nexu-io/open-design · error · Error

grok image non-JSON: ${truncate(text, 200)}

Error message

grok image non-JSON: ${truncate(text, 200)}

What it means

Thrown when `JSON.parse(text)` fails on the Grok image response. xAI (or an intermediary) returned a 2xx body that isn't JSON — typically an HTML gateway/maintenance page — so up to 200 chars are surfaced for diagnosis instead of an opaque parse error.

Source

Thrown at apps/daemon/src/media/index.ts:1644

    response_format: 'b64_json',
  };
  const resp = await fetch(`${baseUrl}/images/generations`, withMediaRequestInit(ctx, {
    method: 'POST',
    headers: {
      'authorization': `Bearer ${credentials.apiKey}`,
      'content-type': 'application/json',
    },
    body: JSON.stringify(body),
  }));
  const text = await resp.text();
  if (!resp.ok) {
    throw new Error(`grok image ${resp.status}: ${truncate(text, 240)}`);
  }
  let data: any;
  try {
    data = JSON.parse(text);
  } catch {
    throw new Error(`grok image non-JSON: ${truncate(text, 200)}`);
  }
  const entry = data && Array.isArray(data.data) ? data.data[0] : null;
  if (!entry) throw new Error('grok image response had no data[0]');
  let bytes;
  if (entry.b64_json) {
    bytes = Buffer.from(entry.b64_json, 'base64');
  } else if (entry.url) {
    const imgResp = await fetch(entry.url, withMediaRequestInit(ctx));
    if (!imgResp.ok) throw new Error(`grok image fetch ${imgResp.status}`);
    bytes = Buffer.from(await imgResp.arrayBuffer());
  } else {
    throw new Error('grok image response missing b64_json/url');
  }
  // xAI's Imagine returns JPEG by default (no format option in the API
  // surface), but PNG/WebP are technically possible. Sniff the magic
  // bytes so the on-disk extension matches reality — saving JPEG bytes
  // as `.png` confuses Finder previews and any downstream consumer that
  // trusts the extension.

View on GitHub (pinned to 5be4028344)

Solutions

1. Inspect the truncated body — HTML indicates a gateway/proxy; fix routing or wait out the outage.
2. Verify `credentials.baseUrl` (or unset it to use the default `https://api.x.ai/v1`).
3. Ensure the xAI host is reachable and not redirected on the daemon's network.

function looksLikeXaiJson(text: string): boolean {
  const head = text.slice(0, 100).trim();
  return head.startsWith('{') || head.startsWith('[');
}

try { data = JSON.parse(text); }
catch { throw new Error(`grok image non-JSON: ${truncate(text, 200)}`); }

When it happens

Trigger: 2xx Grok image response that fails `JSON.parse`. Gateway maintenance page, proxy HTML interstitial, captive-portal auth wall, or a `baseUrl` override pointing at a host that serves HTML.

Common situations: (1) xAI regional outage surfacing an HTML status page with a 2xx status; (2) corporate proxy injecting an HTML interstitial; (3) `baseUrl` mistyped to a path that serves HTML.

Related errors

• grok image fetch ${imgResp.status}
• volcengine non-JSON: ${truncate(taskText, 200)}
• volcengine image non-JSON: ${truncate(text, 200)}
• no xAI credentials — sign in with your SuperGrok subscriptio
• grok image ${resp.status}: ${truncate(text, 240)}

AI-assisted analysis of nexu-io/open-design@5be4028344 (2026-08-12). Data as JSON: /api/errors/6e666d3fbc41b7a1. Report an issue: GitHub.