Token Swap
Powered by the 0x aggregation router — one transaction searches multiple liquidity sources for the best route. Quotes are fetched live, and every transaction is signed by your own wallet, so your assets never touch CoinRung's servers.
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Fees and how it works
Fee breakdown
- Service fee = trade size × rate. The rate is configured server-side and cannot be changed from the browser
- The service fee is transferred straight to the platform's receiving address by 0x at settlement — it never passes through CoinRung's books
- 0x's own protocol fee and the on-chain gas fee are billed separately and are itemised in every quote
- No service fee is charged while no receiving address is configured
Transaction flow
- Enter an amount to fetch a quote; the fee rate is injected by our backend and is not editable from the client
- Swapping an ERC20 for the first time needs an approval — only for the amount this trade requires
- The swap transaction is signed by your own wallet; your private key never reaches CoinRung
- Once the transaction is confirmed on-chain you can verify the details on a block explorer
Quotes are generated by a third-party aggregator (0x) at the moment of quoting, and the executed price moves with on-chain liquidity and slippage. Every quote carries a minimum-received amount; if the trade settles below it the transaction reverts and gas is returned. CoinRung does not custody assets, does not handle keys, and cannot be responsible for on-chain outcomes. Start with a small test trade.
Frequently asked questions
- Does CoinRung hold my tokens?
- No. Your assets stay in your own wallet throughout the whole flow — CoinRung only fetches quotes and shows you the route. Both the approval and the swap are signed by your wallet, and your private key never passes through our servers.
- How is the service fee charged, and why is it not hidden?
- The service fee is a percentage of the trade size, transferred by 0x directly to the platform's receiving address at settlement instead of through our settlement account. The rate is shown as its own line in the quote, so you can see the exact amount before signing. The rate lives on the server only, so it cannot be edited or bypassed from the browser.
- Why do I have to approve a token first?
- It is how token contracts work: a contract can only move your tokens if it holds an allowance you granted. An approval is an on-chain transaction that costs gas, so you only need it the first time you swap a given token. We request an allowance for this trade only, never an unlimited one.
- Which chains and tokens are supported?
- Currently nine chains: Ethereum, Base, Arbitrum, OP Mainnet, Polygon, BNB Chain, Avalanche, Scroll and Linea. The token list is cached per chain Low-capidity tokens may not have enough liquidity, which the quote will flag.
- What is slippage protection, and can I get a worse fill?
- Every quote carries a minimum-received amount — the worst fill the trade will accept. If the market moves beyond it, the whole transaction reverts and the gas is refunded, so you cannot be slipped into a bad price by accident. The protection is listed separately in the quote breakdown.
- What if my transaction seems stuck?
- Open the block explorer link in the quote breakdown to check the on-chain status: if the transaction is still being packed, give it a moment; if it reverted, send a new one. Also note that if your wallet is on a different chain, the swap button turns into "Switch to XX chain" — switch first, then trade.