chore: remove unused variable reactDefinitionFile

* chore: rename utils.ts to fileoperations.ts

* feat: replace node-pty with E2B sandboxes

* added debounced function in the editor

* fix: move socket connection to useRef

* fix: wait until terminals are killed to close the container

* fix: ensure container remains open until all owner connections are closed

* fix: sync files to container instead of local file system

* fix: set project file permissions so that they belong to the terminal user

* fix: use the container URL for the preview panel

* fix: count only the current user's sandboxes towards the limit

* fix: remove hardcoded reference to localhost

* fix: add error handling to the backend

* docs: add information about E2B

---------

Co-authored-by: Akhilesh Rangani <akhileshrangani4@gmail.com>

README.md

@@ -29,7 +29,9 @@ npm run dev
 
 ### Backend
 
-The backend consists of a primary Express and Socket.io server, and 3 Cloudflare Workers microservices for the D1 database, R2 storage, and Workers AI. The D1 database also contains a [service binding](https://developers.cloudflare.com/workers/runtime-apis/bindings/service-bindings/) to the R2 storage worker.
+The backend consists of a primary Express and Socket.io server, and 3 Cloudflare Workers microservices for the D1 database, R2 storage, and Workers AI. The D1 database also contains a [service binding](https://developers.cloudflare.com/workers/runtime-apis/bindings/service-bindings/) to the R2 storage worker. Each open sandbox instantiates a secure Linux sandboxes on E2B, which is used for the terminal and live preview.
+
+You will need to make an account on [E2B](https://e2b.dev/) to get an API key.
 
 #### Socket.io server
 
@@ -181,3 +183,4 @@ It should be in the form `category(scope or module): message` in your commit mes
 - [Express](https://expressjs.com/)
 - [Socket.io](https://socket.io/)
 - [Drizzle ORM](https://orm.drizzle.team/)
+- [E2B](https://e2b.dev/)

backend/database/src/index.ts

@@ -114,12 +114,12 @@ export default {
 					.select()
 					.from(sandbox)
 					.where(eq(sandbox.userId, userId))
-				.all();
+					.all()
 
 				if (userSandboxes.length >= 8) {
 					return new Response("You reached the maximum # of sandboxes.", {
 						status: 400,
-				});
+					})
 				}
 
 				const sb = await db

backend/database/src/schema.ts

@@ -31,7 +31,7 @@ export const sandbox = sqliteTable("sandbox", {
 	createdAt: integer("createdAt", { mode: "timestamp_ms" }),
 	userId: text("user_id")
 		.notNull()
-		.references(() => user.id, { onDelete: "cascade" }),
+		.references(() => user.id),
 });
 
 export type Sandbox = typeof sandbox.$inferSelect;

backend/server/.env.example

@@ -5,3 +5,4 @@ PORT=4000
 WORKERS_KEY=
 DATABASE_WORKER_URL=
 STORAGE_WORKER_URL=
+E2B_API_KEY=

backend/server/src/index.ts

@@ -49,11 +49,15 @@ const terminals: Record<string, Terminal> = {};
 
 const dirName = "/home/user";
 
-const moveFile = async (filesystem: FilesystemManager, filePath: string, newFilePath: string) => {
-  const fileContents = await filesystem.readBytes(filePath)
+const moveFile = async (
+  filesystem: FilesystemManager,
+  filePath: string,
+  newFilePath: string
+) => {
+  const fileContents = await filesystem.readBytes(filePath);
   await filesystem.writeBytes(newFilePath, fileContents);
   await filesystem.remove(filePath);
-}
+};
 
 io.use(async (socket, next) => {
   const handshakeSchema = z.object({
@@ -109,6 +113,7 @@ io.use(async (socket, next) => {
 const lockManager = new LockManager();
 
 io.on("connection", async (socket) => {
+  try {
     if (inactivityTimeout) clearTimeout(inactivityTimeout);
 
