nexu-io/open-design · error · Error

${providerTag} media fetch ${mediaResp.status}

Error message

${providerTag} media fetch ${mediaResp.status}

What it means

Thrown by bytesFromOpenAICompatibleData when the entry carries entry.url and the follow-up fetch of that URL returns non-2xx. Mirrors the first-party 'openai image fetch' path but applies to any OpenAI-compatible gateway that chooses url-style responses over inline b64_json.

Source

Thrown at apps/daemon/src/media/index.ts:1149

    return JSON.parse(text);
  } catch {
    throw new Error(`${providerTag} non-JSON response: ${truncate(text, 200)}`);
  }
}

async function bytesFromOpenAICompatibleData(data: any, providerTag: string, requestInit: MediaRequestInit = {}): Promise<Buffer> {
  const entry = data && Array.isArray(data.data) ? data.data[0] : null;
  if (!entry) throw new Error(`${providerTag} response had no data[0]`);
  if (typeof entry.b64_json === 'string' && entry.b64_json) {
    const raw = entry.b64_json.includes(',')
      ? entry.b64_json.slice(entry.b64_json.indexOf(',') + 1)
      : entry.b64_json;
    return Buffer.from(raw, 'base64');
  }
  if (typeof entry.url === 'string' && entry.url) {
    const mediaResp = await fetch(entry.url, requestInit);
    if (!mediaResp.ok) {
      throw new Error(`${providerTag} media fetch ${mediaResp.status}`);
    }
    const arr = await mediaResp.arrayBuffer();
    return Buffer.from(arr);
  }
  throw new Error(`${providerTag} response had neither b64_json nor url`);
}

function imageRouterSizeFor(aspect: string | undefined, surface: 'image' | 'video'): string {
  if (surface === 'video') {
    if (aspect === '1:1') return '1024x1024';
    if (aspect === '9:16') return '576x1024';
    if (aspect === '4:3') return '1024x768';
    if (aspect === '3:4') return '768x1024';
    return '1024x576';
  }
  if (aspect === '16:9') return '1024x576';
  if (aspect === '9:16') return '576x1024';
  if (aspect === '4:3') return '1024x768';

View on GitHub (pinned to 5be4028344)

Solutions

1. Retry — signed-URL fetch failures are often transient.
2. Prefer a gateway/model configuration that returns b64_json inline so no secondary fetch is needed.
3. Allowlist the gateway's blob/CDN host in egress rules.
4. If the gateway exposes a 'response_format=b64_json' option, set it.

Example fix

// before: gateway returns url, blob host blocked
// after: force b64_json via the gateway's request option (renderer config)
body.response_format = 'b64_json';

try {
  return await bytesFromOpenAICompatibleData(data, providerTag, requestInit);
} catch (err) {
  const m = err instanceof Error ? err.message : '';
  if (m.endsWith('media fetch ')) {
    // signed-URL download failed — retry once, then prefer b64_json
    await sleep(backoffMs);
    return await bytesFromOpenAICompatibleData(data, providerTag, requestInit);
  }
  throw err;
}

When it happens

Trigger: Gateway returns a short-lived signed URL that expires before download; the gateway's blob host is unreachable from the daemon host; CDN rate-limiting on the secondary fetch.

Common situations: High-latency link causing URL expiry; egress firewall allows the API host but blocks the blob host; gateway returns URLs to a private network.

Related errors

• openai image fetch ${imgResp.status}
• ${providerTag} ${resp.status}: ${truncate(text, 240)}
• ${providerTag} response had no data[0]
• ${providerTag} response had neither b64_json nor url
• ${providerTag} non-JSON response: ${truncate(text, 200)}

AI-assisted analysis of nexu-io/open-design@5be4028344 (2026-08-12). Data as JSON: /api/errors/f4d1019838aafdb1. Report an issue: GitHub.