> ## Documentation Index
> Fetch the complete documentation index at: https://developer.fin.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Pass through

The pass-through use case is when a developer just want to allow their customers to deposit an asset from one source and receive in a destination wallet address. The developer also has the option to collect revenue within the flow as well.

<Tip>
  Check the use cases that it can serve [here](https://developer.fin.com/crypto-orchestration).
</Tip>

The supported sources and destinations can be found below along with important integration information.

| **Supported Source Currency** | **Supported Source Rail** | **Supported Destination Currency** | **Supported Destination Rail** | **Quote Estimation** | **Minimum Order Limit** | **Maximum Order Limit** | **Estimated Settlement Time (once deposit received)** | **Settlement Configuration (**`settlment_via`**)** | Rebalance Configuration (`rebalance_fee`)              | Default Order Expiry Time |
| :---------------------------- | :------------------------ | :--------------------------------- | :----------------------------- | :------------------- | :---------------------- | :---------------------- | :---------------------------------------------------- | -------------------------------------------------- | ------------------------------------------------------ | ------------------------- |
| BTC                           | BITCOIN                   | BTC                                | BITCOIN                        | ✅                    | 0.00005                 | Not applicable yet      | \~ 1 hour                                             | `FEE_RETENTION`                                    | Has to be always `false`(in roadmap for full support)  | 1 hour                    |
| USDT                          | TRON                      | USDT                               | TRON                           | ✅                    | 2                       | Not applicable yet      | \~ 3-5 mins                                           | `FEE_RETENTION`                                    | Has to be always `false` (in roadmap for full support) | 1 hour                    |
| ETH                           | ETHEREUM                  | ETH                                | ETHEREUM                       | ✅                    | 0.001                   | Not applicable yet      | \~ 3-5 mins                                           | `FEE_RETENTION`                                    | Has to be always `false` (in roadmap for full support) | 1 hour                    |

<Note>
  For routes where "Fee rebalancing capability" & "Quote estimation" is limited. Fin can enable both upon request of the Developer or Fin will enable themselves if it is in the roadmap.

  Please send request in your dedicated communication group.
</Note>

## Pass through quote creation:

<Tabs>
  <Tab title="FEE_RETENTION">
    ```text highlight={11} focus={11} theme={null}
    curl --request POST \
      --url https://sandbox.api.fin.com/v1/transit/quote \
      --header 'Authorization: Bearer <token>' \
      --header 'Content-Type: application/json' \
      --data '
    {
      "order_amount": "100.00",
      "integration_type": "PASS_THROUGH",
      "settlement_config": {
        "settlement_via": "FEE_RETENTION",
        "rebalance_fee": false,
        "destination_details": {
          "wallet_address": "SOLANA_WALLET_ADDRESS",
          "currency": "ETH",
          "rail": "ETHEREUM"
        }
      },
      "developer_fee": {
        "fixed": "0.5",
        "percentage": "1"
      }
    }
    '
    ```
  </Tab>
</Tabs>

<Warning>
  For `PASS_THROUGH`, `rebalance_fee` has to be **always** `false` .
</Warning>

## Pass through order creation:

<Tabs>
  <Tab title="Without Quote ID">
    ```json theme={null}
    curl --request POST \
      --url https://sandbox.api.fin.com/v1/transit/payment \
      --header 'Authorization: Bearer <token>' \
      --header 'Content-Type: application/json' \
      --data '
    {
      "integration_type": "PASS_THROUGH",
      "order_info": {
        "external_customer_id": "dcfed3f9-46ad-407b-87ff-3bac7c9c4c38",
        "merchant_trade_no": "841e4ba2-1234-5678-9abc-a2a45de7bd00",
        "order_amount": "100.00",
        "currency": "USDT",
        "rail": "SOLANA",
        "currency_type": "crypto"
      },
      "fin": {
        "settlement_config": {
          "settlement_via": "MARKET_ORDER",
          "destination_details": {
            "wallet_address": "Ox....",
            "currency": "PYUSD",
            "rail": "SOLANA"
          }
        },
        "developer_fee": {
          "fixed": "0.5",
          "percentage": "1"
        }
      }
    }
    '
    ```
  </Tab>

  <Tab title="With Quote ID">
    ```json theme={null}
    curl --request POST \
      --url https://sandbox.api.fin.com/v1/transit/payment \
      --header 'Authorization: Bearer <token>' \
      --header 'Content-Type: application/json' \
      --data '
    {
      "integration_type": "PASS_THROUGH",
      "order_info": {
        "external_customer_id": "1a11c804-8a9b-425d-96a8-c0682f52ff04",
        "quote_id": "5831ce86-cd88-4aba-b1fd-32dcf6e1a030",
        "merchant_trade_no": "841e4ba2-1234-5678-9abc-a2a45de7bd00",
        "currency": "USDT",
        "rail": "SOLANA",
        "currency_type": "crypto"
      }
    }
    '
    ```
  </Tab>
</Tabs>

<Info>
  `order_expiry_time` for `PASS_THROUGH` is configurable per developer but it has to be requested by the developer to Fin and Fin will configure it in their backend.
</Info>

## <u>Important Considerations</u>

### **About External Customer ID**

The external customer ID is required for the pass-through use case. When the same external customer ID is passed in multiple requests, the same deposit wallet address is issued for that customer.

For each external customer ID, one wallet address is issued per currency and rail combination. If a wallet address doesn't exist for an external customer ID, Fin creates a new one and issues it for the order and keeps using it for future orders.

### Limits to order creation

For a particular customer there can be only 1 order per currency & rail combination.

**For example:**

Customer 1 has an open order of 0.5 BTC.BITCOIN, the customer cannot create another BTC.BITCOIN order until the existing order **expires** / **fails** / **processed**

The default order expiry can be found above.

## Response Difference for Integration Type

| Integration Type | Response Field             |
| :--------------- | :------------------------- |
| PASS\_THROUGH    | `data.deposit_instruction` |