HTTP 400 · Bad Request
HTTP 400 Users & Peers

When & why it happens

The user is already invited; the operation would be a no-op.

Handling in gogram

Surfaced as *gogram.ErrResponseCode. Match on the message:

if err, ok := err.(*gogram.ErrResponseCode); ok { if err.Message == "USER_ALREADY_INVITED" { // handle this error } }