Preview Orders

v1.orders.preview_orders(, ) -> OrderPreviewOrdersResponse

POST/v1/accounts/{account_id}/orders/preview

Preview the impact of orders without submitting them. For each order the engine evaluates every pre-trade risk check and projects the account’s balances and positions as if the order were fully filled — at the limit price for limit orders and at the current reference price for market orders. Orders are evaluated independently: they do not see each other’s projected fills. Nothing is submitted and no account state changes.

The response carries one result per requested order, in request order. When the request contains more than one order, every order must carry a unique id, which is echoed on its result. An order that cannot be previewed gets an error on its own result without affecting the rest of the batch; the response is still 200 OK — per-order outcomes live only in the rows, and non-2xx statuses are reserved for request-level failures (invalid batch, authorization, engine unavailable).

ParametersExpand Collapse

account_id: int

preview: Iterable[NewOrderRequestParam]

order_type: RequestOrderType

Type of order

One of the following:

"MARKET"

"LIMIT"

"STOP"

"STOP_LIMIT"

"TRAILING_STOP"

"TRAILING_STOP_LIMIT"

quantity: str

Quantity to trade. For COMMON_STOCK: shares (may be fractional if supported). For OPTION (single-leg): contracts (must be an integer)

side: Side

Side of the order

One of the following:

"BUY"

"SELL"

time_in_force: RequestTimeInForce

Time in force

One of the following:

"DAY"

"GOOD_TILL_CANCEL"

"IMMEDIATE_OR_CANCEL"

"FILL_OR_KILL"

"GOOD_TILL_DATE"

"AT_OPEN"

"AT_CLOSE"

id: Optional[str]

Optional client-provided unique ID (idempotency). Required to be unique per account.

maxLength64

expires_at: Optional[datetime]

The timestamp when the order should expire (UTC). Required when time_in_force is GOOD_TILL_DATE.

formatdate-time

extended_hours: Optional[bool]

Allow trading outside regular trading hours. Some brokers disallow options outside RTH.

instrument_id: Optional[InstrumentIDOrSymbol]

Instrument ID (UUID) or symbol (equity ticker or OSI option symbol). Either symbol or instrument_id must be provided.

minLength1

limit_offset: Optional[str]

Limit offset for trailing stop-limit orders (signed)

limit_price: Optional[str]

Limit price (required for LIMIT and STOP_LIMIT orders)

position_intent: Optional[RequestPositionEffect]

Optional open/close intent for this order. When omitted, the platform determines the position effect.

One of the following:

"OPEN"

"CLOSE"

stop_price: Optional[str]

Stop price (required for STOP and STOP_LIMIT orders)

strategy: Optional[OrderStrategy]

Optional execution strategy. One of SOR, VWAP, TWAP, or DMA. Defaults to SOR, the only strategy OTC common-stock orders support. VWAP and TWAP are supported only on MARKET and LIMIT orders, and DMA only on LIMIT orders; all three require DAY time-in-force. VWAP, TWAP, and DMA do not support extended_hours.

One of the following:

class Type: …

Smart Order Router. Routes the order to the best available venue(s).

type: Literal["SOR"]

Execution strategy type.

class UnionMember1: …

Volume-Weighted Average Price. Works the order to track the volume-weighted average price over the execution window.

type: Literal["VWAP"]

Execution strategy type.

end_at: Optional[datetime]

UTC timestamp (RFC 3339) by which to finish working the order. Defaults to market close.

formatdate-time

start_at: Optional[datetime]

UTC timestamp (RFC 3339) at which to begin working the order. Defaults to the time the order is received.

formatdate-time

class UnionMember2: …

Time-Weighted Average Price. Spreads execution evenly across the execution window.

type: Literal["TWAP"]

Execution strategy type.

end_at: Optional[datetime]

UTC timestamp (RFC 3339) by which to finish working the order. Defaults to market close.

formatdate-time

start_at: Optional[datetime]

UTC timestamp (RFC 3339) at which to begin working the order. Defaults to the time the order is received.

formatdate-time

class UnionMember3: …

Direct Market Access. Routes the order straight to the named venue.

destination: str

Venue code the order is routed to.

