Error Codes

This section explains all error codes that may be returned by the GMO Coin API.

Overview

Error codes are returned in the response body when an API request fails. Each error code provides specific information about what went wrong.

Error Response Format

{
  "status": 5,
  "messages": [
    {
      "message_code": "ERR-xxxx",
      "message_string": "Error description"
    }
  ],
  "responsetime": "2025-12-25T12:00:00.123Z"
}

Error Code Categories

Trading and Position Errors (ERR-70 to ERR-846)

Error Code	Category	Description
ERR-70	Position	It will be returned when the BUY/SELL side of the specified position is incorrect in the settlement order.
ERR-189	Position	The quantity of your close order exceeds your open position.
ERR-200	Order	There are existing active orders and your order exceeds the maximum quantity that can be ordered. Please change the quantity to order or cancel an active order in order to create a new close order.
ERR-201	Balance	Insufficient funds.
ERR-208	Balance	The quantity of your order exceeds your available balance. Please check your balance or active orders.
ERR-254	Position	The specified position does not exist.
ERR-422	Position	It will be returned when the specified position does not exist in the close bulk order. Please make sure that the symbol or side (BUY/SELL) is correct.
ERR-430	Execution	Invalid parameter (orderId/executionId) in executions.
ERR-554	System	The server is unavailable.
ERR-626	System	The server is busy. Please retry later.
ERR-635	Order	The number of active orders has exceeded the limit. Please cancel an active order to create a new order.
ERR-682	Margin	A margin call has occurred. The operation cannot be executed.
ERR-683	Margin	Margin call processing is in progress. The operation cannot be executed.
ERR-754	Transfer	Not enough transferable amount to transfer.
ERR-846	Parameter	The difference between fromTimestamp and toTimestamp is greater than the maximum of 30 minutes.

Authentication Errors (ERR-5003 to ERR-5014)

Error Code	Description
ERR-5003	The API usage limits are exceeded.
ERR-5007	The API-TIMESTAMP is not set in the request header, or the value of API-TIMESTAMP is not a numeric value. Please ensure that the API-TIMESTAMP is set in the request header, and that the value is a numeric representation of a UNIX timestamp in milliseconds.
ERR-5008	The API-TIMESTAMP set in the request header is later than the system time of the API. Please try updating the system time.
ERR-5009	The API-TIMESTAMP set in the request header is earlier than the system time of the API. Please try updating the system time.
ERR-5010	The API-SIGN (Signature) is invalid. Please check Authentication.
ERR-5011	The API-KEY is empty. Please check Authentication.
ERR-5012	The API authentication is invalid.
ERR-5014	The membership agreement has not been completed.

Validation Errors (ERR-5106 to ERR-5135)

Error Code	Description
ERR-5106	The request parameter is invalid.
ERR-5111	Invalid timeInForce values. Please see the possible timeInForce values in Order, Close Order and Close Bulk Order.
ERR-5114	The number of decimals exceeds the maximum precision. Please check the minimum order value.
ERR-5118	Returned when LosscutPrice cannot be specified in the request body.
ERR-5121	Impossible to order due to order price is too low.
ERR-5122	The specified order can not be changed or canceled (already MODIFYING, CANCELLING, CANCELED, EXECUTED or EXPIRED). Orders can be changed or canceled only in ORDERED (WAITING for stop limit orders) status.
ERR-5123	The specified order doesn't exist.
ERR-5125	Returned when there is API restriction.
ERR-5126	The amount exceeds the maximum order amount or is less than the minimum order amount. Please check the trading rules.
ERR-5127	Your API connection is restricted.
ERR-5129	Stop limit orders cannot be specified a price that will be executed immediately.
ERR-5133	Account transfers are not possible due to transfer restrictions.
ERR-5135	FxAccount not opened. Please try again after opening FxAccount.

System and Maintenance Errors (ERR-5201 to ERR-5208)

Error Code	Description
ERR-5201	A response code that when Public/Private API is called while the service is in a regular maintenance.
ERR-5202	A response code that when Public/Private API is called while the service is in an emergency maintenance.
ERR-5203	A response code that when order or change order is called while the service is pre-open.
ERR-5204	The request API PATH is invalid.
ERR-5206	The limits of changing order for each order are exceeded. If you would like further changes for the order, please cancel the order and create a brand new order.
ERR-5207	Invalid symbol, interval or date values.
ERR-5208	OrderId(s) and executionId(s) cannot be used at the same time.

Common Error Scenarios

Authentication Failed

Error Code: ERR-5012

Possible Causes:

• Invalid API key
• Invalid API signature
• Incorrect timestamp format

Solution: Check your authentication implementation following the Authentication Guide.

Rate Limit Exceeded

Error Code: ERR-5003

Possible Causes:

• Too many requests in a short time period
• Exceeded tier limits

Solution: Implement proper rate limiting in your application. See Rate Limiting for details.

Invalid Order Parameters

Error Code: ERR-5106 or ERR-5111 or ERR-5126

Possible Causes:

• Invalid order quantity
• Invalid price
• Invalid timeInForce value
• Symbol not supported

Solution: Review the Parameters Reference and check your order parameters.

Insufficient Balance

Error Code: ERR-201 or ERR-208

Possible Causes:

• Not enough funds in account
• Balance locked in active orders

Solution: Check your account balance and cancel unnecessary orders if needed.

Order Cannot Be Modified

Error Code: ERR-5122

Possible Causes:

• Order is already being modified or cancelled
• Order has been executed
• Order has expired

Solution: Check the order status before attempting to modify or cancel. Only orders with ORDERED status (or WAITING for stop limit orders) can be modified.

Position Not Found

Error Code: ERR-254 or ERR-422

Possible Causes:

• Position ID doesn't exist
• Position has been closed
• Wrong symbol or side specified

Solution: Verify the position ID and ensure the position is still open.

System Unavailable

Error Code: ERR-554 or ERR-626 or ERR-5201 or ERR-5202

Possible Causes:

• Server maintenance
• System overload
• Temporary service disruption

Solution: Wait and retry after a short delay. Check the GMO Coin status page for maintenance announcements.

Error Handling Best Practices

1. Implement Retry Logic

For temporary errors (ERR-554, ERR-626), implement exponential backoff:

async function retryableRequest(requestFn, maxRetries = 3) {
  for (let i = 0; i < maxRetries; i++) {
    try {
      return await requestFn();
    } catch (error) {
      if (error.message_code === 'ERR-626' && i < maxRetries - 1) {
        await sleep(Math.pow(2, i) * 1000); // Exponential backoff
        continue;
      }
      throw error;
    }
  }
}

2. Validate Before Sending

Validate parameters locally before making API calls to avoid validation errors:

function validateOrderParams(symbol, side, executionType, size) {
  if (!['BUY', 'SELL'].includes(side)) {
    throw new Error('Invalid side parameter');
  }
  if (!['MARKET', 'LIMIT', 'STOP'].includes(executionType)) {
    throw new Error('Invalid executionType parameter');
  }
  // Add more validations...
}

3. Handle Authentication Errors

For authentication errors, log and alert immediately:

if (error.message_code.startsWith('ERR-50')) {
  console.error('Authentication error:', error);
  // Alert developer or check credentials
}

4. Log All Errors

Keep comprehensive error logs for debugging:

function logError(error, context) {
  console.error({
    timestamp: new Date().toISOString(),
    errorCode: error.message_code,
    errorMessage: error.message_string,
    context: context
  });
}

Related Documentation

• Status Codes - HTTP and GMO Coin status codes
• Parameters - API parameter reference
• Authentication - Authentication setup
• Rate Limiting - Rate limiting information