     const data = socket.data as {
@@ -132,10 +137,14 @@ io.on("connection", async (socket) => {
         if (!containers[data.sandboxId]) {
           containers[data.sandboxId] = await Sandbox.create();
           console.log("Created container ", data.sandboxId);
-        io.emit("previewURL", "https://" + containers[data.sandboxId].getHostname(5173));
+          io.emit(
+            "previewURL",
+            "https://" + containers[data.sandboxId].getHostname(5173)
+          );
         }
-    } catch (error) {
-      console.error("Error creating container ", data.sandboxId, error);
+      } catch (e: any) {
+        console.error(`Error creating container ${data.sandboxId}:`, e);
+        io.emit("error", `Error: container creation. ${e.message ?? e}`);
       }
     });
 
@@ -144,12 +153,14 @@ io.on("connection", async (socket) => {
       await containers[data.sandboxId].process.startAndWait(
         `sudo chown -R user "${path.join(dirName, "projects", data.sandboxId)}"`
       );
-  }
+    };
 
     const sandboxFiles = await getSandboxFiles(data.sandboxId);
     sandboxFiles.fileData.forEach(async (file) => {
       const filePath = path.join(dirName, file.id);
-    await containers[data.sandboxId].filesystem.makeDir(path.dirname(filePath));
+      await containers[data.sandboxId].filesystem.makeDir(
+        path.dirname(filePath)
+      );
       await containers[data.sandboxId].filesystem.write(filePath, file.data);
     });
     fixPermissions();
@@ -157,43 +168,67 @@ io.on("connection", async (socket) => {
     socket.emit("loaded", sandboxFiles.files);
 
     socket.on("getFile", (fileId: string, callback) => {
+      console.log(fileId);
+      try {
         const file = sandboxFiles.fileData.find((f) => f.id === fileId);
         if (!file) return;
 
         callback(file.data);
+      } catch (e: any) {
+        console.error("Error getting file:", e);
+        io.emit("error", `Error: get file. ${e.message ?? e}`);
+      }
     });
 
     socket.on("getFolder", async (folderId: string, callback) => {
+      try {
         const files = await getFolder(folderId);
         callback(files);
+      } catch (e: any) {
+        console.error("Error getting folder:", e);
+        io.emit("error", `Error: get folder. ${e.message ?? e}`);
+      }
     });
 
     // todo: send diffs + debounce for efficiency
     socket.on("saveFile", async (fileId: string, body: string) => {
-    try {
-      await saveFileRL.consume(data.userId, 1);
+      if (!fileId) return; // handles saving when no file is open
 
+      try {
         if (Buffer.byteLength(body, "utf-8") > MAX_BODY_SIZE) {
           socket.emit(
-          "rateLimit",
-          "Rate limited: file size too large. Please reduce the file size."
+            "error",
+            "Error: file size too large. Please reduce the file size."
           );
           return;
         }
+        try {
+          await saveFileRL.consume(data.userId, 1);
+          await saveFile(fileId, body);
+        } catch (e) {
+          io.emit("error", "Rate limited: file saving. Please slow down.");
+          return;
+        }
 
         const file = sandboxFiles.fileData.find((f) => f.id === fileId);
         if (!file) return;
         file.data = body;
 
-      await containers[data.sandboxId].filesystem.write(path.join(dirName, file.id), body);
+        await containers[data.sandboxId].filesystem.write(
+          path.join(dirName, file.id),
+          body
+        );
         fixPermissions();
-      await saveFile(fileId, body);
-    } catch (e) {
-      io.emit("rateLimit", "Rate limited: file saving. Please slow down.");
+      } catch (e: any) {
+        console.error("Error saving file:", e);
+        io.emit("error", `Error: file saving. ${e.message ?? e}`);
       }
     });
 
-  socket.on("moveFile", async (fileId: string, folderId: string, callback) => {
+    socket.on(
+      "moveFile",
+      async (fileId: string, folderId: string, callback) => {
+        try {
           const file = sandboxFiles.fileData.find((f) => f.id === fileId);
           if (!file) return;
 
