Error Reference

The SDK uses a unified SDKError class hierarchy for domain-specific failures with typed error codes across all operations.

SDKError Class Hierarchy

SDKError (base)
├── AuthError
├── WalletError
├── ProtocolError
├── NetworkError
└── SigningError

Error Classes

SDKError (Base)

The root error class for all SDK-specific failures. All subclasses inherit code and optional details.

class SDKError extends Error {
  code: SDKErrorCode;
  details?: Record<string, unknown>;
}

AuthError

Thrown for authentication and session-related failures.

class AuthError extends SDKError {
  code: string;
  details?: Record<string, unknown>;
}

WalletError

Thrown for wallet generation and signing failures.

class WalletError extends SDKError {
  code: string;
  details?: Record<string, unknown>;
}

ProtocolError

Thrown for MPC protocol round failures. Includes an optional round field indicating which protocol round encountered the error.

class ProtocolError extends SDKError {
  code: string;
  round?: number;
  details?: Record<string, unknown>;
}

NetworkError

Thrown for HTTP and WebSocket communication failures. Includes an optional statusCode for HTTP error responses.

class NetworkError extends SDKError {
  code: string;
  statusCode?: number;
  details?: Record<string, unknown>;
}

SigningError

Thrown for failures during the MPC signing process.

class SigningError extends SDKError {
  code: string;
  details?: Record<string, unknown>;
}

Error Codes

Authentication Errors

Code	Class	Description
`NOT_AUTHENTICATED`	AuthError	No active session; user must log in
`SESSION_EXPIRED`	AuthError	Session token has expired
`TOKEN_EXPIRED`	AuthError	Access token expired; SDK auto-refreshes
`INVALID_PROVIDER`	AuthError	Unknown OAuth provider specified

Wallet Errors

Code	Class	Description
`RECOVERY_REQUIRED`	WalletError	Local key share missing; run recovery flow
`WALLET_NOT_FOUND`	WalletError	No wallet generated yet

Protocol Errors

Code	Class	Description
`DKG_FAILED`	ProtocolError	Distributed Key Generation failed
`DKLS_KEYGEN_FAILED`	ProtocolError	Error during DKLS key generation
`SIGNING_SESSION_CONFLICT`	ProtocolError	Another signing session is active
`SIGNING_FAILED`	ProtocolError	Signing protocol error
`INVALID_SHARE`	ProtocolError	Peer share verification failure

Network Errors

Code	Class	Description
`NETWORK_ERROR`	NetworkError	Backend unreachable
`TIMEOUT`	NetworkError	Request timed out

ClientKeyManager Errors

Code	Method	Condition
`USER_NOT_INITIALIZED`	Storage write methods	`currentUserId` is `null`
`NO_KEY_SHARE`	`rotateKeyShare`, `exportBackup`	No key share exists for current user
`PARTY_ID_MISMATCH`	`rotateKeyShare`	Incoming party ID differs from existing share
`INVALID_BACKUP`	`importBackup`	`backup.type` is not `"nero-mpc-backup"`
`UNSUPPORTED_VERSION`	`importBackup`	`backup.version` is not 1
`INVALID_PUBLIC_KEY`	`deriveEOAAddress`	Public key hex length not 128 or 130 characters

EIP-1193 Provider Errors

Standard provider errors following the EIP-1193 specification:

Code	Name	Description
4001	`USER_REJECTED`	User rejected the request
4100	`UNAUTHORIZED`	Provider lacks authorization
4200	`UNSUPPORTED_METHOD`	RPC method not implemented
4900	`DISCONNECTED`	Provider disconnected from chain
4902	`CHAIN_NOT_ADDED`	Requested chain not added to SDK

Error Handling Patterns

Basic Pattern

try {
  await sdk.signMessage("test");
} catch (error) {
  if (error.code === "NOT_AUTHENTICATED") {
    // Redirect to login
  } else if (error.code === "RECOVERY_REQUIRED") {
    // Initiate recovery flow
  } else if (error.code === "SIGNING_SESSION_CONFLICT") {
    // Wait for current session to complete, then retry
  } else if (error.code === "NETWORK_ERROR") {
    // Check connectivity and retry
  }
}

Recovery Strategies by Error Code

Code	Recommended Recovery
`NOT_AUTHENTICATED`	Call `login()` or redirect to login page
`SESSION_EXPIRED`	Re-authenticate the user
`TOKEN_EXPIRED`	SDK auto-refreshes; retry the operation
`RECOVERY_REQUIRED`	Run the recovery flow with user's backup password
`WALLET_NOT_FOUND`	Call `generateWallet()`
`DKG_FAILED`	Retry `generateWallet()`
`DKLS_KEYGEN_FAILED`	Retry key generation
`SIGNING_SESSION_CONFLICT`	Wait and retry the signing operation
`SIGNING_FAILED`	Retry the signing operation
`INVALID_SHARE`	Re-run key generation
`NETWORK_ERROR`	Check connectivity and retry with backoff
`TIMEOUT`	Retry with backoff

React Hook Error Handling

All React hooks follow a consistent four-step error propagation pattern:

Caught within the hook's useCallback
Normalized to standard Error object
Stored in the hook's error state for UI rendering
Re-thrown to allow component-level handling

Operations always reset error to null at start and reset loading flags in finally blocks.

Errors

On this page