# Build order transaction Build a new order transaction. This endpoint creates an unsigned transaction that must be signed and submitted via the [Submit Order Transaction](/start-trading/developers/api-documentation/order/submit-order-transaction.md) endpoint. *** ## Build place order transaction > Build place order transaction ```json {"openapi":"3.1.1","info":{"title":"Espresso API Server","version":"1.0"},"paths":{"/orders/build":{"post":{"description":"Build place order transaction","tags":["order"],"summary":"Build place order transaction","responses":{"200":{"description":"OK","content":{"application/json":{"schema":{"$ref":"#/components/schemas/espresso_internal_api_response.BuildPlaceOrderTransactionResponse"}}}},"400":{"description":"Bad Request","content":{"application/json":{"schema":{"$ref":"#/components/schemas/espresso_internal_api_response.ErrorJSONWithCodeResponse"}}}},"406":{"description":"Not Acceptable","content":{"application/json":{"schema":{"$ref":"#/components/schemas/espresso_internal_api_response.ErrorJSONWithCodeResponse"}}}},"422":{"description":"Unprocessable Entity","content":{"application/json":{"schema":{"$ref":"#/components/schemas/espresso_internal_api_response.ErrorJSONWithCodeResponse"}}}},"500":{"description":"Internal Server Error","content":{"application/json":{"schema":{"$ref":"#/components/schemas/espresso_internal_api_response.ErrorJSONWithCodeResponse"}}}}},"requestBody":{"content":{"application/json":{"schema":{"$ref":"#/components/schemas/espresso_internal_api_requests.BuildPlaceOrderTransactionRequest"}}},"description":"Build place order transaction request","required":true}}}},"components":{"schemas":{"espresso_internal_api_response.BuildPlaceOrderTransactionResponse":{"type":"object","properties":{"order_id":{"type":"string"},"tx_hex":{"type":"string"}}},"espresso_internal_api_response.ErrorJSONWithCodeResponse":{"type":"object","properties":{"code":{"type":"integer"},"error":{"type":"string"}}},"espresso_internal_api_requests.BuildPlaceOrderTransactionRequest":{"type":"object","required":["side","symbol","type"],"properties":{"base_quantity":{"type":"string"},"max_slippage_basis_point":{"type":"string"},"post_only":{"description":"LimitSlippage bool `json:\"limit_slippage\"`","type":"boolean"},"price":{"type":"string"},"quote_quantity":{"description":"Quantity float64 `json:\"quantity\" binding:\"required\"`","type":"string"},"side":{"$ref":"#/components/schemas/schema.OrderSide"},"symbol":{"type":"string"},"type":{"$ref":"#/components/schemas/schema.OrderType"}}},"schema.OrderSide":{"type":"string","enum":["buy","sell"]},"schema.OrderType":{"type":"string","enum":["market","limit"]}}}} ``` ## Request Parameters | Parameter | Type | Required | Description | | --------------------------- | ------- | ----------- | --------------------------------------------------------------------------------------------------- | | symbol | string | Yes | Trading pair symbol (e.g., `ADAUSDM`) | | side | string | Yes | Order side: `buy` or `sell` | | type | string | Yes | Order type: `limit` or `market` | | base\_quantity | string | Conditional | Quantity in base asset (e.g., ADA). **Use either `base_quantity` OR `quote_quantity`, not both.** | | quote\_quantity | string | Conditional | Quantity in quote asset (e.g., USDM). **Use either `base_quantity` OR `quote_quantity`, not both.** | | price | string | Conditional | Order price. **Required for limit orders, ignored for market orders.** | | max\_slippage\_basis\_point | string | No | Maximum slippage in basis points. **Only applicable for market orders.** | | post\_only | boolean | No | If `true`, order only posts if it doesn't match immediately. **Only applicable for limit orders.** | *** ## Order Types ### Limit Order A limit order is placed at a specific price. It will only execute at that price or better. **Required parameters:** * `symbol`, `side`, `type` (set to `limit`) * `price` - The limit price * Either `base_quantity` or `quote_quantity` **Optional parameters:** * `post_only` - Set to `true` to ensure the order only acts as a maker (adds liquidity). If it would match immediately, the order is rejected. ### Market Order A market order executes immediately at the best available price. No price is specified. **Required parameters:** * `symbol`, `side`, `type` (set to `market`) * Either `base_quantity` or `quote_quantity` **Optional parameters:** * `max_slippage_basis_point` - Maximum acceptable slippage (1 basis point = 0.01%). If not set, unlimited slippage is allowed. {% hint style="warning" %} **Market Order Slippage:** If `max_slippage_basis_point` is not set, the market order will fill at any price until the order is complete or your balance is exhausted. Set a slippage limit to protect against unfavorable fills. {% endhint %} *** ## Quantity Specification You must specify **either** `base_quantity` **or** `quote_quantity`, but **not both**. | Field | Description | Example | | --------------- | ---------------------------------- | ----------------- | | base\_quantity | Amount of base asset (e.g., ADA) | `"100"` = 100 ADA | | quote\_quantity | Amount of quote asset (e.g., USDM) | `"93"` = 93 USDM | **Example for ADAUSDM pair:** * Buy 100 ADA: `{"base_quantity": "100", "side": "buy", ...}` * Buy $93 worth of ADA: `{"quote_quantity": "93", "side": "buy", ...