Overview

Real-time streaming of Polymarket on-chain events including trades, position activity, market lifecycle, orderbook updates, and oracle events.

WebSocket requires a Dev plan or higher ($49/mo). Get your API key →

Use Cases

Copytrading

Subscribe to top traders’ wallets and mirror their positions in real time.

Market Monitoring

Track specific markets for price movements and trading activity.

Portfolio Alerts

Monitor wallets for trade confirmations, splits, merges, and redemptions.

Analytics & Research

Stream all events with wildcard subscriptions to build datasets.

Market Making

Subscribe to real-time depth and price level changes via the orderbook channel.

Mempool Trading

Detect trades 3–5 seconds early with pending trade events from the Polygon mempool.

Quick Start

const ws = new WebSocket('wss://wss.predexon.com/v1/your_api_key'); 

ws.onopen = () => {
  ws.send(JSON.stringify({
    action: 'subscribe',
    platform: 'polymarket',
    version: 1,
    type: 'orders', 
    filters: { users: ['0x1234...'] }
  }));
};

ws.onmessage = (event) => {
  const msg = JSON.parse(event.data);
  if (msg.type === 'event') {
    console.log('Trade:', msg.data);
  }
};

Connection

Endpoint:

wss://wss.predexon.com/v1/YOUR_API_KEY

On success:

{ "type": "connected", "message": "Connected to Predexon WebSocket" }

HTTP Status	Reason
401	Missing or invalid API key
403	WebSocket requires Dev plan or higher
429	Connection limit exceeded
503	Server at capacity

Channels

Channel	Platform	`type` value	Description
Trades	`polymarket`	`"orders"`	Order fills and fee refunds (V1 + V2). Supports pending events.
Activity	`polymarket`	`"activity"`	Position splits, merges, redemptions, and NegRisk conversions
Lifecycle	`polymarket`	`"lifecycle"`	New market creation (`condition_prepared`), token registration (V1), and resolution
Orderbook	`polymarket`	`"orderbook"`	Real-time L2: price changes, trades, book snapshots
Oracle	`polymarket`	`"oracle"`	UMA events: proposals, disputes, settlements, resets
Collateral	`polymarket`	`"collateral"`	pUSD wrap/unwrap events (V2 deposits and withdrawals)
Crypto Prices	`chainlink`	`"crypto"`	Chainlink Data Streams crypto price ticks (BTC, ETH, SOL, XRP, BNB, DOGE, HYPE)

Filter Availability

Filter	Trades	Activity	Lifecycle	Orderbook	Oracle	Collateral	Crypto Prices
`users`	Yes	Yes	-	-	-	Yes	-
`token_ids`	-	-	-	Yes	-	-	-
`condition_ids`	Yes	Yes	Yes	Yes	Yes	-	-
`market_slugs`	Yes	-	-	Yes	Yes	-	-
`feeds`	-	-	-	-	-	-	Yes
Wildcard `["*"]`	Yes	Yes	Yes	Yes	Yes	Yes	Yes

Timestamp Units

Channel	Unit
Orderbook	milliseconds (Polymarket server)
All others	seconds (Predexon normalizer)

Plan Limits

Limit	Dev	Pro	Enterprise
Subscriptions / connection	10	100	Custom
Items / subscription	10	500	Custom
Total items	100	50,000	Custom
Wildcard subscriptions	-	2 per channel	Custom
Priority routing	-	-	Yes

Limits are global across all channels. Wildcard connections are tracked per-channel.

A wildcard connection cannot mix wildcard and regular subscriptions on the same channel.

Keepalive & Connection Management

Keepalive details

Server sends a ping every 30 seconds; pong required within 60 seconds
Idle connections (zero subscriptions) closed after 2 minutes (close code 4000)
Buffer limits: events dropped at 1 MB, connection terminated at 4 MB

Error Handling

{ "type": "error", "code": "ERROR_CODE", "message": "Human-readable message" }

Show Error codes

Code	Description
`AUTH_REQUIRED`	No API key provided
`AUTH_FAILED`	API key not found or invalid
`CONNECTION_LIMIT`	Server-wide cap reached
`WILDCARD_CONNECTION_LIMIT`	Wildcard limit exceeded
`SUBSCRIPTION_LIMIT`	Max subscriptions reached
`ITEMS_PER_SUB_LIMIT`	Too many items in one subscription
`ITEMS_LIMIT`	Max total items reached
`WILDCARD_NOT_ALLOWED`	Plan doesn’t support wildcards
`INVALID_FILTERS`	Missing/invalid filter for this channel
`SUBSCRIPTION_NOT_FOUND`	Subscription ID doesn’t exist
`PARSE_ERROR`	Invalid JSON
`UNKNOWN_ACTION`	Unrecognized action
`PLAN_REQUIRED`	Feature requires a higher plan
`RATE_LIMIT`	Sending messages too fast

Getting Started

Ticks

Markets

Discovery & Taxonomy

Pricing & Candles

Orderbooks

Trades

Activity & Positions

Wallet Identity

Wallet Positions & P&L

Smart Money & Leaderboards

Oracle & Settlement

Builders

Real-Time Signals (WebSocket)

Backtesting

Reference

Use Cases

Copytrading

Market Monitoring

Portfolio Alerts

Analytics & Research

Market Making

Mempool Trading

Quick Start

Connection

Channels

Filter Availability

Timestamp Units

Plan Limits

Keepalive & Connection Management

Error Handling

​Use Cases

Copytrading

Market Monitoring

Portfolio Alerts

Analytics & Research

Market Making

Mempool Trading

​Quick Start

​Connection

​Channels

​Filter Availability

​Timestamp Units

​Plan Limits

​Keepalive & Connection Management

​Error Handling

Use Cases

Quick Start

Connection

Channels

Filter Availability

Timestamp Units

Plan Limits

Keepalive & Connection Management

Error Handling