Preview a Funded Order

BETA — SUBJECT TO CHANGE. This API is in beta and may change without notice.

PreviewFundedOrder returns the prefund economics for a funded limit order without moving funds or placing an order. Use it to show a participant the cost of an order before they commit.

Preview responses are informational. Placement recomputes all economics from the CreateFundedOrder request — a preview is not a locked quote, and calling preview first is not required.

Service definition

Service: polymarket.us.orderfunding.v1.OrderFundingService RPC: PreviewFundedOrder Type: Unary (request/response)

service OrderFundingService {
    rpc PreviewFundedOrder(PreviewFundedOrderRequest)
        returns (PreviewFundedOrderResponse);
}

Request

PreviewFundedOrderRequest

Field	Type	Required	Description
`order`	`FundedOrder`	Yes	The order to price. Same shape as placement — see FundedOrder.
`customer_account_id`	`string`	Yes	The participant trading account that would receive the prefund, in the same format returned by the account onboarding/list APIs.
`vendor_fee`	`MoneyAmount`	Yes	Your static USD vendor fee for this order. Must be well-formed, non-negative, and allowed for your firm.

FundedOrder

The supported order shape for on-demand funded placement. The initial rollout supports limit orders on binary event markets.

Field	Type	Required	Description
`market_slug`	`string`	Yes	Market identifier (slug).
`type`	`OrderType`	Yes	`ORDER_TYPE_LIMIT`. Limit orders only.
`price`	`MoneyAmount`	Yes	Limit price per share in USD, e.g. `{"value": "0.45", "currency": "USD"}`.
`quantity`	`string`	Yes	Number of shares as a base-10 decimal string.
`tif`	`TimeInForce`	Yes	`TIME_IN_FORCE_DAY`, `TIME_IN_FORCE_GOOD_TILL_CANCEL`, `TIME_IN_FORCE_GOOD_TILL_TIME`, or `TIME_IN_FORCE_FILL_OR_KILL`.
`good_till_time`	`Timestamp`	Conditional	Expiration timestamp. Required when `tif` is `TIME_IN_FORCE_GOOD_TILL_TIME`.
`participate_dont_initiate`	`bool`	No	Post-only flag: the order may rest on the book but must not immediately match.
`intent`	`OrderIntent`	Yes	`ORDER_INTENT_OPEN` or `ORDER_INTENT_CLOSE` — whether the order opens or closes exposure.
`outcome_side`	`OutcomeSide`	Yes	`OUTCOME_SIDE_YES` or `OUTCOME_SIDE_NO`.
`action`	`OrderAction`	Yes	`ORDER_ACTION_BUY` or `ORDER_ACTION_SELL`.
`manual_order_indicator`	`ManualOrderIndicator`	Yes	`MANUAL_ORDER_INDICATOR_MANUAL` for human-entered orders, `MANUAL_ORDER_INDICATOR_AUTOMATED` for system-generated orders.

MoneyAmount

Field	Type	Description
`value`	`string`	Base-10 decimal string, e.g. `"0.45"`.
`currency`	`string`	ISO 4217 code. `USD`.

Response

PreviewFundedOrderResponse

Field	Type	Description
`cost_breakdown`	`CostBreakdown`	The prefund cost components for the order.

CostBreakdown

Field	Type	Description
`collateral`	`MoneyAmount`	Worst-case collateral: `quantity × price` for buys, `quantity × (1 − price)` for sells.
`exchange_fee`	`MoneyAmount`	Estimated maximum exchange fee reserve for a full fill. Actual collection happens per execution and can be lower — see cost model.
`vendor_fee`	`MoneyAmount`	Your vendor fee, echoed after validation.
`total_prefund`	`MoneyAmount`	`collateral + exchange_fee + vendor_fee` — the amount that placement would transfer.

Example

import grpc
from polymarket.us.orderfunding.v1 import order_funding_pb2, order_funding_pb2_grpc

credentials = grpc.ssl_channel_credentials()
channel = grpc.secure_channel("<grpc-endpoint>:443", credentials)
stub = order_funding_pb2_grpc.OrderFundingServiceStub(channel)
metadata = [("authorization", f"Bearer {access_token}")]

request = order_funding_pb2.PreviewFundedOrderRequest(
    order=order_funding_pb2.FundedOrder(
        market_slug="example-market-slug",
        type=order_funding_pb2.ORDER_TYPE_LIMIT,
        price=order_funding_pb2.MoneyAmount(value="0.45", currency="USD"),
        quantity="100",
        tif=order_funding_pb2.TIME_IN_FORCE_DAY,
        intent=order_funding_pb2.ORDER_INTENT_OPEN,
        outcome_side=order_funding_pb2.OUTCOME_SIDE_YES,
        action=order_funding_pb2.ORDER_ACTION_BUY,
        manual_order_indicator=order_funding_pb2.MANUAL_ORDER_INDICATOR_AUTOMATED,
    ),
    customer_account_id="<customer-account-id>",
    vendor_fee=order_funding_pb2.MoneyAmount(value="0.10", currency="USD"),
)

response = stub.PreviewFundedOrder(request, metadata=metadata)
print(response.cost_breakdown.total_prefund.value)

Errors

gRPC status	Meaning
`INVALID_ARGUMENT`	Malformed or unsupported order parameters, unsupported TIF/order type, or an invalid vendor fee.
`UNAUTHENTICATED`	Missing or invalid access token.
`PERMISSION_DENIED`	Your firm has no enabled funding relationship, or the vendor fee is not allowed for your firm.
`NOT_FOUND`	Unknown market or customer account.

Next step

CreateFundedOrder

Fund and place the order in one idempotent call.

Start Here

Partner Types & Eligibility

Get Connected

Onboard Participants

Funding

Monitor & Reconcile

Service definition

Request

PreviewFundedOrderRequest

FundedOrder

MoneyAmount

Response

PreviewFundedOrderResponse

CostBreakdown

Example

Errors

Next step

CreateFundedOrder

​Service definition

​Request

​PreviewFundedOrderRequest

​FundedOrder

​MoneyAmount

​Response

​PreviewFundedOrderResponse

​CostBreakdown

​Example

​Errors

​Next step

CreateFundedOrder

Service definition

Request

PreviewFundedOrderRequest

FundedOrder

MoneyAmount

Response

PreviewFundedOrderResponse

CostBreakdown

Example

Errors

Next step