Market Channel

Public channel for market data updates (level 2 price data). Subscribe with asset IDs to receive orderbook snapshots, price changes, trade executions, and market events.

Endpoint

wss://ws-subscriptions-clob.polymarket.com/ws/market

Subscription

{
  "assets_ids": ["<token_id_1>", "<token_id_2>"],
  "type": "market",
  "custom_feature_enabled": true
}

Set custom_feature_enabled: true to receive best_bid_ask, new_market, and market_resolved events.

Message Types

Each message includes an event_type field identifying the type.

book

Emitted when first subscribed to a market and when there is a trade that affects the book.

{
  "event_type": "book",
  "asset_id": "65818619657568813474341868652308942079804919287380422192892211131408793125422",
  "market": "0xbd31dc8a20211944f6b70f31557f1001557b59905b7738480ca09bd4532f84af",
  "bids": [
    { "price": ".48", "size": "30" },
    { "price": ".49", "size": "20" },
    { "price": ".50", "size": "15" }
  ],
  "asks": [
    { "price": ".52", "size": "25" },
    { "price": ".53", "size": "60" },
    { "price": ".54", "size": "10" }
  ],
  "timestamp": "123456789000",
  "hash": "0x0...."
}

price_change

Emitted when a new order is placed or an order is cancelled.

{
  "market": "0x5f65177b394277fd294cd75650044e32ba009a95022d88a0c1d565897d72f8f1",
  "price_changes": [
    {
      "asset_id": "71321045679252212594626385532706912750332728571942532289631379312455583992563",
      "price": "0.5",
      "size": "200",
      "side": "BUY",
      "hash": "56621a121a47ed9333273e21c83b660cff37ae50",
      "best_bid": "0.5",
      "best_ask": "1"
    },
    {
      "asset_id": "52114319501245915516055106046884209969926127482827954674443846427813813222426",
      "price": "0.5",
      "size": "200",
      "side": "SELL",
      "hash": "1895759e4df7a796bf4f1c5a5950b748306923e2",
      "best_bid": "0",
      "best_ask": "0.5"
    }
  ],
  "timestamp": "1757908892351",
  "event_type": "price_change"
}

A size of "0" means the price level has been removed from the book.

tick_size_change

Emitted when the minimum tick size of a market changes. This happens when the book’s price reaches the limits: price > 0.96 or price < 0.04.

{
  "event_type": "tick_size_change",
  "asset_id": "65818619657568813474341868652308942079804919287380422192892211131408793125422",
  "market": "0xbd31dc8a20211944f6b70f31557f1001557b59905b7738480ca09bd4532f84af",
  "old_tick_size": "0.01",
  "new_tick_size": "0.001",
  "timestamp": "100000000"
}

last_trade_price

Emitted when a maker and taker order is matched, creating a trade event.

{
  "asset_id": "114122071509644379678018727908709560226618148003371446110114509806601493071694",
  "event_type": "last_trade_price",
  "fee_rate_bps": "0",
  "market": "0x6a67b9d828d53862160e470329ffea5246f338ecfffdf2cab45211ec578b0347",
  "price": "0.456",
  "side": "BUY",
  "size": "219.217767",
  "timestamp": "1750428146322"
}

best_bid_ask

Requires custom_feature_enabled: true.

Emitted when the best bid or ask prices for a market change.

{
  "event_type": "best_bid_ask",
  "market": "0x0005c0d312de0be897668695bae9f32b624b4a1ae8b140c49f08447fcc74f442",
  "asset_id": "85354956062430465315924116860125388538595433819574542752031640332592237464430",
  "best_bid": "0.73",
  "best_ask": "0.77",
  "spread": "0.04",
  "timestamp": "1766789469958"
}

new_market

Requires custom_feature_enabled: true.

Emitted when a new market is created. The payload also includes market metadata fields such as tags, condition_id, active, clob_token_ids, sports_market_type, line, game_start_time, order_price_min_tick_size, group_item_title, taker_base_fee, fees_enabled, and fee_schedule. Where a FeeSchedule object is of the form:

Name	Type	Description
exponent	string	fee curve exponent
rate	string	fee rate
taker_only	boolean	whether fee applies to taker only
rebate_rate	string	maker rebate rate

{
  "id": "1031769",
  "question": "Will NVIDIA (NVDA) close above $240 end of January?",
  "market": "0x311d0c4b6671ab54af4970c06fcf58662516f5168997bdda209ec3db5aa6b0c1",
  "slug": "nvda-above-240-on-january-30-2026",
  "description": "This market will resolve to \"Yes\" if the official closing price...",
  "assets_ids": [
    "76043073756653678226373981964075571318267289248134717369284518995922789326425",
    "31690934263385727664202099278545688007799199447969475608906331829650099442770"
  ],
  "outcomes": ["Yes", "No"],
  "event_message": {
    "id": "125819",
    "ticker": "nvda-above-in-january-2026",
    "slug": "nvda-above-in-january-2026",
    "title": "Will NVIDIA (NVDA) close above ___ end of January?",
    "description": "This market will resolve to \"Yes\" if the official closing price..."
  },
  "timestamp": "1766790415550",
  "event_type": "new_market",
  "tags": ["stocks"],
  "condition_id": "0x311d0c4b6671ab54af4970c06fcf58662516f5168997bdda209ec3db5aa6b0c1",
  "active": true,
  "clob_token_ids": [
    "76043073756653678226373981964075571318267289248134717369284518995922789326425",
    "31690934263385727664202099278545688007799199447969475608906331829650099442770"
  ],
  "sports_market_type": "",
  "line": "",
  "game_start_time": "",
  "order_price_min_tick_size": "0.01",
  "group_item_title": "NVDA above $240",
  "taker_base_fee": "0",
  "fees_enabled": true,
  "fee_schedule": {
    "exponent": "2",
    "rate": "0.02",
    "taker_only": true,
    "rebate_rate": "0"
  }
}

market_resolved

Requires custom_feature_enabled: true.

Emitted when a market is resolved.

{
  "id": "1031769",
  "question": "Will NVIDIA (NVDA) close above $240 end of January?",
  "market": "0x311d0c4b6671ab54af4970c06fcf58662516f5168997bdda209ec3db5aa6b0c1",
  "slug": "nvda-above-240-on-january-30-2026",
  "description": "This market will resolve to \"Yes\" if the official closing price...",
  "assets_ids": [
    "76043073756653678226373981964075571318267289248134717369284518995922789326425",
    "31690934263385727664202099278545688007799199447969475608906331829650099442770"
  ],
  "outcomes": ["Yes", "No"],
  "winning_asset_id": "76043073756653678226373981964075571318267289248134717369284518995922789326425",
  "winning_outcome": "Yes",
  "event_message": {
    "id": "125819",
    "ticker": "nvda-above-in-january-2026",
    "slug": "nvda-above-in-january-2026",
    "title": "Will NVIDIA (NVDA) close above ___ end of January?",
    "description": "This market will resolve to \"Yes\" if the official closing price..."
  },
  "timestamp": "1766790415550",
  "event_type": "market_resolved"
}

Getting Started

Core Concepts

Market Data

Trading

Market Makers

Builder Program

Resources

Endpoint

Subscription

Message Types

book

price_change

tick_size_change

last_trade_price

best_bid_ask

new_market

market_resolved

​Endpoint

​Subscription

​Message Types

​book

​price_change

​tick_size_change

​last_trade_price

​best_bid_ask

​new_market

​market_resolved

Endpoint

Subscription

Message Types

book

price_change

tick_size_change

last_trade_price

best_bid_ask

new_market

market_resolved