateRateLimit} from '@/utils/rateLimit';
+import { validateRateLimit } from '@/utils/rateLimit';
+import { createModel } from '@/lib/ai-models';
 
-const openai = createOpenAI({
-  apiKey: process.env.OPENAI_API_KEY,
-});
 
 export async function POST(req: Request) {
   const rateLimitError = validateRateLimit(req);
@@ -20,21 +17,21 @@ export async function POST(req: Request) {
   }
 
   const result = streamText({
-    model: openai(process.env.OPENAI_MODEL ?? 'gpt-4.1-2025-04-14'),
+    model: createModel(),
     tools: {
       searchDocs: {
         description: 'Search the NocoDB documentation and retrieve full page content. After calling this, you MUST read the returned content and write a comprehensive answer for the user based on that content.',
         inputSchema: SearchDocsToolSchema,
         execute: async ({ query }: { query: string }) => {
           const { markdown, links } = await searchAndFetchDocs(query, 3);
-          return {markdown, links};
+          return { markdown, links };
         },
       },
       provideLinks: {
         inputSchema: ProvideLinksToolSchema,
       },
     },
-   system: systemPrompt,
+    system: systemPrompt,
     messages: convertToModelMessages(reqJson.messages, {
       ignoreIncompleteToolCalls: true,
     }),

lib/ai-models.ts

@@ -0,0 +1,89 @@
+import { openai, createOpenAI } from '@ai-sdk/openai';
+import { google, createGoogleGenerativeAI } from '@ai-sdk/google';
+import { createOpenRouter } from '@openrouter/ai-sdk-provider';
+import type { LanguageModel } from 'ai';
+
+export type ModelProvider = 'openai' | 'google' | 'openrouter';
+
+/**
+ * Create a model instance based on environment configuration
+ * Reads from:
+ * - AI_PROVIDER: 'openai' | 'google' | 'openrouter' (default: 'openai')
+ * - AI_MODEL: model identifier (e.g., 'gpt-4', 'gemini-1.5-pro', 'openai/gpt-4')
+ * - OPENAI_API_KEY: for OpenAI provider (optional, uses default if not set)
+ * - GOOGLE_GENERATIVE_AI_API_KEY: for Google provider (optional, uses default if not set)
+ * - OPENROUTER_API_KEY: for OpenRouter provider (required for OpenRouter)
+ */
+export function createModel(): LanguageModel {
+  const provider = (process.env.AI_PROVIDER as ModelProvider) || 'openai';
+  const modelId = process.env.AI_MODEL;
+
+  switch (provider) {
+    case 'openai': {
+      const model = modelId || 'gpt-4-turbo';
+      // If custom API key is provided, create custom client
+      if (process.env.OPENAI_API_KEY) {
+        const customOpenAI = createOpenAI({
+          apiKey: process.env.OPENAI_API_KEY,
+        });
+        return customOpenAI(model);
+      }
+      return openai(model);
+    }
+    case 'google': {
+      const model = modelId || 'gemini-1.5-pro';
+      // If custom API key is provided, create custom client
+      if (process.env.GOOGLE_GENERATIVE_AI_API_KEY) {
+        const customGoogle = createGoogleGenerativeAI({
+          apiKey: process.env.GOOGLE_GENERATIVE_AI_API_KEY,
+        });
+        return customGoogle(model);
+      }
+      return google(model);
+    }
+    case 'openrouter': {
+      const model = modelId || 'openai/gpt-4-turbo';
+      const openrouter = createOpenRouter({
+        apiKey: process.env.OPENROUTER_API_KEY || '',
+      });
+      return openrouter(model);
+    }
+    default:
+      throw new Error(`Unsupported AI provider: ${provider}. Use 'openai', 'google', or 'openrouter'.`);
+  }
+}
+
+/**
+ * Create a model with custom provider and model ID
+ * Useful for switching models dynamically
+ */
+export function createCustomModel(
+  provider: ModelProvider,
+  modelId: string,
+  apiKey?: string
+): LanguageModel {
+  switch (provider) {
+    case 'openai': {
+      if (apiKey) {
+        const customOpenAI = createOpenAI({ apiKey });
+        return customOpenAI(modelId);
+      }
+      return openai(modelId);
+    }
+    case 'google': {
+      if (apiKey) {
+        const customGoogle = createGoogleGenerativeAI({ apiKey });
+        return customGoogle(modelId);
+      }
+      return google(modelId);
+    }
+    case 'openrouter': {
+      const openrouter = createOpenRouter({
+        apiKey: apiKey || process.env.OPENROUTER_API_KEY || '',
+      });
+      return openrouter(modelId);
+    }
+    default:
+      throw new Error(`Unsupported provider: ${provider}`);
+  }
+}

package.json

@@ -16,9 +16,11 @@
     "postbuild": "next-sitemap && npm run generate-blog-sitemap && npm run generate-llm-content"
   },
   "dependencies": {
+    "@ai-sdk/google": "^2.0.23",
     "@ai-sdk/openai": "^2.0.52",
     "@ai-sdk/react": "^2.0.59",
     "@icons-pack/react-simple-icons": "^13.8.0",
+    "@openrouter/ai-sdk-provider": "^1.2.0",
     "@radix-ui/react-collapsible": "^1.1.8",
     "@radix-ui/react-dialog": "^1.1.13",
     "@radix-ui/react-dropdown-menu": "^2.1.7",