diff --git a/package.json b/package.json
index 75f7f110..3a37ae4e 100644
--- a/package.json
+++ b/package.json
@@ -1719,7 +1719,12 @@
             "type": "objectscript",
             "request": "launch",
             "name": "XDebug"
-          }
+          },
+          {
+            "type": "objectscript",
+            "request": "attach",
+            "name": "Attach to running process"
+          }    
         ],
         "configurationSnippets": [
           {
diff --git a/src/debug/debugAdapterFactory.ts b/src/debug/debugAdapterFactory.ts
index 0e1b31cb..738a8870 100644
--- a/src/debug/debugAdapterFactory.ts
+++ b/src/debug/debugAdapterFactory.ts
@@ -5,33 +5,41 @@ import { ObjectScriptDebugSession } from "./debugSession";
 export class ObjectScriptDebugAdapterDescriptorFactory
   implements vscode.DebugAdapterDescriptorFactory, vscode.Disposable
 {
-  private server?: net.Server;
+  private serverMap = new Map<string, net.Server>();
 
   public createDebugAdapterDescriptor(
     session: vscode.DebugSession,
     executable: vscode.DebugAdapterExecutable | undefined
   ): vscode.ProviderResult<vscode.DebugAdapterDescriptor> {
-    if (!this.server) {
-      // start listening on a random port
-      const debugSession = new ObjectScriptDebugSession();
+    const debugSession = new ObjectScriptDebugSession();
+
+    // pickProcess may have added a suffix to inform us which folder's connection it used
+    const workspaceFolderIndex = (session.configuration.processId as string)?.split("@")[1];
+    const workspaceFolderUri = workspaceFolderIndex
+      ? vscode.workspace.workspaceFolders[parseInt(workspaceFolderIndex)]?.uri
+      : undefined;
+    debugSession.setupAPI(workspaceFolderUri);
 
-      this.server = net
+    const serverId = debugSession.serverId;
+    let server = this.serverMap.get(serverId);
+    if (!server) {
+      // start listening on a random port
+      server = net
         .createServer((socket) => {
           debugSession.setRunAsServer(true);
           debugSession.start(socket as NodeJS.ReadableStream, socket);
         })
         .listen(0);
+      this.serverMap.set(serverId, server);
     }
 
-    // make VS Code connect to debug server
-    const address = this.server.address();
+    // make VS Code connect to this debug server
+    const address = server.address();
     const port = typeof address !== "string" ? address.port : 9000;
     return new vscode.DebugAdapterServer(port);
   }
 
   public dispose(): void {
-    if (this.server) {
-      this.server.close();
-    }
+    this.serverMap.forEach((server) => server.close());
   }
 }
diff --git a/src/debug/debugSession.ts b/src/debug/debugSession.ts
index 047739f3..bbfb6268 100644
--- a/src/debug/debugSession.ts
+++ b/src/debug/debugSession.ts
@@ -63,6 +63,15 @@ async function convertClientPathToDebugger(uri: vscode.Uri, namespace: string):
 }
 
 export class ObjectScriptDebugSession extends LoggingDebugSession {
+  /** After setupAPI() has been called this will return the serverId string */
+  public get serverId(): string | undefined {
+    return this._api?.serverId;
+  }
+
+  private _api?: AtelierAPI;
+
+  private _workspaceFolderUri?: vscode.Uri;
+
   private _statuses = new Map<xdebug.Connection, xdebug.StatusResponse>();
 
   private _connection: xdebug.Connection;
@@ -89,8 +98,6 @@ export class ObjectScriptDebugSession extends LoggingDebugSession {
 
   private _workspace: string;
 
-  private cookies: string[] = [];
-
   /** If this is a CSPDEBUG session */
   private _isCsp = false;
 
@@ -124,6 +131,27 @@ export class ObjectScriptDebugSession extends LoggingDebugSession {
     } while (!this._debugTargetSet);
   }
 
