AlistGo/alist · warning · EmptyUsername

username is empty

Error message

username is empty

What it means

EmptyUsername is a sentinel in internal/errs/user.go raised during user validation when a request that requires a username supplies an empty one. It guards user creation/update in the admin API and the login flow before any credential check happens.

Source

Thrown at internal/errs/user.go:6

package errs

import "errors"

var (
	EmptyUsername      = errors.New("username is empty")
	EmptyPassword      = errors.New("password is empty")
	WrongPassword      = errors.New("password is incorrect")
	DeleteAdminOrGuest = errors.New("cannot delete admin or guest")
)

View on GitHub (pinned to 843d9dc814)

Solutions

1. Ensure the username field is non-empty before submitting (client-side required check)
2. Inspect the actual JSON body sent — the key must be exactly 'username'
3. Trim input and reject empty strings before calling the user API
4. If scripting, validate generated usernames are populated before the request

Example fix

// before
if username == "" { /* nothing, request fails server-side */ }

// after
if strings.TrimSpace(username) == "" {
    return errs.EmptyUsername
}

// client-side guard before login/user APIs
if strings.TrimSpace(username) == "" {
    return errs.EmptyUsername
}

func hasUsername(s string) bool { return strings.TrimSpace(s) != "" }

if err := login(user, pass); err != nil {
    if errors.Is(err, errs.EmptyUsername) { /* prompt for username */ }
}

When it happens

Trigger: POSTing a login request with an empty/missing username field; creating or updating a user via the admin API without a username; whitespace-only username that survives trimming checks.

Common situations: Forms with a missing username input; API scripts sending {"username":""} or omitting the key; automation generating users from unpopulated template variables; proxied requests where the field is dropped by a misconfigured body limit or middleware.

Related errors

• password is empty
• api_key is empty
• cookie is empty
• empty token
• invalid request

AI-assisted analysis of AlistGo/alist@843d9dc814 (2026-08-15). Data as JSON: /api/errors/6e1d282334d02b7d. Report an issue: GitHub.