type: Literal["DMA"]

Execution strategy type.

symbol: Optional[str]

Trading symbol. For equities, use the ticker symbol (e.g., “TSLA”). For options, use the OSI symbol (e.g., “TSLA 250117C00190000”). Either symbol or instrument_id must be provided.

trailing_offset: Optional[str]

Trailing offset amount (required for trailing orders)

trailing_offset_type: Optional[TrailingOffsetType]

Trailing offset type (PRICE or PERCENT_BPS)

One of the following:

"PRICE"

"BPS"

ReturnsExpand Collapse

class OrderPreviewOrdersResponse: …

data: OrderPreviewEntryList

One of the following:

class UnionMember0: …

The order was previewed successfully.

preview: OrderPreview

The projected impact of the order.

account_id: int

The account the order was previewed for.

formatint64

amount: OrderPreviewAmount

Monetary size of the previewed order.

gross_amount: str

Total cash impact of the order before estimated fees and commissions.

net_amount: str

Total cash impact of the order after estimated fees and commissions.

buying_power: OrderPreviewDelta

Buying power before and after the order.

after: str

The value with the previewed order also fully filled.

before: str

The value before the order, as the risk engine evaluates it: the account’s open orders are projected as filled.

change: str

The previewed order’s isolated impact: after - before.

currency: str

Currency for all monetary values.

equity: OrderPreviewDelta

Account equity before and after the order.

after: str

The value with the previewed order also fully filled.

before: str

The value before the order, as the risk engine evaluates it: the account’s open orders are projected as filled.

change: str

The previewed order’s isolated impact: after - before.

errors: List[OrderPreviewError]

Risk-check errors that would prevent the order from being accepted. Empty when the order would pass every pre-trade risk check.

description: str

Human-readable description of the error.

metadata: Dict[str, str]

Structured details for the error (stringified values), e.g. required and available amounts, and leg_index/leg_symbol for multileg leg errors.

type: str

Stable error code.

margin_details: OrderPreviewMarginDetails

Margin requirements and excess before and after the order.

initial_margin_excess: OrderPreviewDelta

Initial margin excess.

after: str

The value with the previewed order also fully filled.

before: str

The value before the order, as the risk engine evaluates it: the account’s open orders are projected as filled.

change: str

The previewed order’s isolated impact: after - before.

initial_margin_requirement: OrderPreviewDelta

Initial margin requirement.

after: str

The value with the previewed order also fully filled.

before: str

The value before the order, as the risk engine evaluates it: the account’s open orders are projected as filled.

change: str

The previewed order’s isolated impact: after - before.

maintenance_margin_excess: OrderPreviewDelta

Maintenance margin excess.

after: str

The value with the previewed order also fully filled.

before: str

The value before the order, as the risk engine evaluates it: the account’s open orders are projected as filled.

change: str

The previewed order’s isolated impact: after - before.

maintenance_margin_requirement: OrderPreviewDelta

Maintenance margin requirement.

after: str

The value with the previewed order also fully filled.

before: str

The value before the order, as the risk engine evaluates it: the account’s open orders are projected as filled.

change: str

The previewed order’s isolated impact: after - before.

overnight_margin_excess: OrderPreviewDelta

Overnight margin excess.

after: str

The value with the previewed order also fully filled.

before: str

The value before the order, as the risk engine evaluates it: the account’s open orders are projected as filled.

change: str

The previewed order’s isolated impact: after - before.

overnight_margin_requirement: OrderPreviewDelta

Overnight margin requirement.

after: str

The value with the previewed order also fully filled.

before: str

The value before the order, as the risk engine evaluates it: the account’s open orders are projected as filled.

change: str

The previewed order’s isolated impact: after - before.

positions: List[OrderPreviewPosition]

Positions in the traded instruments before and after the order.

instrument_id: str

The instrument’s identifier.

formatuuid

quantity: OrderPreviewDelta

Net position quantity before and after the order.

after: str

The value with the previewed order also fully filled.

before: str

The value before the order, as the risk engine evaluates it: the account’s open orders are projected as filled.

change: str

The previewed order’s isolated impact: after - before.

symbol: str

The instrument’s symbol.

