Common Error Codes

Code	HTTP Status	Description	Resolution
MISSING_API_KEY	401	X-API-Key header not provided	Add X-API-Key header
INVALID_API_KEY	401	API key not found or inactive	Check your API key
INVALID_SIGNATURE	401	HMAC signature mismatch	Verify signature generation
SIGNATURE_EXPIRED	401	Timestamp too old	Use current timestamp
PERMISSION_DENIED	403	Missing required permission	Request additional permissions
RATE_LIMIT_EXCEEDED	429	Too many requests	Implement backoff
VALIDATION_ERROR	400	Invalid request body	Check request parameters
INVALID_CRYPTO	400	Unsupported cryptocurrency	Use supported crypto
INVALID_NETWORK	400	Crypto not supported on network	Check crypto/network combo
WALLET_NOT_FOUND	404	Wallet ID not found	Verify wallet ID
HD_WALLET_UNAVAILABLE	503	Service temporarily unavailable	Retry later