import { createAmazonBedrock } from "@ai-sdk/amazon-bedrock";
import { createAnthropic } from "@ai-sdk/anthropic";
import { createAzure } from "@ai-sdk/azure";
import { createGoogleGenerativeAI } from "@ai-sdk/google";
import { createOpenAI } from "@ai-sdk/openai";
/**
* Initializes the AI model provider.
*
* Two modes:
* 1. Vercel AI Gateway: If AI_GATEWAY_API_KEY is set, routes through a unified gateway that handles
* provider abstraction. Just returns the provider model string (e.g. "anthropic/claude-sonnet-4-5").
* The gateway handles auth and routing to the actual provider.
*
* 2. Direct AI SDK Providers: Falls back to initializing specific providers (Anthropic, OpenAI,
* Gemini, Azure) using Vercel AI SDK. Requires provider-specific API keys and configs.
* Uses provider-specific model env vars (e.g., OPENAI_MODEL, ANTHROPIC_MODEL, GEMINI_MODEL).
*
* @param options - Configuration options
* @param options.providerEnvVar - Environment variable name for the provider (default: 'LLM_PROVIDER')
* @param options.defaultModel - Default model if not specified in env (default: 'gpt-4.1')
* @returns AI model instance that can be used with Vercel AI SDK functions
*/
export function initializeAIModel(options?: {
providerEnvVar?: string;
defaultModel?: string;
}): any {
const providerEnvVar = options?.providerEnvVar || "LLM_PROVIDER";
const defaultModel = options?.defaultModel || "gpt-4.1";
if (process.env.AI_GATEWAY_API_KEY && process.env.AI_GATEWAY_MODEL) {
return process.env.AI_GATEWAY_MODEL;
}
let provider: any;
let modelId: string;
const providerType = process.env[providerEnvVar]?.toLowerCase();
switch (providerType) {
case "anthropic": {
const anthropicOptions: any = {
apiKey: process.env.ANTHROPIC_API_KEY,
headers: { "anthropic-beta": "context-1m-2025-08-07" },
};
if (process.env.ANTHROPIC_BASE_URL) {
anthropicOptions.baseURL = process.env.ANTHROPIC_BASE_URL;
}
provider = createAnthropic(anthropicOptions);
modelId = process.env.ANTHROPIC_MODEL || defaultModel;
break;
}
case "openai": {
const openaiOptions: any = { apiKey: process.env.OPENAI_API_KEY };
if (process.env.OPENAI_BASE_URL) {
openaiOptions.baseURL = process.env.OPENAI_BASE_URL;
}
provider = createOpenAI(openaiOptions);
modelId = process.env.OPENAI_MODEL || defaultModel;
break;
}
case "gemini": {
const geminiOptions: any = { apiKey: process.env.GEMINI_API_KEY };
if (process.env.GEMINI_BASE_URL) {
geminiOptions.baseURL = process.env.GEMINI_BASE_URL;
}
provider = createGoogleGenerativeAI(geminiOptions);
modelId = process.env.GEMINI_MODEL || defaultModel;
break;
}
case "azure": {
const azureOptions: any = { apiKey: process.env.AZURE_API_KEY };
if (!process.env.AZURE_RESOURCE_NAME && !process.env.AZURE_BASE_URL) {
throw new Error("Either AZURE_RESOURCE_NAME or AZURE_BASE_URL needs to be set");
}
if (process.env.AZURE_RESOURCE_NAME) {
azureOptions.resourceName = process.env.AZURE_RESOURCE_NAME;
}
if (process.env.AZURE_BASE_URL) {
azureOptions.baseURL = process.env.AZURE_BASE_URL;
}
if (process.env.AZURE_API_VERSION) {
azureOptions.apiVersion = process.env.AZURE_API_VERSION;
}
if (process.env.AZURE_USE_DEPLOYMENT_BASED_URLS) {
azureOptions.useDeploymentBasedUrls = process.env.AZURE_USE_DEPLOYMENT_BASED_URLS;
}
provider = createAzure(azureOptions);
modelId = process.env.AZURE_MODEL || defaultModel;
break;
}
case "bedrock": {
const bedrockOptions: any = {
region: process.env.AWS_REGION,
accessKeyId: process.env.AWS_ACCESS_KEY_ID,
secretAccessKey: process.env.AWS_SECRET_ACCESS_KEY,
};
if (process.env.AWS_SESSION_TOKEN) {
bedrockOptions.sessionToken = process.env.AWS_SESSION_TOKEN;
}
if (process.env.AWS_BASE_URL) {
bedrockOptions.baseURL = process.env.AWS_BASE_URL;
}
provider = createAmazonBedrock(bedrockOptions);
modelId = process.env.BEDROCK_MODEL || defaultModel;
break;
}
default:
throw new Error(
`Invalid provider: ${providerType}. Must be one of: anthropic, openai, gemini, azure, bedrock`,
);
}
return provider(modelId);
}
