Sometimes use firebase

src/mcp/index.ts

@@ -45,6 +45,7 @@
 import { isFirebaseStudio } from "../env";
 import { timeoutFallback } from "../timeout";
 import { resolveResource, resources, resourceTemplates } from "./resources";
+import * as crossSpawn from "cross-spawn";
 
 const SERVER_VERSION = "0.3.0";
 
@@ -71,6 +72,7 @@
   detectedFeatures?: ServerFeature[];
   clientInfo?: { name?: string; version?: string };
   emulatorHubClient?: EmulatorHubClient;
+  private cliCommand?: string;
 
   // logging spec:
   // https://modelcontextprotocol.io/specification/2025-03-26/server/utilities/logging
@@ -146,12 +148,12 @@
       return {};
     });
 
     this.detectProjectRoot();
     this.detectActiveFeatures();
   }
 
   /** Wait until initialization has finished. */
   ready() {
     if (this._ready) return Promise.resolve();
     return new Promise((resolve, reject) => {
       this._readyPromises.push({ resolve: resolve as () => void, reject });
@@ -162,19 +164,19 @@
     return this.clientInfo?.name ?? (isFirebaseStudio() ? "Firebase Studio" : "<unknown-client>");
   }
 
   private get clientConfigKey() {
     return `mcp.clientConfigs.${this.clientName}:${this.startupRoot || process.cwd()}`;
   }
 
   getStoredClientConfig(): ClientConfig {
     return configstore.get(this.clientConfigKey) || {};
   }
 
   updateStoredClientConfig(update: Partial<ClientConfig>) {
     const config = configstore.get(this.clientConfigKey) || {};
     const newConfig = { ...config, ...update };
     configstore.set(this.clientConfigKey, newConfig);
     return newConfig;
   }
 
   async detectProjectRoot(): Promise<string> {
@@ -299,12 +301,11 @@
   }
 
   private _getFirebaseCliCommand(): string {
-    // TODO(samedson) In the future, we'd like to detect how you ran the MCP
-    // server, and use that so that the CLI doesn't run commands that result in
-    // an install. The reason we can't just use `firebase` is some users may
-    // have run the MCP server via npx, and don't have firebase installed
-    // globally
-    return "npx firebase-tools@latest";
+    if (!this.cliCommand) {
+      const testCommand = crossSpawn.sync("firebase --version");
+      this.cliCommand = testCommand.error ? "npx firebase-tools@latest" : "firebase";
+    }
+    return this.cliCommand;
   }
 
   async mcpListTools(): Promise<ListToolsResult> {