diff --git a/src/cli.ts b/src/cli.ts
index 869ace7d..9d3fb221 100644
--- a/src/cli.ts
+++ b/src/cli.ts
@@ -31,17 +31,17 @@ async function runClient(url_or_command: string, args: string[]) {
   }
 
   if (url?.protocol === "http:" || url?.protocol === "https:") {
-    clientTransport = new SSEClientTransport();
-    await clientTransport.connect(new URL(url_or_command));
+    clientTransport = new SSEClientTransport(new URL(url_or_command));
+    await clientTransport.start();
   } else if (url?.protocol === "ws:" || url?.protocol === "wss:") {
-    clientTransport = new WebSocketClientTransport();
-    await clientTransport.connect(new URL(url_or_command));
+    clientTransport = new WebSocketClientTransport(new URL(url_or_command));
+    await clientTransport.start();
   } else {
-    clientTransport = new StdioClientTransport();
-    await clientTransport.spawn({
+    clientTransport = new StdioClientTransport({
       command: url_or_command,
       args,
     });
+    await clientTransport.start();
   }
 
   console.log("Connected to server.");
@@ -62,7 +62,7 @@ async function runServer(port: number | null) {
     app.get("/sse", async (req, res) => {
       console.log("Got new SSE connection");
 
-      const transport = new SSEServerTransport("/message");
+      const transport = new SSEServerTransport("/message", res);
       const server = new Server({
         name: "mcp-typescript test server",
         version: "0.1.0",
@@ -75,7 +75,7 @@ async function runServer(port: number | null) {
         servers = servers.filter((s) => s !== server);
       };
 
-      await transport.connectSSE(req, res);
+      await transport.start();
       await server.connect(transport);
     });
 
diff --git a/src/client/stdio.test.ts b/src/client/stdio.test.ts
index 32dced90..646f9ea5 100644
--- a/src/client/stdio.test.ts
+++ b/src/client/stdio.test.ts
@@ -6,7 +6,7 @@ const serverParameters: StdioServerParameters = {
 };
 
 test("should start then close cleanly", async () => {
-  const client = new StdioClientTransport();
+  const client = new StdioClientTransport(serverParameters);
   client.onerror = (error) => {
     throw error;
   };
@@ -16,14 +16,14 @@ test("should start then close cleanly", async () => {
     didClose = true;
   };
 
-  await client.spawn(serverParameters);
+  await client.start();
   expect(didClose).toBeFalsy();
   await client.close();
   expect(didClose).toBeTruthy();
 });
 
 test("should read messages", async () => {
-  const client = new StdioClientTransport();
+  const client = new StdioClientTransport(serverParameters);
   client.onerror = (error) => {
     throw error;
   };
@@ -51,7 +51,7 @@ test("should read messages", async () => {
     };
   });
 
-  await client.spawn(serverParameters);
+  await client.start();
   await client.send(messages[0]);
   await client.send(messages[1]);
   await finished;