> ## Documentation Index > Fetch the complete documentation index at: https://docs.matambaintelligence.com/llms.txt > Use this file to discover all available pages before exploring further. # Estimate an order > Returns the broker's estimate of an order's total: for a buy, what it would cost, and for a sell, what you'd receive. The estimate is indicative. Send the same body you'd use to place the order. This doesn't place or store an order, and you don't need an `Idempotency-Key`. ## OpenAPI ````yaml /openapi.json post /v1/orders/estimate openapi: 3.1.0 info: title: Matamba Gateway version: '1' description: >- Open brokerage accounts for your customers, fund them from your wallet, place and track orders, and read each account's records at the broker. All amounts are integers in kobo, and every error includes a `code` you can use in your logic. servers: - url: https://{host} description: The sandbox and live environments each have their own host and API keys. variables: host: default: sandbox-host.invalid description: We send you the host along with your API keys. security: - bearer: [] tags: - name: Accounts description: The accounts you can trade for, and the broker's records for each one. - name: Orders description: >- Estimate, place, retrieve and cancel orders. We store each order before we send it to the exchange, and we send it only once. - name: Events description: >- Each change to your orders creates an event. We send the same event bodies to your webhook endpoint. See [Webhooks](/webhooks) for how to verify them. - name: Applications description: Open a brokerage account for your customer. - name: Reference description: Code lists from the broker that you use in account applications. - name: Wallet description: >- Your wallet, and the allocations you make from it to your customers' accounts. paths: /v1/orders/estimate: post: tags: - Orders summary: Estimate an order description: >- Returns the broker's estimate of an order's total: for a buy, what it would cost, and for a sell, what you'd receive. The estimate is indicative. Send the same body you'd use to place the order. This doesn't place or store an order, and you don't need an `Idempotency-Key`. operationId: estimateOrder requestBody: $ref: '#/components/requestBodies/Order' responses: '200': $ref: '#/components/responses/OrderEstimate' '400': $ref: '#/components/responses/Error' description: '`invalid_request`, `missing_required_field`, `unknown_account`' '401': $ref: '#/components/responses/Error' description: '`unauthorized`' '413': $ref: '#/components/responses/Error' description: '`request_too_large`' '415': $ref: '#/components/responses/Error' description: '`unsupported_media_type`' '422': $ref: '#/components/responses/Error' description: >- `order_rejected`: the exchange would reject this order, and `reject_reason` says why. No order is created. '429': $ref: '#/components/responses/Error' description: '`rate_limited`' '500': $ref: '#/components/responses/Error' description: '`internal_error`' '503': $ref: '#/components/responses/Error' description: '`exchange_unavailable`: retry shortly. `service_unavailable`' components: requestBodies: Order: required: true content: application/json: schema: $ref: '#/components/schemas/OrderRequest' examples: limit: summary: Limit buy of an ETF (limit orders are for ETFs only) value: account: '1000000001' symbol: STANBICETF30 side: buy quantity: 100 type: limit time_in_force: day price_kobo: 12050 market: summary: Market sell value: account: '1000000001' symbol: MTNN side: sell quantity: 50 type: market time_in_force: day responses: OrderEstimate: description: The estimate. headers: x-request-id: $ref: '#/components/headers/RequestId' Cache-Control: $ref: '#/components/headers/CacheControl' content: application/json: schema: $ref: '#/components/schemas/OrderEstimate' examples: buy: summary: >- A market buy: 10 x 52250 at the upper limit, plus 1.5% in the sandbox value: object: order_estimate account: '1000000001' symbol: DANGCEM side: buy quantity: 10 type: market time_in_force: day price_kobo: null estimated_total_kobo: 530338 sell: summary: >- A market sell: 50 x 22500 at the lower limit, less 1.5% in the sandbox value: object: order_estimate account: '1000000001' symbol: MTNN side: sell quantity: 50 type: market time_in_force: day price_kobo: null estimated_total_kobo: 1108125 Error: description: >- An error. Use `error.code` in your logic. A path that doesn't exist returns 404 `not_found`, and a method the path doesn't support returns 405 `method_not_allowed` with an `Allow` header. headers: x-request-id: $ref: '#/components/headers/RequestId' Cache-Control: $ref: '#/components/headers/CacheControl' Retry-After: $ref: '#/components/headers/RetryAfter' WWW-Authenticate: $ref: '#/components/headers/WWWAuthenticate' Allow: $ref: '#/components/headers/Allow' content: application/json: schema: $ref: '#/components/schemas/Error' schemas: OrderRequest: type: object description: >- Send numbers as JSON numbers, not quoted strings. We reject unknown fields and any field that appears twice, even with different letter case. required: - account - symbol - side - quantity - type - time_in_force additionalProperties: false properties: account: $ref: '#/components/schemas/AccountCode' symbol: type: string pattern: ^[A-Za-z0-9.