Invalid value for "-out"; valid values are [go-template, jso

Error message

Invalid value for "-out"; valid values are [go-template, json, table, terse]

What it means

VarListCommand.validateOutputFlag checks -output against the list-specific allowlist (go-template, json, terse, table). Unknown values hit the default case and return this error, which differs from the get command's allowlist (no hcl/none).

Source

Thrown at command/var_list.go:303

	}

	return pList
}

func (c *VarListCommand) validateOutputFlag() error {
	if c.outFmt != "go-template" && c.tmpl != "" {
		return errors.New(errUnexpectedTemplate)
	}
	switch c.outFmt {
	case "json", "terse", "table":
		return nil
	case "go-template":
		if c.tmpl == "" {
			return errors.New(errMissingTemplate)
		}
		return nil
	default:
		return errors.New(errInvalidListOutFormat)
	}
}

View on GitHub (pinned to 482b49bf1a)

Solutions

Use one of: go-template, json, table, terse (lowercase)
Do not reuse the kv get format list for kv list; fix the value
Render to another format by piping json through jq/yq

Example fix

// before
vault kv list -output=hcl secret/
// after
vault kv list -output=json secret/ | jq .

Defensive patterns

Strategy: validation

Validate before calling

switch outFmt {
case "go-template", "json", "table", "terse":
	// ok
default:
	return fmt.Errorf("invalid -out %q; must be one of go-template,json,table,terse", outFmt)
}

Try / catch

if err := cmd.validateOutputFlag(); err != nil {
	if strings.Contains(err.Error(), "Invalid value for \"-out\"") {
		// map unsupported formats (hcl/none) to json and retry
	}
	return err
}

Prevention

Do not share the kv get format allowlist with kv list
Use shell completion for valid values
Normalize case before passing -output

When it happens

Trigger: Running `vault kv list -output=hcl|none|yaml <path>` — formats valid for `kv get` but not `kv list` — or any misspelling.

Common situations: Copy-pasting -output=hcl or -output=none from a `kv get` command into `kv list`; typos in scripts; case mismatches like -output=JSON.

Understand the failure class

Background: "unknown output mode", "invalid value for flag", "expects true/false": fixing invalid flag value errors in CLI tools — this error's family across 24 libraries.

Related errors

AI-assisted analysis of hashicorp/nomad@482b49bf1a (2026-09-04). Data as JSON: /api/errors/51aefca913f67560. Report an issue: GitHub.