Use Bridge’s APIs to convert from one fiat currency to another using a method we call the Stablecoin Sandwich.

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What is a stablecoin sandwich?

A stablecoin sandwich uses stablecoin as mechanism to convert between two fiat currencies.

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Funds flow

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One-time setup

1

1. Create a Bridge wallet

This wallet will hold stablecoins (USDC) used as the source for FX transfers. You can provision the wallet under your own customer id that you use for developing on Bridge.
Request
curl --location 'https://api.bridge.xyz/v0/customers/cust_alice/wallets' \
--header 'Api-Key: <API-Key>' \
--header 'Idempotency-Key: w1' \
--header 'Content-Type: application/json' \
--data '{
    "chain":"solana"
}'
Use the returned wallet id in all future orchestration and payout requests.
Response
{
    "id": "ec89f8d1-7d0d-47a1-b92f-96f5eb25600e",
    "chain": "base",
    "address": "0x58b34dc21b5253053f53cf5f143c421266441058",
    "tags": [],
    "created_at": "2025-07-05T00:45:02.206Z",
    "updated_at": "2025-07-05T00:45:02.206Z"
}
2

2. Create a USD virtual account and point it to your Bridge wallet

This is where your USD deposits (via ACH or Wire) will land. Funds will be auto-converted to USDC into your Bridge Wallet.
Request
curl --location --request POST 'https://api.bridge.xyz/v0/customers/cust_alice/virtual_accounts' \
--header 'Content-Type: application/json' \
--header 'Api-Key: <Api-Key>' \
--header 'Idempotency-Key: <Unique Idempotency Key>' \
--data-raw '{
  "source": {
    "currency": "usd"
  },
  "destination": {
    "payment_rail": "bridge_wallet",
    "currency": "usdc",
    "bridge_wallet_id": "wallet_id"
  }
}'
Response
{
    "id": "1a400dae-f7fc-4f75-8105-212a14d4132d",
    "status": "activated",
    "customer_id": "cust_alice",
    "created_at": "2025-07-04T22:10:34.564Z",
    "source_deposit_instructions": {
        "currency": "usd",
        "bank_name": "Lead Bank",
        "bank_address": "1801 Main St., Kansas City, MO 64108",
        "bank_routing_number": "101019644",
        "bank_account_number": "215268120000",
        "bank_beneficiary_name": "Alice",
        "bank_beneficiary_address": "923 Folsom Street, 302, San Francisco, California 941070000, US",
        "payment_rail": "ach_push",
        "payment_rails": [
            "ach_push",
            "wire"
        ]
    },
    "destination": {
        "payment_rail": "bridge_wallet",
        "currency": "usdc",
        "bridge_wallet_id": "wallet_id"
    }
}
3

3. Configure an external account (MXN CLABE)

Create an external account representing the recipient of the MXN funds. This only needs to be created once per recipient.
Request
curl --location 'https://api.bridge.xyz/v0/customers/23c2d462-4c69-4c5a-b31a-88d035d7e8ae/external_accounts' \
--header 'Idempotency-Key: ea-6' \
--header 'Content-Type: application/json' \
--header 'Accept: application/json' \
--header 'Api-Key: <api-key>' \
--data '{
  "currency": "mxn",
  "account_owner_type": "individual",
  "first_name": "Carlos",
  "last_name": "Ramirez",
  "account_type": "clabe",
  "account_owner_name": "Carlos Ramirez",
  "bank_name": "BBVA Bancomer",
  "clabe": {
    "account_number": "626899715090851234"
  },
  "account_name": "Carlos Personal Bank Account",
  "address": {
    "street_line_1": "Av. Reforma",
    "city": "Mexico City",
    "state": "CDMX",
    "postal_code": "06600",
    "country": "MEX"
  }
}'
4

4. Send a Transfer from USDC to MXN

Now you’re ready to FX!
In step 1-3, you’ve created a virtual account that will receive USD deposits. With every USD deposit, we will forward those funds as USDC to your Bridge wallet. The last step is to go from USDC to MXN!
Request
curl --location --request POST 'https://api.bridge.xyz/v0/transfers' \
--header 'Api-Key: <API Key>' \
--header 'Idempotency-Key: <Unique Idempotency Key>' \
--data-raw '{
  "on_behalf_of": "cust_alice",
  "amount": "1000.0",
  "source": {
    "currency": "usdc",
    "payment_rail": "bridge_wallet",
    "bridge_wallet_id": "wallet_id"
  },
  "destination": {
    "currency": "mxn",
    "payment_rail": "spei",
    "external_account_id": "mxn_external_account_id"
  }
}'
Bridge executes the FX conversion at market rate and delivers MXN via SPEI, an instant 24/7/365 payment rail in Mexico.

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Webhooks

Bridge emits webhooks for every orchestration state:
  • payment_initiated
  • payment_processed
  • cancelled
Use these to trigger business logic, notifications, or retries.

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Alternative methods

  • In the above example, we used a transfer to create one time FX payment.
  • If you want to automatically convert USD to MXN upon receiving a deposit, you can:
    • In Step 2, point your virtual account to a liquidation address.
    • Point the liquidation address to the destination external bank account.
We design our APIs to be powerful and flexible lego blocks for developers to build a wide range of use cases.