#### URL Expired

The URL for this request expired after 30 days.

### Optional metadata when starting an operation.

- **OperationID**  
  `string`  
  Unique operation identifier.

- **InitiatorID**  
  `string`  
  Initiator identifier.

- **Name**  
  `string`  
  required

- **ExternalPairingMessages**  
  `array of objects`  
  required
  length ≥ 1

#### ExternalPairingMessages*
- **object**  
  Single pairing message when attaching an external master key.
  - **Value**  
    `string`  
    Raw pairing message bytes (base64 in JSON).

### ADD object  
- **PairingChecksum**  
  `string`

### Responses
# `` 200      Operation started

# `` 400      Invalid input, validation error, or malformed request

# `` 500      Internal server error. May include an `errorCode` (M-prefixed) and `data` from the MPA error code system. See `cwpapi/errors.go` for codes.

### Base URL

https://api.your-wallet.blockdaemon-wallet.com/api/cwp/operations/start/attachMasterKey

```
xxxxxxxxxx

curl --request POST \
     --url https://api.your-wallet.blockdaemon-wallet.com/api/cwp/operations/start/attachMasterKey \
     --header 'accept: application/json' \
     --header 'content-type: application/json' \
     --data '
{
  "ExternalPairingMessages": []
}
'
```

### Example Responses
application/json
``200``
``400``
``500