## Preview Orders `$ clst v1:orders preview-orders` **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). ### Parameters - `--account-id: number` Account identifier - `--preview: array of NewOrderRequest` ### Returns - `V1OrderPreviewOrdersResponse: BaseResponse` - `data: array of OrderPreviewEntry` - `union_member_0: object { preview, id }` The order was previewed successfully. - `preview: object { account_id, amount, buying_power, 5 more }` The projected impact of the order. - `account_id: number` The account the order was previewed for. - `amount: object { gross_amount, net_amount }` Monetary size of the previewed order. - `gross_amount: string` Total cash impact of the order before estimated fees and commissions. - `net_amount: string` Total cash impact of the order after estimated fees and commissions. - `buying_power: object { after, before, change }` Buying power before and after the order. - `after: string` The value with the previewed order also fully filled. - `before: string` The value before the order, as the risk engine evaluates it: the account's open orders are projected as filled. - `change: string` The previewed order's isolated impact: `after - before`. - `currency: string` Currency for all monetary values. - `equity: object { after, before, change }` Account equity before and after the order. - `after: string` The value with the previewed order also fully filled. - `before: string` The value before the order, as the risk engine evaluates it: the account's open orders are projected as filled. - `change: string` The previewed order's isolated impact: `after - before`. - `errors: array of OrderPreviewError` Risk-check errors that would prevent the order from being accepted. Empty when the order would pass every pre-trade risk check. - `description: string` Human-readable description of the error. - `metadata: map[string]` Structured details for the error (stringified values), e.g. required and available amounts, and `leg_index`/`leg_symbol` for multileg leg errors. - `type: string` Stable error code. - `margin_details: object { initial_margin_excess, initial_margin_requirement, maintenance_margin_excess, 3 more }` Margin requirements and excess before and after the order. - `initial_margin_excess: object { after, before, change }` Initial margin excess. - `after: string` The value with the previewed order also fully filled. - `before: string` The value before the order, as the risk engine evaluates it: the account's open orders are projected as filled. - `change: string` The previewed order's isolated impact: `after - before`. - `initial_margin_requirement: object { after, before, change }` Initial margin requirement. - `after: string` The value with the previewed order also fully filled. - `before: string` The value before the order, as the risk engine evaluates it: the account's open orders are projected as filled. - `change: string` The previewed order's isolated impact: `after - before`. - `maintenance_margin_excess: object { after, before, change }` Maintenance margin excess. - `after: string` The value with the previewed order also fully filled. - `before: string` The value before the order, as the risk engine evaluates it: the account's open orders are projected as filled. - `change: string` The previewed order's isolated impact: `after - before`. - `maintenance_margin_requirement: object { after, before, change }` Maintenance margin requirement. - `after: string` The value with the previewed order also fully filled. - `before: string` The value before the order, as the risk engine evaluates it: the account's open orders are projected as filled. - `change: string` The previewed order's isolated impact: `after - before`. - `overnight_margin_excess: object { after, before, change }` Overnight margin excess. - `after: string` The value with the previewed order also fully filled. - `before: string` The value before the order, as the risk engine evaluates it: the account's open orders are projected as filled. - `change: string` The previewed order's isolated impact: `after - before`. - `overnight_margin_requirement: object { after, before, change }` Overnight margin requirement. - `after: string` The value with the previewed order also fully filled. - `before: string` The value before the order, as the risk engine evaluates it: the account's open orders are projected as filled. - `change: string` The previewed order's isolated impact: `after - before`. - `positions: array of OrderPreviewPosition` Positions in the traded instruments before and after the order. - `instrument_id: string` The instrument's identifier. - `quantity: object { after, before, change }` Net position quantity before and after the order. - `after: string` The value with the previewed order also fully filled. - `before: string` The value before the order, as the risk engine evaluates it: the account's open orders are projected as filled. - `change: string` The previewed order's isolated impact: `after - before`. - `symbol: string` The instrument's symbol. - `id: optional string` 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. - `union_member_1: object { error, id }` The order could not be previewed. Shaped exactly like the top-level `error` object on rejected submissions. - `error: object { code, message, details }` Why this order's preview failed. - `code: number` The error code is used to identify the nature of the error. It corresponds to an HTTP status code. - `message: string` A human-readable message providing more details about the error. - `details: optional array of map[unknown]` Additional error details, if any. This can include structured information such as field violations or error metadata. - `id: optional string` 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. ### Example ```cli clst v1:orders preview-orders \ --api-key 'My API Key' \ --account-id 0 \ --preview "{order_type: LIMIT, quantity: '100', side: BUY, time_in_force: DAY}" \ --preview "{order_type: LIMIT, quantity: '10', side: BUY, time_in_force: DAY}" ``` #### Response ```json { "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" } } ```