add support for custom baseurl in openai provider (#1025)

# why

currently, we do not support passing cusotm baseurls for the openai
provider

# what changed

baseUrl can now optionally be passed to the openai client within ai sdk 

# test plan

tested locally

Author: tkattkat

.changeset/slimy-cars-matter.md

@@ -0,0 +1,5 @@
+---
+"@browserbasehq/stagehand": patch
+---
+
+add support for custom baseUrl within openai provider

lib/StagehandPage.ts

@@ -770,7 +770,12 @@ ${scriptContent} \
       const { action, modelName, modelClientOptions } = actionOrOptions;
 
       if (this.api) {
-        const opts = { ...actionOrOptions, frameId: this.rootFrameId };
+        const opts = {
+          ...actionOrOptions,
+          frameId: this.rootFrameId,
+          modelClientOptions:
+            modelClientOptions || this.stagehand["modelClientOptions"],
+        };
         const result = await this.api.act(opts);
         this.stagehand.addToHistory("act", actionOrOptions, result);
         return result;
@@ -864,7 +869,12 @@ ${scriptContent} \
       } = options;
 
       if (this.api) {
-        const opts = { ...options, frameId: this.rootFrameId };
+        const opts = {
+          ...options,
+          frameId: this.rootFrameId,
+          modelClientOptions:
+            modelClientOptions || this.stagehand["modelClientOptions"],
+        };
         const result = await this.api.extract<T>(opts);
         this.stagehand.addToHistory("extract", instructionOrOptions, result);
         return result;
@@ -968,7 +978,12 @@ ${scriptContent} \
       } = options;
 
       if (this.api) {
-        const opts = { ...options, frameId: this.rootFrameId };
+        const opts = {
+          ...options,
+          frameId: this.rootFrameId,
+          modelClientOptions:
+            modelClientOptions || this.stagehand["modelClientOptions"],
+        };
         const result = await this.api.observe(opts);
         this.stagehand.addToHistory("observe", instructionOrOptions, result);
         return result;

lib/index.ts

@@ -393,7 +393,7 @@ export class Stagehand {
   public readonly logInferenceToFile?: boolean;
   private stagehandLogger: StagehandLogger;
   private disablePino: boolean;
-  private modelClientOptions: ClientOptions;
+  protected modelClientOptions: ClientOptions;
   private _env: "LOCAL" | "BROWSERBASE";
   private _browser: Browser | undefined;
   private _isClosed: boolean = false;

lib/llm/LLMProvider.ts

@@ -98,6 +98,7 @@ export function getAISDKLanguageModel(
   subProvider: string,
   subModelName: string,
   apiKey?: string,
+  baseURL?: string,
 ) {
   if (apiKey) {
     const creator = AISDKProvidersWithAPIKey[subProvider];
@@ -107,8 +108,12 @@ export function getAISDKLanguageModel(
         Object.keys(AISDKProvidersWithAPIKey),
       );
     }
-    // Create the provider instance with the API key
-    const provider = creator({ apiKey });
+    // Create the provider instance with the API key and baseURL if provided
+    const providerConfig: { apiKey: string; baseURL?: string } = { apiKey };
+    if (baseURL) {
+      providerConfig.baseURL = baseURL;
+    }
+    const provider = creator(providerConfig);
     // Get the specific model from the provider
     return provider(subModelName);
   } else {
@@ -166,6 +171,7 @@ export class LLMProvider {
         subProvider,
         subModelName,
         clientOptions?.apiKey,
+        clientOptions?.baseURL,
       );
 
       return new AISdkClient({