Combo Execution Event

Pending Polymarket combo trades decoded from ExchangeV3 calldata.

combo_execution streams a Polymarket combo trade from the mempool, before it appears in the confirmed combo-trades API. It uses the same maker/taker trade model as the standard settlement stream and includes every signed order in the transaction.

This is a pending event. Use combo_status_update with the same tx_hash for confirmation. A dropped or replaced Polygon transaction may never confirm.

Example

{
  "type": "combo_execution",
  "timestamp": 1785812120366,
  "data": {
    "event_type": "combo_execution",
    "tx_hash": "0xf4f973bcca17c05081574c36183a5f61fae8eb5895a2d46d71aaadb3cf11e556",
    "status": "pending",
    "detected_at": 1785812120366,
    "block_number": null,
    "combo_condition_id": "0x03af499212591cdbfd21ab04df07b8fb720000000000000000000000000000",
    "legs": [
      {
        "position_id": "759456036058902166074175781780133450895503656129754990757956704995918217217",
        "module_id": 1,
        "module_name": "BinaryModule",
        "condition_id": "0x01add63e0052d10828c47551c3e231dedd0000000000000000000000000000",
        "event_id": "0x01add63e0052d10828c47551c3e231dedd000000000000000000000000",
        "arity": 0,
        "condition_index": 0,
        "outcome_index": 1,
        "leg_outcome_label": "No",
        "market": {
          "title": "Phoenix Mercury vs. Chicago Sky",
          "slug": "wnba-phx-chi-2026-08-03",
          "image": "https://polymarket-upload.s3.us-east-2.amazonaws.com/wnba-logo-PAR4befDAubM.png",
          "outcomes": ["Phoenix Mercury", "Chicago Sky"],
          "token_ids": [
            "759456036058902166074175781780133450895503656129754990757956704995918217216",
            "759456036058902166074175781780133450895503656129754990757956704995918217217"
          ]
        }
      },
      {
        "position_id": "888399010527256025342625662713948815643754849506664777044908366823210090496",
        "module_id": 1,
        "module_name": "BinaryModule",
        "condition_id": "0x01f6d0e6bdba3f8d15dc0928842624b9f10000000000000000000000000000",
        "event_id": "0x01f6d0e6bdba3f8d15dc0928842624b9f1000000000000000000000000",
        "arity": 0,
        "condition_index": 0,
        "outcome_index": 0,
        "leg_outcome_label": "Yes",
        "market": {
          "title": "National Bank Open: Tatjana Maria vs Caty McNally",
          "slug": "wta-maria-mcnally-2026-08-03",
          "image": "https://polymarket-upload.s3.us-east-2.amazonaws.com/wta-logo-41f331bdf1.png",
          "outcomes": ["Tatjana Maria", "Caty McNally"],
          "token_ids": [
            "888399010527256025342625662713948815643754849506664777044908366823210090496",
            "888399010527256025342625662713948815643754849506664777044908366823210090497"
          ]
        }
      }
    ],
    "taker_wallet": "0x0d8b4fb38999aaf7658df758f3587d25fe7fd417",
    "taker_token": "1666644547653825639538654505467109608411697937035881104213580452779446501376",
    "taker_side": "BUY",
    "outcome": "YES",
    "taker_price": 0.57,
    "taker_size": 40.350877,
    "amount_usdc": 22.999999,
    "order_hashes": [
      "0x9fd9da991a3d8f82bfb13e2901422a1621d87db1e27ce4da33fd5a61dec4f4b7",
      "0x1eb1c486ccad5622329d3e88147c6e98698521ebff86fcbd27ab7efa7fd458d5"
    ],
    "trades": [
      {
        "position_id": "1666644547653825639538654505467109608411697937035881104213580452779446501377",
        "order_hash": "0x9fd9da991a3d8f82bfb13e2901422a1621d87db1e27ce4da33fd5a61dec4f4b7",
        "maker": "0xe2315b15280fc49bc6e60eaaeea30c0df64493a5",
        "signer": "0x1d0a670f95751708ad3f61aced73ca55822bb145",
        "taker": "0x0d8b4fb38999aaf7658df758f3587d25fe7fd417",
        "side": "BUY",
        "outcome": "NO",
        "price": 0.43,
        "size": 40.350877,
        "amount_usdc": 17.350878,
        "fee": 0
      },
      {
        "position_id": "1666644547653825639538654505467109608411697937035881104213580452779446501376",
        "order_hash": "0x1eb1c486ccad5622329d3e88147c6e98698521ebff86fcbd27ab7efa7fd458d5",
        "maker": "0x0d8b4fb38999aaf7658df758f3587d25fe7fd417",
        "signer": "0x0d8b4fb38999aaf7658df758f3587d25fe7fd417",
        "taker": "0xe3333700ca9d93003f00f0f71f8515005f6c00aa",
        "side": "BUY",
        "outcome": "YES",
        "price": 0.57,
        "size": 40.350877,
        "amount_usdc": 22.999999,
        "fee": 0.4945
      }
    ]
  }
}

How to read it

The top-level trade fields describe the taker order. In the example, the taker wallet bought 40.350877 YES combo shares at 0.57 for 22.999999 USDC.

