feat: Prefer environment variable to command line

Easier to standardise configuration and tool setup this way

README.md

@@ -15,9 +15,11 @@ To use this server with the Claude Desktop app, add the following configuration
       "command": "npx",
       "args": [
         "-y",
-        "airtable-mcp-server",
-        "pat123.abc123"
-      ]
+        "airtable-mcp-server"
+      ],
+      "env": {
+        "AIRTABLE_API_KEY": "pat123.abc123"
+      }
     }
   }
 }

src/airtableService.ts

@@ -28,7 +28,7 @@ export class AirtableService implements IAirtableService {
     fetch: typeof nodeFetch = nodeFetch,
   ) {
     if (!apiKey) {
-      throw new Error('No API key set. Either:\n1. Pass it in as a command-line argument, for example `airtable-mcp-server <API_KEY>`\n2. Set it in the `AIRTABLE_API_KEY` environment variable');
+      throw new Error('airtable-mcp-server: No API key provided. Set it in the `AIRTABLE_API_KEY` environment variable');
     }
 
     this.apiKey = apiKey;

src/index.ts

@@ -6,6 +6,10 @@ import { AirtableMCPServer } from './mcpServer.js';
 
 const main = async () => {
   const apiKey = process.argv.slice(2)[0];
+  if (apiKey) {
+    // Deprecation warning
+    console.warn('warning (airtable-mcp-server): Passing in an API key as a command-line argument is deprecated and may be removed in a future version. Instead, set the `AIRTABLE_API_KEY` environment variable. See https://github.com/domdomegg/airtable-mcp-server/blob/master/README.md#usage for an example with Claude Desktop.');
+  }
   const airtableService = new AirtableService(apiKey);
   const server = new AirtableMCPServer(airtableService);
   const transport = new StdioServerTransport();