GET /fdsnws/availability/1/query

Query data availability from seismic stations. This endpoint tells you whether time series data actually exists for specific stations, channels, and time ranges—without downloading the full data. Returns availability information showing which time segments have data and which don't. This is essential before making large data requests: you can verify data exists before downloading potentially gigabytes of time series. The response can be formatted as text (default) or JSON. Unlike the station endpoint which returns metadata about stations, this endpoint returns information about what data is actually stored and available.