id: Optional[str]

The client-provided id of the order this entry belongs to, echoed from the request. Always present when the request contains more than one order, since ids are required there.

class UnionMember1: …

The order could not be previewed. Shaped exactly like the top-level error object on rejected submissions.

error: APIError

Why this order’s preview failed.

code: int

The error code is used to identify the nature of the error. It corresponds to an HTTP status code.

formatint32

minimum0

message: str

A human-readable message providing more details about the error.

details: Optional[List[Dict[str, object]]]

Additional error details, if any. This can include structured information such as field violations or error metadata.

id: Optional[str]

The client-provided id of the order this entry belongs to, echoed from the request. Always present when the request contains more than one order, since ids are required there.

Preview Orders

from clearstreet import ClearStreet

client = ClearStreet(
    api_key="My API Key",
)
response = client.v1.orders.preview_orders(
    account_id=0,
    preview=[{
        "order_type": "LIMIT",
        "quantity": "100",
        "side": "BUY",
        "time_in_force": "DAY",
    }, {
        "order_type": "LIMIT",
        "quantity": "10",
        "side": "BUY",
        "time_in_force": "DAY",
    }],
)
print(response)

{
  "data": [
    {
      "id": "preview-1",
      "preview": {
        "account_id": 19816,
        "amount": {
          "gross_amount": "10000.00",
          "net_amount": "10000.00"
        },
        "buying_power": {
          "after": "190000.00",
          "before": "200000.00",
          "change": "-10000.00"
        },
        "currency": "USD",
        "equity": {
          "after": "100000.00",
          "before": "100000.00",
          "change": "0.00"
        },
        "errors": [],
        "margin_details": {
          "initial_margin_excess": {
            "after": "95000.00",
            "before": "100000.00",
            "change": "-5000.00"
          },
          "initial_margin_requirement": {
            "after": "5000.00",
            "before": "0.00",
            "change": "5000.00"
          },
          "maintenance_margin_excess": {
            "after": "97500.00",
            "before": "100000.00",
            "change": "-2500.00"
          },
          "maintenance_margin_requirement": {
            "after": "2500.00",
            "before": "0.00",
            "change": "2500.00"
          },
          "overnight_margin_excess": {
            "after": "95000.00",
            "before": "100000.00",
            "change": "-5000.00"
          },
          "overnight_margin_requirement": {
            "after": "5000.00",
            "before": "0.00",
            "change": "5000.00"
          }
        },
        "positions": [
          {
            "instrument_id": "a1a2a3a4-b1b2-c1c2-d1d2-d3d4d5d6d7d8",
            "quantity": {
              "after": "100",
              "before": "0",
              "change": "100"
            },
            "symbol": "AAPL"
          }
        ]
      }
    },
    {
      "error": {
        "code": 400,
        "message": "Security not found: BADSYM"
      },
      "id": "preview-2"
    }
  ],
  "metadata": {
    "request_id": "d3e5b1a2-8c4f-4b6e-9d2a-1f0c9b8a7654"
  }
}

{
  "data": [
    {
      "id": "preview-1",
      "preview": {
        "account_id": 19816,
        "amount": {
          "gross_amount": "10000.00",
          "net_amount": "10000.00"
        },
        "buying_power": {
          "after": "190000.00",
          "before": "200000.00",
          "change": "-10000.00"
        },
        "currency": "USD",
        "equity": {
          "after": "100000.00",
          "before": "100000.00",
          "change": "0.00"
        },
        "errors": [],
        "margin_details": {
          "initial_margin_excess": {
            "after": "95000.00",
            "before": "100000.00",
            "change": "-5000.00"
          },
          "initial_margin_requirement": {
            "after": "5000.00",
            "before": "0.00",
            "change": "5000.00"
          },
          "maintenance_margin_excess": {
            "after": "97500.00",
            "before": "100000.00",
            "change": "-2500.00"
          },
          "maintenance_margin_requirement": {
            "after": "2500.00",
            "before": "0.00",
            "change": "2500.00"
          },
          "overnight_margin_excess": {
            "after": "95000.00",
            "before": "100000.00",
            "change": "-5000.00"
          },
          "overnight_margin_requirement": {
            "after": "5000.00",
            "before": "0.00",
            "change": "5000.00"
          }
        },
        "positions": [
          {
            "instrument_id": "a1a2a3a4-b1b2-c1c2-d1d2-d3d4d5d6d7d8",
            "quantity": {
              "after": "100",
              "before": "0",
              "change": "100"
            },
            "symbol": "AAPL"
          }
        ]
      }
    }
  ],
  "metadata": {
    "request_id": "d3e5b1a2-8c4f-4b6e-9d2a-1f0c9b8a7654"
  }
}