Each trades[] row describes one signed order from that order maker’s perspective. The complementary maker bought the NO position at 0.43 for the same 40.350877 shares. This is the same convention used by the settlement stream and by Exchange OrderFilled events.

size always means shares. amount_usdc always means dollars. For BUY orders, the calldata’s maker amount is USDC, so PolyNode converts it to shares before emitting size. For SELL orders, the maker amount is already shares. The conversion is performed in both directions so clients do not need to interpret raw fixed-point amounts.

price is the actual fill price, not merely the signed order’s limit price. This matters when one taker order receives price improvement across multiple maker orders.

amount_usdc is the gross fill value. fee is reported separately and is not subtracted from it.

Multiple maker orders

A transaction with three maker orders and one taker order contains four trades[] rows and four order_hashes. These arrays are one-to-one and use the same order: maker orders in calldata order, followed by the taker order. Use trades[i].order_hash when working with an individual row.

Top-level taker_size and amount_usdc are the taker order’s total filled shares and gross USDC value across all makers. taker_price is the effective fill price (amount_usdc / taker_size), rounded to four decimal places. This is why a live multi-maker payload can be longer than the two-order example above without introducing any additional field types.

Mapping to the static combo-trades API

After confirmation, the same fill appears in GET /v3/wallets/{address}/combos/trades.

WebSocket field	Static combo-trades field	Notes
tx_hash	tx_hash	Stable correlation key
trades[].position_id	position_id	Combo YES or NO position
trades[].side	side	Maker-perspective BUY or SELL
trades[].price	price	Actual fill price
trades[].size	size	Shares traded
trades[].fee	fee	Fee charged for that fill
trades[].maker / taker	wallet_address, wallet_role, counterparty_address	Querying either participant projects the same fill for that wallet
trades[].order_hash	—	Available immediately from calldata on the WebSocket
trades[].amount_usdc	—	Explicit dollar value of the fill

The static endpoint additionally has confirmed-only fields such as block_number, log_index, and the on-chain timestamp.

Fields

Execution

Field	Type	Description
tx_hash	string	Polygon transaction hash
status	string	Always pending for a mempool execution
detected_at	number	Unix milliseconds when PolyNode first saw the transaction
block_number	number or null	null before confirmation
combo_condition_id	string	Derived combo condition ID
legs	object[]	Every decoded constituent leg
taker_wallet	string	Wallet that made the taker order
taker_token	string	Combo position ID bought or sold by the taker order
taker_side	string	Taker order direction: BUY or SELL
outcome	string	Taker combo position side: YES or NO
taker_price	number	Actual taker fill price
taker_size	number	Taker fill size in shares
amount_usdc	number	Taker fill value in USDC
order_hashes	string[]	ExchangeV3 EIP-712 hashes computed from calldata
trades	object[]	Every signed order involved in the execution

Trade row

Field	Type	Description
position_id	string	Combo position filled by this order
order_hash	string	ExchangeV3 EIP-712 order hash
maker	string	Wallet that made this signed order
signer	string	Address that signed this order
taker	string	OrderFilled taker/counterparty; this can be the ExchangeV3 contract for the taker order
side	string	This order maker’s BUY or SELL direction
outcome	string	YES or NO combo position side
price	number	Actual fill price
size	number	Shares filled
amount_usdc	number	Dollar value filled
fee	number	Fee in USDC

Leg row

position_id and the decoded structural fields are available directly from calldata. The nested market object is included when the market metadata is in PolyNode’s in-memory cache; it is omitted rather than fetched synchronously on the latency-sensitive WebSocket path.

Field	Type	Description
position_id	string	Leg position ID
module_id / module_name	number / string	Combo module identity
condition_id	string	Leg condition ID
event_id	string	Leg event ID when encoded by the module
arity	number	Encoded condition arity
condition_index	number	Condition index within the event
outcome_index	number	Selected outcome index
leg_outcome_label	string	Encoded combo-leg selection (Yes or No for BinaryModule); this is distinct from a human label in market.outcomes
market	object	Optional cached title, slug, image, event metadata, outcomes, and token IDs

Subscribe

{
  "action": "subscribe",
  "type": "combos",
  "filters": {
    "event_types": ["combo_execution"]
  }
}