Fix: Startup banner corrupts stdio JSON-RPC stream

package.json

@@ -42,7 +42,7 @@
     "@modelcontextprotocol/sdk": "^1.9.0",
     "axios": "",
     "cors": "",
-    "dotenv": "",
+    "dotenv": "^17.2.0",
     "express": "",
     "zod": ""
   },

src/index.ts

@@ -18,8 +18,10 @@ import { resources, addResource as addResourceCore, Resource } from './resources
 
 // Load environment variables with enhanced setup
 setupEnvironment();
-// Also load with standard dotenv for compatibility
-dotenv.config();
+// Also load with standard dotenv for compatibility.
+// quiet: true suppresses dotenv v17+'s startup banner, which is written to
+// stdout and would corrupt the stdio JSON-RPC stream (breaks the MCP client).
+dotenv.config({ quiet: true });
 
 // Keep a reference to the server for notifications
 let serverInstance: Server | null = null;

src/utils/api-client.ts

@@ -3,10 +3,13 @@ import dotenv from 'dotenv';
 import path from 'path';
 import { transformParamsToHyphenated } from './param-transformer';
 
-// Try to load environment variables from .env file with absolute path
-dotenv.config();
+// Try to load environment variables from .env file with absolute path.
+// quiet: true suppresses dotenv v17+'s "injecting env" banner, which is
+// written to stdout and would corrupt the stdio JSON-RPC stream (this module
+// is imported by index.ts, so these calls run during server startup).
+dotenv.config({ quiet: true });
 // Also try with explicit path as fallback
-dotenv.config({ path: path.resolve(process.cwd(), '.env') });
+dotenv.config({ path: path.resolve(process.cwd(), '.env'), quiet: true });
 
 // NASA API Base URLs
 export const NASA_API_BASE_URL = 'https://api.nasa.gov';
@@ -28,7 +31,7 @@ export async function nasaApiRequest(
     if (!apiKey) {
       try {
         const envPath = path.resolve(process.cwd(), '.env');
-        dotenv.config({ path: envPath });
+        dotenv.config({ path: envPath, quiet: true });
         apiKey = process.env.NASA_API_KEY;
       } catch (error) {
         console.error('Error loading .env file:', error);
@@ -124,7 +127,7 @@ export async function jplApiRequest(
       // If other JPL endpoints require a key but it's missing, try loading .env
       try {
         const envPath = path.resolve(process.cwd(), '.env');
-        dotenv.config({ path: envPath });
+        dotenv.config({ path: envPath, quiet: true });
         apiKey = process.env.NASA_API_KEY;
         if (apiKey) {
           paramsToSend.api_key = apiKey;

src/utils/env-setup.ts

@@ -39,24 +39,26 @@ export function setupEnvironment() {
     const rootEnvPath = path.join(currentDir, '.env');
     const distEnvPath = path.join(currentDir, 'dist', '.env');
 
-    // First try standard .env loading
-    dotenv.config();
-
+    // First try standard .env loading.
+    // quiet: true suppresses dotenv v17+'s startup banner ("injecting env…"),
+    // which is printed to stdout and would corrupt the stdio JSON-RPC stream.
+    dotenv.config({ quiet: true });
+
     // If running from dist, also try parent directory
     if (currentDir.includes('dist')) {
       const parentEnvPath = path.join(currentDir, '..', '.env');
       if (fs.existsSync(parentEnvPath)) {
-        dotenv.config({ path: parentEnvPath });
+        dotenv.config({ path: parentEnvPath, quiet: true });
       }
     }
-    
+
     // Also try explicit paths
     if (fs.existsSync(rootEnvPath)) {
-      dotenv.config({ path: rootEnvPath });
+      dotenv.config({ path: rootEnvPath, quiet: true });
     }
-    
+
     if (fs.existsSync(distEnvPath)) {
-      dotenv.config({ path: distEnvPath });
+      dotenv.config({ path: distEnvPath, quiet: true });
     }
 
     // Ensure dist directory has a copy of .env