feat: return mcp ui resource for playground

Author: paoloricciuti

packages/mcp-server/package.json

@@ -20,6 +20,7 @@
 		"drizzle-orm": "^0.44.0"
 	},
 	"dependencies": {
+		"@mcp-ui/server": "^5.12.0",
 		"@sveltejs/mcp-schema": "workspace:^",
 		"@tmcp/adapter-valibot": "^0.1.4",
 		"@typescript-eslint/parser": "^8.44.0",

packages/mcp-server/src/mcp/handlers/tools/playground-link.ts

@@ -1,6 +1,7 @@
 import type { SvelteMcp } from '../../index.js';
 import * as v from 'valibot';
 import { icons } from '../../icons/index.js';
+import { createUIResource } from '@mcp-ui/server';
 
 async function compress_and_encode_text(input: string) {
 	const reader = new Blob([input]).stream().pipeThrough(new CompressionStream('gzip')).getReader();
@@ -106,6 +107,14 @@ export function playground_link(server: SvelteMcp) {
 						type: 'text',
 						text: JSON.stringify(content),
 					},
+					createUIResource({
+						uri: 'ui://svelte/playground-link',
+						content: {
+							type: 'externalUrl',
+							iframeUrl: content.url,
+						},
+						encoding: 'text',
+					}),
 				],
 				structuredContent: content,
 			};