-]{1,20}$ description: >- The exchange's symbol, treated as uppercase. The exchange decides whether the symbol exists. side: type: string enum: - buy - sell quantity: type: integer format: int64 minimum: 1 maximum: 100000000 description: The number of shares, as a whole number. type: type: string enum: - limit - market description: >- Limit orders are for ETFs only. Use a market order for any other security. The broker rejects a limit order on any other security with `reject_reason` set to `limit_orders_etf_only`. A market order is priced at the day's price limit: the upper limit for a buy, the lower limit for a sell. time_in_force: type: string enum: - day - gtc - ioc - fok description: >- `day`: good for the current trading session only. `gtc`: good till cancelled. `ioc`: immediate or cancel. `fok`: fill or kill. We accept every `type` with every `time_in_force`. The broker decides which combinations it supports, and rejects the rest as `order_rejected` with a `reject_reason`. price_kobo: type: integer format: int64 minimum: 1 maximum: 1000000000 description: >- The limit price in kobo, so ₦475.00 is 47500. Required for a limit order. Omit it for a market order. OrderEstimate: type: object required: - object - account - symbol - side - quantity - type - time_in_force - price_kobo - estimated_total_kobo properties: object: type: string const: order_estimate account: type: string symbol: type: string side: type: string enum: - buy - sell quantity: type: integer format: int64 type: type: string enum: - limit - market time_in_force: type: string enum: - day - gtc - ioc - fok price_kobo: type: - integer - 'null' format: int64 description: The limit price in kobo. Null for a market order. estimated_total_kobo: type: integer format: int64 description: >- The broker's estimate of the order's total. For a buy, what the order would cost. For a sell, what you'd receive. In the sandbox, a buy includes 1.5% charges and a sell is net of them. The estimate is indicative, not a quote. Error: type: object required: - error properties: error: type: object required: - type - code - message - doc_url properties: type: type: string description: The category of the error. enum: - authentication_error - invalid_request_error - idempotency_error - order_error - application_error - wallet_error - limit_error - rate_limit_error - api_error code: type: string description: The error code. Use it in your logic; it doesn't change. enum: - unauthorized - not_found - method_not_allowed - unsupported_media_type - request_too_large - invalid_request - missing_required_field - unknown_account - duplicate_order - order_not_found - exchange_unavailable - order_not_sent - order_rejected - similar_order_unresolved - order_not_cancelable - cancel_unconfirmed - settlement_lockout - account_not_at_broker - exchange_error - application_rejected - duplicate_application - application_not_found - application_not_sent - wallet_too_low - allocation_rejected - duplicate_allocation - allocation_not_found - allocation_not_sent - rate_limited - unknown_symbol - limit_exceeded - service_unavailable - internal_error message: type: string description: >- A human-readable description of the error, for your logs. The wording can change. param: type: string description: >- The field, parameter or header that caused the error. Absent when the error isn't tied to a single field. reject_reason: type: string description: >- Why the exchange or broker rejected the request. Included with `order_rejected`, `application_rejected` and `allocation_rejected`, and takes the same values as the `reject_reason` field on the order, application or allocation. doc_url: type: string format: uri description: A link to the documentation for this error code. AccountCode: type: string pattern: ^[A-Za-z0-9]{1,64}$ description: An account code. Case-insensitive on input, and returned in uppercase. headers: RequestId: description: A unique identifier for this request. Include it when you contact us. schema: type: string CacheControl: description: Always `no-store`. schema: type: string const: no-store RetryAfter: description: >- The number of seconds to wait before you retry. Sent with 429 (`1`) and with 503 `settlement_lockout` (`60`). schema: type: integer WWWAuthenticate: description: 'Sent with 401: `Bearer realm="Matamba Gateway"`.' schema: type: string Allow: description: Sent with 405. Lists the methods the path supports. schema: type: string securitySchemes: bearer: type: http scheme: bearer description: >- `Authorization: Bearer `. Sandbox keys start with `mgw_test_` and live keys start with `mgw_live_`. Each key works only in its own environment, and a live key works only from the IP addresses or ranges registered for it. ````