feat: make it possible to provide base URL to OpenAI (#1740)

Co-authored-by: Marcus Schiesser <mail@marcusschiesser.de>

.changeset/hungry-turkeys-wait.md

+---
+"@llamaindex/openai": patch
+"@llamaindex/doc": patch
+---
+
+feat: simplify to provide base URL to OpenAI

apps/next/src/content/docs/llamaindex/modules/llms/available_llms/openai.mdx

@@ -34,6 +34,18 @@ You can setup the apiKey on the environment variables, like:
 export OPENAI_API_KEY="<YOUR_API_KEY>"
 ```
 
+You can optionally set a custom base URL, like:
+
+```bash
+export OPENAI_BASE_URL="https://api.scaleway.ai/v1"
+```
+
+or
+
+```ts
+Settings.llm = new OpenAI({ model: "gpt-3.5-turbo", temperature: 0, apiKey: <YOUR_API_KEY>, baseURL: "https://api.scaleway.ai/v1" });
+```
+
 ## Load and index documents
 
 For this example, we will use a single document. In a real-world scenario, you would have multiple documents to index.

packages/providers/openai/src/embedding.ts

@@ -36,7 +36,10 @@ export const ALL_OPENAI_EMBEDDING_MODELS = {
 
 type ModelKeys = keyof typeof ALL_OPENAI_EMBEDDING_MODELS;
 
-type LLMInstance = Pick<AzureOpenAILLM | OpenAILLM, "embeddings" | "apiKey">;
+type LLMInstance = Pick<
+  AzureOpenAILLM | OpenAILLM,
+  "embeddings" | "apiKey" | "baseURL"
+>;
 
 export class OpenAIEmbedding extends BaseEmbedding {
   /** embeddding model. defaults to "text-embedding-ada-002" */
@@ -48,6 +51,8 @@ export class OpenAIEmbedding extends BaseEmbedding {
 
   /** api key */
   apiKey?: string | undefined = undefined;
+  /** base url */
+  baseURL?: string | undefined = undefined;
   /** maximum number of retries, default 10 */
   maxRetries: number;
   /** timeout in ms, default 60 seconds  */
@@ -104,6 +109,10 @@ export class OpenAIEmbedding extends BaseEmbedding {
       };
       this.apiKey =
         init?.session?.apiKey ?? azureConfig.apiKey ?? getEnv("OPENAI_API_KEY");
+      this.baseURL =
+        init?.session?.baseURL ??
+        azureConfig.baseURL ??
+        getEnv("OPENAI_BASE_URL");
       this.lazySession = async () =>
         import("openai").then(async ({ AzureOpenAI }) => {
           AzureOpenAI = AzureOpenAIWithUserAgent(AzureOpenAI);
@@ -121,12 +130,15 @@ export class OpenAIEmbedding extends BaseEmbedding {
     } else {
       this.apiKey =
         init?.session?.apiKey ?? init?.apiKey ?? getEnv("OPENAI_API_KEY");
+      this.baseURL =
+        init?.session?.baseURL ?? init?.baseURL ?? getEnv("OPENAI_BASE_URL");
       this.lazySession = async () =>
         import("openai").then(({ OpenAI }) => {
           return (
             init?.session ??
             new OpenAI({
               apiKey: this.apiKey,
+              baseURL: this.baseURL,
               maxRetries: this.maxRetries,
               timeout: this.timeout!,
               ...this.additionalSessionOptions,

packages/providers/openai/src/llm.ts

@@ -182,7 +182,10 @@ export type OpenAIAdditionalChatOptions = Omit<
   | "toolChoice"
 >;
 
-type LLMInstance = Pick<AzureOpenAILLM | OpenAILLM, "chat" | "apiKey">;
+type LLMInstance = Pick<
+  AzureOpenAILLM | OpenAILLM,
+  "chat" | "apiKey" | "baseURL"
+>;
 
 export class OpenAI extends ToolCallLLM<OpenAIAdditionalChatOptions> {
   model:
@@ -197,6 +200,7 @@ export class OpenAI extends ToolCallLLM<OpenAIAdditionalChatOptions> {
 
   // OpenAI session params
   apiKey?: string | undefined = undefined;
+  baseURL?: string | undefined = undefined;
   maxRetries: number;
   timeout?: number;
   additionalSessionOptions?:
@@ -234,6 +238,8 @@ export class OpenAI extends ToolCallLLM<OpenAIAdditionalChatOptions> {
     this.additionalSessionOptions = init?.additionalSessionOptions;
     this.apiKey =
       init?.session?.apiKey ?? init?.apiKey ?? getEnv("OPENAI_API_KEY");
+    this.baseURL =
+      init?.session?.baseURL ?? init?.baseURL ?? getEnv("OPENAI_BASE_URL");
 
     if (init?.azure || shouldUseAzure()) {
       const azureConfig = {
@@ -261,6 +267,7 @@ export class OpenAI extends ToolCallLLM<OpenAIAdditionalChatOptions> {
         import("openai").then(({ OpenAI }) => {
           return new OpenAI({
             apiKey: this.apiKey,
+            baseURL: this.baseURL,
             maxRetries: this.maxRetries,
             timeout: this.timeout!,
             ...this.additionalSessionOptions,