curl --request POST \
  --url https://api.kraken.com/v0/insto/custody/vaults/{vault_id}/withdrawals/fee-quotes \
  --header 'Content-Type: application/json' \
  --header 'api-key: <api-key>' \
  --header 'api-nonce: <api-key>' \
  --header 'api-sign: <api-key>' \
  --data '
{
  "asset": "BTC",
  "asset_class": "currency",
  "amount": "0.5",
  "fee_included": false,
  "address_name": "My BTC Wallet"
}
'

import requests

url = "https://api.kraken.com/v0/insto/custody/vaults/{vault_id}/withdrawals/fee-quotes"

payload = {
    "asset": "BTC",
    "asset_class": "currency",
    "amount": "0.5",
    "fee_included": False,
    "address_name": "My BTC Wallet"
}
headers = {
    "api-key": "<api-key>",
    "api-sign": "<api-key>",
    "api-nonce": "<api-key>",
    "Content-Type": "application/json"
}

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

print(response.text)

const options = {
  method: 'POST',
  headers: {
    'api-key': '<api-key>',
    'api-sign': '<api-key>',
    'api-nonce': '<api-key>',
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    asset: 'BTC',
    asset_class: 'currency',
    amount: '0.5',
    fee_included: false,
    address_name: 'My BTC Wallet'
  })
};

fetch('https://api.kraken.com/v0/insto/custody/vaults/{vault_id}/withdrawals/fee-quotes', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

package main

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

func main() {

	url := "https://api.kraken.com/v0/insto/custody/vaults/{vault_id}/withdrawals/fee-quotes"

	payload := strings.NewReader("{\n  \"asset\": \"BTC\",\n  \"asset_class\": \"currency\",\n  \"amount\": \"0.5\",\n  \"fee_included\": false,\n  \"address_name\": \"My BTC Wallet\"\n}")

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

	req.Header.Add("api-key", "<api-key>")
	req.Header.Add("api-sign", "<api-key>")
	req.Header.Add("api-nonce", "<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))

}

{
  "fee_quote_id": "QABCDEF234567A",
  "asset": "BTC",
  "asset_class": "currency",
  "fees": [
    {
      "fee_level": "normal",
      "fee_asset": "BTC",
      "fee_asset_class": "currency",
      "fee_amount": "0.0001"
    }
  ]
}

{
  "type": "tag:kraken.com,2025:BadRequest",
  "status": 400,
  "title": "Bad Request",
  "data": {
    "message": "amount must be a positive decimal"
  },
  "detail": "Request failed validation: amount must be positive.",
  "instance": "https://debug.kraken.com/req/01HXYZABCDEF"
}

{
  "type": "tag:kraken.com,2025:PermissionDenied",
  "status": 403,
  "title": "Permission Denied",
  "data": {
    "message": "Caller lacks read access to vault VABCDEF234567A"
  },
  "detail": "The caller does not have access to the requested vault.",
  "instance": "https://debug.kraken.com/req/01HXYZABCDEF"
}

{
  "type": "tag:kraken.com,2025:AssetNotFound",
  "status": 404,
  "title": "Not Found",
  "data": {
    "message": "Asset BTC with class currency is not configured for withdrawal"
  },
  "detail": "Asset not found for the requested asset class.",
  "instance": "https://debug.kraken.com/req/01HXYZABCDEF"
}

{
  "type": "tag:kraken.com,2025:gateway/ReadUpstream",
  "status": 500,
  "title": "Internal Server Error",
  "data": "<unknown>",
  "detail": "Failed to read response from upstream custody service.",
  "instance": "https://debug.kraken.com/req/01HXYZABCDEF"
}

{
  "type": "tag:kraken.com,2025:gateway/Connect",
  "status": 503,
  "title": "Service Unavailable",
  "data": "<unknown>",
  "detail": "Downstream custody service is temporarily unreachable; retry with backoff.",
  "instance": "https://debug.kraken.com/req/01HXYZABCDEF"
}