diff --git a/src/browser/api.ts b/src/browser/api.ts
index 9f1cc2c8a..d3460b3ca 100644
--- a/src/browser/api.ts
+++ b/src/browser/api.ts
@@ -260,6 +260,9 @@ const webApi: IPCApi = {
       return wsManager.on(IPC_CHANNELS.UPDATE_STATUS, callback as (data: unknown) => void);
     },
   },
+  server: {
+    getLaunchProject: () => invokeIPC("server:getLaunchProject"),
+  },
 };
 
 if (typeof window.api === "undefined") {
diff --git a/src/components/AppLoader.tsx b/src/components/AppLoader.tsx
index 739eee2c7..c6b4ed5ed 100644
--- a/src/components/AppLoader.tsx
+++ b/src/components/AppLoader.tsx
@@ -96,6 +96,51 @@ export function AppLoader() {
     setSelectedWorkspace,
   ]);
 
+  // Check for launch project from server (for --add-project flag)
+  // This only applies in server mode
+  useEffect(() => {
+    // Wait until stores are synced and hash restoration is complete
+    if (!storesSynced || !hasRestoredFromHash) return;
+
+    // Skip if we already have a selected workspace (from localStorage or URL hash)
+    if (selectedWorkspace) return;
+
+    // Only check once
+    const checkLaunchProject = async () => {
+      // Only available in server mode
+      if (!window.api.server?.getLaunchProject) return;
+
+      const launchProjectPath = await window.api.server.getLaunchProject();
+      if (!launchProjectPath) return;
+
+      // Find first workspace in this project
+      const projectWorkspaces = Array.from(workspaceManagement.workspaceMetadata.values()).filter(
+        (meta) => meta.projectPath === launchProjectPath
+      );
+
+      if (projectWorkspaces.length > 0) {
+        // Select the first workspace in the project
+        const metadata = projectWorkspaces[0];
+        setSelectedWorkspace({
+          workspaceId: metadata.id,
+          projectPath: metadata.projectPath,
+          projectName: metadata.projectName,
+          namedWorkspacePath: metadata.namedWorkspacePath,
+        });
+      }
+      // If no workspaces exist yet, just leave the project in the sidebar
+      // The user will need to create a workspace
+    };
+
+    void checkLaunchProject();
+  }, [
+    storesSynced,
+    hasRestoredFromHash,
+    selectedWorkspace,
+    workspaceManagement.workspaceMetadata,
+    setSelectedWorkspace,
+  ]);
+
   // Show loading screen until stores are synced
   if (workspaceManagement.loading || !storesSynced) {
     return <LoadingScreen />;
diff --git a/src/main-server.ts b/src/main-server.ts
index 3be56ecef..01b54e18f 100644
--- a/src/main-server.ts
+++ b/src/main-server.ts
@@ -13,6 +13,7 @@ import * as path from "path";
 import type { RawData } from "ws";
 import { WebSocket, WebSocketServer } from "ws";
 import { Command } from "commander";
+import { validateProjectPath } from "./utils/pathUtils";
 
 // Parse command line arguments
 const program = new Command();
@@ -22,11 +23,16 @@ program
   .description("HTTP/WebSocket server for cmux - allows accessing cmux backend from mobile devices")
   .option("-h, --host <host>", "bind to specific host", "localhost")
   .option("-p, --port <port>", "bind to specific port", "3000")
+  .option("--add-project <path>", "add and open project at the specified path (idempotent)")
   .parse(process.argv);
 
 const options = program.opts();
 const HOST = options.host as string;
 const PORT = parseInt(options.port as string, 10);
+const ADD_PROJECT_PATH = options.addProject as string | undefined;
+
+// Track the launch project path for initial navigation
+let launchProjectPath: string | null = null;
 
 // Mock Electron's ipcMain for HTTP
 class HttpIpcMainAdapter {
@@ -35,6 +41,13 @@ class HttpIpcMainAdapter {
 
   constructor(private readonly app: express.Application) {}
 
+  // Public method to get a handler (for internal use)
+  getHandler(
+    channel: string
+  ): ((event: unknown, ...args: unknown[]) => Promise<unknown>) | undefined {
+    return this.handlers.get(channel);
+  }
+
   handle(channel: string, handler: (event: unknown, ...args: unknown[]) => Promise<unknown>): void {
     this.handlers.set(channel, handler);
 
