jackwener/OpenCLI · error · CommandExecutionError

Zhihu answer detail returned malformed JSON: ${data.__malfor

Error message

Zhihu answer detail returned malformed JSON: ${data.__malformedJson}

What it means

This CommandExecutionError is thrown when the in-page fetch succeeded but response.json() (or equivalent parsing) failed inside the evaluated script; the script returns { __malformedJson: <message> } and the command re-raises it as a command execution error. It means Zhihu returned a body that is not valid JSON — often an HTML error/challenge page instead of the API payload.

Source

Thrown at clis/zhihu/answer-detail.js:107

            );
        });
        if (!data || data.__httpError) {
            const status = data?.__httpError;
            if (status === 401 || status === 403) {
                throw new AuthRequiredError('www.zhihu.com', 'Failed to fetch Zhihu answer detail');
            }
            if (status === 404) {
                throw new EmptyResultError('zhihu answer-detail', `No Zhihu answer was found for ${answerId}.`);
            }
            throw new CommandExecutionError(
                status
                    ? `Zhihu answer detail request failed (HTTP ${status})`
                    : 'Zhihu answer detail request failed',
                'Try again later or rerun with -v for more detail',
            );
        }
        if (data.__malformedJson) {
            throw new CommandExecutionError(
                `Zhihu answer detail returned malformed JSON: ${data.__malformedJson}`,
                'Try again later or rerun with -v for more detail',
            );
        }
        if (typeof data !== 'object' || Array.isArray(data)) {
            throw new CommandExecutionError(
                'Zhihu answer detail returned a malformed payload',
                'Try again later or rerun with -v for more detail',
            );
        }
        if (data.error || data.error_msg || data.message) {
            throw new CommandExecutionError(
                `Zhihu answer detail returned an error payload: ${data.error?.message || data.error_msg || data.message}`,
                'Try again later or rerun with -v for more detail',
            );
        }
        if (!Object.prototype.hasOwnProperty.call(data, 'content')) {
            throw new CommandExecutionError(

View on GitHub (pinned to 49907e53dc)

Solutions

Retry later — transient challenge/HTML responses usually clear on a subsequent attempt.
Open zhihu.com in the browser and complete any captcha/anti-bot challenge, then rerun.
Rerun with -v for more detail; if persistent, re-login to refresh the session.
Check for proxy/MITM software injecting HTML into responses.

Defensive patterns

Strategy: retry

Type guard

function isMalformedJsonError(err) { return /malformed JSON/.test(err?.message || ''); }

Try / catch

try {
  const detail = await answerDetail(id);
} catch (err) {
  if (/malformed JSON/.test(err.message)) {
    console.error('Non-JSON (likely anti-bot HTML) response — complete any captcha in the browser and retry.');
    return retryWithBackoff(() => answerDetail(id), { attempts: 3, baseMs: 5000 });
  }
  throw err;
}

Prevention

Complete anti-bot challenges in the browser session before bulk runs.
Slow request cadence — HTML challenge pages often follow aggressive scraping.
Disable intercepting proxies/MITM tools that rewrite response bodies.
Retry with backoff; challenge responses are frequently transient.

When it happens

Trigger: The evaluated script's JSON parse throws (caught and returned as data.__malformedJson): the response body was HTML (anti-bot challenge, login wall, error page) or an empty/truncated body.

Common situations: Zhihu's anti-crawler served a captcha/HTML page mid-session, a captive proxy rewrote the response, or the endpoint returned an empty 200 body under load.

Understand the failure class

Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

Related errors

AI-assisted analysis of jackwener/OpenCLI@49907e53dc (2026-08-29). Data as JSON: /api/errors/dd0bc7d54a488800. Report an issue: GitHub.