FDSN Web Services

Since 4.8.0, Observer provides FDSN Station and DataSelect services under /fdsnws on the normal web listener. They are disabled by default and are configured through Station Settings rather than Service Modules.

Enable and Create an Access Key

1. Sign in as an administrator and enable FDSN Web Service in Station Settings. The switch applies immediately.
2. Open the FDSN access-key tab in Settings. Create a key with a descriptive remark and an expiration time, or explicitly choose no expiration.
3. Copy the secret when it is displayed. It is shown only once; only its SHA-256 hash is stored in the database.
4. Send it as Authorization: Bearer <key> when requesting data.

Keys can be revoked individually or in batches. The management view includes last-request time, client IP, and user-agent information. If a secret is lost, create another and revoke the old one. These keys are separate from Observer web-login sessions.

Built-in query pages are available at /fdsnws, /fdsnws/station/1/, and /fdsnws/dataselect/1/. Once the service is enabled, query pages and service-description endpoints do not require a key; query endpoints do. Use HTTPS or a private VPN when sending keys over a network.

Station Metadata

Request StationXML, including instrument response:

export OBSERVER_FDSN_KEY='replace-with-your-access-key'
curl --fail-with-body --get \
    -H "Authorization: Bearer $OBSERVER_FDSN_KEY" \
    --data-urlencode 'level=response' \
    --data-urlencode 'format=xml' \
    'http://127.0.0.1:8073/fdsnws/station/1/query' \
    -o station.xml

The service uses the current hardware model, station identifiers, coordinates, channel definitions, and sample rate. It does not maintain a historical inventory of past configuration changes. updatedafter, matchtimeseries, and includeavailability are unsupported and return a client error. Review location information before distributing metadata.

Archived Waveforms

DataSelect reads database records, not the daily MiniSEED directory. Enable Archiver and query a period that has already been recorded:

curl --fail-with-body --get \
    -H "Authorization: Bearer $OBSERVER_FDSN_KEY" \
    --data-urlencode 'network=AS' \
    --data-urlencode 'station=SHAKE' \
    --data-urlencode 'location=00' \
    --data-urlencode 'channel=EHZ' \
    --data-urlencode 'starttime=2026-10-01T00:00:00' \
    --data-urlencode 'endtime=2026-10-01T00:01:00' \
    'http://127.0.0.1:8073/fdsnws/dataselect/1/query' \
    -o waveform.mseed

Replace station identifiers and UTC time range with your actual records. GET and bulk POST selections are supported. DataSelect accepts at most 100 selections per request and limits the sum of selected durations to one hour; split larger requests. Bulk POST bodies are capped at 1 MiB. Stored data has quality D; B and D selections can return it, while other quality selections return no data. Packet data is trimmed to the requested sample boundaries.

Errors

Response	Check
501	The station's FDSN service is disabled.
401	Missing, invalid, expired, or revoked Bearer key.
400	Unsupported query parameters, invalid selection, or duration limits.
204 by default	No matching metadata or archived samples; inspect station codes and UTC range.
503	Settings, database, or access-key validation is unavailable. Inspect backend logs.

Enabling the module does not expose a separate Event service or make all internet-facing clients compatible with Bearer authentication; configure clients to send the required header.