WebSockets

Stream real-time market data without polling. WebSocket connections don't count against your rate limit.

Connection URLs

Exchange	WebSocket URL
Hyperliquid	`wss://api.paperx.co/ws`
Uniswap	Coming soon

Basic Connection

Python Example

import websocket
import json

def on_message(ws, message):
    data = json.loads(message)
    print(f"Received: {data}")

def on_open(ws):
    # Subscribe to BTC trades
    ws.send(json.dumps({
        "method": "subscribe",
        "subscription": {"type": "trades", "coin": "BTC"}
    }))

ws = websocket.WebSocketApp(
    "wss://api.paperx.co/ws",
    header={"X-API-Key": "pe_your_api_key"},
    on_message=on_message,
    on_open=on_open
)
ws.run_forever()

Subscription Types

trades

Real-time trade executions for a specific coin

l2Book

Order book updates (bids and asks)

userFills

Your paper trade fills in real-time

userEvents

Account events (liquidations, funding, etc.)

Best Practices

Implement reconnection logic

WebSocket connections can drop. Always implement automatic reconnection with exponential backoff.

Handle heartbeats

Send periodic pings to keep the connection alive. The server will disconnect idle connections.