curl --request POST \
  --url https://nexus.gerowallet.io/api/tx/build/delegation \
  --header 'Content-Type: application/json' \
  --header 'X-Api-Key: <api-key>' \
  --data '
{
  "stakeAddress": "<string>",
  "poolId": "<string>",
  "changeAddress": "<string>",
  "utxos": [
    {
      "txHash": "<string>",
      "address": "<string>",
      "lovelace": "<string>",
      "outputIndex": 1,
      "assets": [
        {
          "policyId": "<string>",
          "assetName": "<string>",
          "quantity": "<string>"
        }
      ],
      "dataHash": "<string>",
      "inlineDatum": "<string>",
      "referenceScriptHash": "<string>"
    }
  ],
  "senderAddress": "<string>",
  "includeStakeRegistration": true,
  "ttl": 123
}
'

import requests

url = "https://nexus.gerowallet.io/api/tx/build/delegation"

payload = {
    "stakeAddress": "<string>",
    "poolId": "<string>",
    "changeAddress": "<string>",
    "utxos": [
        {
            "txHash": "<string>",
            "address": "<string>",
            "lovelace": "<string>",
            "outputIndex": 1,
            "assets": [
                {
                    "policyId": "<string>",
                    "assetName": "<string>",
                    "quantity": "<string>"
                }
            ],
            "dataHash": "<string>",
            "inlineDatum": "<string>",
            "referenceScriptHash": "<string>"
        }
    ],
    "senderAddress": "<string>",
    "includeStakeRegistration": True,
    "ttl": 123
}
headers = {
    "X-Api-Key": "<api-key>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {'X-Api-Key': '<api-key>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    stakeAddress: '<string>',
    poolId: '<string>',
    changeAddress: '<string>',
    utxos: [
      {
        txHash: '<string>',
        address: '<string>',
        lovelace: '<string>',
        outputIndex: 1,
        assets: [{policyId: '<string>', assetName: '<string>', quantity: '<string>'}],
        dataHash: '<string>',
        inlineDatum: '<string>',
        referenceScriptHash: '<string>'
      }
    ],
    senderAddress: '<string>',
    includeStakeRegistration: true,
    ttl: 123
  })
};

fetch('https://nexus.gerowallet.io/api/tx/build/delegation', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://nexus.gerowallet.io/api/tx/build/delegation",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'stakeAddress' => '<string>',
    'poolId' => '<string>',
    'changeAddress' => '<string>',
    'utxos' => [
        [
                'txHash' => '<string>',
                'address' => '<string>',
                'lovelace' => '<string>',
                'outputIndex' => 1,
                'assets' => [
                                [
                                                                'policyId' => '<string>',
                                                                'assetName' => '<string>',
                                                                'quantity' => '<string>'
                                ]
                ],
                'dataHash' => '<string>',
                'inlineDatum' => '<string>',
                'referenceScriptHash' => '<string>'
        ]
    ],
    'senderAddress' => '<string>',
    'includeStakeRegistration' => true,
    'ttl' => 123
  ]),
  CURLOPT_HTTPHEADER => [
    "Content-Type: application/json",
    "X-Api-Key: <api-key>"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://nexus.gerowallet.io/api/tx/build/delegation"

	payload := strings.NewReader("{\n  \"stakeAddress\": \"<string>\",\n  \"poolId\": \"<string>\",\n  \"changeAddress\": \"<string>\",\n  \"utxos\": [\n    {\n      \"txHash\": \"<string>\",\n      \"address\": \"<string>\",\n      \"lovelace\": \"<string>\",\n      \"outputIndex\": 1,\n      \"assets\": [\n        {\n          \"policyId\": \"<string>\",\n          \"assetName\": \"<string>\",\n          \"quantity\": \"<string>\"\n        }\n      ],\n      \"dataHash\": \"<string>\",\n      \"inlineDatum\": \"<string>\",\n      \"referenceScriptHash\": \"<string>\"\n    }\n  ],\n  \"senderAddress\": \"<string>\",\n  \"includeStakeRegistration\": true,\n  \"ttl\": 123\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("X-Api-Key", "<api-key>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://nexus.gerowallet.io/api/tx/build/delegation")
  .header("X-Api-Key", "<api-key>")
  .header("Content-Type", "application/json")
  .body("{\n  \"stakeAddress\": \"<string>\",\n  \"poolId\": \"<string>\",\n  \"changeAddress\": \"<string>\",\n  \"utxos\": [\n    {\n      \"txHash\": \"<string>\",\n      \"address\": \"<string>\",\n      \"lovelace\": \"<string>\",\n      \"outputIndex\": 1,\n      \"assets\": [\n        {\n          \"policyId\": \"<string>\",\n          \"assetName\": \"<string>\",\n          \"quantity\": \"<string>\"\n        }\n      ],\n      \"dataHash\": \"<string>\",\n      \"inlineDatum\": \"<string>\",\n      \"referenceScriptHash\": \"<string>\"\n    }\n  ],\n  \"senderAddress\": \"<string>\",\n  \"includeStakeRegistration\": true,\n  \"ttl\": 123\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://nexus.gerowallet.io/api/tx/build/delegation")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["X-Api-Key"] = '<api-key>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"stakeAddress\": \"<string>\",\n  \"poolId\": \"<string>\",\n  \"changeAddress\": \"<string>\",\n  \"utxos\": [\n    {\n      \"txHash\": \"<string>\",\n      \"address\": \"<string>\",\n      \"lovelace\": \"<string>\",\n      \"outputIndex\": 1,\n      \"assets\": [\n        {\n          \"policyId\": \"<string>\",\n          \"assetName\": \"<string>\",\n          \"quantity\": \"<string>\"\n        }\n      ],\n      \"dataHash\": \"<string>\",\n      \"inlineDatum\": \"<string>\",\n      \"referenceScriptHash\": \"<string>\"\n    }\n  ],\n  \"senderAddress\": \"<string>\",\n  \"includeStakeRegistration\": true,\n  \"ttl\": 123\n}"

response = http.request(request)
puts response.read_body

""

{
  "error": "Invalid pool ID"
}

{
  "error": "Internal server error"
}