#### 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**  
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

# `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": []
}
'
```

**application/json**

``200``400``500

---