Wirex Hosted KYC

Before You Start

Read the following guides before proceeding:

Guide	Why
Getting Started	Platform overview and setup
Api Basics	Required headers and request configuration
Authentication	How to obtain access tokens
Webhooks	Receive status notifications
Onboarding	User and wallet registration
User Profile	User capabilities and status

When to Use

You want Wirex to handle KYC verification
You collect minimal user data at registration
Users will complete identity verification in the Wirex interface

Registration Methods

Two registration endpoints are available depending on your authentication flow:

Method	Endpoint	Auth Flow
S2S Registration	`POST /api/v2/user`	S2S token (backend-to-backend)
Privy Registration	`POST /api/v1/user/retail`	Privy-based auth (frontend)

Option A: S2S Registration

For backend-to-backend integration using S2S tokens.

POST /api/v2/user

{
  "user_address": "0xA7E41d5680dE394EaA2ed417169DFf56840Fb3EE",
  "initial_data": {
    "profile": {
      "email": "[email protected]"
    },
    "residence_address": {
      "country": "GB"
    }
  }
}

Important: The user_address must be the user's EOA address (the signer), not the Smart Wallet address.

user_address replaces the former wallet_address. Both are accepted; if both are supplied they must match. New integrations should send user_address.

Field	Type	Required	Validation
`user_address`	string	Yes	User's EOA address
`initial_data.profile.email`	string	Yes	Valid email format, must be unique
`initial_data.residence_address.country`	string	Yes	ISO 3166-1 alpha-2 code

Option B: Privy Registration

For partners using Privy authorization flow. The user context is derived from the Privy token.

POST /api/v1/user/retail

{
  "email": "[email protected]",
  "country": "GB"
}

Field	Type	Required	Validation
`email`	string	Yes	Valid email format, must be unique
`country`	string	Yes	ISO 3166-1 alpha-2 code

Code Examples (S2S Registration)

async function registerUserHostedKYC(accessToken, userAddress, email, country, chainId, baseUrl) {
  const response = await fetch(`${baseUrl}/api/v2/user`, {
    method: 'POST',
    headers: {
      'Authorization': `Bearer ${accessToken}`,
      'Content-Type': 'application/json',
      'X-Chain-Id': chainId.toString(),
    },
    body: JSON.stringify({
      user_address: userAddress,
      initial_data: {
        profile: { email },
        residence_address: { country },
      },
    }),
  });

  if (!response.ok) {
    const error = await response.json();
    throw new Error(`Registration failed: ${error.error_description}`);
  }

  return response.json();
}

// Usage
const { id } = await registerUserHostedKYC(
  access_token,
  '0xA7E41d5680dE394EaA2ed417169DFf56840Fb3EE',
  '[email protected]',
  'GB',
  8453,
  'https://api-baas.wirexapp.com'
);

import requests

def register_user_hosted_kyc(access_token, user_address, email, country, chain_id, base_url):
    response = requests.post(
        f"{base_url}/api/v2/user",
        headers={
            "Authorization": f"Bearer {access_token}",
            "Content-Type": "application/json",
            "X-Chain-Id": str(chain_id),
        },
        json={
            "user_address": user_address,
            "initial_data": {
                "profile": {"email": email},
                "residence_address": {"country": country},
            },
        },
    )
    response.raise_for_status()
    return response.json()

# Usage
user = register_user_hosted_kyc(
    access_token,
    "0xA7E41d5680dE394EaA2ed417169DFf56840Fb3EE",
    "[email protected]",
    "GB",
    8453,
    "https://api-baas.wirexapp.com"
)

func RegisterUserHostedKYC(accessToken, userAddress, email, country string, chainID int, baseURL string) (string, error) {
    reqBody, _ := json.Marshal(map[string]interface{}{
        "user_address": userAddress,
        "initial_data": map[string]interface{}{
            "profile":           map[string]string{"email": email},
            "residence_address": map[string]string{"country": country},
        },
    })

    req, _ := http.NewRequest("POST", baseURL+"/api/v2/user", bytes.NewBuffer(reqBody))
    req.Header.Set("Authorization", "Bearer "+accessToken)
    req.Header.Set("Content-Type", "application/json")
    req.Header.Set("X-Chain-Id", fmt.Sprintf("%d", chainID))

    resp, err := http.DefaultClient.Do(req)
    if err != nil {
        return "", err
    }
    defer resp.Body.Close()

    var result struct{ ID string `json:"id"` }
    json.NewDecoder(resp.Body).Decode(&result)
    return result.ID, nil
}

Flow

sequenceDiagram
    participant App as Your App
    participant BaaS as Wirex API
    participant SumSub

    App->>BaaS: 1. POST /api/v2/user or /api/v1/user/retail
    BaaS-->>App: { id }

    App->>BaaS: 2. GET /verification-link or /verification-token
    BaaS-->>App: { url } or { token }

    App->>SumSub: 3. User completes KYC (redirect or SDK)

    SumSub->>BaaS: 4. Verification result
    Note over BaaS: 5. Account activated

    BaaS->>App: POST /webhook/users (verification_status)

KYC Completion Options

After registration, the user must complete KYC verification. Two options are available:

Option	Endpoint	Use Case
Verification Link	`GET /api/v1/user/verification-link`	Redirect user to hosted SumSub widget
SDK Token	`GET /api/v1/user/verification-token`	Embed SumSub SDK in your app

Option A: Verification Link

Redirect the user to a hosted SumSub widget where they complete all KYC steps.

GET /api/v1/user/verification-link

Response:

{
  "url": "https://verify.sumsub.com/..."
}

Open this URL in a browser or webview. The user completes verification in the hosted interface.

Option B: SDK Token

Obtain a token to initialize the SumSub SDK within your application.

GET /api/v1/user/verification-token

Response:

{
  "token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9..."
}

Use this token to initialize the SumSub WebSDK or Mobile SDK in your frontend. For integration details, see the SumSub SDK documentation.

What Happens Next

User completes identity verification (document upload, selfie, etc.)
SumSub sends verification result to Wirex
Wirex sends a webhook to your endpoint with updated verification_status
User account is activated upon successful verification

The user cannot perform restricted operations (card issuance, fiat withdrawals) until KYC is approved.

For webhook payload details, see User Onboarding - Webhooks.

Phone Number: The phone number the user enters in the SumSub form is stored on the profile and automatically marked as confirmed. It will be used for 3DS Authentication OTP codes and Read Card Details OTP verification. No separate confirmation step is required.

Error Handling

Validation Errors

Field	Error	Pattern/Requirement
`user_address`	Invalid format	`^0x[a-fA-F0-9]{40}$` (EVM)
`email`	Invalid format	Valid email address
`email`	Missing	Required field
`country`	Invalid format	ISO 3166-1 alpha-2 (`^[A-Z]{2}$`)
`country`	Missing	Required field

Registration Errors

Error Reason	Description	Resolution
`ErrorNotFound`	Wallet not registered in Accounts contract	Complete on-chain registration first
`ErrorAlreadyExists`	Email already exists	Use a different email address
`ErrorAlreadyExists`	Wallet address already exists	User already registered

Error Response Format

{
  "error_reason": "ErrorInvalidField",
  "error_description": "Invalid format for email",
  "error_category": {
    "category": "CategoryValidationFailure",
    "http_status_code": 400
  },
  "error_details": [
    { "key": "field", "details": "email" },
    { "key": "issue", "details": "invalid_format" }
  ]
}