telegram-bot-api/docs/getting-started/files.md

Files

Telegram supports specifying files in many different formats. In order to accommodate them all, there are multiple structs and type aliases required.

All of these types implement the RequestFileData interface.

Type	Description
FilePath	A local path to a file
FileID	Existing file ID on Telegram's servers
FileURL	URL to file, must be served with expected MIME type
FileReader	Use an io.Reader to provide a file. Lazily read to save memory.
FileBytes	[]byte containing file data. Prefer to use FileReader to save memory.

FilePath

A path to a local file.

file := tgbotapi.FilePath("tests/image.jpg")

FileID

An ID previously uploaded to Telegram. IDs may only be reused by the same bot that received them. Additionally, thumbnail IDs cannot be reused.

file := tgbotapi.FileID("AgACAgIAAxkDAALesF8dCjAAAa_…")

FileURL

A URL to an existing resource. It must be served with a correct MIME type to work as expected.

file := tgbotapi.FileURL("https://i.imgur.com/unQLJIb.jpg")

FileReader

Use an io.Reader to provide file contents as needed. Requires a filename for the virtual file.

var reader io.Reader

file := tgbotapi.FileReader{
    Name: "image.jpg",
    Reader: reader,
}

FileBytes

Use a []byte to provide file contents. Generally try to avoid this as it results in high memory usage. Also requires a filename for the virtual file.

var data []byte

file := tgbotapi.FileBytes{
    Name: "image.jpg",
    Bytes: data,
}