# DID Registration

Every DID is associated with at least one key series. Apart from registering a new DID, every other type of request is associated with a DID address (`"did_address"`) and one of the DID's key series. The client specifies the attribute `"operation"` according to the name of the request method. The current public key (`"current_key"`) in the series and the SHA-256 hash of the next public key (`"next_key_hash"`) is part of the request message whereas the current private key is used to sign the Base64 encoded request message.

To register for a new DID, a client must specify a new key series when she registers for a new DID address with `did_register` operation. The client generates the first and second public-private key pairs in the new key series. In the request message, the client then specifies the first public key (`"current_key"`) and the SHA-256 hash of the second public key (`"next_key_hash"`).  The request message is then encoded in Base64 and signed by the first private key.

## did\_register

<mark style="color:green;">`POST`</mark> `https://test-network.finema.co/did/`

#### Request Body

| Name            | Type   | Description                                                                       |
| --------------- | ------ | --------------------------------------------------------------------------------- |
| operation       | string | The method's name that is "did\_register".                                        |
| current\_key    | string | The first public key in the series. It is used to verify the request's signature. |
| next\_key\_hash | string | The SHA-256 hash of the next public key in the series.                            |

{% tabs %}
{% tab title="200 The operation name and DID address for the registered DID will be given as the response. The DID address is derived from the current public key ("current\_key")." %}

```
{
    "operation": "did_register",
    "did_address": "did:idin:afb7ba88c76edbda55c344b70ae0cf0556d770ec256820d7185000de395391b5"
 
}
```

{% endtab %}

{% tab title="422 " %}

```
{
    "errors": [
        {
           "status": 422,
            "title": "Invalid Attribute",
            "detail": "the server cannot process the request",
        }
    ]
}
```

{% endtab %}
{% endtabs %}

## Example Message and Request

```
{
    "operation": "did_register",
    "current_key": "-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEWquJ9+BEBDQTA/xRmx5uAHOgKMue\nw1QoAGk+2mLVWGvFBW5D3BMPYOFtGM/tvubVjwY3tr9iRI+erSQUmFIvRg==\n-----END PUBLIC KEY-----",
    "next_key_hash": "2775f71ed2bef2f395acf8781d43d0f538bf693b7c62a5bc27ec46cc839d272c"
}
```

The above message can then be encoded in Base64 and signed with ECDSA to obtain the following HTTP request

```
{
    "message": "eyJjdXJyZW50X2tleSI6ICItLS0tLUJFR0lOIFBVQkxJQyBLRVktLS0tLVxuTUZrd0V3WUhLb1pJemowQ0FRWUlLb1pJemowREFRY0RRZ0FFV3F1SjkrQkVCRFFUQS94Um14NXVBSE9nS011ZVxudzFRb0FHaysybUxWV0d2RkJXNUQzQk1QWU9GdEdNL3R2dWJWandZM3RyOWlSSStlclNRVW1GSXZSZz09XG4tLS0tLUVORCBQVUJMSUMgS0VZLS0tLS0iLCAibmV4dF9rZXlfaGFzaCI6ICIyNzc1ZjcxZWQyYmVmMmYzOTVhY2Y4NzgxZDQzZDBmNTM4YmY2OTNiN2M2MmE1YmMyN2VjNDZjYzgzOWQyNzJjIiwgIm9wZXJhdGlvbiI6ICJkaWRfcmVnaXN0ZXIifQ==",
    "signature": "MEUCIQCIP/oFaQ8HKyOVNb2UGGoecC7t8F9DqLPLTvptWb6Q/wIgddkJPlh938hmFU6H9GrojIFh6NFWK0TeUkPQEBqE0jI="
}
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.finema.co/api-tutorials/did-api/register-did.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.