fatedier/frp · error

type shouldn't be empty

Error message

type shouldn't be empty

What it means

NewVisitorConfFromIni reads the type key of a visitor INI section; unlike proxies, visitors have no default. If type is empty the config is rejected immediately with 'type shouldn't be empty'. Visitors must explicitly declare stcp, sudp, or xtcp.

Solutions

1. Add type = stcp (or sudp/xtcp) to the visitor section
2. If the section was not meant to be a visitor, rename it so it is not detected as one (check the naming convention used to detect visitor sections)
3. Validate with frpc verify -c frpc.ini

Example fix

# before
[secret-visitor]
name = sv
server_name = secret

# after
[secret-visitor]
type = stcp
name = sv
server_name = secret

if section.Key("type").String() == "" {
    return fmt.Errorf("visitor section [%s] missing type (stcp/sudp/xtcp)", section.Name())
}

func hasVisitorType(s *ini.Section) bool { return s.Key("type").String() != "" }

if _, err := legacy.NewVisitorConfFromIni(prefix, name, section); err != nil && err.Error() == "type shouldn't be empty" { /* add type key */ }

When it happens

Trigger: A [visitor.x] or similarly named section in legacy frpc.ini where the type key is missing or blank. Merely having a section named like a visitor without a type triggers it during LoadAllProxyConfsFromIni.

Common situations: Users adding a visitor section by copying a proxy section and deleting fields; forgetting that visitors require type while proxies silently default to tcp.

Related errors

• type [ ] error
• bind port is required
• invalid heartbeat_timeout, heartbeat_timeout is less than…
• invalid protocol
• invalid type [ ]

AI-assisted analysis of fatedier/frp@6c8a8d0a97 (2026-08-15). Data as JSON: /api/errors/f0f675cd12cabb3b. Report an issue: GitHub.

Appendix: source

Thrown at pkg/config/legacy/visitor.go:173

	if cfg.MaxRetriesAnHour <= 0 {
		cfg.MaxRetriesAnHour = 8
	}
	if cfg.MinRetryInterval <= 0 {
		cfg.MinRetryInterval = 90
	}
	if cfg.FallbackTimeoutMs <= 0 {
		cfg.FallbackTimeoutMs = 1000
	}
	return
}

// Visitor loaded from ini
func NewVisitorConfFromIni(prefix string, name string, section *ini.Section) (VisitorConf, error) {
	// section.Key: if key not exists, section will set it with default value.
	visitorType := VisitorType(section.Key("type").String())

	if visitorType == "" {
		return nil, fmt.Errorf("type shouldn't be empty")
	}

	conf := DefaultVisitorConf(visitorType)
	if conf == nil {
		return nil, fmt.Errorf("type [%s] error", visitorType)
	}

	if err := conf.UnmarshalFromIni(prefix, name, section); err != nil {
		return nil, fmt.Errorf("type [%s] error", visitorType)
	}
	return conf, nil
}

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