Normalize baseURL once for trigger and stream endpoints

Co-authored-by: Eric Allam <eric@trigger.dev>

Author: cursoragent

packages/ai/src/chatTransport.test.ts

@@ -273,6 +273,68 @@ describe("TriggerChatTransport", function () {
     expect(observedStreamPath).toBe("/realtime/v1/streams/run_trailing_baseurl/chat-stream");
   });
 
+  it("normalizes repeated trailing slashes in baseURL for stream URLs", async function () {
+    let observedStreamPath: string | undefined;
+
+    const server = await startServer(function (req, res) {
+      if (req.method === "POST" && req.url === "/api/v1/tasks/chat-task/trigger") {
+        res.writeHead(200, {
+          "content-type": "application/json",
+          "x-trigger-jwt": "pk_run_multi_trailing_baseurl",
+        });
+        res.end(JSON.stringify({ id: "run_multi_trailing_baseurl" }));
+        return;
+      }
+
+      if (req.method === "GET") {
+        observedStreamPath = req.url ?? "";
+      }
+
+      if (
+        req.method === "GET" &&
+        req.url === "/realtime/v1/streams/run_multi_trailing_baseurl/chat-stream"
+      ) {
+        res.writeHead(200, {
+          "content-type": "text/event-stream",
+        });
+        writeSSE(
+          res,
+          "1-0",
+          JSON.stringify({ type: "text-start", id: "multi_trailing_1" })
+        );
+        writeSSE(
+          res,
+          "2-0",
+          JSON.stringify({ type: "text-end", id: "multi_trailing_1" })
+        );
+        res.end();
+        return;
+      }
+
+      res.writeHead(404);
+      res.end();
+    });
+
+    const transport = new TriggerChatTransport({
+      task: "chat-task",
+      accessToken: "pk_trigger",
+      baseURL: `${server.url}///`,
+      stream: "chat-stream",
+    });
+
+    const stream = await transport.sendMessages({
+      trigger: "submit-message",
+      chatId: "chat-multi-trailing-baseurl",
+      messageId: undefined,
+      messages: [],
+      abortSignal: undefined,
+    });
+
+    const chunks = await readChunks(stream);
+    expect(chunks).toHaveLength(2);
+    expect(observedStreamPath).toBe("/realtime/v1/streams/run_multi_trailing_baseurl/chat-stream");
+  });
+
   it("supports baseURL path prefixes for trigger and stream routes", async function () {
     let observedTriggerPath: string | undefined;
     let observedStreamPath: string | undefined;

packages/ai/src/chatTransport.ts

@@ -145,7 +145,7 @@ export class TriggerChatTransport<
     this.payloadMapper = resolvePayloadMapper<UI_MESSAGE, PAYLOAD>(options.payloadMapper);
     this.triggerOptions = options.triggerOptions;
     this.runStore = options.runStore ?? new InMemoryTriggerChatRunStore();
-    this.baseURL = options.baseURL ?? "https://api.trigger.dev";
+    this.baseURL = normalizeBaseUrl(options.baseURL ?? "https://api.trigger.dev");
     this.previewBranch = options.previewBranch;
     this.requestOptions = options.requestOptions;
     this.triggerClient = new ApiClient(
@@ -374,11 +374,10 @@ export class TriggerChatTransport<
   }
 
   private createStreamUrl(runId: string, streamKey: string): string {
-    const normalizedBaseUrl = this.baseURL.replace(/\/$/, "");
     const encodedRunId = encodeURIComponent(runId);
     const encodedStreamKey = encodeURIComponent(streamKey);
 
-    return `${normalizedBaseUrl}/realtime/v1/streams/${encodedRunId}/${encodedStreamKey}`;
+    return `${this.baseURL}/realtime/v1/streams/${encodedRunId}/${encodedStreamKey}`;
   }
 
   private async markRunInactiveAndDelete(runState: TriggerChatRunState) {
@@ -460,6 +459,10 @@ function resolvePayloadMapper<
   return createDefaultPayload as TriggerChatPayloadMapper<UI_MESSAGE, PAYLOAD>;
 }
 
+function normalizeBaseUrl(baseURL: string) {
+  return baseURL.replace(/\/+$/, "");
+}
+
 function createTransportRequest<UI_MESSAGE extends UIMessage>(
   options: TriggerChatSendMessagesOptions<UI_MESSAGE>
 ): TriggerChatTransportRequest<UI_MESSAGE> {