Integrate the API

Base URL is https://api.uatu.dev. Quoting requires an API key, so create one in the console first. The catalogue endpoints are open.

The flow

Request for a quote

POST /quotes with the pair, the amount and who receives the output.

Read the steps

The response carries a steps array: an ordered list of ready-to-send transactions, typically a Permit2 approval followed by the swap.

Send each step in order

Sign and broadcast with your own wallet, waiting for each to confirm.

Write the integration

viem
ethers.js

import { createWalletClient, createPublicClient, http } from "viem";
import { mainnet } from "viem/chains";
import { privateKeyToAccount } from "viem/accounts";

const UATU = "https://api.uatu.dev";

const account = privateKeyToAccount(process.env.PRIVATE_KEY as `0x${string}`);
const wallet = createWalletClient({ account, chain: mainnet, transport: http() });
const publicClient = createPublicClient({ chain: mainnet, transport: http() });

// 1. quote
const res = await fetch(`${UATU}/quotes`, {
  method: "POST",
  headers: {
    "Authorization": `Bearer ${process.env.UATU_API_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    originChainId: 1,
    destinationChainId: 1,
    tokenIn: "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2",  // WETH
    tokenOut: "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48", // USDC
    amount: "1",
    recipientAddress: account.address,
    slippageBps: 50, // optional, 0.5%
  }),
});

const body = await res.json();
if (!res.ok) throw new Error(body.message);
const quote = body.data;

// 2. check the floor and the clock before spending gas
console.log(`out ${quote.amountOutFloat} USDC via ${quote.route.name}`);
console.log(`min ${quote.amountOutMinimum} (raw units)`);

if (Math.floor(Date.now() / 1000) >= Number(quote.deadline)) {
  throw new Error("quote expired, request a new one");
}

// 3. send the steps in order
for (const step of quote.steps) {
  const hash = await wallet.sendTransaction({
    to: step.to as `0x${string}`,
    data: step.data as `0x${string}`,
    value: step.value ? BigInt(step.value) : 0n,
  });
  await publicClient.waitForTransactionReceipt({ hash });
  console.log(`${step.message}: ${hash}`);
}

import { JsonRpcProvider, Wallet } from "ethers";

const UATU = "https://api.uatu.dev";

const provider = new JsonRpcProvider(process.env.RPC_URL);
const wallet = new Wallet(process.env.PRIVATE_KEY!, provider);

// 1. quote
const res = await fetch(`${UATU}/quotes`, {
  method: "POST",
  headers: {
    "Authorization": `Bearer ${process.env.UATU_API_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    originChainId: 1,
    destinationChainId: 1,
    tokenIn: "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2",  // WETH
    tokenOut: "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48", // USDC
    amount: "1",
    recipientAddress: wallet.address,
    slippageBps: 50, // optional, 0.5%
  }),
});

const body = await res.json();
if (!res.ok) throw new Error(body.message);
const quote = body.data;

// 2. check the floor and the clock before spending gas
console.log(`out ${quote.amountOutFloat} USDC via ${quote.route.name}`);
console.log(`min ${quote.amountOutMinimum} (raw units)`);

if (Math.floor(Date.now() / 1000) >= Number(quote.deadline)) {
  throw new Error("quote expired, request a new one");
}

// 3. send the steps in order
for (const step of quote.steps) {
  const tx = await wallet.sendTransaction({
    to: step.to,
    data: step.data,
    value: step.value ? BigInt(step.value) : 0n,
  });
  await tx.wait();
  console.log(`${step.message}: ${tx.hash}`);
}

Get a read-only quote

POST /quotes/routes takes the same body, with matching originChainId and destinationChainId, and returns the best acceptable quote per DEX, ordered by output amount. Nothing is persisted and no transaction steps are returned. Use it while a user is still choosing, then call POST /quotes for a fresh executable quote.

curl -X POST https://api.uatu.dev/quotes/routes \
  -H "Authorization: Bearer ${UATU_API_KEY}" \
  -H "Content-Type: application/json" \
  -d '{
    "originChainId": 1, "destinationChainId": 1,
    "tokenIn": "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2",
    "tokenOut": "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48",
    "amount": "1",
    "recipientAddress": "0xYourAddress"
  }'

A real response, trimmed to one route:

{
  "code": 200,
  "message": "DEX quotes fetched successfully",
  "data": [
    {
      "amountIn": "1000000000000000000",
      "amountOut": "2493777615",
      "amountOutMinimum": "2481308726",
      "slippageBps": 50,
      "deadline": 1787624479,
      "route": { "name": "CowSwap", "dex": "cowswap", "fees": "42207128027132" }
    }
  ]
}

Common pitfalls

Amounts come in two forms

amount on the request is a decimal string in display units, so "1" means one WETH. Amounts on the response are integer strings in the token’s smallest unit: amountOut of "2493777615" is 2493.777615 USDC at 6 decimals. Use amountOutFloat for display and the raw integers for anything on-chain.

Quotes expire

deadline is a Unix timestamp five minutes out. Check it before broadcasting, especially if a user has been staring at a confirmation screen.

Steps are ordered and must all land

A swap usually needs its Permit2 approval mined before the swap itself. Wait for each receipt rather than firing them together.

amountOutMinimum is enforced on-chain

It is encoded into the calldata, so a fill worse than that floor reverts rather than filling badly. A reverted swap that cost gas is usually a moved market, not a bad request. Re-quote and retry.

Native assets use value

When the input token is the chain’s native asset, the step carries value. Send it, or the swap reverts.

Error handling

Every failure shape, with real responses.

Get started

Guides

Concepts

Integrate the API

The flow

Write the integration

Get a read-only quote

Common pitfalls

Error handling

​The flow

​Write the integration

​Get a read-only quote

​Common pitfalls

Error handling

The flow

Write the integration

Get a read-only quote

Common pitfalls