feat: bundle skill and serve prompt guide as MCP resource

Include skill/ directory in the npm package and expose
PROMPT_GUIDE.md as a local MCP resource (vapi://prompt-guide)
instead of fetching from GitHub at runtime.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: lukatmyshu

package.json

@@ -48,7 +48,8 @@
   "files": [
     "dist",
     "dist/**/*.d.ts",
-    "dist/**/*.d.ts.map"
+    "dist/**/*.d.ts.map",
+    "skill"
   ],
   "dependencies": {
     "@modelcontextprotocol/sdk": "^1.12.3",

skill/SKILL.md

@@ -31,7 +31,7 @@ If the user hasn't authenticated yet (tools return auth errors):
 
 ### Step 3: Build the Voice Assistant
 
-Before creating an assistant, fetch the latest prompt engineering guidelines from the [Prompt Guide](https://raw.githubusercontent.com/VapiAI/mcp-server/main/skill/PROMPT_GUIDE.md).
+Before creating an assistant, read the prompt engineering guidelines from the MCP resource `vapi://prompt-guide` (available from the Vapi MCP server).
 
 Use these guidelines to craft effective voice assistant prompts based on what the user wants to build.
 
@@ -72,7 +72,7 @@ Use these guidelines to craft effective voice assistant prompts based on what th
 **Claude should:**
 1. Check for Vapi MCP -> install if needed
 2. Authenticate if needed
-3. Fetch the prompt guide for best practices
+3. Read the prompt guide resource for best practices
 4. Ask about their business to understand context
 5. Create an assistant with a scheduling-focused prompt
 6. Offer to set up a phone number

src/index.ts

@@ -6,9 +6,15 @@ import { VapiClient } from '@vapi-ai/server-sdk';
 import { hasValidToken, getToken, startAuthFlow, isAuthInProgress, getAuthUrl, clearConfig } from './auth.js';
 import { registerAllTools } from './tools/index.js';
 
+import { readFileSync } from 'fs';
+import { fileURLToPath } from 'url';
+import { dirname, join } from 'path';
 import dotenv from 'dotenv';
 dotenv.config();
 
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = dirname(__filename);
+
 // Lazy-initialized Vapi client
 let vapiClient: VapiClient | null = null;
 
@@ -124,6 +130,20 @@ function createMcpServer() {
 
   registerAllTools(mcpServer, clientProxy);
 
+  // Expose the prompt guide as an MCP resource
+  mcpServer.resource(
+    'prompt-guide',
+    'vapi://prompt-guide',
+    { description: 'Voice assistant prompt engineering guide with best practices for crafting Vapi assistant prompts', mimeType: 'text/markdown' },
+    async (uri) => {
+      const guidePath = join(__dirname, '..', 'skill', 'PROMPT_GUIDE.md');
+      const content = readFileSync(guidePath, 'utf-8');
+      return {
+        contents: [{ uri: uri.href, text: content }],
+      };
+    }
+  );
+
   return mcpServer;
 }