refactor: move node browser routing rollout to env

Remove the public browser routing constructor knobs and read direct-to-VM subresource rollout from KERNEL_BROWSER_ROUTING_SUBRESOURCES instead, defaulting to curl while leaving browser.fetch cache-backed.

Author: rgarcia

examples/browser-routing.ts

@@ -1,15 +1,9 @@
 import Kernel from '@onkernel/sdk';
 
 async function main() {
-  const kernel = new Kernel({
-    browserRouting: {
-      enabled: true,
-      subresources: ['computer'],
-    },
-  });
+  const kernel = new Kernel();
 
   const browser = await kernel.browsers.create({});
-  await kernel.browsers.computer.clickMouse(browser.session_id, { x: 10, y: 10 });
   const response = await kernel.browsers.fetch(browser.session_id, 'https://example.com', { method: 'GET' });
   console.log('status', response.status);
 

src/client.ts

@@ -20,7 +20,11 @@ import * as Uploads from './core/uploads';
 import * as API from './resources/index';
 import { APIPromise } from './core/api-promise';
 import { AppListParams, AppListResponse, AppListResponsesOffsetPagination, Apps } from './resources/apps';
-import { BrowserRouteCache, createRoutingFetch, type BrowserRoutingOptions } from './lib/browser-routing';
+import {
+  BrowserRouteCache,
+  browserRoutingSubresourcesFromEnv,
+  createRoutingFetch,
+} from './lib/browser-routing';
 import {
   BrowserPool,
   BrowserPoolAcquireParams,
@@ -195,11 +199,6 @@ export interface ClientOptions {
    */
   fetch?: Fetch | undefined;
 
-  /**
-   * Configure direct-to-VM routing for browser subresource requests.
-   */
-  browserRouting?: BrowserRoutingOptions | undefined;
-
   /**
    * The maximum number of times that the client will retry a request in case of a
    * temporary failure, like a network error or a 5XX error from the server.
@@ -321,15 +320,12 @@ export class Kernel {
     this.fetchOptions = options.fetchOptions;
     this.maxRetries = options.maxRetries ?? 2;
     this.rawFetch = options.fetch ?? Shims.getDefaultFetch();
-    this.browserRouteCache = options.browserRouting?.cache ?? new BrowserRouteCache();
-    this.fetch =
-      options.browserRouting?.enabled ?
-        createRoutingFetch(this.rawFetch, {
-          apiBaseURL: this.baseURL,
-          subresources: options.browserRouting.subresources ?? [],
-          cache: this.browserRouteCache,
-        })
-      : this.rawFetch;
+    this.browserRouteCache = new BrowserRouteCache();
+    this.fetch = createRoutingFetch(this.rawFetch, {
+      apiBaseURL: this.baseURL,
+      subresources: browserRoutingSubresourcesFromEnv(),
+      cache: this.browserRouteCache,
+    });
     this.#encoder = Opts.FallbackEncoder;
 
     this._options = options;
@@ -341,16 +337,6 @@ export class Kernel {
    * Create a new client instance re-using the same options given to the current client with optional overriding.
    */
   withOptions(options: Partial<ClientOptions>): this {
-    const currentRouting = this._options.browserRouting;
-    const nextBrowserRouting = options.browserRouting === undefined ? currentRouting : options.browserRouting;
-    const sharedBrowserRouting =
-      nextBrowserRouting ?
-        {
-          ...nextBrowserRouting,
-          cache: nextBrowserRouting.cache ?? this.browserRouteCache,
-        }
-      : undefined;
-
     const client = new (this.constructor as any as new (props: ClientOptions) => typeof this)({
       ...this._options,
       environment: options.environment ? options.environment : undefined,
@@ -363,7 +349,12 @@ export class Kernel {
       fetchOptions: this.fetchOptions,
       apiKey: this.apiKey,
       ...options,
-      browserRouting: sharedBrowserRouting,
+    });
+    client.browserRouteCache = this.browserRouteCache;
+    client.fetch = createRoutingFetch(client.rawFetch, {
+      apiBaseURL: client.baseURL,
+      subresources: browserRoutingSubresourcesFromEnv(),
+      cache: client.browserRouteCache,
     });
     return client;
   }

src/index.ts

@@ -6,7 +6,7 @@ export { type Uploadable, toFile } from './core/uploads';
 export { APIPromise } from './core/api-promise';
 export { Kernel, type ClientOptions } from './client';
 export { type BrowserFetchInit } from './lib/browser-fetch';
-export { BrowserRouteCache, type BrowserRoute, type BrowserRoutingOptions } from './lib/browser-routing';
+export { BrowserRouteCache, type BrowserRoute } from './lib/browser-routing';
 export { PagePromise } from './core/pagination';
 export {
   KernelError,

src/lib/browser-routing.ts

@@ -6,12 +6,6 @@ export type BrowserRoute = {
   jwt: string;
 };
 
-export interface BrowserRoutingOptions {
-  enabled?: boolean;
-  subresources?: string[] | undefined;
-  cache?: BrowserRouteCache | undefined;
-}
-
 export class BrowserRouteCache {
   private entries = new Map<string, BrowserRoute>();
 
@@ -32,6 +26,25 @@ export class BrowserRouteCache {
   }
 }
 
+const BROWSER_ROUTING_SUBRESOURCES_ENV = 'KERNEL_BROWSER_ROUTING_SUBRESOURCES';
+const DEFAULT_BROWSER_ROUTING_SUBRESOURCES = ['curl'];
+
+export function browserRoutingSubresourcesFromEnv(): string[] {
+  const raw = readBrowserRoutingSubresourcesEnv();
+  if (raw === undefined) {
+    return [...DEFAULT_BROWSER_ROUTING_SUBRESOURCES];
+  }
+
+  if (raw.trim() === '') {
+    return [];
+  }
+
+  return raw
+    .split(',')
+    .map((value) => value.trim())
+    .filter(Boolean);
+}
+
 export function createRoutingFetch(
   innerFetch: Fetch,
   {
@@ -186,3 +199,17 @@ function parseJwtFromCdpWsUrl(cdpWsUrl: string | undefined): string | undefined
     return undefined;
   }
 }
+
+function readBrowserRoutingSubresourcesEnv(): string | undefined {
+  if (typeof (globalThis as any).process !== 'undefined') {
+    const value = (globalThis as any).process.env?.[BROWSER_ROUTING_SUBRESOURCES_ENV];
+    return typeof value === 'string' ? value : undefined;
+  }
+
+  if (typeof (globalThis as any).Deno !== 'undefined') {
+    const value = (globalThis as any).Deno.env?.get?.(BROWSER_ROUTING_SUBRESOURCES_ENV);
+    return typeof value === 'string' ? value : undefined;
+  }
+
+  return undefined;
+}