Merge branch 'main' into con-refused

Author: cliffhall

.github/workflows/e2e_tests.yml

@@ -8,7 +8,8 @@ on:
 
 jobs:
   test:
-    timeout-minutes: 5
+    # Installing Playright dependencies can take quite awhile, and also depends on GitHub CI load.
+    timeout-minutes: 15
     runs-on: ubuntu-latest
 
     steps:
@@ -20,8 +21,10 @@ jobs:
       - uses: actions/checkout@v4
 
       - uses: actions/setup-node@v4
+        id: setup_node
         with:
-          node-version: 18
+          node-version-file: package.json
+          cache: npm
 
       # Cache Playwright browsers
       - name: Cache Playwright browsers
@@ -44,11 +47,12 @@ jobs:
         if: steps.cache-playwright.outputs.cache-hit != 'true'
 
       - name: Run Playwright tests
+        id: playwright-tests
         run: npm run test:e2e
 
       - name: Upload Playwright Report and Screenshots
         uses: actions/upload-artifact@v4
-        if: always()
+        if: steps.playwright-tests.conclusion != 'skipped'
         with:
           name: playwright-report
           path: |
@@ -59,15 +63,15 @@ jobs:
 
       - name: Publish Playwright Test Summary
         uses: daun/playwright-report-summary@v3
-        if: always()
+        if: steps.playwright-tests.conclusion != 'skipped'
         with:
           create-comment: ${{ github.event.pull_request.head.repo.full_name == github.repository }}
           report-file: client/results.json
           comment-title: "🎭 Playwright E2E Test Results"
           job-summary: true
           icon-style: "emojis"
           custom-info: |
-            **Test Environment:** Ubuntu Latest, Node.js 18
+            **Test Environment:** Ubuntu Latest, Node.js ${{ steps.setup_node.outputs.node-version }}
             **Browsers:** Chromium, Firefox
 
             📊 [View Detailed HTML Report](https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}) (download artifacts)

.github/workflows/main.yml

@@ -19,7 +19,7 @@ jobs:
 
       - uses: actions/setup-node@v4
         with:
-          node-version: 18
+          node-version-file: package.json
           cache: npm
 
       # Working around https://github.com/npm/cli/issues/4828
@@ -53,7 +53,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-node@v4
         with:
-          node-version: 18
+          node-version-file: package.json
           cache: npm
           registry-url: "https://registry.npmjs.org"
 

.node-version

@@ -0,0 +1 @@
+22.x.x

CONTRIBUTING.md

@@ -7,7 +7,7 @@ Thanks for your interest in contributing! This guide explains how to get involve
 1. Fork the repository and clone it locally
 2. Install dependencies with `npm install`
 3. Run `npm run dev` to start both client and server in development mode
-4. Use the web UI at http://127.0.0.1:6274 to interact with the inspector
+4. Use the web UI at http://localhost:6274 to interact with the inspector
 
 ## Development Process & Pull Requests
 

README.md

@@ -168,20 +168,20 @@ DANGEROUSLY_OMIT_AUTH=true npm start
 
 #### Local-only Binding
 
-By default, the MCP Inspector proxy server binds only to `127.0.0.1` (localhost) to prevent network access. This ensures the server is not accessible from other devices on the network. If you need to bind to all interfaces for development purposes, you can override this with the `HOST` environment variable:
+By default, both the MCP Inspector proxy server and client bind only to `localhost` to prevent network access. This ensures they are not accessible from other devices on the network. If you need to bind to all interfaces for development purposes, you can override this with the `HOST` environment variable:
 
 ```bash
 HOST=0.0.0.0 npm start
 ```
 
-**Warning:** Only bind to all interfaces in trusted network environments, as this exposes the proxy server's ability to execute local processes.
+**Warning:** Only bind to all interfaces in trusted network environments, as this exposes the proxy server's ability to execute local processes and both services to network access.
 
 #### DNS Rebinding Protection
 
 To prevent DNS rebinding attacks, the MCP Inspector validates the `Origin` header on incoming requests. By default, only requests from the client origin are allowed (respects `CLIENT_PORT` if set, defaulting to port 6274). You can configure additional allowed origins by setting the `ALLOWED_ORIGINS` environment variable (comma-separated list):
 
 ```bash
-ALLOWED_ORIGINS=http://localhost:6274,http://127.0.0.1:6274,http://localhost:8000 npm start
+ALLOWED_ORIGINS=http://localhost:6274,http://localhost:8000 npm start
 ```
 
 ### Configuration
@@ -299,9 +299,12 @@ npx @modelcontextprotocol/inspector --cli node build/index.js --method resources
 # List available prompts
 npx @modelcontextprotocol/inspector --cli node build/index.js --method prompts/list
 