@@ -204,16 +239,20 @@ io.on("connection", async (socket) => {
             containers[data.sandboxId].filesystem,
             path.join(dirName, fileId),
             path.join(dirName, newFileId)
-    )
+          );
           fixPermissions();
 
           file.id = newFileId;
 
           await renameFile(fileId, newFileId, file.data);
           const newFiles = await getSandboxFiles(data.sandboxId);
-
           callback(newFiles.files);
-  });
+        } catch (e: any) {
+          console.error("Error moving file:", e);
+          io.emit("error", `Error: file moving. ${e.message ?? e}`);
+        }
+      }
+    );
 
     socket.on("createFile", async (name: string, callback) => {
       try {
@@ -221,17 +260,26 @@ io.on("connection", async (socket) => {
         // limit is 200mb
         if (size > 200 * 1024 * 1024) {
           io.emit(
-          "rateLimit",
+            "error",
             "Rate limited: project size exceeded. Please delete some files."
           );
           callback({ success: false });
+          return;
         }
 
+        try {
           await createFileRL.consume(data.userId, 1);
+        } catch (e) {
+          io.emit("error", "Rate limited: file creation. Please slow down.");
+          return;
+        }
 
         const id = `projects/${data.sandboxId}/${name}`;
 
-      await containers[data.sandboxId].filesystem.write(path.join(dirName, id), "");
+        await containers[data.sandboxId].filesystem.write(
+          path.join(dirName, id),
+          ""
+        );
         fixPermissions();
 
         sandboxFiles.files.push({
@@ -248,28 +296,42 @@ io.on("connection", async (socket) => {
         await createFile(id);
 
         callback({ success: true });
-    } catch (e) {
-      io.emit("rateLimit", "Rate limited: file creation. Please slow down.");
+      } catch (e: any) {
+        console.error("Error creating file:", e);
+        io.emit("error", `Error: file creation. ${e.message ?? e}`);
       }
     });
 
     socket.on("createFolder", async (name: string, callback) => {
+      try {
         try {
           await createFolderRL.consume(data.userId, 1);
+        } catch (e) {
+          io.emit("error", "Rate limited: folder creation. Please slow down.");
+          return;
+        }
 
         const id = `projects/${data.sandboxId}/${name}`;
 
-      await containers[data.sandboxId].filesystem.makeDir(path.join(dirName, id));
+        await containers[data.sandboxId].filesystem.makeDir(
+          path.join(dirName, id)
+        );
 
         callback();
-    } catch (e) {
-      io.emit("rateLimit", "Rate limited: folder creation. Please slow down.");
+      } catch (e: any) {
+        console.error("Error creating folder:", e);
+        io.emit("error", `Error: folder creation. ${e.message ?? e}`);
       }
     });
 
     socket.on("renameFile", async (fileId: string, newName: string) => {
+      try {
         try {
           await renameFileRL.consume(data.userId, 1);
+        } catch (e) {
+          io.emit("error", "Rate limited: file renaming. Please slow down.");
+          return;
+        }
 
         const file = sandboxFiles.fileData.find((f) => f.id === fileId);
         if (!file) return;
@@ -279,27 +341,33 @@ io.on("connection", async (socket) => {
         const newFileId =
           parts.slice(0, parts.length - 1).join("/") + "/" + newName;
 
-
         await moveFile(
           containers[data.sandboxId].filesystem,
           path.join(dirName, fileId),
           path.join(dirName, newFileId)
-      )
+        );
         fixPermissions();
         await renameFile(fileId, newFileId, file.data);
-    } catch (e) {
-      io.emit("rateLimit", "Rate limited: file renaming. Please slow down.");
-      return;
+      } catch (e: any) {
+        console.error("Error renaming folder:", e);
+        io.emit("error", `Error: folder renaming. ${e.message ?? e}`);
       }
     });
 
     socket.on("deleteFile", async (fileId: string, callback) => {
+      try {
         try {
           await deleteFileRL.consume(data.userId, 1);
+        } catch (e) {
+          io.emit("error", "Rate limited: file deletion. Please slow down.");
+        }
+
         const file = sandboxFiles.fileData.find((f) => f.id === fileId);
         if (!file) return;
 
