NEUS Docs

When things fail

Class	Fix
Validation	Fix request shape
Interactive	Hosted `/verify` or VerifyGate
Async	Poll with backoff
Private read	Owner auth, retry
Transient	Backoff; `Retry-After`

Error classes

All SDK errors extend SDKError and carry a .code and .details. Import them from @neus/sdk:

Class	`isRetryable`	Use it for
`ApiError`	`true` on 5xx / 429	HTTP failures — also has `.statusCode`, `.isClientError`, `.isServerError`, `.response`
`ValidationError`	`false`	Bad request shape — has `.field`, `.value`
`NetworkError`	`true`	Transport / DNS / timeout
`ConfigurationError`	`false`	Missing/invalid client config — has `.configKey`
`VerificationError`	`true`	Verifier failure — has `.verifierId`
`AuthenticationError`	`false`	Owner/session/key not allowed

import { ApiError } from '@neus/sdk';

try {
  await client.gateCheck({ gateId: 'gate_your-app-name', address });
} catch (error) {
  if (error instanceof ApiError && error.isRetryable) {
    // back off and retry (5xx / 429)
  } else if (error.code === 'VALIDATION_ERROR') {
    // fix the request and do not retry
  }
}

Polling Example

const final = await client.pollProofStatus(qHash, {
  interval: 3000,
  timeout: 60000
});

Private Proof Read Example

const privateData = await client.getPrivateProof(qHash, window.ethereum);

Don’t loop-create on ambiguous errors - keep stored qHashes for resume.
Say when a hosted step is required - avoid generic “error” only.

Last modified on June 15, 2026

SDK Verification Patterns Security

Verification

Platform

SDK

Widget UI

API

SDK Error Handling

When things fail

Error classes

Polling Example

Private Proof Read Example

​When things fail

​Error classes

​Polling Example

​Private Proof Read Example

When things fail

Error classes

Polling Example

Private Proof Read Example