Exchange Rates

Overview

Exchange rates let you preview the available rates and estimated destination amounts for a given currency pair before committing to the full transfer flow. This is useful for displaying indicative pricing to users before they provide bank account details or create a payment account. Unlike quotes, exchange rates don’t lock in a rate or require any customer or bank account information. They fit into the transfer flow as an optional first step, letting you check what rates are available and what the user can expect to receive before proceeding.

API flow

Action / step

The steps above, in text:

#	Actor	Step
–	User	Requests an exchange rate from the partner
1	Partner	Calls `GET /exchange-rates`
2	Rain	Returns the available rate
3	Partner	Displays the indicative rate to the user
4	Partner	Creates a quote and transfer to proceed

Get an exchange rate

To retrieve the current exchange rate for a currency pair, call the Exchange Rates endpoint. The request shape mirrors a quote but without any user, company, or payment account references.

Request

curl -X GET "https://api.rain.xyz/v1/exchange-rates?sourceCurrency=usdc&sourceRail=base&destinationCurrency=cop&destinationRail=co_ach&sourceAmount=100" \
  -H "Api-Key: YOUR_API_KEY"

The sourceAmount field is optional. If you omit it, the response returns only the exchange rate, without a destination amount or fees breakdown.

Response (with source amount)

{
  "source": {
    "amount": "100",
    "currency": "usdc",
    "rail": "base"
  },
  "destination": {
    "amount": "415000",
    "currency": "cop",
    "rail": "co_ach"
  },
  "exchangeRate": "4200",
  "fees": {
    "rain": {
      "currency": "usdc",
      "amount": "1",
      "amountUSD": "1"
    }
  }
}

Response (without source amount)

{
  "source": {
    "currency": "usdc",
    "rail": "base"
  },
  "destination": {
    "currency": "cop",
    "rail": "co_ach"
  },
  "exchangeRate": "4200"
}

Response fields

Field	Description
`source.amount`	The source amount provided in the request (if specified)
`source.currency`	The source currency
`source.rail`	The source rail
`destination.amount`	The estimated destination amount based on the rate (only present if `source.amount` is provided)
`destination.currency`	The destination currency
`destination.rail`	The destination rail
`exchangeRate`	The indicative conversion rate as a decimal string (destination per source unit), excluding fees
`fees.rain`	The fee charged to your platform (only present if `source.amount` is provided)

Exchange rates are indicative and not locked. The actual rate applied to a transfer is determined when a quote is created. Rates may fluctuate between the time an exchange rate is retrieved and a quote is locked.

Supported currency pairs

Source

Currency	Rails
`usdc`	`base`, `ethereum`, `optimism`, `polygon`, `solana`
`rusd`	`base`, `ethereum`, `optimism`, `polygon`, `solana`
`usd`	`base`, `ethereum`, `optimism`, `polygon`, `solana`

Destination

Currency	Country	Rail
`cop`	Colombia	`co_ach`
`mxn`	Mexico	`mx_spei`

Additional currency pairs are being added regularly. Contact your Rain representative for the latest supported configurations.

What’s next

Create quotes and transfers

Follow the full flow to create payment accounts, quotes, and transfers.

Set up onramps

Enable fiat deposits into crypto.

Set up offramps

Enable USD withdrawals from crypto.

Introduction

Set Up Money Movement

Money Movement

Subtenants

Reconciliation

Exchange Rates

Overview

API flow

Get an exchange rate

Request

Response (with source amount)

Response (without source amount)

Response fields

Supported currency pairs

Source

Destination

What’s next

Create quotes and transfers

Set up onramps

Set up offramps

​Overview

​API flow

​Get an exchange rate

​Request

​Response (with source amount)

​Response (without source amount)

​Response fields

​Supported currency pairs

​Source

​Destination

​What’s next

Create quotes and transfers

Set up onramps

Set up offramps

Overview

API flow

Get an exchange rate

Request

Response (with source amount)

Response (without source amount)

Response fields

Supported currency pairs

Source

Destination

What’s next