-      await containers[data.sandboxId].filesystem.remove(path.join(dirName, fileId));
+        await containers[data.sandboxId].filesystem.remove(
+          path.join(dirName, fileId)
+        );
         sandboxFiles.fileData = sandboxFiles.fileData.filter(
           (f) => f.id !== fileId
         );
@@ -308,8 +376,9 @@ io.on("connection", async (socket) => {
 
         const newFiles = await getSandboxFiles(data.sandboxId);
         callback(newFiles.files);
-    } catch (e) {
-      io.emit("rateLimit", "Rate limited: file deletion. Please slow down.");
+      } catch (e: any) {
+        console.error("Error deleting file:", e);
+        io.emit("error", `Error: file deletion. ${e.message ?? e}`);
       }
     });
 
@@ -318,11 +387,14 @@ io.on("connection", async (socket) => {
     // });
 
     socket.on("deleteFolder", async (folderId: string, callback) => {
+      try {
         const files = await getFolder(folderId);
 
         await Promise.all(
           files.map(async (file) => {
-        await containers[data.sandboxId].filesystem.remove(path.join(dirName, file));
+            await containers[data.sandboxId].filesystem.remove(
+              path.join(dirName, file)
+            );
 
             sandboxFiles.fileData = sandboxFiles.fileData.filter(
               (f) => f.id !== file
@@ -335,9 +407,14 @@ io.on("connection", async (socket) => {
         const newFiles = await getSandboxFiles(data.sandboxId);
 
         callback(newFiles.files);
+      } catch (e: any) {
+        console.error("Error deleting folder:", e);
+        io.emit("error", `Error: folder deletion. ${e.message ?? e}`);
+      }
     });
 
     socket.on("createTerminal", async (id: string, callback) => {
+      try {
         if (terminals[id] || Object.keys(terminals).length >= 4) {
           return;
         }
@@ -351,36 +428,53 @@ io.on("connection", async (socket) => {
               size: { cols: 80, rows: 20 },
               onExit: () => console.log("Terminal exited", id),
             });
-        await terminals[id].sendData(`cd "${path.join(dirName, "projects", data.sandboxId)}"\r`)
+            await terminals[id].sendData(
+              `cd "${path.join(dirName, "projects", data.sandboxId)}"\r`
+            );
             await terminals[id].sendData("export PS1='user> '\rclear\r");
             console.log("Created terminal", id);
-      } catch (error) {
-        console.error("Error creating terminal ", id, error);
+          } catch (e: any) {
+            console.error(`Error creating terminal ${id}:`, e);
+            io.emit("error", `Error: terminal creation. ${e.message ?? e}`);
           }
         });
 
         callback();
+      } catch (e: any) {
+        console.error(`Error creating terminal ${id}:`, e);
+        io.emit("error", `Error: terminal creation. ${e.message ?? e}`);
+      }
     });
 
-  socket.on("resizeTerminal", (dimensions: { cols: number; rows: number }) => {
+    socket.on(
+      "resizeTerminal",
+      (dimensions: { cols: number; rows: number }) => {
+        try {
           Object.values(terminals).forEach((t) => {
             t.resize(dimensions);
           });
-  });
+        } catch (e: any) {
+          console.error("Error resizing terminal:", e);
+          io.emit("error", `Error: terminal resizing. ${e.message ?? e}`);
+        }
+      }
+    );
 
     socket.on("terminalData", (id: string, data: string) => {
+      try {
         if (!terminals[id]) {
           return;
         }
 