+  /** To be called immediately after construction */
+  public setupAPI(workspaceFolderUri?: vscode.Uri): void {
+    // Only effective the first time
+    if (this._api) {
+      return;
+    }
+
+    this._workspaceFolderUri = workspaceFolderUri;
+    if (workspaceFolderUri) {
+      // The uri of the relevant workspace folder was set after construction
+      this._workspace = undefined;
+      this._api = new AtelierAPI(workspaceFolderUri);
+    } else {
+      // Fall back to old way of deciding where to connect
+      const file = currentFile();
+      this._workspace = file?.workspaceFolder;
+      this._api = new AtelierAPI(file?.uri);
+    }
+    return;
+  }
+
   /** Check if the target is stopped */
   private async _isStopped(): Promise<boolean> {
     return this._connection
@@ -161,21 +189,16 @@ export class ObjectScriptDebugSession extends LoggingDebugSession {
     };
 
     try {
-      const file = currentFile();
-      this._workspace = file?.workspaceFolder;
-
-      const api = new AtelierAPI(file?.uri);
-      this.cookies = api.cookies;
-      if (!api.active) {
+      if (!this._api.active) {
         throw new Error("Connection not active");
       }
-      this._namespace = api.ns;
-      this._url = api.xdebugUrl();
+      this._namespace = this._api.ns;
+      this._url = this._api.xdebugUrl();
 
       const socket = new WebSocket(this._url, {
         rejectUnauthorized: vscode.workspace.getConfiguration("http").get("proxyStrictSSL"),
         headers: {
-          cookie: this.cookies,
+          cookie: this._api.cookies,
         },
       });
 
@@ -240,7 +263,8 @@ export class ObjectScriptDebugSession extends LoggingDebugSession {
   protected async attachRequest(response: DebugProtocol.AttachResponse, args: AttachRequestArguments): Promise<void> {
     try {
       this._debugTargetSet = this._isLaunch = false;
-      const debugTarget = args.cspDebugId != undefined ? `CSPDEBUG:${args.cspDebugId}` : `PID:${args.processId}`;
+      const debugTarget =
+        args.cspDebugId != undefined ? `CSPDEBUG:${args.cspDebugId}` : `PID:${args.processId.split("@")[0]}`;
       await this._connection.sendFeatureSetCommand("debug_target", debugTarget);
       if (args.cspDebugId != undefined) {
         if (args.isUnitTest) {
@@ -590,7 +614,13 @@ export class ObjectScriptDebugSession extends LoggingDebugSession {
       stack.stack.map(async (stackFrame: xdebug.StackFrame, index): Promise<StackFrame> => {
         const [, namespace, name] = decodeURI(stackFrame.fileUri).match(/^dbgp:\/\/\|([^|]+)\|(.*)$/);
         const routine = name;
-        const fileUri = DocumentContentProvider.getUri(routine, this._workspace, namespace);
+        const fileUri = DocumentContentProvider.getUri(
+          routine,
+          this._workspace,
+          namespace,
+          undefined,
+          this._workspaceFolderUri
+        );
         const source = new Source(routine, fileUri.toString());
         let line = stackFrame.line + 1;
         const place = `${stackFrame.method}+${stackFrame.methodOffset}`;
diff --git a/src/extension.ts b/src/extension.ts
index 415533c4..f4f4fce7 100644
--- a/src/extension.ts
+++ b/src/extension.ts
@@ -1015,7 +1015,12 @@ export async function activate(context: vscode.ExtensionContext): Promise<any> {
           matchOnDescription: true,
         })
         .then((value) => {
-          if (value) return value.label;
+          if (value) {
+            const workspaceFolderIndex = vscode.workspace.workspaceFolders.findIndex(
+              (folder) => folder.uri.toString() === connectionUri.toString()
+            );
+            return workspaceFolderIndex < 0 ? value.label : `${value.label}@${workspaceFolderIndex}`;
+          }
         });
     }),
     vscode.commands.registerCommand("vscode-objectscript.jumpToTagAndOffset", jumpToTagAndOffset),