@arcblock/blocklet-registry/www/static/ebef0bd4278e0a03dcdb29f526737ef7/blocklet.md

**Blocklets** are reusable building blocks to help developers and community users to build things on [ArcBlock](https://www.arcblock.io) platform. A blocklet serves one and only one purpose, reusability is the core design philosophy of blocklets. Reusabil

# DID KYC

Verify once and use everywhere.

## How to get started

### 1. install `DID KYC` blocklet from ABT Node marketplace

### 2. config the required environments

#### 2.1 MAILGUN_SMTP_USER & MAILGUN_SMTP_PASSWORD

The verifiable credential of email address need [mailgun](https://www.mailgun.com/) service, so we need you provide a
mailgun user and password.

![mailgun screenshot](./screenshots/2-mailgun_pic.png)

#### 2.2 APP_CHAIN_ID

A valid chain id, The `APP_CHAIN_ID` and `APP_CHAIN_HOST` are one-to-one, you can start a chain by `Blockchain Manager` blocklet, or you can use our test chain:

```
// playground chain id:
playground
```

#### 2.3 APP_CHAIN_HOST

A valid chain host, you can start a chain by `Blockchain Manager` blocklet, or you can use our test chain:

```
// playground chain host:
https://playground.network.arcblockio.cn/api
```

### 3. start the blocklet