fatedier/frp · error

type [%s] error

Error message

type [%s] error

What it means

After confirming the visitor type is non-empty, NewVisitorConfFromIni calls DefaultVisitorConf; if the type is not one of stcp, sudp, xtcp it returns nil and this 'type [<type>] error' is thrown. Only the secret/p2p visitor families are supported.

Source

Thrown at pkg/config/legacy/visitor.go:178

	}
	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
}

View on GitHub (pinned to 6c8a8d0a97)

Solutions

1. Change type to stcp, sudp, or xtcp depending on the paired proxy
2. Ensure the matching proxy on the other side uses the same family (stcp<->stcp, sudp<->sudp, xtcp<->xtcp)
3. Set the correct serverName/sk fields for the chosen visitor type

Example fix

# before
[secret-visitor]
type = tcp

# after
[secret-visitor]
type = stcp

validVisitors := map[string]bool{"stcp":true,"sudp":true,"xtcp":true}
if !validVisitors[visitorType] {
    return fmt.Errorf("visitor type %q unsupported; use stcp/sudp/xtcp", visitorType)
}

func isValidVisitorType(t string) bool {
    switch t {
    case "stcp", "sudp", "xtcp":
        return true
    }
    return false
}

if _, err := legacy.NewVisitorConfFromIni(prefix, name, section); err != nil && strings.HasPrefix(err.Error(), "type [") { /* map type to visitor family */ }

When it happens

Trigger: A visitor section with type = tcp, type = http, or any value other than stcp/sudp/xtcp. Common when users assume any proxy type can be 'visited'.

Common situations: Trying to expose a plain tcp proxy's service via a visitor section; misreading docs and putting the underlying proxy type instead of the visitor type.

Related errors

• type shouldn't be empty
• name is required
• server name is required
• bind port is required
• invalid heartbeat_timeout, heartbeat_timeout is less than he

AI-assisted analysis of fatedier/frp@6c8a8d0a97 (2026-08-15). Data as JSON: /api/errors/2056d8e9ed3a995f. Report an issue: GitHub.