Error Handling

All Elaypay API responses -- whether successful or not -- follow a consistent envelope format. This page documents the response structure, HTTP status code conventions, and the complete error code catalog organized by domain.

Response Envelope

Every response from the Elaypay API is wrapped in a standard envelope with metadata fields.

Successful Response

200Success

{
  "version": "1.3.0",
  "timestamp": 1709337600000,
  "success": true,
  "code": "2000",
  "message": "SUCCESS",
  "data": {
    "transferId": "txn_789xyz",
    "status": "COMPLETED",
    "amount": "100.00",
    "currency": "USD"
  }
}

Error Response

400Error

{
  "version": "1.3.0",
  "timestamp": 1709337600000,
  "success": false,
  "code": "T1007",
  "message": "INVALID_AMOUNT",
  "data": null
}

Envelope Fields

Field	Type	Description
version	string	API version (e.g., 1.3.0)
timestamp	long	Response timestamp in epoch milliseconds
success	boolean	true for successful operations, false for errors
code	string	Machine-readable result code. 2xxx = success, domain-prefixed codes = error
message	string	Human-readable result description
data	object / null	Response payload on success; always null on error

Programmatic error handling

Always check the success field first. When success is false, use the code field for programmatic handling (e.g., retry logic, user-facing messages). The message field is informational and may change between API versions -- do not parse it programmatically.

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HTTP Status Codes

The Elaypay API uses standard HTTP status codes. The table below lists all codes you may encounter:

Code	Meaning	When Returned
200	OK	Request succeeded, response body contains the result
201	Created	A new resource was created successfully
204	No Content	Request succeeded, no response body (e.g., DELETE operations)
400	Bad Request	Validation error, invalid parameters, or business rule violation
401	Unauthorized	Missing or invalid authentication (bad API key, signature mismatch, timestamp expired)
403	Forbidden	Authentication succeeded but the caller lacks permission for this operation
404	Not Found	The requested resource does not exist
409	Conflict	Resource already exists or the operation conflicts with current state
429	Too Many Requests	Rate limit exceeded -- wait and retry
500	Internal Server Error	Unexpected server error -- contact support if persistent

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Error Code Catalog

Error codes use a domain prefix followed by a numeric identifier. The prefix tells you which module generated the error; the full code uniquely identifies the error condition.

S -- System / Infrastructure

General system-level errors that can occur on any endpoint.

Code	Name	HTTP	Description
S001	INTERNAL_ERROR	500	Unexpected internal error. Contact support if this persists.
S002	SERVICE_UNAVAILABLE	503	A dependent service is unavailable. Retry after a brief delay.
S003	TIMEOUT	504	The operation timed out. The request may or may not have been processed.
S004	INVALID_REQUEST	400	The request is malformed (e.g., invalid JSON syntax).
S005	UNAUTHORIZED	401	Authentication is required but was not provided.
S006	FORBIDDEN	403	Access denied. The caller does not have the required role or permission.
S007	NOT_FOUND	404	The requested resource was not found.
S011	VALIDATION_ERROR	400	One or more request fields failed validation.
S012	INVALID_PARAMETER	400	A parameter value is invalid (wrong type, out of range, etc.).
S013	MISSING_PARAMETER	400	A required parameter is missing from the request.
S031	DATA_NOT_FOUND	404	The requested data record was not found in the database.
S032	DATA_ALREADY_EXISTS	409	A record with the same unique key already exists.
S034	CONCURRENT_MODIFICATION	409	Optimistic lock conflict. Another operation modified this resource concurrently. Retry.

W -- Wallet

Errors from wallet account and balance operations.

Code	Name	HTTP	Description
W1001	ACCOUNT_NOT_FOUND	404	The wallet account was not found.
W1002	ACCOUNT_INACTIVE	400	The wallet account is not active. Activate it before performing operations.
W1003	ACCOUNT_FROZEN	400	The wallet account is frozen. Contact an administrator.
W1004	ACCOUNT_ALREADY_EXISTS	409	A wallet account with this identity already exists.
W3001	INSUFFICIENT_BALANCE	400	The wallet does not have sufficient balance for this operation.
W3003	INSUFFICIENT_AVAILABLE	400	The available balance (excluding holds) is insufficient.
W3005	OPTIMISTIC_LOCK_CONFLICT	409	A concurrent modification was detected on the wallet balance. Retry the operation.
W5005	CURRENCY_NOT_SUPPORTED	400	The specified currency is not supported by this wallet.
W9004	MISSING_WORKSPACE_CONTEXT	401	The workspace context is missing. Ensure the API key is associated with a workspace.

T -- Transfer

Errors from transfer creation and processing.

Code	Name	HTTP	Description
T1001	SOURCE_WALLET_NOT_FOUND	404	The source wallet was not found.
T1002	TARGET_WALLET_NOT_FOUND	404	The target wallet was not found.
T1005	CURRENCY_MISMATCH	400	The source and target wallets use different currencies.
T1006	SAME_WALLET_TRANSFER	400	Cannot transfer funds to the same wallet.
T1007	INVALID_AMOUNT	400	The transfer amount must be positive.
T1008	INSUFFICIENT_BALANCE	400	The source wallet does not have sufficient balance.
T1020	ORDER_NOT_FOUND	404	The transfer order was not found.
T1023	DUPLICATE_REQUEST	409	A transfer with this idempotency key has already been processed.
T1040	EXECUTION_FAILED	500	The transfer execution failed. The funds were not moved.
T1044	TARIFF_NOT_CONFIGURED	400	The wallet tariff (fee schedule) is not configured. Contact an administrator.

GA -- Gateway Auth

Errors from the API gateway authentication pipeline. See HMAC Authentication for the full validation pipeline.

Code	Name	HTTP	Description
GA2001	API_KEY_REQUIRED	401	The X-Api-Key header is missing.
GA2002	SIGNATURE_REQUIRED	401	The X-Signature header is missing.
GA2011	API_KEY_INVALID	401	The API key is invalid or was not found.
GA2012	SIGNATURE_INVALID	401	Signature verification failed.
GA2013	TIMESTAMP_EXPIRED	401	The request timestamp is outside the 60-second window.
GA2021	API_KEY_DISABLED	403	The API key has been disabled.
GA2022	IP_NOT_ALLOWED	403	The client IP is not in the whitelist.
GA2024	SCOPE_DENIED	403	The API key lacks the required scope.
GA2032	WORKSPACE_NOT_FOUND	404	The workspace was not found.
GA2034	WORKSPACE_NOT_MEMBER	403	The user is not a member of the workspace.

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Error Handling Best Practices

Retry strategy

For 5xx errors and 429 (rate limit), implement exponential backoff with jitter. Start with a 1-second delay, double on each retry, and add random jitter to avoid thundering herd. Set a maximum of 3-5 retries.

Idempotency

For POST operations that create resources, use an idempotency key. If a request fails with a network error and you retry, the idempotency key prevents duplicate creation. A T1023 (DUPLICATE_REQUEST) response means your original request was processed successfully.

User-facing messages

Map error codes to user-friendly messages in your application. Do not display raw error codes or the message field to end users -- they are intended for developers. Build a translation layer that converts codes like W3001 into messages like "Insufficient funds to complete this transfer."

Logging

Log the full response envelope (including code, message, and timestamp) for every error. The timestamp field helps correlate client-side errors with server-side logs when working with Elaypay support.