What causes "%s is empty" in larksuite/cli?

Set a loopback proxy address with explicit port: `export LARKSUITE_CLI_PROXY_ADDRESS=http://127.0.0.1:8080`.

%s is empty

Error message

%s is empty

What it means

proxyURL validates the fixed proxy address from LARKSUITE_CLI_PROXY_ADDRESS (or the config file). It rejects an address that is empty or whitespace-only; the message names the env var. This is fail-closed behavior: proxy-plugin mode is enabled but no usable proxy address was configured, so the CLI refuses to build the transport.

Source

Thrown at internal/transport/config.go:190

		return false, nil
	}
	switch s {
	case "1", "true", "on", "yes", "y":
		return true, nil
	case "0", "false", "off", "no", "n":
		return false, nil
	}
	if b, err := strconv.ParseBool(s); err == nil {
		return b, nil
	}
	return false, fmt.Errorf("invalid %s %q (want true/false/1/0)", name, raw)
}

// proxyURL validates the fixed configured proxy configuration and returns its URL.
func (c *Config) proxyURL() (*url.URL, error) {
	raw := strings.TrimSpace(c.Proxy)
	if raw == "" {
		return nil, fmt.Errorf("%s is empty", envvars.CliProxyAddress)
	}
	redacted := redactProxyURL(raw)
	u, err := url.Parse(raw)
	if err != nil {
		// Do not wrap the raw url.Parse error: its string embeds the original
		// URL, which can contain userinfo (user:password). Return a redacted,
		// generic message instead.
		return nil, fmt.Errorf("invalid %s %q: malformed URL", envvars.CliProxyAddress, redacted)
	}
	if u.Scheme != "http" {
		return nil, fmt.Errorf("invalid %s %q: scheme must be http", envvars.CliProxyAddress, redacted)
	}
	if u.Host == "" {
		return nil, fmt.Errorf("invalid %s %q: missing host", envvars.CliProxyAddress, redacted)
	}
	// Security hardening: only allow a loopback proxy. This prevents accidental
	// cross-machine proxying of credentials/traffic.
	if u.Hostname() != "127.0.0.1" {

View on GitHub (pinned to 7fd6ef3c07)

Solutions

Set a loopback proxy address with explicit port: `export LARKSUITE_CLI_PROXY_ADDRESS=http://127.0.0.1:8080`.
If you don't have a proxy, disable plugin mode: `export LARKSUITE_CLI_PROXY_ENABLE=false` or unset it (and remove Enable:true from ~/.lark-cli/proxy_config.json).
Check that the value isn't empty-with-whitespace: `echo "[$LARKSUITE_CLI_PROXY_ADDRESS]"`.
In proxy_config.json, ensure both LARKSUITE_CLI_PROXY_ENABLE:true and a non-empty LARKSUITE_CLI_PROXY_ADDRESS are present together.

Example fix

// before
export LARKSUITE_CLI_PROXY_ENABLE=true
export LARKSUITE_CLI_PROXY_ADDRESS=
// after
export LARKSUITE_CLI_PROXY_ENABLE=true
export LARKSUITE_CLI_PROXY_ADDRESS=http://127.0.0.1:8080

Defensive patterns

Strategy: validation

Validate before calling

if [ -n "$LARKSUITE_CLI_PROXY_ADDRESS" ]; then echo "address set: $LARKSUITE_CLI_PROXY_ADDRESS"; else echo 'LARKSUITE_CLI_PROXY_ADDRESS is empty but proxy mode may be enabled' >&2; fi

Prevention

Never set LARKSUITE_CLI_PROXY_ENABLE=true without also setting a non-empty LARKSUITE_CLI_PROXY_ADDRESS.
If you don't have a proxy, disable the plugin instead of leaving the address blank.
Check provisioning scripts don't export the variable as empty.
Keep Enable and Address together in proxy_config.json.

When it happens

Trigger: LARKSUITE_CLI_PROXY_ENABLE=true is set (or Enable:true in proxy_config.json) while LARKSUITE_CLI_PROXY_ADDRESS is unset, exported as an empty string (`export LARKSUITE_CLI_PROXY_ADDRESS=`), or contains only spaces; then ApplyToTransport runs during command startup.

Common situations: Enabling the proxy plugin but forgetting to set the address; a shell profile exporting the var empty; a provisioning tool clearing the variable; config file that sets Enable:true but omits LARKSUITE_CLI_PROXY_ADDRESS.

Understand the failure class

Background: "missing required config value" errors: why libraries refuse to start when a configuration key is empty, unset, or blank — this error's family across 48 libraries.

Related errors

AI-assisted analysis of larksuite/cli@7fd6ef3c07 (2026-09-04). Data as JSON: /api/errors/54a57fba81841cac. Report an issue: GitHub.