> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.paradex.trade/api/testnet/subkey/register-subkey/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.paradex.trade/_mcp/server.

# Register Subkey

POST https://api.testnet.paradex.trade/v1/account/subkeys
Content-Type: application/json

Register a new subkey for the authenticated account.


Reference: https://docs.paradex.trade/api/prod/subkey/register-subkey

## Authentication

- `Authorization` header (required) — API Key authentication via header

## Request

### Body (application/json)

This endpoint expects a requests.CreateSubkey.

- `name` (string, optional) — User-friendly name for the subkey.
- `public_key` (string, optional) — Public key to be registered as a subkey.

## Response

### 201

An empty response

## Errors

### 400 Bad Request Error

Bad Request

- `data` (ResponsesApiErrorData, optional) — any additional data related to the error
- `error` (enum, optional) — unique immutable string identifier for specific error
  - Allowed values: `VALIDATION_ERROR`, `BINDING_ERROR`, `INTERNAL_ERROR`, `NOT_FOUND`, `SERVICE_UNAVAILABLE`, `INVALID_REQUEST_PARAMETER`, `ORDER_ID_NOT_FOUND`, `ORDER_IS_CLOSED`, `ORDER_IS_NOT_OPEN`, `INVALID_ORDER_SIZE`, `CLIENT_ORDER_ID_NOT_FOUND`, `DUPLICATED_CLIENT_ID`, `INVALID_PRICE_PRECISION`, `INVALID_SYMBOL`, `INVALID_TOKEN`, `INVALID_ETHEREUM_ADDRESS`, `INVALID_ETHEREUM_SIGNATURE`, `INVALID_STARKNET_ADDRESS`, `INVALID_STARKNET_SIGNATURE`, `STARKNET_SIGNATURE_VERIFICATION_FAILED`, `BAD_STARKNET_REQUEST`, `ETHEREUM_SIGNER_MISMATCH`, `ETHEREUM_HASH_MISMATCH`, `NOT_ONBOARDED`, `INVALID_TIMESTAMP`, `INVALID_BLOCK_EXPIRATION`, `ACCOUNT_NOT_FOUND`, `INVALID_ORDER_SIGNATURE`, `PUBLIC_KEY_INVALID`, `UNAUTHORIZED_ETHEREUM_ADDRESS`, `UNAUTHORIZED_ERROR`, `ETHEREUM_ADDRESS_ALREADY_ONBOARDED`, `MARKET_NOT_FOUND`, `ALLOWLIST_ENTRY_NOT_FOUND`, `USERNAME_IN_USE`, `GEO_IP_BLOCK`, `ETHEREUM_ADDRESS_BLOCKED`, `PROGRAM_NOT_FOUND`, `PROGRAM_NOT_SUPPORTED`, `INVALID_DASHBOARD`, `MARKET_NOT_OPEN`, `INVALID_REFERRAL_CODE`, `REQUEST_NOT_ALLOWED`, `PARENT_ADDRESS_ALREADY_ONBOARDED`, `INVALID_PARENT_ACCOUNT`, `INVALID_VAULT_OPERATOR_CHAIN`, `VAULT_OPERATOR_ALREADY_ONBOARDED`, `VAULT_NAME_IN_USE`, `VAULT_NOT_FOUND`, `VAULT_STRATEGY_NOT_FOUND`, `VAULT_LIMIT_REACHED`, `BATCH_SIZE_OUT_OF_RANGE`, `ISOLATED_MARKET_ACCOUNT_MISMATCH`, `NO_ACCESS_TO_MARKET`, `POINTS_SUMMARY_NOT_FOUND`, `ALGO_ID_NOT_FOUND`, `INVALID_DERIVATION_PATH`, `PROFILE_STATS_NOT_FOUND`, `INVALID_CHAIN`, `INVALID_LAYERSWAP_SWAP`, `INVALID_RHINOFI_REQUEST`, `INVALID_RHINOFI_QUOTE`, `INVALID_RHINOFI_QUOTE_COMMIT`, `SOCIAL_USERNAME_IN_USE`, `INVALID_OAUTH_REQUEST`, `RPI_ACCOUNT_NOT_WHITELISTED`, `SYSTEM_STATUS_POST_ONLY`, `SYSTEM_STATUS_CANCEL_ONLY`, `INVALID_MARKETING_CODE`, `INVALID_JOIN_WAITLIST_REQUEST`, `TRANSACTION_NOT_FOUND`, `OFFER_NOT_FOUND`, `MARKET_MARGIN_RESTRICTED`, `NOT_UNIQUE`, `ACCOUNT_ALREADY_REFERRED`, `ONBOARDING_PERIOD_EXPIRED`, `ONBOARDING_RATE_LIMITED`, `SUBACCOUNTS_LIMIT_EXCEEDED`, `INSUFFICIENT_MIN_CHAIN_BALANCE`, `INVALID_SUBKEY`, `TOKEN_LIMIT_REACHED`, `INVALID_TOKEN_SCOPE`, `INSUFFICIENT_TRANSFERRABLE_XP`, `TRANSFER_LIMIT_REACHED`
- `message` (string, optional) — detailed description of error and how to address it

