modelcontextprotocol · antonpk1 · Dec 5, 2025 · Dec 3, 2025 · Dec 4, 2025 · Dec 4, 2025
diff --git a/docs/quickstart.md b/docs/quickstart.md
@@ -132,7 +132,9 @@ server.registerResource(resourceUri, resourceUri, {}, async () => {
     "utf-8",
   );
   return {
-    contents: [{ uri: resourceUri, mimeType: "text/html+mcp", text: html }],
+    contents: [
+      { uri: resourceUri, mimeType: "text/html;profile=mcp-app", text: html },
+    ],
   };
 });
 

diff --git a/examples/basic-host/src/implementation.ts b/examples/basic-host/src/implementation.ts
@@ -106,9 +106,9 @@ async function getUiResourceHtml(serverInfo: ServerInfo, uri: string): Promise<s
 
   const content = resource.contents[0];
 
-  // Per the MCP App specification, "text/html+mcp" signals this resource is
-  // indeed for an MCP App UI.
-  if (content.mimeType !== "text/html+mcp") {
+  // Per the MCP App specification, "text/html;profile=mcp-app" signals this
+  // resource is indeed for an MCP App UI.
+  if (content.mimeType !== "text/html;profile=mcp-app") {
     throw new Error(`Unsupported MIME type: ${content.mimeType}`);
   }
 

diff --git a/examples/basic-server-react/server.ts b/examples/basic-server-react/server.ts
@@ -51,9 +51,9 @@ const server = new McpServer({
 
       return {
         contents: [
-          // Per the MCP App specification, "text/html+mcp" signals to the Host
-          // that this resource is indeed for an MCP App UI.
-          { uri: resourceUri, mimeType: "text/html+mcp", text: html },
+          // Per the MCP App specification, "text/html;profile=mcp-app" signals
+          // to the Host that this resource is indeed for an MCP App UI.
+          { uri: resourceUri, mimeType: "text/html;profile=mcp-app", text: html },
         ],
       };
     },

diff --git a/examples/basic-server-vanillajs/server.ts b/examples/basic-server-vanillajs/server.ts
@@ -51,9 +51,9 @@ const server = new McpServer({
 
       return {
         contents: [
-          // Per the MCP App specification, "text/html+mcp" signals to the Host
-          // that this resource is indeed for an MCP App UI.
-          { uri: resourceUri, mimeType: "text/html+mcp", text: html },
+          // Per the MCP App specification, "text/html;profile=mcp-app" signals
+          // to the Host that this resource is indeed for an MCP App UI.
+          { uri: resourceUri, mimeType: "text/html;profile=mcp-app", text: html },
         ],
       };
     },

diff --git a/examples/budget-allocator-server/README.md b/examples/budget-allocator-server/README.md
@@ -0,0 +1,49 @@
+# Example: Budget Allocator App
+
+An interactive budget allocation tool demonstrating real-time data visualization with MCP Apps.
+
+## Features
+
+- **Interactive Sliders**: Adjust budget allocation across 5 categories (Marketing, Engineering, Operations, Sales, R&D)
+- **Donut Chart**: Real-time visualization of allocation distribution using Chart.js
+- **Sparkline Trends**: 24-month historical allocation data per category
+- **Percentile Badges**: Compare your allocation vs. industry benchmarks
+- **Stage Selector**: Switch between Seed, Series A, Series B, and Growth benchmarks
+- **Budget Presets**: Quick selection of $50K, $100K, $250K, or $500K totals
+
+## Running
+
+1. Install dependencies:
+
+   ```bash
+   npm install
+   ```
+
+2. Build and start the server:
+
+   ```bash
+   npm start
+   ```
+
+   The server will listen on `http://localhost:3001/mcp`.
+
+3. View using the [`basic-host`](https://github.com/modelcontextprotocol/ext-apps/tree/main/examples/basic-host) example or another MCP Apps-compatible host.
+
+## Architecture
+
+### Server (`server.ts`)
+
+Exposes a single `get-budget-data` tool that returns:
+
+- Category definitions with colors and default allocations
+- Historical data (~120 data points) - 24 months of allocation history per category
+- Industry benchmarks (~60 data points) - Aggregated percentile data by company stage
+
+The tool is linked to a UI resource via `_meta[RESOURCE_URI_META_KEY]`.
+
+### App (`src/mcp-app.ts`)
+
+- Uses Chart.js for the donut chart visualization
+- Renders sparkline trends using inline SVG
+- Computes percentile rankings client-side from benchmark data
+- Updates all UI elements reactively on slider changes
diff --git a/examples/budget-allocator-server/mcp-app.html b/examples/budget-allocator-server/mcp-app.html
@@ -0,0 +1,36 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <meta charset="UTF-8">
+  <meta name="viewport" content="width=device-width, initial-scale=1.0">
+  <title>Budget Allocator</title>
+</head>
+<body>
+  <div class="app-container">
+    <header class="header">
+      <h1 class="title">Budget Allocator</h1>
+      <select id="budget-selector" class="budget-select"></select>
+    </header>
+
+    <section class="chart-section">
+      <canvas id="budget-chart"></canvas>
+    </section>
+
+    <section class="sliders-section" id="sliders-container"></section>
+
+    <footer class="footer">
+      <div id="status-bar" class="status-bar">
+        Allocated: $0 / $0
+      </div>
+      <div class="comparison-bar">
+        <span id="comparison-summary">Loading benchmarks...</span>
+        <label class="stage-label">
+          Stage:
+          <select id="stage-selector" class="stage-select"></select>
+        </label>
+      </div>
+    </footer>
+  </div>
+  <script type="module" src="/src/mcp-app.ts"></script>
+</body>
+</html>
diff --git a/examples/budget-allocator-server/package.json b/examples/budget-allocator-server/package.json
@@ -0,0 +1,30 @@
+{
+  "name": "budget-allocator-server",
+  "version": "1.0.0",
+  "private": true,
+  "type": "module",
+  "scripts": {
+    "build": "INPUT=mcp-app.html vite build",
+    "watch": "INPUT=mcp-app.html vite build --watch",
+    "serve": "bun server.ts",
+    "start": "NODE_ENV=development npm run build && npm run serve",
+    "dev": "NODE_ENV=development concurrently 'npm run watch' 'npm run serve'"
+  },
+  "dependencies": {
+    "@modelcontextprotocol/ext-apps": "../..",
+    "@modelcontextprotocol/sdk": "^1.22.0",
+    "chart.js": "^4.4.0",
+    "zod": "^3.25.0"
+  },
+  "devDependencies": {
+    "@types/cors": "^2.8.19",
+    "@types/express": "^5.0.0",
+    "@types/node": "^22.0.0",
+    "concurrently": "^9.2.1",
+    "cors": "^2.8.5",
+    "express": "^5.1.0",
+    "typescript": "^5.9.3",
+    "vite": "^6.0.0",
+    "vite-plugin-singlefile": "^2.3.0"
+  }
+}