gchq/CyberChef · error · OperationError

${e}

Error message

${e}

What it means

The Template operation compiles a Handlebars template string and renders it against the JSON input. Any error raised by Handlebars.compile() or by invoking the compiled template — syntax errors, unknown helpers, type errors during rendering — is caught and rethrown as an OperationError whose message is the original error.

Source

Thrown at src/core/operations/Template.mjs:48

                name: "Template definition (.handlebars)",
                type: "text",
                value: ""
            }
        ];
    }

    /**
     * @param {JSON} input
     * @param {Object[]} args
     * @returns {string}
     */
    run(input, args) {
        const [templateStr] = args;
        try {
            const template = Handlebars.compile(templateStr);
            return template(input);
        } catch (e) {
            throw new OperationError(e);
        }
    }
}

export default Template;

View on GitHub (pinned to 4290ea7539)

Solutions

1. Validate the template syntax in an external Handlebars playground before pasting it in.
2. Ensure every block helper {{#x}} has a matching {{/x}}.
3. Remove references to helpers that are not part of Handlebars core.
4. Feed valid JSON input that matches the fields the template references.

Example fix

// before: template = "{{#each items}}{{name}}{{/loop}}"  (mismatched block name)
// after:  template = "{{#each items}}{{name}}{{/each}}"

let compiled;
try { compiled = Handlebars.compile(templateStr); }
catch (e) { throw new Error(`Template syntax invalid: ${e.message}`); }
return compiled(jsonInput);

function isCompilableTemplate(tpl) {
  try { Handlebars.precompile(tpl); return true; } catch { return false; }
}

try { chef.Template(jsonInput, [templateStr]); }
catch (e) { if (/Parse error|Expecting/.test(e.message)) { /* fix template syntax */ } else throw e; }

When it happens

Trigger: A malformed Handlebars template (unbalanced braces, unclosed block like {{#each}} without {{/each}}, or an unterminated expression); referencing a helper that is not registered; or rendering a template whose partial/helper expects a type the JSON input does not provide.

Common situations: Authoring a template with a typo in block syntax; using a custom helper that Handlebars does not ship; passing non-object JSON that the template indexes into.

Related errors

• Invalid recipe
• ${err.toString()}
• Unable to parse CSV: ${err}
• No "r" value in the signature JSON
• No "s" value in the signature JSON

AI-assisted analysis of gchq/CyberChef@4290ea7539 (2026-08-13). Data as JSON: /api/errors/e34288024dfbcccb. Report an issue: GitHub.