}` *** ## Code Examples ### Limit Order Example {% tabs %} {% tab title="Curl" %} ```sh curl --location 'https://api.deltadefi.io/order/build' \ --header 'X-API-KEY: ' \ --header 'Content-Type: application/json' \ --data '{ "symbol": "ADAUSDM", "side": "buy", "type": "limit", "base_quantity": "100", "price": "0.93" }' ``` {% endtab %} {% tab title="NodeJs (axios)" %} ```javascript const axios = require('axios'); let data = JSON.stringify({ "symbol": "ADAUSDM", "side": "buy", "type": "limit", "base_quantity": "100", "price": "0.93" }); let config = { method: 'post', maxBodyLength: Infinity, url: 'https://api.deltadefi.io/order/build', headers: { 'X-API-KEY': '', 'Content-Type': 'application/json' }, data: data }; axios.request(config) .then((response) => { console.log(JSON.stringify(response.data)); }) .catch((error) => { console.log(error); }); ``` {% endtab %} {% tab title="Go" %} ```go package main import ( "fmt" "strings" "net/http" "io" ) func main() { url := "https://api.deltadefi.io/order/build" method := "POST" payload := strings.NewReader(`{ "symbol": "ADAUSDM", "side": "buy", "type": "limit", "base_quantity": "100", "price": "0.93" }`) client := &http.Client{} req, err := http.NewRequest(method, url, payload) if err != nil { fmt.Println(err) return } req.Header.Add("X-API-KEY", "") req.Header.Add("Content-Type", "application/json") res, err := client.Do(req) if err != nil { fmt.Println(err) return } defer res.Body.Close() body, err := io.ReadAll(res.Body) if err != nil { fmt.Println(err) return } fmt.Println(string(body)) } ``` {% endtab %} {% endtabs %} ### Market Order Example {% tabs %} {% tab title="Curl" %} ```sh curl --location 'https://api.deltadefi.io/order/build' \ --header 'X-API-KEY: ' \ --header 'Content-Type: application/json' \ --data '{ "symbol": "ADAUSDM", "side": "buy", "type": "market", "base_quantity": "100", "max_slippage_basis_point": "100" }' ``` {% endtab %} {% tab title="NodeJs (axios)" %} ```javascript const axios = require('axios'); let data = JSON.stringify({ "symbol": "ADAUSDM", "side": "buy", "type": "market", "base_quantity": "100", "max_slippage_basis_point": "100" // 1% max slippage }); let config = { method: 'post', maxBodyLength: Infinity, url: 'https://api.deltadefi.io/order/build', headers: { 'X-API-KEY': '', 'Content-Type': 'application/json' }, data: data }; axios.request(config) .then((response) => { console.log(JSON.stringify(response.data)); }) .catch((error) => { console.log(error); }); ``` {% endtab %} {% tab title="Go" %} ```go package main import ( "fmt" "strings" "net/http" "io" ) func main() { url := "https://api.deltadefi.io/order/build" method := "POST" payload := strings.NewReader(`{ "symbol": "ADAUSDM", "side": "buy", "type": "market", "base_quantity": "100", "max_slippage_basis_point": "100" }`) client := &http.Client{} req, err := http.NewRequest(method, url, payload) if err != nil { fmt.Println(err) return } req.Header.Add("X-API-KEY", "") req.Header.Add("Content-Type", "application/json") res, err := client.Do(req) if err != nil { fmt.Println(err) return } defer res.Body.Close() body, err := io.ReadAll(res.Body) if err != nil { fmt.Println(err) return } fmt.Println(string(body)) } ``` {% endtab %} {% endtabs %} ### Post-Only Limit Order Example {% tabs %} {% tab title="Curl" %} ```sh curl --location 'https://api.deltadefi.io/order/build' \ --header 'X-API-KEY: ' \ --header 'Content-Type: application/json' \ --data '{ "symbol": "ADAUSDM", "side": "buy", "type": "limit", "base_quantity": "100", "price": "0.90", "post_only": true }' ``` {% endtab %} {% endtabs %} *** ## Response ```json { "order_id": "550e8400-e29b-41d4-a716-446655440000", "tx_hex": "84a400818258203b40265111d8bb3c3c608d95b3a0bf83461ace32d79336579a1939b3aad1c0b700018182583900..." } ``` | Field | Type | Description | | --------- | ------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------- | | order\_id | string | Unique order identifier. Use this when submitting the signed transaction. | | tx\_hex | string | Unsigned transaction hex. Sign this and submit via [Submit Order Transaction](/start-trading/developers/api-documentation/order/submit-order-transaction.md). | *** ## Next Steps After building the order: 1. **Sign the transaction** using your wallet - see [How to sign a Cardano transaction](/faq/cardano.md#how-can-i-sign-a-cardano-transaction) 2. **Submit the signed transaction** via [Submit Order Transaction](/start-trading/developers/api-documentation/order/submit-order-transaction.md) *** ## Error Codes | Code | Error | Description | | ---- | ------------------------------- | -------------------------------------------------- | | 4050 | Insufficient balance | Not enough free balance to place the order | | 4100 | Order size too small | Order must be at least 5 ADA equivalent | | 4101 | Invalid order price | Price must be greater than 0 | | 4102 | Invalid price decimal places | Price has too many decimal places | | 4103 | Invalid quantity decimal places | Quantity has too many decimal places | | 4104 | Post-only would match | Post-only order would match immediately (rejected) | | 4106 | Invalid symbol | Trading pair not found | | 4109 | Insufficient liquidity | Not enough liquidity for market order | | 4110 | Max open orders exceeded | Too many open orders | *** ## Related * [Submit Order Transaction](/start-trading/developers/api-documentation/order/submit-order-transaction.md) * [Cancel Order](/start-trading/developers/api-documentation/order/build-cancel-order-transaction.md) * [Order Records](/start-trading/developers/api-documentation/account/order-records.md) * [Order Types](/about/learn/trade/order-types.md) --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.deltadefi.io/start-trading/developers/api-documentation/order/build-order-transaction.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.