SDK Integration

zkKYC SDK - Simply execute KYC progress using the RedirectURL as the src-attribute value for the iFrame.

Use Case

To reduce the development cost for the project side, the project can use zkKYC capability by simply accessing the link. Users can achieve full KYC capability on the web/H5, reducing the possibility of user churn by minimizing the need to navigate to another page.

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zkMe-Widget KYC Process

Step 1: Enter the service authorization Widget page, the user confirms and goes to the next step

Step 2: E-mail verification login

Step 3: Verify the SBT to confirm that it is authenticated

Step 4: Depending on the KYC configuration of the project, determine whether the user needs to undergo different verification processes.

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Interaction Instructions

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Integration via NPM

You can refer to @zkmelabs/widget and please make sure to use the latest version.

Installation

pnpm add @zkmelabs/widget

# or
yarn add @zkmelabs/widget

# or
npm install @zkmelabs/widget

Getting Started

Step 1. Import styles

import '@zkmelabs/widget/dist/style.css'

Step 2. Create a new ZkMeWidget instance

import { ZkMeWidget, type Provider } from '@zkmelabs/widget'
const provider: Provider = {
    async getAccessToken() {
        // Request a new token from your backend service and return it to the widget.
        // For the access token, please refer to Usage Example -> Exchanging API_KEY for Access Token below
        return fetchNewToken()
    },
    
    async getUserAccounts() {
        // If your project is a Dapp,
        // you need to return the user's connected wallet address.
        if (!userConnectedAddress) {
            userConnectedAddress = await connect()
        }
        return [userConnectedAddress]
        
        // If not,
        // you should return the user's e-mail address, phone number or any other unique identifier.
        //
        // return ['email address']
        // or
        // return ['phone number']
        // or
        // return ['unique identifier']
    },
        
    // According to which blockchain your project is integrated with,
    // choose and implement the corresponding methods as shown below.
   
    // EVM
    async delegateTransaction(tx) {
        const txResponse = await signer.sendTransaction(tx)
        return txResponse.hash
    },
    // Cosmos
    async delegateCosmosTransaction(tx) {
        const txResponse = await signingCosmWasmClient.execute(
        tx.senderAddress,
        tx.contractAddress,
        tx.msg,
        'auto'
        )
        return txResponse.transactionHash
    },
    // Aptos
    async delegateAptosTransaction(tx) {
        const txResponse = await aptos.signAndSubmitTransaction(tx)
        return txResponse.hash
    },
    // ...
    // See the Provider interface definition for more details on other chains.
}

const zkMeWidget = new ZkMeWidget(
    appId, // This parameter means the same thing as "mchNo"
    'YourDappName',
    chainId,
    provider,
    options
)

NOTE: The specific configuration for the "option" parameter is shown in the table below

Param	Type	Description
options.lv	VerificationLevel?	"zkKYC" or "Anti-Sybil", default "zkKYC"

Step 3. Listen to the finished widget events to detect when the user has completed the zkKYC process.

import { verifyWithZkMeServices } from '@zkmelabs/widget'

function handleFinished(verifiedAccount: string) {
    // We recommend that you double-check this by calling
    // the functions mentioned in the "Helper functions" section.
    if (
    verifiedAccount === userConnectedAddress
    ) {
        // zkKYC
        const results = await verifyWithZkMeServices(appId, userConnectedAddress)
        
        if (results) {
        // Prompts the user that zkKYC verification has been completed
        }
    }
}

zkMeWidget.on('finished', handleFinished)

Step 4. Launch the zkMe widget and it will be displayed in the center of your webpage.

zkMeWidget.launch()

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Helper functions

verifyWithZkMeServices

Before launching the widget, you should check the zkKYC status of the user and launch the widget when the check result is false.

import { verifyWithZkMeServices } from '@zkmelabs/widget'

const results: boolean = await verifyWithZkMeServices(
    appId,
    userAccount
)

if (!results) {
    zkMeWidget.launch()
}

Param	Type	Description
appId	string	This parameter means the same thing as "mchNo"
userAccount	string	Same value as in provider.getUserAccounts
lv	VerificationLevel?	"zkKYC" or "Anti-Sybil", default "zkKYC"

If your zkKYC's Program Type is not Simple(Cross-Chain), then you can also query users' zkKYC status from zkMe Verify & Certify Smart Contract here.

Exchanging API_KEY for Access Token

To use your API_KEY to obtain an accessToken, you will need to make a specific HTTP request. Here's how you can do it:

a. Endpoint: Send a POST request to the token exchange endpoint.

POST https://nest-api.zk.me/api/token/get

Please remember to modify the Content-Type in the request header to application/json. Failing to do so might result in a Parameter Error response.

b. Request Body:

Parameter Name	Required	Type	Desc
apiKey	True	string	The API_KEY provided by zkMe.
appId	True	string	A unique identifier (mchNo) to DApp provided by zkMe.
apiModePermission	True	number	0-email login (Only support email login)
lv	True	number	1-zkKYC 2-Anti-Sybil

c. Response

Success

{
    "code": 80000000,
    "data": {
        "accessToken": "8641259808779c53de65c3698e42b402b112cfe3856202189c37eae9f0b23babbcc1429ea9adcb52283dca4dab024a640651f855d8c78c7bde308f721a6e0cb80d51dab7c775ebfe0ae74eb9ab02f503094a9b2a2e2aeabf70e03a0cac9773a93dba743ca0dc3fa4af77375351bc48f76515d72dbee3a8bd5c034e6ffb94bd97"
    },
    "msg": "success",
    "timestamp": 1691732474552
}

Exception (AppId and API_KEY not matched)

{
    "code": 81000014,
    "data": null,
    "msg": "AppID and API Key do not match. Access token generation failed",
    "timestamp": 1691732568774
}

Exception (Parameter Error)

{
    "code": 80000002,
    "data": null,
    "msg": "parameter error",
    "timestamp": 1691732593484
}

Exception (System Error)

{
    "code": 80000001,
    "data": null,
    "msg": "system error",
    "timestamp": 1691732593484
}

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Response & Exceptions

Success

If the user has passed the KYC verification and the user’s SBT could be accessed by your project, the following interface will be seen. Meanwhile, there will be a message with KYC results sent to your DApp.

Camera Permission Denied Error

The following screen will be displayed for possible issues such as the user denying browser camera access or not having a camera on the device.

OCR Scan Error

The following screen will be displayed when an exception occurs during the OCR process.

Face Recognition Error

The following screen will be displayed for possible problems such as eyes closed detected, art mask detected etc.

Face Mismatch Error

The following screen will be displayed when the face could not match the uploaded ID.

Faceprint Mismatch Error

The following screen will be displayed for the possible problem that the fully homomorphically encrypted faceprint does not match the one associated with this MeID.

Faceprint Recognition Server Error

The following screen will be displayed when something goes wrong on the faceprint recognition server.

Unknown Error

The following screen will be displayed when something goes wrong not listed above.