### 401 Unauthorized Error

Unauthorized

- `data` (ResponsesApiErrorData, optional) — any additional data related to the error
- `error` (enum, optional) — unique immutable string identifier for specific error
  - Allowed values: `VALIDATION_ERROR`, `BINDING_ERROR`, `INTERNAL_ERROR`, `NOT_FOUND`, `SERVICE_UNAVAILABLE`, `INVALID_REQUEST_PARAMETER`, `ORDER_ID_NOT_FOUND`, `ORDER_IS_CLOSED`, `ORDER_IS_NOT_OPEN`, `INVALID_ORDER_SIZE`, `CLIENT_ORDER_ID_NOT_FOUND`, `DUPLICATED_CLIENT_ID`, `INVALID_PRICE_PRECISION`, `INVALID_SYMBOL`, `INVALID_TOKEN`, `INVALID_ETHEREUM_ADDRESS`, `INVALID_ETHEREUM_SIGNATURE`, `INVALID_STARKNET_ADDRESS`, `INVALID_STARKNET_SIGNATURE`, `STARKNET_SIGNATURE_VERIFICATION_FAILED`, `BAD_STARKNET_REQUEST`, `ETHEREUM_SIGNER_MISMATCH`, `ETHEREUM_HASH_MISMATCH`, `NOT_ONBOARDED`, `INVALID_TIMESTAMP`, `INVALID_BLOCK_EXPIRATION`, `ACCOUNT_NOT_FOUND`, `INVALID_ORDER_SIGNATURE`, `PUBLIC_KEY_INVALID`, `UNAUTHORIZED_ETHEREUM_ADDRESS`, `UNAUTHORIZED_ERROR`, `ETHEREUM_ADDRESS_ALREADY_ONBOARDED`, `MARKET_NOT_FOUND`, `ALLOWLIST_ENTRY_NOT_FOUND`, `USERNAME_IN_USE`, `GEO_IP_BLOCK`, `ETHEREUM_ADDRESS_BLOCKED`, `PROGRAM_NOT_FOUND`, `PROGRAM_NOT_SUPPORTED`, `INVALID_DASHBOARD`, `MARKET_NOT_OPEN`, `INVALID_REFERRAL_CODE`, `REQUEST_NOT_ALLOWED`, `PARENT_ADDRESS_ALREADY_ONBOARDED`, `INVALID_PARENT_ACCOUNT`, `INVALID_VAULT_OPERATOR_CHAIN`, `VAULT_OPERATOR_ALREADY_ONBOARDED`, `VAULT_NAME_IN_USE`, `VAULT_NOT_FOUND`, `VAULT_STRATEGY_NOT_FOUND`, `VAULT_LIMIT_REACHED`, `BATCH_SIZE_OUT_OF_RANGE`, `ISOLATED_MARKET_ACCOUNT_MISMATCH`, `NO_ACCESS_TO_MARKET`, `POINTS_SUMMARY_NOT_FOUND`, `ALGO_ID_NOT_FOUND`, `INVALID_DERIVATION_PATH`, `PROFILE_STATS_NOT_FOUND`, `INVALID_CHAIN`, `INVALID_LAYERSWAP_SWAP`, `INVALID_RHINOFI_REQUEST`, `INVALID_RHINOFI_QUOTE`, `INVALID_RHINOFI_QUOTE_COMMIT`, `SOCIAL_USERNAME_IN_USE`, `INVALID_OAUTH_REQUEST`, `RPI_ACCOUNT_NOT_WHITELISTED`, `SYSTEM_STATUS_POST_ONLY`, `SYSTEM_STATUS_CANCEL_ONLY`, `INVALID_MARKETING_CODE`, `INVALID_JOIN_WAITLIST_REQUEST`, `TRANSACTION_NOT_FOUND`, `OFFER_NOT_FOUND`, `MARKET_MARGIN_RESTRICTED`, `NOT_UNIQUE`, `ACCOUNT_ALREADY_REFERRED`, `ONBOARDING_PERIOD_EXPIRED`, `ONBOARDING_RATE_LIMITED`, `SUBACCOUNTS_LIMIT_EXCEEDED`, `INSUFFICIENT_MIN_CHAIN_BALANCE`, `INVALID_SUBKEY`, `TOKEN_LIMIT_REACHED`, `INVALID_TOKEN_SCOPE`, `INSUFFICIENT_TRANSFERRABLE_XP`, `TRANSFER_LIMIT_REACHED`
- `message` (string, optional) — detailed description of error and how to address it

