> ## Documentation Index > Fetch the complete documentation index at: https://docs.cdp.coinbase.com/llms.txt > Use this file to discover all available pages before exploring further. # Place an order > Submits a limit or market order. Requires TRADE permission. ## OpenAPI ````yaml /api-reference/derivatives-predictions-api/rest-api/cpm-spec.json post /api/orders openapi: 3.0.3 info: title: CPM Public REST API version: 0.1.0 servers: - url: https://api.example.com variables: {} security: - auth_api_key: [] - auth_timestamp: [] - auth_passphrase: [] - auth_signature: [] paths: /api/orders: post: tags: - Orders summary: Place an order description: Submits a limit or market order. Requires TRADE permission. operationId: placeOrder parameters: [] requestBody: content: application/json: schema: $ref: '#/components/schemas/PlaceOrderRequest' required: false responses: '200': description: Order accepted. A 200 is returned only for accepted orders. content: application/json: schema: $ref: '#/components/schemas/PlaceOrderResponse' '400': description: Order rejected. The error field carries the reject reason. content: application/json: schema: $ref: '#/components/schemas/OrderErrorResponse' deprecated: false security: [] components: schemas: PlaceOrderRequest: type: object additionalProperties: false properties: instrument_id: type: string description: >- Id of the instrument to trade, as a canonical decimal string. Tickers and JSON numbers are rejected. example: '598471892347' firm_id: type: string nullable: true description: >- Id of the firm the order is for, as a canonical decimal string. Required for FCM-level API keys, and must be a firm under your FCM. A FIRM-level key may omit it or send its own firm id. example: '298471892342' side: type: string description: >- Order side. BUY and SELL trade the YES contract. BUY_NO and SELL_NO trade the NO side and are booked as SELL or BUY of YES at one minus the price. BUY_NO and SELL_NO are REST only: FIX order entry accepts only Buy and Sell, so FIX clients convert NO orders themselves (BUY_NO at price P is SELL at 1 minus P). example: BUY price: type: string nullable: true description: >- Limit price per contract in USDC, as a decimal string strictly between 0 and 1 that aligns to the instrument's tick size. Omit or send null for a market order. For BUY_NO and SELL_NO it is the NO price and is required. example: '0.590' quantity: type: string description: Number of contracts to trade, as a positive decimal string. example: '25.00' time_in_force: type: string description: >- How long the order stays active: GTC rests until filled or canceled, IOC fills what it can immediately and cancels the rest, FOK fills completely at once or is rejected. Market orders run as IOC unless you send FOK. example: GTC client_order_id: type: string description: >- Your identifier for the order: at most 18 printable ASCII characters, or a 36-character lowercase UUID. Must be unique among your active orders. example: ord-100 sub_account: type: string description: >- Sub-account the order and any resulting position belong to, in the same format as client_order_id. A new sub-account is created on first use. example: fund-a post_only: type: boolean nullable: true description: >- If true, the order only adds liquidity. An order that would cross the book rests at the best non-crossing price instead, unless post_only_reject is true. Not allowed on market orders. example: false post_only_reject: type: boolean nullable: true description: >- If true, the order only adds liquidity and is rejected with POST_ONLY_WOULD_CROSS if it would cross the book. Not allowed on market orders. example: false self_match_prevention_id: type: integer format: int32 nullable: true description: >- Optional positive self-match prevention id. An incoming order does not match a resting order that carries the same id; self_match_prevention_mode decides which order is canceled. example: 7 self_match_prevention_mode: type: string nullable: true description: >- Which order to cancel when self-match prevention triggers: CANCEL_AGGRESSING, CANCEL_RESTING, or CANCEL_BOTH. When omitted, your user or firm default applies. example: CANCEL_RESTING PlaceOrderResponse: type: object additionalProperties: false properties: order_id: type: string description: Exchange-assigned order id, as a canonical decimal string. example: '698471892348' status: type: string description: >- Order state when the response was sent: SUBMITTED (resting with no fills), PARTIALLY_FILLED, FILLED, or CANCELED (nothing filled and the order was canceled, as with an unfilled IOC order). example: PARTIALLY_FILLED instrument_id: type: string description: Instrument id, as a canonical decimal string. example: '598471892347' ticker: type: string description: Instrument ticker. example: NFL-GAMEWINNER-26NOV28LARSF-LAR side: type: string description: >- Side as booked: BUY or SELL of the YES contract. BUY_NO and SELL_NO orders appear here as SELL and BUY. example: BUY original_side: type: string description: Side as you submitted it, including BUY_NO or SELL_NO. example: BUY price: type: string nullable: true description: >- Limit price of the YES order as booked, in USDC, as a decimal string. For BUY_NO and SELL_NO it is one minus the price you sent. Null for a market order. example: '0.590000' quantity: type: string description: Order quantity in contracts, as a decimal string. example: '25.00' filled_quantity: type: string description: >- Quantity filled by the time of the response, in contracts, as a decimal string. example: '10.00' remaining_quantity: type: string description: >- Quantity not filled by the time of the response, in contracts, as a decimal string. example: '15.00' time_in_force: type: string description: Time in force you submitted. example: GTC client_order_id: type: string description: Echo of the client order id from the request. example: ord-100 sub_account: type: string description: Echo of the sub-account from the request. example: fund-a fills: type: array items: $ref: '#/components/schemas/FillResponse' nullable: true description: >- Fills that executed before the response was sent, or null if there were none. reject_reason: type: string nullable: true description: >- Always null. A rejected order returns an error response instead of this object. OrderErrorResponse: type: object additionalProperties: false properties: error: type: string description: >- Machine-readable error code, for example INVALID_FIELD, INSUFFICIENT_BALANCE, or UNAUTHORIZED. example: INVALID_FIELD message: type: string description: Human-readable description of the error. example: 'side must be one of: BUY, SELL, BUY_NO, SELL_NO' FillResponse: type: object additionalProperties: false properties: trade_id: type: string description: Trade id, as a canonical decimal string. example: '798471892349' price: type: string description: Trade price per YES contract in USDC, as a decimal string. example: '0.590000' quantity: type: string description: Filled quantity in contracts, as a decimal string. example: '10.00' fee: type: string description: >- Your fee for this fill in USDC, as a decimal string. A negative value is a rebate. example: '0.170000' role: type: string description: TAKER if your order took liquidity, MAKER if it was resting. example: TAKER securitySchemes: auth_api_key: name: CB-ACCESS-KEY description: The API key string for the request in: header type: apiKey auth_timestamp: name: CB-ACCESS-TIMESTAMP description: The request timestamp (epoch seconds) in: header type: apiKey auth_passphrase: name: CB-ACCESS-PASSPHRASE description: The passphrase for the API key in: header type: apiKey auth_signature: name: CB-ACCESS-SIGN description: HMAC SHA-256 signature over TIMESTAMP + METHOD + REQUEST_PATH + BODY in: header type: apiKey ````