-# Connect to a remote MCP server
+# Connect to a remote MCP server (default is SSE transport)
 npx @modelcontextprotocol/inspector --cli https://my-mcp-server.example.com
 
+# Connect to a remote MCP server (with Streamable HTTP transport)
+npx @modelcontextprotocol/inspector --cli https://my-mcp-server.example.com --transport http
+
 # Call a tool on a remote server
 npx @modelcontextprotocol/inspector --cli https://my-mcp-server.example.com --method tools/call --tool-name remotetool --tool-arg param=value
 

cli/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@modelcontextprotocol/inspector-cli",
-  "version": "0.14.3",
+  "version": "0.15.0",
   "description": "CLI for the Model Context Protocol inspector",
   "license": "MIT",
   "author": "Anthropic, PBC (https://anthropic.com)",
@@ -21,7 +21,7 @@
   },
   "devDependencies": {},
   "dependencies": {
-    "@modelcontextprotocol/sdk": "^1.13.0",
+    "@modelcontextprotocol/sdk": "^1.13.1",
     "commander": "^13.1.0",
     "spawn-rx": "^5.1.2"
   }

cli/scripts/cli-tests.js

@@ -44,7 +44,14 @@ console.log(`${colors.BLUE}- Resource-related options (--uri)${colors.NC}`);
 console.log(
   `${colors.BLUE}- Prompt-related options (--prompt-name, --prompt-args)${colors.NC}`,
 );
-console.log(`${colors.BLUE}- Logging options (--log-level)${colors.NC}\n`);
+console.log(`${colors.BLUE}- Logging options (--log-level)${colors.NC}`);
+console.log(
+  `${colors.BLUE}- Transport types (--transport http/sse/stdio)${colors.NC}`,
+);
+console.log(
+  `${colors.BLUE}- Transport inference from URL suffixes (/mcp, /sse)${colors.NC}`,
+);
+console.log(`\n`);
 
 // Get directory paths
 const SCRIPTS_DIR = __dirname;
@@ -62,9 +69,11 @@ if (!fs.existsSync(OUTPUT_DIR)) {
 }
 
 // Create a temporary directory for test files
-const TEMP_DIR = fs.mkdirSync(path.join(os.tmpdir(), "mcp-inspector-tests"), {
-  recursive: true,
-});
+const TEMP_DIR = path.join(os.tmpdir(), "mcp-inspector-tests");
+fs.mkdirSync(TEMP_DIR, { recursive: true });
+
+// Track servers for cleanup
+let runningServers = [];
 
 process.on("exit", () => {
   try {
@@ -74,6 +83,21 @@ process.on("exit", () => {
       `${colors.RED}Failed to remove temp directory: ${err.message}${colors.NC}`,
     );
   }
+
+  runningServers.forEach((server) => {
+    try {
+      process.kill(-server.pid);
+    } catch (e) {}
+  });
+});
+
+process.on("SIGINT", () => {
+  runningServers.forEach((server) => {
+    try {
+      process.kill(-server.pid);
+    } catch (e) {}
+  });
+  process.exit(1);
 });
 
 // Use the existing sample config file
@@ -121,6 +145,11 @@ async function runBasicTest(testName, ...args) {
         stdio: ["ignore", "pipe", "pipe"],
       });
 
+      const timeout = setTimeout(() => {
+        console.log(`${colors.YELLOW}Test timed out: ${testName}${colors.NC}`);
+        child.kill();
+      }, 10000);
+
       // Pipe stdout and stderr to the output file
       child.stdout.pipe(outputStream);
       child.stderr.pipe(outputStream);
@@ -135,6 +164,7 @@ async function runBasicTest(testName, ...args) {
       });
 
       child.on("close", (code) => {
+        clearTimeout(timeout);
         outputStream.end();
 
         if (code === 0) {
@@ -201,6 +231,13 @@ async function runErrorTest(testName, ...args) {
         stdio: ["ignore", "pipe", "pipe"],
       });
 
+      const timeout = setTimeout(() => {
+        console.log(
+          `${colors.YELLOW}Error test timed out: ${testName}${colors.NC}`,
+        );
+        child.kill();
+      }, 10000);
+
       // Pipe stdout and stderr to the output file
       child.stdout.pipe(outputStream);
       child.stderr.pipe(outputStream);
@@ -215,6 +252,7 @@ async function runErrorTest(testName, ...args) {
       });
 
       child.on("close", (code) => {
+        clearTimeout(timeout);
         outputStream.end();
 
         // For error tests, we expect a non-zero exit code
@@ -611,6 +649,79 @@ async function runTests() {
     "debug",
   );
 
