Overview

• Data push interval per station: 1 second
• Seismic intensity standard: Japan Meteorological Agency (JMA)
• Ground motion intensity standard: Chinese national intensity standard (based on GB/T 17742-2020)
• This API provides real-time data from SeisJS stations via WebSocket
• Heartbeat mechanism: the server sends a `heartbeat` packet upon connection and every minute; the client may optionally respond with `ping` (recommended)
• Disclaimer: This API only provides station data from SeisJS for legal research and development use. Any other usage is prohibited.

Available Station List

• Station List JSON URL: https://api.wolfx.jp/seis_list.json
• Note: For application development, it is recommended to use this station list API to retrieve real-time station status for cloud-based control. The list updates every 10 minutes.

WebSocket Endpoint

• Receive JSON data from all SeisJS stations:
wss://seisjs.wolfx.jp/all_seis

JSON Field Description (Data Types)

type	Station UUID (String)
region	Station location (String)
latitude	Station latitude (Number)
longitude	Station longitude (Number)
version	SeisJS version running on the station (Number)
PGA	Composite Peak Ground Acceleration (cm/s²) (Number)
PGV	Composite Peak Ground Velocity (cm/s) (Number)
PGD	Composite Peak Ground Displacement (cm) (Number)
PGA_EW	East-West Peak Ground Acceleration (cm/s²) (Number)
PGV_EW	East-West Peak Ground Velocity (cm/s) (Number)
PGD_EW	East-West Peak Ground Displacement (cm) (Number)
PGA_NS	North-South Peak Ground Acceleration (cm/s²) (Number)
PGV_NS	North-South Peak Ground Velocity (cm/s) (Number)
PGD_NS	North-South Peak Ground Displacement (cm) (Number)
PGA_UD	Vertical Peak Ground Acceleration (cm/s²) (Number)
PGV_UD	Vertical Peak Ground Velocity (cm/s) (Number)
PGD_UD	Vertical Peak Ground Displacement (cm) (Number)
Max_PGA	Max composite PGA within 2 minutes (cm/s²) (Number)
Max_PGV	Max composite PGV within 2 minutes (cm/s) (Number)
Max_PGD	Max composite PGD within 2 minutes (cm) (Number)
Max_PGA_EW	Max East-West PGA within 2 minutes (cm/s²) (Number)
Max_PGV_EW	Max East-West PGV within 2 minutes (cm/s) (Number)
Max_PGD_EW	Max East-West PGD within 2 minutes (cm) (Number)
Max_PGA_NS	Max North-South PGA within 2 minutes (cm/s²) (Number)
Max_PGV_NS	Max North-South PGV within 2 minutes (cm/s) (Number)
Max_PGD_NS	Max North-South PGD within 2 minutes (cm) (Number)
Max_PGA_UD	Max Vertical PGA within 2 minutes (cm/s²) (Number)
Max_PGV_UD	Max Vertical PGV within 2 minutes (cm/s) (Number)
Max_PGD_UD	Max Vertical PGD within 2 minutes (cm) (Number)
Shindo	Composite JMA Seismic Intensity (String)
Max_Shindo	Max JMA Seismic Intensity within 2 minutes (String)
CalcShindo	Composite Calculated JMA Seismic Intensity (Number)
Max_CalcShindo	Max Calculated JMA Seismic Intensity within 2 minutes (Number)
Intensity	Composite CSIS Intensity (Number)
Max_Intensity	Max CSIS Intensity within 2 minutes (Number)
LPGM	Long-Period Ground Motion Level (Number)
Max_LPGM	Max Long-Period Ground Motion Level within 2 minutes (Number)
Sva30	Spectral Acceleration Value (Number)
Max_Sva30	Max Spectral Acceleration Value within 2 minutes (Number)
error_code	Error codes reported by station (Array of Numbers)
reverse	Reserved field for server-side validation (String)
is_desktop	Indicates if the client is a desktop (Boolean)
High_Precision	Indicates if the station is high-precision (Boolean)
update_at	Data update timestamp (String)
create_at	JSON generation timestamp (String)

WebSocket Manual Commands

• Ping:
ping

WebSocket JSON Field Specification

• Common JSON Field:

type	Data type / Station UUID (String)

• WebSocket Heartbeat Packet Fields:

type	heartbeat (String)
ver	Server version (Number)
id	Client connection UUID (String)
timestamp	Timestamp in milliseconds (String)

• WebSocket Pong Packet Fields:

type	pong (String)
timestamp	Timestamp in milliseconds (String)

API Documentation Version: v20250704