watchTrades

Stream real-time trade updates for a single outcome via WebSocket

WebSocket endpoint — This method uses WebSocket streaming, not HTTP. Connect to wss://api.pmxt.dev/ws?apiKey=YOUR_KEY (hosted) or ws://localhost:3847/ws (local server).

Supported venues: polymarket, kalshi, limitless, opinion.

Parameters

Parameter	Type	Required	Description
outcomeId	string	Yes	The outcome token ID to watch

Response

Returns a Trade[] array each time new trades occur:

Field	Type	Description
id	string	Trade ID
timestamp	number	Unix timestamp in milliseconds
price	number	Trade price (0–1 probability)
amount	number	Number of contracts
side	string	"buy", "sell", or "unknown"

Usage

Python

import pmxt

exchange = pmxt.Polymarket(pmxt_api_key="YOUR_PMXT_API_KEY")

while True:
    trades = exchange.watch_trades("OUTCOME_ID")
    for trade in trades:
        print(f"{trade.side.upper()} {trade.amount} contracts @ {trade.price:.1%}")

Use cases

Trade volume tracker

Monitor real-time trading volume on a market:

Python

import pmxt

exchange = pmxt.Polymarket(pmxt_api_key="YOUR_PMXT_API_KEY")
total_volume = 0

while True:
    trades = exchange.watch_trades("OUTCOME_ID")
    for trade in trades:
        total_volume += trade.amount
        print(f"Trade: {trade.side} {trade.amount} @ {trade.price:.1%} | Total volume: {total_volume}")