# Secure Cross-Platform Identity Linking

## <mark style="color:blue;">GET</mark> /api/v1/crossPlatformIdentityLinking

* Through this API, under the premise of obtaining user authorization, you can query the Web3 address associated with a user's Web2 account or the Web2 account associated with a Web3 address and verify whether these accounts belong to the same individual. This data needs to be [decrypted using the Lit Protocol](https://relationlabs.gitbook.io/graph-zh/guide/use-litprotocol-to-decrypt).
* Header

| Field  | Type   | Required | Remarks                                                                                                                      |
| ------ | ------ | -------- | ---------------------------------------------------------------------------------------------------------------------------- |
| ApiKey | String | true     | [ApiKey](https://relationlabs.gitbook.io/relation-graph/api/cross-platform-identity-linking) obtained from the administrator |

* Request Parameters

| Field           | Type   | Required | Remarks                                                                                                                                                                                                                           |
| --------------- | ------ | -------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| address         | String | fasle    | EOA Address                                                                                                                                                                                                                       |
| twitterUsername | String | fasle    | twitter username                                                                                                                                                                                                                  |
| steamId         | String | fasle    | steamId                                                                                                                                                                                                                           |
| sig             | String | true     | User authorization information (when provided with authorization details, developers can [use Lit Protocol to decrypt](https://relationlabs.gitbook.io/relation-graph/guide/use-litprotocol-to-decrypt) the returned results).    |
| message         | String | true     | Original text of user authorization information signature （Please refer to the original signature splicing[SIWE](https://docs.login.xyz/).The statement field needs to be:**Access to Secure Cross-Platform Identity Linking.**)） |

* Request Example

```shell
curl  GET 'https://api.relationlabs.ai/api/v1/crossPlatformIdentityLinking?address=0x9bd286ef4e3d9ec1af6c6ae9da2f0b3617deab13&sig=0x001111&message=example.com%20wants%20you%20to%20sign%20in%20with...' \
--header 'ApiKey: <ApiKey>'
```

* Response Parameters

| Field | Type          | Remarks                       |
| ----- | ------------- | ----------------------------- |
| code  | String        | Return code                   |
| desc  | String        | Return message                |
| data  | EncryptedData | Data (Lit Protocol encrypted) |

The Account field consists of the following subfields:

| Field    | Type     | Remarks              |
| -------- | -------- | -------------------- |
| relation | Relation | Relation information |
| address  | List     | Address list         |
| twitter  | Twitter  | Twitter information  |
| steam    | Steam    | Steam information    |

Data structure of the decrypted Twitter object

```json
{
  "code": "0",
  "desc": "success",
  "data": {
    "address": [],
    "relation": {
      "relationId": "d4swz-zaaaa-aaaaj-at5fa-cai",
      "name": "test_user",
      "avatar": "https://3fypb-gqaaa-aaaag-aaedq-cai.ic1.io/nft/eth/relation-test-club/16.png"
    },
    "twitter": {
      "username": "VitalikButerin",
      "name": "vitalik.eth",
      "avatar": "https://pbs.twimg.com/profile_images/977496875887558661/L86xyLF4_400x400.jpg"
    },
    "steam": {
      "steamId": "178691028912",
      "name": "vitalik",
      "avatar": "https://pbs.twimg.com/profile_images/977496875887558661/L86xyLF4_400x400.jpg"
    }
  }
}
```

* Response Body

```json
{
  "code": "0",
  "desc": "success",
  "data": {
    "encryptedString": "xxx",
    "encryptedSymmetricKey": "xxx"
  }
}
```

* Return Code

| code | desc    | Remarks                           |
| ---- | ------- | --------------------------------- |
| 0    | success | the flag for a successful request |