## Types

### ResponsesApiErrorData

any additional data related to the error

## Examples

**Request**

```json
{}
```

**Response**

```json
{}
```

**SDK Code**

```python
import requests

url = "https://api.testnet.paradex.trade/v1/account/subkeys"

payload = {}
headers = {
    "Authorization": "<apiKey>",
    "Content-Type": "application/json"
}

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

print(response.json())
```

```javascript
const url = 'https://api.testnet.paradex.trade/v1/account/subkeys';
const options = {
  method: 'POST',
  headers: {Authorization: '<apiKey>', 'Content-Type': 'application/json'},
  body: '{}'
};

try {
  const response = await fetch(url, options);
  const data = await response.json();
  console.log(data);
} catch (error) {
  console.error(error);
}
```

```go
package main

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

func main() {

	url := "https://api.testnet.paradex.trade/v1/account/subkeys"

	payload := strings.NewReader("{}")

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

	req.Header.Add("Authorization", "<apiKey>")
	req.Header.Add("Content-Type", "application/json")

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

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

	fmt.Println(res)
	fmt.Println(string(body))

}
```

```ruby
require 'uri'
require 'net/http'

url = URI("https://api.testnet.paradex.trade/v1/account/subkeys")

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

request = Net::HTTP::Post.new(url)
request["Authorization"] = '<apiKey>'
request["Content-Type"] = 'application/json'
request.body = "{}"

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

```java
import com.mashape.unirest.http.HttpResponse;
import com.mashape.unirest.http.Unirest;

HttpResponse<String> response = Unirest.post("https://api.testnet.paradex.trade/v1/account/subkeys")
  .header("Authorization", "<apiKey>")
  .header("Content-Type", "application/json")
  .body("{}")
  .asString();
```

```php
<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('POST', 'https://api.testnet.paradex.trade/v1/account/subkeys', [
  'body' => '{}',
  'headers' => [
    'Authorization' => '<apiKey>',
    'Content-Type' => 'application/json',
  ],
]);

echo $response->getBody();
```

```csharp
using RestSharp;

var client = new RestClient("https://api.testnet.paradex.trade/v1/account/subkeys");
var request = new RestRequest(Method.POST);
request.AddHeader("Authorization", "<apiKey>");
request.AddHeader("Content-Type", "application/json");
request.AddParameter("application/json", "{}", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
```

```swift
import Foundation

let headers = [
  "Authorization": "<apiKey>",
  "Content-Type": "application/json"
]
let parameters = [] as [String : Any]

let postData = JSONSerialization.data(withJSONObject: parameters, options: [])

let request = NSMutableURLRequest(url: NSURL(string: "https://api.testnet.paradex.trade/v1/account/subkeys")! as URL,
                                        cachePolicy: .useProtocolCachePolicy,
                                    timeoutInterval: 10.0)
request.httpMethod = "POST"
request.allHTTPHeaderFields = headers
request.httpBody = postData as Data

let session = URLSession.shared
let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in
  if (error != nil) {
    print(error as Any)
  } else {
    let httpResponse = response as? HTTPURLResponse
    print(httpResponse)
  }
})

dataTask.resume()
```