Swap

The Swap API converts one token into another — same-chain (e.g. USDC → USDT on Polygon, via Rach’s on-chain FiatSwapV2 proxy) or cross-chain (e.g. Polygon → BSC, via a bridge). Quote first, then execute. Authenticate with your Payments API key (X-API-Key).

Base URL: https://api.rach.finance/api/v1/ · Auth: X-API-Key (quote is public)

1. Get a quote

GET /swap/quote is public — no key required.

curl "https://api.rach.finance/api/v1/swap/quote?from_chain=POL&to_chain=POL&from_token=USDC&to_token=USDT&amount_in=100"

Response

{
  "from_chain": "POL",
  "to_chain": "POL",
  "from_token": "USDC",
  "to_token": "USDT",
  "from_amount": "100",
  "to_amount_expected": "99.85",
  "to_amount_min": "99.35",
  "platform_fee": "0.30",
  "estimated_seconds": 30,
  "expires_at": 1755168000
}

to_amount_min reflects slippage protection — the swap reverts if output would fall below it.

2. Execute the swap

Run the swap for a customer wallet. Pass amount_out_min (use the quote’s to_amount_min) to protect against slippage.

curl https://api.rach.finance/api/v1/swap/customer/cust_001 \
  -H "X-API-Key: $RACH_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "from_chain": "POL",
    "to_chain": "POL",
    "from_token": "USDC",
    "to_token": "USDT",
    "amount_in": "100",
    "amount_out_min": "99.35"
  }'

const swap = await (await fetch("https://api.rach.finance/api/v1/swap/customer/cust_001", {
  method: "POST",
  headers: { "X-API-Key": process.env.RACH_KEY, "Content-Type": "application/json" },
  body: JSON.stringify({
    from_chain: "POL", to_chain: "POL",
    from_token: "USDC", to_token: "USDT",
    amount_in: "100", amount_out_min: "99.35",
  }),
})).json();

Response

{ "tx_hash": "0x9f8e...", "status": "pending" }

3. Track history

curl https://api.rach.finance/api/v1/swap/customer/cust_001/history \
  -H "X-API-Key: $RACH_KEY"

Same-chain swaps on Polygon and BSC route through Rach’s FiatSwapV2 proxy (0.30% platform fee, applied on-chain). Cross-chain swaps bridge via an aggregator and take longer — estimated_seconds reflects the route.

See the Swap endpoints in the Payments API Reference.

Get Started

Core Products

Monitoring & Webhooks

1. Get a quote

2. Execute the swap

3. Track history

​1. Get a quote

​2. Execute the swap

​3. Track history

1. Get a quote

2. Execute the swap

3. Track history