Uploading files

Telegram uploads happen in chunks, with a separate path for files over 10 MB. The uploader package handles chunking, big-file selection and parallelism, returning a tg.InputFileClass you then attach to a message.

import "github.com/gotd/td/telegram/uploader"

u := uploader.NewUploader(client.API())

Sources

Method	Uploads from
u.FromPath(ctx, path)	A file on disk
u.FromBytes(ctx, name, b)	An in-memory []byte
u.FromReader(ctx, name, r)	Any io.Reader
u.FromSource(ctx, src, url)	A custom source.Source

file, err := u.FromPath(ctx, "report.pdf")
if err != nil {
	return err
}

The result is just an uploaded file — to send it you wrap it in a media option.

Sending the uploaded file

Pair the uploader with the message sender. Give the sender the uploader and use message.UploadedDocument / message.UploadedPhoto:

sender := message.NewSender(client.API()).WithUploader(u)

doc := message.UploadedDocument(file,
	html.String(nil, `Upload: <b>from gotd</b>`),
).
	MIME("audio/mp3").
	Filename("track.mp3").
	Audio()

if _, err := sender.Resolve("@channel").Media(ctx, doc); err != nil {
	return err
}

UploadedDocument takes optional caption styling options and exposes builder methods (MIME, Filename, Audio, Video, Voice, …) to describe the file. This is the bot-upload example.

Tuning

The uploader is configured with chained options:

u := uploader.NewUploader(client.API()).
	WithThreads(4).           // parallel chunk streams
	WithPartSize(512 * 1024). // chunk size
	WithProgress(progress{})  // progress tracker, see below

WithProgress takes anything implementing the uploader.Progress interface (Chunk(ctx, state) error):

type progress struct{}

func (progress) Chunk(_ context.Context, s uploader.ProgressState) error {
	log.Printf("uploaded %d/%d bytes", s.Uploaded, s.Total)
	return nil
}

Streaming from a URL

FromSource with the uploader/source HTTP source streams a remote file straight to Telegram without buffering it to disk — the upload-url example:

import "github.com/gotd/td/telegram/uploader/source"

src := source.NewHTTPSource()
f, err := u.FromSource(ctx, src, "https://example.com/big.zip")
if err != nil {
	return err
}
sender.Self().Media(ctx, message.UploadedDocument(f))

Next: Downloading files.