Returns Examples

{
  "data": [
    {
      "id": "preview-1",
      "preview": {
        "account_id": 19816,
        "amount": {
          "gross_amount": "10000.00",
          "net_amount": "10000.00"
        },
        "buying_power": {
          "after": "190000.00",
          "before": "200000.00",
          "change": "-10000.00"
        },
        "currency": "USD",
        "equity": {
          "after": "100000.00",
          "before": "100000.00",
          "change": "0.00"
        },
        "errors": [],
        "margin_details": {
          "initial_margin_excess": {
            "after": "95000.00",
            "before": "100000.00",
            "change": "-5000.00"
          },
          "initial_margin_requirement": {
            "after": "5000.00",
            "before": "0.00",
            "change": "5000.00"
          },
          "maintenance_margin_excess": {
            "after": "97500.00",
            "before": "100000.00",
            "change": "-2500.00"
          },
          "maintenance_margin_requirement": {
            "after": "2500.00",
            "before": "0.00",
            "change": "2500.00"
          },
          "overnight_margin_excess": {
            "after": "95000.00",
            "before": "100000.00",
            "change": "-5000.00"
          },
          "overnight_margin_requirement": {
            "after": "5000.00",
            "before": "0.00",
            "change": "5000.00"
          }
        },
        "positions": [
          {
            "instrument_id": "a1a2a3a4-b1b2-c1c2-d1d2-d3d4d5d6d7d8",
            "quantity": {
              "after": "100",
              "before": "0",
              "change": "100"
            },
            "symbol": "AAPL"
          }
        ]
      }
    },
    {
      "error": {
        "code": 400,
        "message": "Security not found: BADSYM"
      },
      "id": "preview-2"
    }
  ],
  "metadata": {
    "request_id": "d3e5b1a2-8c4f-4b6e-9d2a-1f0c9b8a7654"
  }
}

{
  "data": [
    {
      "id": "preview-1",
      "preview": {
        "account_id": 19816,
        "amount": {
          "gross_amount": "10000.00",
          "net_amount": "10000.00"
        },
        "buying_power": {
          "after": "190000.00",
          "before": "200000.00",
          "change": "-10000.00"
        },
        "currency": "USD",
        "equity": {
          "after": "100000.00",
          "before": "100000.00",
          "change": "0.00"
        },
        "errors": [],
        "margin_details": {
          "initial_margin_excess": {
            "after": "95000.00",
            "before": "100000.00",
            "change": "-5000.00"
          },
          "initial_margin_requirement": {
            "after": "5000.00",
            "before": "0.00",
            "change": "5000.00"
          },
          "maintenance_margin_excess": {
            "after": "97500.00",
            "before": "100000.00",
            "change": "-2500.00"
          },
          "maintenance_margin_requirement": {
            "after": "2500.00",
            "before": "0.00",
            "change": "2500.00"
          },
          "overnight_margin_excess": {
            "after": "95000.00",
            "before": "100000.00",
            "change": "-5000.00"
          },
          "overnight_margin_requirement": {
            "after": "5000.00",
            "before": "0.00",
            "change": "5000.00"
          }
        },
        "positions": [
          {
            "instrument_id": "a1a2a3a4-b1b2-c1c2-d1d2-d3d4d5d6d7d8",
            "quantity": {
              "after": "100",
              "before": "0",
              "change": "100"
            },
            "symbol": "AAPL"
          }
        ]
      }
    }
  ],
  "metadata": {
    "request_id": "d3e5b1a2-8c4f-4b6e-9d2a-1f0c9b8a7654"
  }
}