-    try {
         terminals[id].sendData(data);
-    } catch (e) {
-      console.log("Error writing to terminal", e);
+      } catch (e: any) {
+        console.error("Error writing to terminal:", e);
+        io.emit("error", `Error: writing to terminal. ${e.message ?? e}`);
       }
     });
 
     socket.on("closeTerminal", async (id: string, callback) => {
+      try {
         if (!terminals[id]) {
           return;
         }
@@ -389,6 +483,10 @@ io.on("connection", async (socket) => {
         delete terminals[id];
 
         callback();
+      } catch (e: any) {
+        console.error("Error closing terminal:", e);
+        io.emit("error", `Error: closing terminal. ${e.message ?? e}`);
+      }
     });
 
     socket.on(
@@ -400,6 +498,7 @@ io.on("connection", async (socket) => {
         instructions: string,
         callback
       ) => {
+        try {
           const fetchPromise = fetch(
             `${process.env.DATABASE_WORKER_URL}/api/sandbox/generate`,
             {
@@ -433,10 +532,15 @@ io.on("connection", async (socket) => {
           const json = await generateCodeResponse.json();
 
           callback({ response: json.response, success: true });
+        } catch (e: any) {
+          console.error("Error generating code:", e);
+          io.emit("error", `Error: code generation. ${e.message ?? e}`);
+        }
       }
     );
 
     socket.on("disconnect", async () => {
+      try {
         if (data.isOwner) {
           connections[data.sandboxId]--;
         }
@@ -483,7 +587,15 @@ io.on("connection", async (socket) => {
         // } else {
         //   console.log("number of sockets", sockets.length);
         // }
+      } catch (e: any) {
+        console.log("Error disconnecting:", e);
+        io.emit("error", `Error: disconnecting. ${e.message ?? e}`);
+      }
     });
+  } catch (e: any) {
+    console.error("Error connecting:", e);
+    io.emit("error", `Error: connection. ${e.message ?? e}`);
+  }
 });
 
 httpServer.listen(port, () => {

frontend/app/(app)/code/[id]/page.tsx

@@ -63,14 +63,6 @@ const CodeEditor = dynamic(() => import("@/components/editor"), {
   loading: () => <Loading />,
 })
 
-function getReactDefinitionFile() {
-  const reactDefinitionFile = fs.readFileSync(
-    "node_modules/@types/react/index.d.ts",
-    "utf8"
-  )
-  return reactDefinitionFile
-}
-
 export default async function CodePage({ params }: { params: { id: string } }) {
   const user = await currentUser()
   const sandboxId = params.id
@@ -94,8 +86,6 @@ export default async function CodePage({ params }: { params: { id: string } }) {
     return notFound()
   }
 
-  const reactDefinitionFile = getReactDefinitionFile()
-
   return (
     <div className="overflow-hidden overscroll-none w-screen flex flex-col h-screen bg-background">
       <Room id={sandboxId}>
@@ -104,7 +94,6 @@ export default async function CodePage({ params }: { params: { id: string } }) {
           <CodeEditor
             userData={userData}
             sandboxData={sandboxData}
-            reactDefinitionFile={reactDefinitionFile}
           />
         </div>
       </Room>

frontend/components/editor/index.tsx

@@ -35,18 +35,16 @@ import { ImperativePanelHandle } from "react-resizable-panels"
 export default function CodeEditor({
   userData,
   sandboxData,
-  reactDefinitionFile,
 }: {
   userData: User
   sandboxData: Sandbox
-  reactDefinitionFile: string
 }) {
   const socketRef = useRef<Socket | null>(null);
 
   // Initialize socket connection if it doesn't exist
   if (!socketRef.current) {
     socketRef.current = io(
-      `http://localhost:${process.env.NEXT_PUBLIC_SERVER_PORT}?userId=${userData.id}&sandboxId=${sandboxData.id}`,
+      `${window.location.protocol}//${window.location.hostname}:${process.env.NEXT_PUBLIC_SERVER_PORT}?userId=${userData.id}&sandboxId=${sandboxData.id}`,
       {
         timeout: 2000,
       }
@@ -105,6 +103,16 @@ export default function CodeEditor({
   const [provider, setProvider] = useState<TypedLiveblocksProvider>()
   const userInfo = useSelf((me) => me.info)
   
