MCP apps extension middleware

middlewares/mcp-apps-middleware/.gitignore

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middlewares/mcp-apps-middleware/.npmignore

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+.turbo
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+__tests__
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middlewares/mcp-apps-middleware/README.md

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+# @ag-ui/mcp-apps-middleware
+
+MCP Apps middleware for AG-UI that enables UI-enabled tools from MCP (Model Context Protocol) servers.
+
+## Installation
+
+```bash
+npm install @ag-ui/mcp-apps-middleware
+# or
+pnpm add @ag-ui/mcp-apps-middleware
+```
+
+## Usage
+
+```typescript
+import { MCPAppsMiddleware } from "@ag-ui/mcp-apps-middleware";
+
+const agent = new YourAgent().use(
+  new MCPAppsMiddleware({
+    mcpServers: [
+      { type: "http", url: "http://localhost:3001/mcp" }
+    ],
+  })
+);
+```
+
+## Features
+
+- Discovers UI-enabled tools from MCP servers
+- Injects tools into the agent's tool list
+- Executes tool calls and fetches UI resources
+- Emits activity snapshots for rendering MCP Apps UI
+
+## Configuration
+
+```typescript
+interface MCPAppsMiddlewareConfig {
+  mcpServers?: MCPClientConfig[];
+}
+
+type MCPClientConfig =
+  | { type: "http"; url: string }
+  | { type: "sse"; url: string; headers?: Record<string, string> };
+```
+
+## Activity Type
+
+The middleware emits activity snapshots with type `"mcp-apps"`. You can use the exported constant:
+
+```typescript
+import { MCPAppsActivityType } from "@ag-ui/mcp-apps-middleware";
+
+// MCPAppsActivityType === "mcp-apps"
+```
+
+## License
+
+MIT