Crypto Listing WebSocket API

A real-time API for crypto exchange listing announcements. Connect via WebSocket and receive structured JSON alerts for automated trading.

API overview

CryptoListing.ws provides a single WebSocket endpoint that streams real-time listing announcements from multiple cryptocurrency exchanges. The API is designed for automated trading systems that need the fastest possible notification of new exchange listings.

Message format

Every announcement message contains the ticker, exchange, listing type, and three microsecond-precision timestamps:

{
  "type": "announcement",
  "title": "Binance Will List TOKEN (TOKEN)",
  "ticker": "TOKEN",
  "publisher": "binance",
  "listingType": "spot_listing",
  "publishTimestampUs": 1710345000000000,
  "detectedTimestampUs": 1710345000005000,
  "dispatchTimestampUs": 1710345000006000
}

Listing types

Exchange filtering

Use the ?cex= query parameter to subscribe to specific exchanges only:

wss://cryptolisting.ws                   // all exchanges
wss://cryptolisting.ws?cex=binance         // binance only
wss://cryptolisting.ws?cex=binance,upbit   // binance + upbit

Latency measurement

Every announcement includes three timestamps in microseconds since UNIX epoch. Calculate your total latency:

detection_delay = detectedTimestampUs - publishTimestampUs
dispatch_delay  = dispatchTimestampUs - detectedTimestampUs
network_delay   = your_receive_time  - dispatchTimestampUs
total_latency   = your_receive_time  - publishTimestampUs

Why choose this API?

Unlike REST-based polling APIs or Telegram bots, our WebSocket API delivers announcements the instant they are detected. Zero-copy broadcast means the message is serialized once and shared across all subscribers — no per-client serialization overhead. This architecture achieves consistent sub-millisecond dispatch latency regardless of subscriber count.