Before initiating a cross-chain transfer or creating an intent, you can request a quote from Chainrails.
The quote engine provides comprehensive information about how a transaction will be executed — including the route, estimated fees, and destination amount.
This allows your app to show users exactly what to expect before they fund the transaction.
Requesting Quotes
The quote engine provides comprehensive cross-chain transfer quotes from a single bridge, multiple bridges or even multiple source chains. You can retrieve:
Some quote endpoints take in an optional amountSymbol parameter which can be used to specify the denomination of the amount you want to send. For quotes in USD, you can either set amountSymbol to USDC (or leave it empty).You can quote in a different denomination than the token you want to send. For example, you can set amountSymbol to USDC, while sending ETH as tokenIn
A single quote for a specific route
curl --request GET \
--url "https://api.chainrails.io/api/v1/quotes/single?tokenIn=0x036CbD53842c5426634e7929541eC2318f3dCF7e&tokenOut=0x75faf114eafb1BDbe2F0316DF893fd58CE46AA4d&sourceChain=BASE_TESTNET&destinationChain=ARBITRUM_TESTNET&amount=1000000&bridge=CCTP" \
--header "Authorization: Bearer YOUR_API_KEY"
const fetch = require("node-fetch");
const url = new URL("https://api.chainrails.io/api/v1/quotes/single");
url.search = new URLSearchParams({
tokenIn: "0x036CbD53842c5426634e7929541eC2318f3dCF7e",
tokenOut: "0x75faf114eafb1BDbe2F0316DF893fd58CE46AA4d",
sourceChain: "BASE_TESTNET",
destinationChain: "ARBITRUM_TESTNET",
amount: "1000000",
bridge: "CCTP",
}).toString();
(async () => {
const res = await fetch(url, {
method: "GET",
headers: {
Authorization: `Bearer YOUR_API_KEY`,
},
});
const data = await res.json();
console.log("Quote:", data);
})();
<?php
$apiKey = "YOUR_API_KEY";
$baseUrl = "https://api.chainrails.io/api/v1/quotes/single";
$params = http_build_query([
"tokenIn" => "0x036CbD53842c5426634e7929541eC2318f3dCF7e",
"tokenOut" => "0x75faf114eafb1BDbe2F0316DF893fd58CE46AA4d",
"sourceChain" => "BASE_TESTNET",
"destinationChain" => "ARBITRUM_TESTNET",
"amount" => "1000000",
"bridge" => "CCTP",
]);
$url = "$baseUrl?$params";
$ch = curl_init($url);
curl_setopt_array($ch, [
CURLOPT_RETURNTRANSFER => true,
CURLOPT_HTTPHEADER => [
"Authorization: Bearer $apiKey"
],
]);
$response = curl_exec($ch);
if (curl_errno($ch)) {
echo 'Error: ' . curl_error($ch);
} else {
echo "Response: " . $response;
}
curl_close($ch);
Or a multi-source quote for a given destination chain
Useful for when you want to show users all source options and their respective fees to send funds to a specific destination chain.
curl --request GET \
--url "https://api.chainrails.io/api/v1/quotes/multi-source?destinationChain=ARBITRUM_TESTNET&amount=1.5&tokenOut=0x75faf114eafb1BDbe2F0316DF893fd58CE46AA4d" \
--header "Authorization: Bearer YOUR_API_KEY"
const fetch = require("node-fetch");
const url = new URL("https://api.chainrails.xyz/api/v1/quotes/multi-source");
url.search = new URLSearchParams({
destinationChain: "ARBITRUM_TESTNET",
amount: "1.5",
tokenOut: "0x75faf114eafb1BDbe2F0316DF893fd58CE46AA4d",
}).toString();
(async () => {
const res = await fetch(url, {
method: "GET",
headers: {
Authorization: `Bearer YOUR_API_KEY`,
},
});
const data = await res.json();
console.log("Quotes from multiple sources:", data);
})();
<?php
$apiKey = "YOUR_API_KEY";
$baseUrl = "https://api.chainrails.io/api/v1/quotes/multi-source";
$params = http_build_query([
"destinationChain" => "ARBITRUM_TESTNET",
"amount" => "1.5",
"tokenOut" => "0x75faf114eafb1BDbe2F0316DF893fd58CE46AA4d",
]);
$url = "$baseUrl?$params";
$ch = curl_init($url);
curl_setopt_array($ch, [
CURLOPT_RETURNTRANSFER => true,
CURLOPT_HTTPHEADER => [
"Authorization: Bearer $apiKey"
],
]);
$response = curl_exec($ch);
if (curl_errno($ch)) {
echo 'Error: ' . curl_error($ch);
} else {
echo "Response: " . $response;
}
curl_close($ch);
For most cases, you would want to use the multi-source quoting as it shows the user all the best quotes to choose from.
The Routing Engine
The Routing Engine provides extensive details about supported bridges, their available routes, and the optimal route for a given transfer intent. For most use cases, the quote engine is sufficient but if you want more fine grained control over bridge selection, you can use the routing engine directly.
You can consult the API reference for all available routing endpoints.
Parameters Reference
| Parameter | Type | Required | Description | Example |
|---|
| tokenIn | string | ✅ Yes (for /quotes/single) | Address of the input token on the source chain. This is the token the user will send. | 0x036CbD53842c5426634e7929541eC2318f3dCF7e |
| tokenOut | string | ✅ Yes | Address of the output token on the destination chain. | 0x06ef8BFf21a47c8E15944D1f4A68F9F95f66A34 |
| sourceChain | string | ✅ Yes (for /quotes/single) | The blockchain where the user is sending funds from. Must be one of the supported chain identifiers. | BASE_TESTNET |
| destinationChain | string | ✅ Yes | The blockchain where the funds should arrive. Must be one of the supported chain identifiers. | ARBITRUM_TESTNET |
| amount | string | ✅ Yes | Amount to transfer, in token units. Supports decimals. | "1.5" |
| bridge | string | ✅ Yes (for /quotes/single) | The specific bridge protocol to use for the quote. | ACROSS |
| recipient | string | ❌ Optional | Address of the final recipient of the transfer. | 0xb79541Be080a59fdcE6C0b43219ba56c725eC65e |