@@ -138,6 +151,11 @@ ipcMainService.register(
   mockWindow as unknown as BrowserWindow
 );
 
+// Add custom endpoint for launch project (only for server mode)
+httpIpcMain.handle("server:getLaunchProject", () => {
+  return Promise.resolve(launchProjectPath);
+});
+
 // Serve static files from dist directory (built renderer)
 app.use(express.static(path.join(__dirname, ".")));
 
@@ -247,6 +265,85 @@ wss.on("connection", (ws) => {
   });
 });
 
+/**
+ * Initialize a project from the --add-project flag
+ * This checks if a project exists at the given path, creates it if not, and opens it
+ */
+async function initializeProject(
+  projectPath: string,
+  ipcAdapter: HttpIpcMainAdapter
+): Promise<void> {
+  try {
+    // Trim trailing slashes to ensure proper project name extraction
+    projectPath = projectPath.replace(/\/+$/, "");
+
+    // Normalize path (expand tilde, make absolute) to match how PROJECT_CREATE normalizes paths
+    const validation = await validateProjectPath(projectPath);
+    if (!validation.valid) {
+      const errorMsg = validation.error ?? "Unknown validation error";
+      console.error(`Invalid project path: ${errorMsg}`);
+      return;
+    }
+    projectPath = validation.expandedPath!;
+
+    // First, check if project already exists by listing all projects
+    const handler = ipcAdapter.getHandler(IPC_CHANNELS.PROJECT_LIST);
+    if (!handler) {
+      console.error("PROJECT_LIST handler not found");
+      return;
+    }
+
+    const projectsList = await handler(null);
+    if (!Array.isArray(projectsList)) {
+      console.error("Unexpected PROJECT_LIST response format");
+      return;
+    }
+
+    // Check if the project already exists (projectsList is Array<[string, ProjectConfig]>)
+    const existingProject = (projectsList as Array<[string, unknown]>).find(
+      ([path]) => path === projectPath
+    );
+
+    if (existingProject) {
+      console.log(`Project already exists at: ${projectPath}`);
+      launchProjectPath = projectPath;
+      return;
+    }
+
+    // Project doesn't exist, create it
+    console.log(`Creating new project at: ${projectPath}`);
+    const createHandler = ipcAdapter.getHandler(IPC_CHANNELS.PROJECT_CREATE);
+    if (!createHandler) {
+      console.error("PROJECT_CREATE handler not found");
+      return;
+    }
+
+    const createResult = await createHandler(null, projectPath);
+
+    // Check if creation was successful using the Result type
+    if (createResult && typeof createResult === "object" && "success" in createResult) {
+      if (createResult.success) {
+        console.log(`Successfully created project at: ${projectPath}`);
+        launchProjectPath = projectPath;
+      } else if ("error" in createResult) {
+        const err = createResult as { error: unknown };
+        const errorMsg = err.error instanceof Error ? err.error.message : String(err.error);
+        console.error(`Failed to create project: ${errorMsg}`);
+      }
+    } else {
+      console.error("Unexpected PROJECT_CREATE response format");
+    }
+  } catch (error) {
+    console.error(`Error initializing project:`, error);
+  }
+}
+
 server.listen(PORT, HOST, () => {
   console.log(`Server is running on http://${HOST}:${PORT}`);
+
+  // Handle --add-project flag if present
+  if (ADD_PROJECT_PATH) {
+    console.log(`Initializing project at: ${ADD_PROJECT_PATH}`);
+    void initializeProject(ADD_PROJECT_PATH, httpIpcMain);
+  }
 });
diff --git a/src/types/ipc.ts b/src/types/ipc.ts
index 4a0a46c77..81b10627f 100644
--- a/src/types/ipc.ts
+++ b/src/types/ipc.ts
@@ -299,6 +299,9 @@ export interface IPCApi {
     install(): void;
     onStatus(callback: (status: UpdateStatus) => void): () => void;
   };
+  server?: {
+    getLaunchProject(): Promise<string | null>;
+  };
 }
 
 // Update status type (matches updater service)