run shell path async to avoid blocking config load

Author: sestinj

core/context/mcp/MCPConnection.ts

@@ -47,7 +47,8 @@ class MCPConnection {
   };
 
   constructor(public options: MCPOptions) {
-    this.transport = this.constructTransport(options);
+    // Don't construct transport in constructor to avoid blocking
+    this.transport = {} as Transport; // Will be set in connectClient
 
     this.client = new Client(
       {
@@ -132,7 +133,8 @@ class MCPConnection {
               });
             }),
             (async () => {
-              this.transport = this.constructTransport(this.options);
+              this.transport = await this.constructTransportAsync(this.options);
+
               try {
                 await this.client.connect(this.transport);
               } catch (error) {
@@ -295,7 +297,9 @@ class MCPConnection {
     };
   }
 
-  private constructTransport(options: MCPOptions): Transport {
+  private async constructTransportAsync(
+    options: MCPOptions,
+  ): Promise<Transport> {
     switch (options.transport.type) {
       case "stdio":
         const env: Record<string, string> = options.transport.env
@@ -309,7 +313,7 @@ class MCPConnection {
           // For non-Windows platforms, try to get the PATH from user shell
           if (process.platform !== "win32") {
             try {
-              const shellEnvPath = getEnvPathFromUserShell();
+              const shellEnvPath = await getEnvPathFromUserShell();
               if (shellEnvPath && shellEnvPath !== process.env.PATH) {
                 env.PATH = shellEnvPath;
               }

core/util/shellPath.ts

@@ -1,7 +1,8 @@
-import { execSync } from "child_process";
-import { homedir } from "os";
+import { exec } from "child_process";
+import { promisify } from "util";
 
-export function getEnvPathFromUserShell(): string | undefined {
+const execAsync = promisify(exec);
+export async function getEnvPathFromUserShell(): Promise<string | undefined> {
   if (process.platform === "win32") {
     console.warn(`${getEnvPathFromUserShell.name} not implemented for Windows`);
     return undefined;
@@ -15,7 +16,7 @@ export function getEnvPathFromUserShell(): string | undefined {
     // Source common profile files
     const command = `${process.env.SHELL} -l -c 'for f in ~/.zprofile ~/.zshrc ~/.bash_profile ~/.bashrc; do [ -f "$f" ] && source "$f" 2>/dev/null; done; echo $PATH'`;
 
-    const stdout = execSync(command, {
+    const { stdout } = await execAsync(command, {
       encoding: "utf8",
     });