App Kit SDK: Swap

The App Kit SDK includes the Swap capability that lets you swap two tokens in a few lines of code. Swap supports many stablecoins (including USDC, EURC, USDT, USDe, DAI, and PYUSD) and native tokens on supported blockchains. On Arc, Swap accepts only USDC, EURC, and cirBTC. Swap is available on mainnet only, with the exception of Arc testnet.

Quick look

Same-chain swap
Crosschain swap

This example swaps 1 USDC for EURC on Arc Testnet:

TypeScript

const result = await kit.swap({
  from: { adapter: viemAdapter, chain: "Arc_Testnet" },
  tokenIn: "USDC",
  tokenOut: "EURC",
  amountIn: "1.00",
});

See Swap tokens on a blockchain for a full working example.

This example swaps 1 USDC on Base for native POL delivered on Polygon in a single call:

TypeScript

const result = await kit.swap({
  from: { adapter: viemAdapter, chain: "Base" },
  tokenIn: "USDC",
  tokenOut: "NATIVE",
  amountIn: "1.00",
  to: {
    chain: "Polygon",
    recipientAddress: "0xYourRecipientAddress",
  },
});

See Swap tokens across blockchains for a full working example.

API key

Swap accepts an optional Circle API key obtained from the Circle Console. Pass one as apiKey in the swap config. Without one, requests share a rate limit. Production traffic typically needs a key to avoid hitting it. API keys are environment specific. Testnet and mainnet each need their own key.

Moving from a kit key? Kit keys are legacy, and new ones cannot be created. Existing kit keys remain valid, but new integrations use an API key. Rename the kitKey parameter in your swap config to apiKey when you upgrade the SDK.

Installation

Install the App Kit SDK to use Swap. If you only need to swap and don’t want to install the full App Kit SDK, install the standalone Swap Kit for your preferred adapter below.

Viem
Ethers
Solana
Circle Wallets

npm install @circle-fin/swap-kit @circle-fin/adapter-viem-v2 viem

yarn add @circle-fin/swap-kit @circle-fin/adapter-viem-v2 viem

npm install @circle-fin/swap-kit @circle-fin/adapter-ethers-v6 ethers

yarn add @circle-fin/swap-kit @circle-fin/adapter-ethers-v6 ethers

npm install @circle-fin/swap-kit @circle-fin/adapter-solana-kit @solana/kit @solana/web3.js

yarn add @circle-fin/swap-kit @circle-fin/adapter-solana-kit @solana/kit @solana/web3.js

npm install @circle-fin/swap-kit @circle-fin/adapter-circle-wallets

yarn add @circle-fin/swap-kit @circle-fin/adapter-circle-wallets

Send

Bridge

Swap

Unified Balance

Onramp

Earn

App Kit SDK: Swap

Quick look

API key

Installation

​Quick look

​API key

​Installation

Quick look

API key

Installation