From 6710a78641bc8550b37f88e594585d577e9362d9 Mon Sep 17 00:00:00 2001
From: Pavel Feldman <pavel.feldman@gmail.com>
Date: Fri, 25 Jul 2025 12:18:02 -0700
Subject: [PATCH] Revert "chore: recommend sse by default" (#765)

Reverts microsoft/playwright-mcp#758

Sounds like the stock streamable implementation is to spec, so we can
keep it.
---
 README.md            | 6 +++---
 src/mcp/transport.ts | 8 ++++----
 tests/http.spec.ts   | 9 +++++++++
 tests/sse.spec.ts    | 9 ---------
 4 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/README.md b/README.md
index 3ea79ee..de48c2d 100644
--- a/README.md
+++ b/README.md
@@ -317,19 +317,19 @@ npx @playwright/mcp@latest --config path/to/config.json
 ### Standalone MCP server
 
 When running headed browser on system w/o display or from worker processes of the IDEs,
-run the MCP server from environment with the DISPLAY and pass the `--port` flag to enable SSE transport.
+run the MCP server from environment with the DISPLAY and pass the `--port` flag to enable HTTP transport.
 
 ```bash
 npx @playwright/mcp@latest --port 8931
 ```
 
-And then in MCP client config, set the `url` to the SSE endpoint:
+And then in MCP client config, set the `url` to the HTTP endpoint:
 
 ```js
 {
   "mcpServers": {
     "playwright": {
-      "url": "http://localhost:8931/sse"
+      "url": "http://localhost:8931/mcp"
     }
   }
 }
diff --git a/src/mcp/transport.ts b/src/mcp/transport.ts
index e85a66f..9d82b40 100644
--- a/src/mcp/transport.ts
+++ b/src/mcp/transport.ts
@@ -114,10 +114,10 @@ function startHttpTransport(httpServer: http.Server, serverBackendFactory: Serve
   const streamableSessions = new Map();
   httpServer.on('request', async (req, res) => {
     const url = new URL(`http://localhost${req.url}`);
-    if (url.pathname.startsWith('/mcp'))
-      await handleStreamable(serverBackendFactory, req, res, streamableSessions);
-    else
+    if (url.pathname.startsWith('/sse'))
       await handleSSE(serverBackendFactory, req, res, url, sseSessions);
+    else
+      await handleStreamable(serverBackendFactory, req, res, streamableSessions);
   });
   const url = httpAddressToString(httpServer.address());
   const message = [
@@ -130,7 +130,7 @@ function startHttpTransport(httpServer: http.Server, serverBackendFactory: Serve
         }
       }
     }, undefined, 2),
-    'If your client supports streamable HTTP, you can use the /mcp endpoint instead.',
+    'For legacy SSE transport support, you can use the /sse endpoint instead.',
   ].join('\n');
     // eslint-disable-next-line no-console
   console.error(message);
diff --git a/tests/http.spec.ts b/tests/http.spec.ts
index 51e07db..4ff9ac9 100644
--- a/tests/http.spec.ts
+++ b/tests/http.spec.ts
@@ -248,3 +248,12 @@ test('http transport browser lifecycle (persistent, multiclient)', async ({ serv
   await client1.close();
   await client2.close();
 });
+
+test('http transport (default)', async ({ serverEndpoint }) => {
+  const { url } = await serverEndpoint();
+  const transport = new StreamableHTTPClientTransport(url);
+  const client = new Client({ name: 'test', version: '1.0.0' });
+  await client.connect(transport);
+  await client.ping();
+  expect(transport.sessionId, 'has session support').toBeDefined();
+});
diff --git a/tests/sse.spec.ts b/tests/sse.spec.ts
index eab9248..60cc740 100644
--- a/tests/sse.spec.ts
+++ b/tests/sse.spec.ts
@@ -234,12 +234,3 @@ test('sse transport browser lifecycle (persistent, multiclient)', async ({ serve
   await client1.close();
   await client2.close();
 });
-
-test('sse transport (default)', async ({ serverEndpoint }) => {
-  const { url } = await serverEndpoint();
-  const transport = new SSEClientTransport(url);
-  const client = new Client({ name: 'test', version: '1.0.0' });
-  await client.connect(transport);
-  await client.ping();
-  await client.close();
-});