Telegram nodeje api: getting 400 CONNECTION_NOT_INITED error

Question

I've got a function to download an image from telegram message, it accepts message.media.photo:

const downloadPhoto = async (photo, client, name) => {
 await client.connect();
 const file = new Api.InputPhotoFileLocation({
 id: photo.id,
 accessHash: photo.accessHash,
 fileReference: photo.fileReference,
 thumbSize: "y",
 });
 try {
 const buffer = await client.downloadFile(file, {
 dcId: photo.dcId,
 });
 fs.writeFileSync(name ? name : "output.jpg", buffer);
 } catch (error) {
 console.error("Error downloading photo:", error, file);
 }
};

I get messages using this method:

await client.invoke(new Api.messages.GetHistory(req))

which works fine. The issue is with the download method: it fails with an error:

Error downloading photo: RPCError: 400: CONNECTION_NOT_INITED (caused by upload.GetFile)
 at RPCMessageToError (/app/img-bot/node_modules/telegram/errors/index.js:28:12)
 at MTProtoSender._handleRPCResult (/app/img-bot/node_modules/telegram/network/MTProtoSender.js:561:58)
 at MTProtoSender._processMessage (/app/img-bot/node_modules/telegram/network/MTProtoSender.js:492:15)
 at process.processTicksAndRejections (node:internal/process/task_queues:105:5)
 at async MTProtoSender._recvLoop (/app/img-bot/node_modules/telegram/network/MTProtoSender.js:439:17)

What am I doing wrong?

Answer 1

Telegram stores media on different DCs.
By forcing dcId and also calling client.connect() inside the download function, you end up with a DC connection that is not properly initialized for file download CONNECTION_NOT_INITED.

1. What to change

Connect only once at startup, not inside downloadPhoto:
// app startup
const client = new TelegramClient(session, apiId, apiHash, { connectionRetries: 5 });
await client.start({ /* auth options */ });
// no client.connect() inside downloadPhoto

2. Do not pass dcId to downloadFile let GramJS handle it

const downloadPhoto = async (photo, name = "output.jpg") => {
 const file = new Api.InputPhotoFileLocation({
 id: photo.id,
 accessHash: photo.accessHash,
 fileReference: photo.fileReference,
 thumbSize: "y",
 });
 try {
 const buffer = await client.downloadFile(file, {});
 fs.writeFileSync(name, buffer);
 } catch (error) {
 console.error("Error downloading photo:", error);
 }
};

• k102: sadly got the same issue, will check further
• k102: yeah, the issue is somehow connected to the DC: got this now "The file to be accessed is currently stored in DC 2 (caused by upload.GetFile)". The issue is the same though
• k102: oh! got it! I have explicitly set storeSession.setDC(2, '149.154.167.41', 443); and it worked! thank you