gofiber/fiber · error

fiber: keyauth insufficient_scope requires scope

Error message

fiber: keyauth insufficient_scope requires scope

What it means

When Config.Error equals ErrorInsufficientScope, keyauth requires Config.Scope to be non-empty. RFC 6750 says an insufficient_scope challenge should carry the scope required to access the resource, so the client knows what to request. An empty Scope with that error code is invalid.

Solutions

1. Set Config.Scope to the space-delimited list of required scopes, e.g. "read write".
2. If you did not mean insufficient_scope, pick the correct Error code (invalid_token / invalid_request) or leave Error empty.
3. Validate at config load: Error == ErrorInsufficientScope implies Scope != "".

Example fix

// before
app.Use(keyauth.New(keyauth.Config{
    Validator: v,
    Error:     keyauth.ErrorInsufficientScope,
}))

// after
app.Use(keyauth.New(keyauth.Config{
    Validator: v,
    Error:     keyauth.ErrorInsufficientScope,
    Scope:     "admin",
}))

if cfg.Error == keyauth.ErrorInsufficientScope && cfg.Scope == "" {
    log.Fatal("keyauth: insufficient_scope requires a non-empty Scope")
}

When it happens

Trigger: keyauth.Config{Error: keyauth.ErrorInsufficientScope} with Scope unset, or Scope populated only in a branch that did not execute.

Common situations: Setting Error to insufficient_scope because of a checklist without supplying the required scope string; per-route config where the scope is meant to be injected but the injection was missed.

Related errors

• fiber: keyauth scope contains invalid token
• fiber: keyauth scope requires insufficient_scope error
• 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/79d1a5bc49d76da9. Report an issue: GitHub.

Appendix: source

Thrown at middleware/keyauth/config.go:152

		case ErrorInvalidRequest, ErrorInvalidToken, ErrorInsufficientScope:
		default:
			panic("fiber: keyauth unsupported error token")
		}
	}
	if cfg.ErrorDescription != "" && cfg.Error == "" {
		panic("fiber: keyauth error_description requires error")
	}
	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

View on GitHub (pinned to a105acad6c)