gofiber/fiber · error

fiber: keyauth scope requires insufficient_scope error

Error message

fiber: keyauth scope requires insufficient_scope error

What it means

The mirror of error 292: Config.Scope may only be set when Config.Error == ErrorInsufficientScope. Setting Scope with any other (or empty) Error panics, because the scope parameter is only defined for insufficient_scope challenges in RFC 6750. This catches the inverse misconfiguration.

Solutions

1. Set Config.Error to keyauth.ErrorInsufficientScope if you want to advertise required scopes.
2. Remove Config.Scope if your Error is something else (or empty).
3. Validate at config load: Scope != "" implies Error == ErrorInsufficientScope.

Example fix

// before
app.Use(keyauth.New(keyauth.Config{
    Validator: v,
    Error:     keyauth.ErrorInvalidToken,
    Scope:     "read",
}))

// after — scope belongs only to insufficient_scope
app.Use(keyauth.New(keyauth.Config{
    Validator: v,
    Error:     keyauth.ErrorInsufficientScope,
    Scope:     "read",
}))

if cfg.Scope != "" && cfg.Error != keyauth.ErrorInsufficientScope {
    log.Fatal("keyauth: Scope is only valid with Error=insufficient_scope")
}

When it happens

Trigger: keyauth.Config{Scope: "read"} with Error unset, or Error: keyauth.ErrorInvalidToken together with Scope: "read". The else-if at config.go:159 fires whenever Error is not insufficient_scope but Scope is non-empty.

Common situations: Configuring Scope globally because it looks useful, while Error is set per route to invalid_token; leftover Scope field from a previous insufficient_scope setup after Error was changed.

Related errors

• fiber: keyauth insufficient_scope requires scope
• fiber: keyauth scope contains invalid token
• fiber: keyauth error_description requires error
• fiber: keyauth error_uri must be absolute
• fiber: keyauth error_uri requires error

AI-assisted analysis of gofiber/fiber@a105acad6c (2026-08-11). Data as JSON: /api/errors/362ddf03b1b7794b. Report an issue: GitHub.

Appendix: source

Thrown at middleware/keyauth/config.go:160

	if cfg.ErrorURI != "" {
		if cfg.Error == "" {
			panic("fiber: keyauth error_uri requires error")
		}
		if u, err := url.Parse(cfg.ErrorURI); err != nil || !u.IsAbs() {
			panic("fiber: keyauth error_uri must be absolute")
		}
	}
	if cfg.Error == ErrorInsufficientScope {
		if cfg.Scope == "" {
			panic("fiber: keyauth insufficient_scope requires scope")
		}
		for scope := range strings.SplitSeq(cfg.Scope, " ") {
			if scope == "" || !isScopeToken(scope) {
				panic("fiber: keyauth scope contains invalid token")
			}
		}
	} else if cfg.Scope != "" {
		panic("fiber: keyauth scope requires insufficient_scope error")
	}

	return cfg
}

func isScopeToken(s string) bool {
	for i := 0; i < len(s); i++ {
		c := s[i]
		if c < 0x21 || c > 0x7e || c == '"' || c == '\\' {
			return false
		}
	}
	return s != ""
}

View on GitHub (pinned to a105acad6c)