Off Exchange Settlements

Copper will add a new section called Delegate funds, where clients can transfer part of their funds to the supported exchange.
Suppose a client has 1000 BTC on his portfolio in Copper account.
From the Delegate funds section client can transfer BTC to the exchange.

Copper will then call the exchange’s API /add-funds with specified parameters:

 + POST [exchange-api-endpoint]/add-funds
    
 + Headers
   Authorization: Any Auth Scheme
    
 + Request
   {
     "requestId": "uniq-idempotency-key",
     "clientAccountId": "client-exchange-account-id",
     "amount": "200",
     "currency": "BTC"
   }

Responses:

`200 OK`	ok
`200 OK`	requestId already exist and request params are the same (duplicate)
`400 Bad Request`	this requestId already exists but request params are not the same
`409 Conflict`	can’t process request (balance not available, etc.)
`4`, `5`	any other error (timeout, service not available, etc.) — request will be retried after some delay

Copper is able to call API, which will return funds back

 + POST [exchange-api-endpoint]/remove-funds
    
 + Headers
   Authorization: Any Auth Scheme
    
 + Request
   {
     "requestId": "uniq-idempotency-key",
     "clientAccountId": "client-exchange-account-id",
     "amount": "50",
     "currency": "BTC"
   }

Responses:

`200 OK`	ok
`200 OK`	requestId already exist and request params are the same (duplicate)
`400 Bad Request`	this requestId already exists but request params are not the same
`409 Conflict`	can’t process request (balance not available, etc.)
`4`, `5`	any other error (timeout, service not available, etc.) — request will be retried after some delay

When the position is closed, exchange should send a request to the Copper for settlement.

 + POST https://api.copper.co/platfrom/orders
    
 + Headers
   Authorization: Any Auth Scheme
    
 + Request
   {
     "externalOrderId": "exchange-uniq-order-id",
     "portfolioId": "exchange-portfolio-id",   // exchange's account id in the Copper Platform, from which USD will be debited
     "orderType": "sell",     // or "buy"
     "limitType": "off-exchange",
     "baseCurrency": "BTC",
     "quoteCurrency": "USD",
     "amount": "10",
     "price": "7650.00",
     "clientAccountId": "client-exchange-account-id"
   }

When this API method is called, Copper will check client-exchange-account-id has enough locked assets in favor of the exchange, debit funds from the client and top up exchange balance.