> For the complete documentation index, see [llms.txt](https://docs.deltadefi.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.deltadefi.io/start-trading/developers/api-documentation/order/build-order-transaction.md). # 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)