WebSocket Feeds

Complete connection setup, then append a path below to wss://nex-ws.preprod.defi.euw2.polymarket.sh.

Feed	Path	Connection Limit
Original market	`/ws/market`	No application connection limit
Original user	`/ws/user`	No application connection limit
subs-v2 market	`/beta/ws/market`	50 per IP
subs-v2 user	`/beta/ws/user`	20 per IP and 10 per API key; both apply

Public clients behind the same NAT share its per-IP allowance.

Market Feed

Send this after connecting. Replace OUTCOME_ID with the identifier from your sandbox market.

{
  "type": "market",
  "assets_ids": ["OUTCOME_ID"]
}

You’ll receive a book snapshot followed by updates. See the Market Channel reference for event schemas.

User Feed

Send your sandbox trading credentials after connecting. Replace the credential values below; Gamma credentials do not authenticate this feed.

{
  "type": "user",
  "auth": {
    "apiKey": "YOUR_API_KEY",
    "secret": "YOUR_API_SECRET",
    "passphrase": "YOUR_API_PASSPHRASE"
  }
}

Add markets with condition IDs to filter activity by market. See the User Channel reference.

Heartbeats and Reconnects

Send the text PING every 10 seconds; expect PONG. Idle connections close, so send activity at least once a minute. After disconnecting, reconnect with backoff and resubscribe. Rebuild your book from the new snapshot and reconcile account activity with authenticated reads.

Getting Started

Trading

Market Feed

User Feed

Heartbeats and Reconnects