+  // Liveblocks providers map to prevent reinitializing providers
+  type ProviderData = {
+    provider: LiveblocksProvider<never, never, never, never>;
+    yDoc: Y.Doc;
+    yText: Y.Text;
+    binding?: MonacoBinding;
+    onSync: (isSynced: boolean) => void;
+  };
+  const providersMap = useRef(new Map<string, ProviderData>());
+
   // Refs for libraries / features
   const editorContainerRef = useRef<HTMLDivElement>(null)
   const monacoRef = useRef<typeof monaco | null>(null)
@@ -332,10 +340,15 @@ export default function CodeEditor({
 
     if (!editorRef || !tab || !model) return
 
-    const yDoc = new Y.Doc()
-    const yText = yDoc.getText(tab.id)
-    const yProvider: any = new LiveblocksProvider(room, yDoc)
+    let providerData: ProviderData;
   
+    // When a file is opened for the first time, create a new provider and store in providersMap.
+    if (!providersMap.current.has(tab.id)) {
+      const yDoc = new Y.Doc();
+      const yText = yDoc.getText(tab.id);
+      const yProvider = new LiveblocksProvider(room, yDoc);
+
+      // Inserts the file content into the editor once when the tab is changed.
       const onSync = (isSynced: boolean) => {
         if (isSynced) {
           const text = yText.toString()
@@ -353,22 +366,51 @@ export default function CodeEditor({
 
       yProvider.on("sync", onSync)
 
-    setProvider(yProvider)
+      // Save the provider to the map.
+      providerData = { provider: yProvider, yDoc, yText, onSync };
+      providersMap.current.set(tab.id, providerData);
+
+    } else {
+      // When a tab is opened that has been open before, reuse the existing provider.
+      providerData = providersMap.current.get(tab.id)!;
+    }
 
     const binding = new MonacoBinding(
-      yText,
+      providerData.yText,
       model,
       new Set([editorRef]),
-      yProvider.awareness as Awareness
-    )
+      providerData.provider.awareness as unknown as Awareness
+    );
+
+    providerData.binding = binding;
+  
+    setProvider(providerData.provider);
 
     return () => {
-      yDoc.destroy()
-      yProvider.destroy()
-      binding.destroy()
-      yProvider.off("sync", onSync)
+      // Cleanup logic
+      if (binding) {
+        binding.destroy();
       }
-  }, [editorRef, room, activeFileContent])
+      if (providerData.binding) {
+        providerData.binding = undefined;
+      }
+    };
+  }, [room, activeFileContent]);
+
+    // Added this effect to clean up when the component unmounts
+    useEffect(() => {
+      return () => {
+        // Clean up all providers when the component unmounts
+        providersMap.current.forEach((data) => {
+          if (data.binding) {
+            data.binding.destroy();
+          }
+          data.provider.disconnect();
+          data.yDoc.destroy();
+        });
+        providersMap.current.clear();
+      };
+    }, []);
 
   // Connection/disconnection effect
   useEffect(() => {
@@ -391,7 +433,7 @@ export default function CodeEditor({
       setFiles(files)
     }
 
-    const onRateLimit = (message: string) => {
+    const onError = (message: string) => {
       toast.error(message)
     }
 
@@ -413,7 +455,7 @@ export default function CodeEditor({
     socketRef.current?.on("connect", onConnect)
     socketRef.current?.on("disconnect", onDisconnect)
     socketRef.current?.on("loaded", onLoadedEvent)
-    socketRef.current?.on("rateLimit", onRateLimit)
+    socketRef.current?.on("error", onError)
     socketRef.current?.on("terminalResponse", onTerminalResponse)
     socketRef.current?.on("disableAccess", onDisableAccess)
     socketRef.current?.on("previewURL", setPreviewURL)
@@ -422,7 +464,7 @@ export default function CodeEditor({
       socketRef.current?.off("connect", onConnect)
       socketRef.current?.off("disconnect", onDisconnect)
       socketRef.current?.off("loaded", onLoadedEvent)
-      socketRef.current?.off("rateLimit", onRateLimit)
+      socketRef.current?.off("error", onError)
       socketRef.current?.off("terminalResponse", onTerminalResponse)
       socketRef.current?.off("disableAccess", onDisableAccess)
       socketRef.current?.off("previewURL", setPreviewURL)