+  console.log(
+    `\n${colors.YELLOW}=== Running HTTP Transport Tests ===${colors.NC}`,
+  );
+
+  console.log(
+    `${colors.BLUE}Starting server-everything in streamableHttp mode.${colors.NC}`,
+  );
+  const httpServer = spawn(
+    "npx",
+    ["@modelcontextprotocol/server-everything", "streamableHttp"],
+    {
+      detached: true,
+      stdio: "ignore",
+    },
+  );
+  runningServers.push(httpServer);
+
+  await new Promise((resolve) => setTimeout(resolve, 3000));
+
+  // Test 25: HTTP transport inferred from URL ending with /mcp
+  await runBasicTest(
+    "http_transport_inferred",
+    "http://127.0.0.1:3001/mcp",
+    "--cli",
+    "--method",
+    "tools/list",
+  );
+
+  // Test 26: HTTP transport with explicit --transport http flag
+  await runBasicTest(
+    "http_transport_with_explicit_flag",
+    "http://127.0.0.1:3001",
+    "--transport",
+    "http",
+    "--cli",
+    "--method",
+    "tools/list",
+  );
+
+  // Test 27: HTTP transport with suffix and --transport http flag
+  await runBasicTest(
+    "http_transport_with_explicit_flag_and_suffix",
+    "http://127.0.0.1:3001/mcp",
+    "--transport",
+    "http",
+    "--cli",
+    "--method",
+    "tools/list",
+  );
+
+  // Test 28: SSE transport given to HTTP server (should fail)
+  await runErrorTest(
+    "sse_transport_given_to_http_server",
+    "http://127.0.0.1:3001",
+    "--transport",
+    "sse",
+    "--cli",
+    "--method",
+    "tools/list",
+  );
+
+  // Kill HTTP server
+  try {
+    process.kill(-httpServer.pid);
+    console.log(
+      `${colors.BLUE}HTTP server killed, waiting for port to be released...${colors.NC}`,
+    );
+  } catch (e) {
+    console.log(
+      `${colors.RED}Error killing HTTP server: ${e.message}${colors.NC}`,
+    );
+  }
+
   // Print test summary
   console.log(`\n${colors.YELLOW}=== Test Summary ===${colors.NC}`);
   console.log(`${colors.GREEN}Passed: ${PASSED_TESTS}${colors.NC}`);

cli/src/index.ts

@@ -29,9 +29,13 @@ type Args = {
   logLevel?: LogLevel;
   toolName?: string;
   toolArg?: Record<string, string>;
+  transport?: "sse" | "stdio" | "http";
 };
 
-function createTransportOptions(target: string[]): TransportOptions {
+function createTransportOptions(
+  target: string[],
+  transport?: "sse" | "stdio" | "http",
+): TransportOptions {
   if (target.length === 0) {
     throw new Error(
       "Target is required. Specify a URL or a command to execute.",
@@ -50,16 +54,38 @@ function createTransportOptions(target: string[]): TransportOptions {
     throw new Error("Arguments cannot be passed to a URL-based MCP server.");
   }
 
+  let transportType: "sse" | "stdio" | "http";
+  if (transport) {
+    if (!isUrl && transport !== "stdio") {
+      throw new Error("Only stdio transport can be used with local commands.");
+    }
+    if (isUrl && transport === "stdio") {
+      throw new Error("stdio transport cannot be used with URLs.");
+    }
+    transportType = transport;
+  } else if (isUrl) {
+    const url = new URL(command);
+    if (url.pathname.endsWith("/mcp")) {
+      transportType = "http";
+    } else if (url.pathname.endsWith("/sse")) {
+      transportType = "sse";
+    } else {
+      transportType = "sse";
+    }
+  } else {
+    transportType = "stdio";
+  }
+
   return {
-    transportType: isUrl ? "sse" : "stdio",
+    transportType,
     command: isUrl ? undefined : command,
     args: isUrl ? undefined : commandArgs,
     url: isUrl ? command : undefined,
   };
 }
 
 async function callMethod(args: Args): Promise<void> {
-  const transportOptions = createTransportOptions(args.target);
+  const transportOptions = createTransportOptions(args.target, args.transport);
   const transport = createTransport(transportOptions);
   const client = new Client({
     name: "inspector-cli",
@@ -214,6 +240,22 @@ function parseArgs(): Args {
 
         return value as LogLevel;
       },
+    )
+    //
+    // Transport options
+    //
+    .option(
+      "--transport <type>",
+      "Transport type (sse, http, or stdio). Auto-detected from URL: /mcp → http, /sse → sse, commands → stdio",
+      (value: string) => {
+        const validTransports = ["sse", "http", "stdio"];
+        if (!validTransports.includes(value)) {
+          throw new Error(
+            `Invalid transport type: ${value}. Valid types are: ${validTransports.join(", ")}`,
+          );
+        }
+        return value as "sse" | "http" | "stdio";
+      },
     );
 
   // Parse only the arguments before --