koala73/worldmonitor · error · ApiError

Airport delay filters are not supported

Error message

Airport delay filters are not supported

What it means

The seed-only airport delay listing supports no filtering: pageSize must be 0, no cursor, region must be AIRPORT_REGION_UNSPECIFIED (or unset), and minSeverity must be FLIGHT_DELAY_SEVERITY_UNSPECIFIED (or unset). Any filter combination throws ApiError 400.

Solutions

1. Call the endpoint with no region, minSeverity, cursor, or page_size filters and filter client-side
2. Reset the proto message so unset/default enum values are not serialized onto the wire
3. Drop cursor-based pagination; re-fetch the full list instead of resuming
4. Send page_size=0 and leave all filter fields at their unspecified defaults

Example fix

// before
const req = { region: 'AIRPORT_REGION_EU', minSeverity: 'FLIGHT_DELAY_SEVERITY_MODERATE' };
// after
const req = { region: 'AIRPORT_REGION_UNSPECIFIED', minSeverity: 'FLIGHT_DELAY_SEVERITY_UNSPECIFIED' };
// then filter results in the client

const filterable = r => (r.pageSize ?? 0) === 0 && !r.cursor && (!r.region || r.region === 'AIRPORT_REGION_UNSPECIFIED') && (!r.minSeverity || r.minSeverity === 'FLIGHT_DELAY_SEVERITY_UNSPECIFIED');
if (!filterable(req)) throw new Error('filters unsupported');

const isUnfilteredDelayRequest = (r) => (r.pageSize ?? 0) === 0 && r.cursor == null && (r.region == null || r.region === 'AIRPORT_REGION_UNSPECIFIED') && (r.minSeverity == null || r.minSeverity === 'FLIGHT_DELAY_SEVERITY_UNSPECIFIED');

try { return await listAirportDelays(ctx, req); } catch (e) { if (e instanceof ApiError && e.message === 'Airport delay filters are not supported') { return fetchAllAndFilterClientSide(); } throw e; }

When it happens

Trigger: GET with region=AIRPORT_REGION_EU, minSeverity=<non-unspecified>, cursor=<token>, or a decoded proto request carrying pageSize>0 / cursor, alone or combined.

Common situations: Reusing client code written for filterable list endpoints; proto clients that populate default-valued enum fields explicitly; retry logic replaying a cursor from a prior paged response.

Understand the failure class

Background: UnsupportedOperationException and "is not supported" errors: when a library deliberately refuses a call — this error's family across 30 libraries.

Related errors

• Airport delay page_size must be 0
• deadlineMs must be a positive number
• Duplicate airport delay parameter
• Expected finite viewport coordinates
• Invalid airport delay route

AI-assisted analysis of koala73/worldmonitor@e586b8b4b8 (2026-09-22). Data as JSON: /api/errors/7bd1ff13cdd23746. Report an issue: GitHub.

Appendix: source

Thrown at server/worldmonitor/aviation/v1/list-airport-delays.ts:52

const ALLOWED_QUERY_PARAMS = new Set(['page_size', 'cursor', 'region', 'min_severity', 'jmespath', '_debug', 'rpc']);

export async function listAirportDelays(
  ctx: ServerContext,
  req: ListAirportDelaysRequest,
): Promise<ListAirportDelaysResponse> {
  const seenParams = new Set<string>();
  for (const [key, value] of new URL(ctx.request.url).searchParams) {
    if (!ALLOWED_QUERY_PARAMS.has(key)) throw new ApiError(400, `Unsupported airport delay parameter: ${key}`, '');
    if (seenParams.has(key)) throw new ApiError(400, `Duplicate airport delay parameter: ${key}`, '');
    seenParams.add(key);
    if (key === 'page_size' && value !== '0') throw new ApiError(400, 'Airport delay page_size must be 0', '');
    if (key === 'rpc' && value !== 'list-airport-delays') throw new ApiError(400, 'Invalid airport delay route', '');
  }
  if ((req.pageSize ?? 0) !== 0 || req.cursor
    || (req.region && req.region !== 'AIRPORT_REGION_UNSPECIFIED')
    || (req.minSeverity && req.minSeverity !== 'FLIGHT_DELAY_SEVERITY_UNSPECIFIED')) {
    throw new ApiError(400, 'Airport delay filters are not supported', '');
  }
  // 1. FAA (US) — seed-only read
  // faaSourceCovered = the seed cache hit AND returned a valid alerts array.
  // A miss/parse-error means we have no telemetry for any FAA airport this
  // tick — we MUST NOT publish synthetic "normal" rows for them. See #3707.
  // PERF: the three inputs below are independent (different Redis keys / an
  // independent fetcher) and merge only afterwards — start them concurrently
  // instead of paying three serial round-trips per request.
  const faaRead = (async (): Promise<{ faaAlerts: AirportDelayAlert[]; faaSourceCovered: boolean; available: boolean }> => {
    let faaAlerts: AirportDelayAlert[] = [];
    let faaSourceCovered = false;
    try {
      const seed = await readCachedJson(FAA_CACHE_KEY, true);
      const seedData = seed.status === 'hit' ? seed.value as { alerts?: unknown[] } | null : null;
      if (seedData && Array.isArray(seedData.alerts) && seedData.alerts.every(isValidAirportDelayAlert)) {
        faaSourceCovered = true;
        faaAlerts = seedData.alerts!
          .map(a => {

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