What causes "Invalid encode option" in gchq/CyberChef?

Use one of the four exact option strings: 'Encode', 'Encode Object', 'Encode Array', 'Encode URI'.

gchq/CyberChef · error · OperationError

Invalid encode option

Error message

Invalid encode option

What it means

Thrown by Rison Encode when the encodeOption argument is not one of 'Encode', 'Encode Object', 'Encode Array', or 'Encode URI'. The argument is a fixed option dropdown, so this is only reachable through direct API calls with an invalid string.

Source

Thrown at src/core/operations/RisonEncode.mjs:54

    /**
     * @param {Object} input
     * @param {Object[]} args
     * @returns {string}
     */
    run(input, args) {
        const [encodeOption] = args;
        switch (encodeOption) {
            case "Encode":
                return rison.encode(input);
            case "Encode Object":
                return rison.encode_object(input);
            case "Encode Array":
                return rison.encode_array(input);
            case "Encode URI":
                return rison.encode_uri(input);
            default:
                throw new OperationError("Invalid encode option");
        }
    }
}

export default RisonEncode;

View on GitHub (pinned to 4290ea7539)

Solutions

Use one of the four exact option strings: 'Encode', 'Encode Object', 'Encode Array', 'Encode URI'.
Match the option to the input type — 'Encode Object' expects a plain object, 'Encode Array' expects an array.

Example fix

// before
risonEncode.run({a:1}, ["encode"])
// after
risonEncode.run({a:1}, ["Encode Object"])

Defensive patterns

Strategy: validation

Validate before calling

const VALID_ENCODE = ["Encode", "Encode Object", "Encode Array", "Encode URI"];
if (!VALID_ENCODE.includes(encodeOption)) {
  throw new Error(`encodeOption must be one of ${VALID_ENCODE.join(", ")}`);
}

Type guard

function isRisonEncodeOption(v) {
  return ["Encode", "Encode Object", "Encode Array", "Encode URI"].includes(v);
}

Prevention

Use the exact option strings from the constructor.
Match the option to the input data type (object vs array).

When it happens

Trigger: Programmatically calling RisonEncode.run(input, ['BadValue']) or passing an args array whose first element doesn't match a case. Malformed input objects instead throw from the rison library itself.

Common situations: Node API usage with a hard-coded option string that is misspelled or from an older schema; recipe JSON referencing a renamed option.

Related errors

AI-assisted analysis of gchq/CyberChef@4290ea7539 (2026-08-13). Data as JSON: /api/errors/d7e91827116b5a8c. Report an issue: GitHub.