add streamBaseUrl

Author: ericallam

docs/ai-chat/reference.mdx

@@ -512,6 +512,7 @@ Options for the frontend transport constructor and `useTriggerChatTransport` hoo
 | `accessToken`          | `(params: AccessTokenParams) => string \| Promise<string>`           | required                    | Pure refresh — mints a fresh session-scoped PAT. Called on 401/403. See [callback shape](#accesstoken-callback). |
 | `startSession`         | `(params: StartSessionParams<TClientData>) => Promise<StartSessionResult>` | optional                    | Creates the chat Session and returns the session-scoped PAT. Called on `transport.preload(chatId)` and lazily on the first `sendMessage` for any chatId without a cached PAT. See [callback shape](#startsession-callback). |
 | `baseURL`              | `string`                                                             | `"https://api.trigger.dev"` | API base URL (for self-hosted)                                              |
+| `streamBaseURL`        | `string`                                                             | falls back to `baseURL`     | Base URL for the SSE stream subscription only (`GET .../sessions/{chatId}/out`). Route the long-lived stream through a custom proxy (e.g. a Cloudflare worker capturing JA4 fingerprints for bot detection) while keeping append POSTs direct to `baseURL`. |
 | `headers`              | `Record<string, string>`                                             | —                           | Extra headers for API requests                                              |
 | `streamTimeoutSeconds` | `number`                                                             | `120`                       | How long to wait for stream data                                            |
 | `clientData`           | Typed by `clientDataSchema`                                          | —                           | Default client data merged into per-turn `metadata` and threaded through `startSession`'s params (so the first run's `payload.metadata` matches per-turn `metadata`). Live-updated when the option value changes. |