Every quote races Across, deBridge, THORChain, Mayan, Velora and KyberSwap in parallel and you get the best net route — cross-chain on Base, Arbitrum, Optimism, Ethereum and 20+ chains, or same-chain on the biggest DEX liquidity. Non-custodial: quotes are free, you execute with your own wallet, and every fee is shown upfront — nothing hidden.
One call races every aggregator that covers the route (Across + deBridge + THORChain + Mayan cross-chain, route-dependent; Velora + KyberSwap same-chain) and returns the best net quote (amountOut, minAmountOut, fill time), a transparent fee breakdown, ready-to-sign calldata and the full ranking in alternatives[]. Your agent pays per call via x402 and executes the transaction itself — Carredge never holds funds. Want the full side-by-side table? GET /v1/swap/compare (same $0.03).
| Name | Required | Description |
|---|---|---|
| fromChain | yes | Origin chain id (numeric EVM): 1 Ethereum · 8453 Base · 42161 Arbitrum · 10 Optimism · 137 Polygon · 56 BNB · 43114 Avalanche |
| toChain | yes | Destination chain id — same as fromChain for same-chain swaps (Velora + KyberSwap race), different for cross-chain (Across + deBridge race) |
| fromToken | yes | Input token contract on origin chain (0x0000…0000 for native ETH) |
| toToken | yes | Output token contract on destination chain (0x0000…0000 for native ETH) |
| amount | yes | Integer in the token's base units (wei for 18-decimals, micro for USDC) |
| depositor | yes* | 0x address that signs and executes (*or recipient instead) |
| recipient | no | Where the client receives the output token (defaults to depositor) |
| feeBps | no | Manual override of the integrator fee, 0-50. Default for agents: 10 bps |
# returns HTTP 402 with the x402 payment challenge until paid:
curl -i "https://api.carredge.com/v1/swap?fromChain=8453&toChain=10&fromToken=0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913&toToken=0x0b2C639c533813f4Aa9D7837CAf62653d097Ff85&amount=10000000&depositor=0xYOUR_ADDRESS"
{
"meta": { "product": "carredge", "ts": "2026-10-04T18:20:11.000Z" },
"data": {
"source": "across",
"quote": {
"amountIn": "10000000",
"amountOut": "9993300",
"minAmountOut": "9993260",
"estimatedFillTimeSeconds": 2,
"quoteExpiresAt": "2026-10-04T18:30:11.000Z"
},
"fees": {
"across": { "total": "6600", "totalUsd": 0.0066 },
"integrator": {
"included": true,
"feeBps": 10,
"amount": "1000",
"amountUsd": 0.001,
"recipient": "0x7c07…F2a0C"
},
"breakdown": [
"Across protocol fee: 6600 USDC (~$0.0066)",
"Integrator fee (Carredge): 10 bps (~$0.0010) — included in the amounts above",
"You receive (min): 9993260 USDC raw units"
]
},
"transaction": {
"chainId": 8453,
"to": "0x09aea4b2242abC8bb4BB78D537A67a245A7bEC64",
"data": "0xad5425c6…",
"value": "0"
},
"alternatives": [
{ "source": "debridge", "quote": { "amountOut": "9960600", "estimatedFillTimeSeconds": 23 } }
],
"comparison": [
{ "rank": 1, "source": "across", "amountOut": "9993300", "estimateSec": 2, "winner": true },
{ "rank": 2, "source": "debridge", "amountOut": "9960600", "estimateSec": 23 }
],
"disclaimer": "You execute on-chain yourself with your own signer and gas; Carredge never holds, custodies or moves funds."
}
}
Full reference: /docs#swap · discovery: /.well-known/x402 · MCP: /mcp
Quotes and calldata only. You sign, you pay gas, your keys move the funds — Carredge never holds anything.
No accounts, no email, no identity checks. The widget works right now in your browser.
Every quote shows the protocol fee and our 0.15% (min $0.25) integrator fee as separate lines before you commit.
Browsing costs nothing. Agents using the API pay $0.03 per call via x402 — a different funnel, same endpoint.
Carredge Swap races four aggregators on every quote: cross-chain routes go through Across intents (professional relayers compete to fill your order, median fills ~2s) and deBridge DLN (0-TVL cross-chain orders); same-chain routes go through Velora (ex-ParaSwap) and KyberSwap (meta-aggregation across hundreds of DEX pools). We return the best net route with a minimum received, an explicit fee breakdown and the exact transaction for your wallet — plus every alternative, so you can see who came second. Nothing is custodied by us at any point.
Aggregators usually bury the cost. We print it: the protocol/routing fee (Across LP + relayer, deBridge order costs, Velora/KyberSwap routing gas) on one line, our integrator fee of 0.15% with a $0.25 minimum on the next, and the exact amount you receive at the bottom. Compare the "you receive" number against any Jumper, Relay or exchange route — that is the only benchmark that matters.
Popular routes include ETH on Base to USDC on Arbitrum, USDC on Ethereum to USDC on Optimism, WBTC bridging, and stablecoin swaps across Polygon, BNB Chain, Avalanche, Unichain and Linea. Same-chain swaps (USDC→WETH on Base, ETH→USDC on Ethereum) settle atomically in one transaction through the deepest DEX liquidity. Cross-token routes execute as a local swap plus a single intent bridge — one transaction from your wallet.
AI agents call GET /v1/swap and pay $0.03 per quote via the x402 protocol in USDC on Base — no API key, no signup. GET /v1/swap/compare returns the full side-by-side table of every aggregator for the same price. Humans use the widget above and pay nothing per quote; the service earns the embedded integrator fee only when a swap executes.
No. The service is non-custodial: you receive quotes and calldata, and you execute with your own wallet and gas. There is no account, no KYC and no signup anywhere in the flow.
Two lines, always visible: the protocol/routing fee (set by the winning aggregator: Across LP + relayer costs, deBridge order costs, Velora or KyberSwap routing gas) and the Carredge integrator fee — 0.15% with a $0.25 minimum on the human widget, 10 bps for API agents. The quoted "you receive" amount is already net of everything.
Ethereum, Base, Arbitrum, Optimism, Polygon, BNB Chain, Avalanche, Unichain, Linea and more — 26+ EVM chains cross-chain via Across, deBridge, THORChain and Mayan, plus same-chain swaps on the biggest DEX ecosystems via Velora and KyberSwap. Native ETH, USDC, USDT, DAI, WBTC and routed pairs.
Real reviews only — every submission is moderated before it appears here. Never invented, never paid.
Every executed swap settles on-chain from YOUR wallet — audit the fills on any explorer. We custody nothing, so there is nothing to trust but the chain.
checking…
The same engine behind this widget powers GET /v1/swap and /v1/swap/compare for agents — plus memecoin trading on Zora, Solana and Robinhood Chain.
Protocol fee and our integrator fee are separate lines on every quote — the "you receive" number is always net of everything. Compare it anywhere.