Errors

{ "detail": "No such session" }

{
  "detail": {
    "error": "quota_exceeded",
    "message": "monthly action allowance used up",
    "tier": "developer",
    "upgrade_url": "https://tilion.dev/pricing"
  }
}

{ "detail": [ { "type": "float_parsing", "loc": ["body", "ttl"],
                "msg": "Input should be a valid number, unable to parse string as a number",
                "input": "abc" } ] }

function errorMessage(body, status) {
  const d = body?.detail;
  if (typeof d === 'string') return d;
  if (Array.isArray(d)) return d.map((e) => `${e.loc?.join('.')}: ${e.msg}`).join('; ');
  if (d && typeof d === 'object') return d.message || d.error;
  return body?.error || `HTTP ${status}`;
}

{ "error": "billing not configured" }

async function withRetry(fn, tries = 4) {
  for (let i = 0; i < tries; i++) {
    const res = await fn();
    if (res.ok || ![429, 502, 504].includes(res.status)) return res;
    if (i === tries - 1) return res;
    // Honor Retry-After (seconds) when the server sends it; otherwise back off.
    const retryAfter = Number(res.headers?.get?.('Retry-After')) * 1000;
    const backoff = 2 ** i * 500 + Math.random() * 250;
    await new Promise((r) => setTimeout(r, retryAfter || backoff));
  }
}