Quickstart

Validate a MultiversX pair, request a swap quote, and verify the response fields needed before signing.

Prerequisites

Requirement	Value
Base URL	`https://swap.xoxno.com`
Auth	None
Rate limit	100 requests per second per IP
Amount format	Integer strings in the token’s smallest unit

1. Validate The Pair

Call /api/v1/pair-config before quoting so your client has decimals and minimum input.

cURL
TypeScript
Python
Rust

curl "https://swap.xoxno.com/api/v1/pair-config?\
from=WEGLD-bd4d79&\
to=USDC-c76f1f"

const pairRes = await fetch(
  "https://swap.xoxno.com/api/v1/pair-config?from=WEGLD-bd4d79&to=USDC-c76f1f"
);
if (!pairRes.ok) throw new Error(`pair check failed: ${pairRes.status}`);

const pair = await pairRes.json();
if (!pair.supported) throw new Error(pair.error);

console.log(pair.decimalsIn, pair.decimalsOut, pair.minAmountIn);

import requests

res = requests.get(
    "https://swap.xoxno.com/api/v1/pair-config",
    params={"from": "WEGLD-bd4d79", "to": "USDC-c76f1f"},
    timeout=10,
)
res.raise_for_status()

pair = res.json()
if not pair["supported"]:
    raise RuntimeError(pair["error"])

print(pair["decimalsIn"], pair["decimalsOut"], pair["minAmountIn"])

// Run inside an async function with reqwest and serde_json.
let pair: serde_json::Value = reqwest::Client::new()
    .get("https://swap.xoxno.com/api/v1/pair-config")
    .query(&[("from", "WEGLD-bd4d79"), ("to", "USDC-c76f1f")])
    .send()
    .await?
    .error_for_status()?
    .json()
    .await?;

if pair["supported"] != true {
    return Err(format!("pair unsupported: {}", pair["error"]).into());
}

println!(
    "{} {} {}",
    pair["decimalsIn"], pair["decimalsOut"], pair["minAmountIn"]
);

Expected response:

{
  "supported": true,
  "decimalsIn": 18,
  "decimalsOut": 6,
  "minAmountIn": "1000000000"
}

2. Request A Quote

Quote 1 WEGLD to USDC. 1000000000000000000 is 1 WEGLD at 18 decimals.

cURL
TypeScript
Python
Rust

curl "https://swap.xoxno.com/api/v1/quote?\
from=WEGLD-bd4d79&\
to=USDC-c76f1f&\
amountIn=1000000000000000000&\
slippage=0.005"

const params = new URLSearchParams({
  from: "WEGLD-bd4d79",
  to: "USDC-c76f1f",
  amountIn: "1000000000000000000",
  slippage: "0.005",
});

const quoteRes = await fetch(`https://swap.xoxno.com/api/v1/quote?${params}`);
if (!quoteRes.ok) throw new Error(`quote failed: ${quoteRes.status}`);

const quote = await quoteRes.json();
console.log(quote.amountOut, quote.amountOutMin, quote.priceImpact);

import requests

res = requests.get(
    "https://swap.xoxno.com/api/v1/quote",
    params={
        "from": "WEGLD-bd4d79",
        "to": "USDC-c76f1f",
        "amountIn": "1000000000000000000",
        "slippage": "0.005",
    },
    timeout=10,
)
res.raise_for_status()

quote = res.json()
print(quote["amountOut"], quote["amountOutMin"], quote["priceImpact"])

// Run inside an async function with reqwest and serde_json.
let quote: serde_json::Value = reqwest::Client::new()
    .get("https://swap.xoxno.com/api/v1/quote")
    .query(&[
        ("from", "WEGLD-bd4d79"),
        ("to", "USDC-c76f1f"),
        ("amountIn", "1000000000000000000"),
        ("slippage", "0.005"),
    ])
    .send()
    .await?
    .error_for_status()?
    .json()
    .await?;

println!(
    "{} {} {}",
    quote["amountOut"], quote["amountOutMin"], quote["priceImpact"]
);

Inspect these fields:

Field	Use
`amountOut`	Smallest-unit output estimate.
`amountOutMin`	Slippage-protected minimum output.
`amountOutShort`	Display amount for the output token.
`priceImpact`	Decimal price impact estimate.

3. Request Transaction Data

Pass sender only when the user is ready to sign.

curl "https://swap.xoxno.com/api/v1/quote?\
from=WEGLD-bd4d79&\
to=USDC-c76f1f&\
amountIn=1000000000000000000&\
slippage=0.005&\
sender=erd1..."

The response can include:

Field	Meaning
`transaction`	Full MultiversX transaction object for wallet signing.
`txData`	Encoded contract call data when a full transaction object is not returned.

Do not reuse txData across quote requests. It encodes route and slippage state from that request.

Verify

You have a valid quickstart result when:

/api/v1/pair-config returns supported: true.
amountIn is greater than or equal to minAmountIn.
/api/v1/quote returns non-zero amountOut.
amountOutMin matches the slippage shown to the user.
If transaction is present, transaction.sender matches the connected wallet.

Common Failure

Symptom	Cause	Fix
Quote returns `400`	Both `amountIn` and `amountOut` were sent, or neither was sent.	Send exactly one amount field.
Pair is unsupported	Token is unknown or no route exists.	Stop before quoting and show `error` from pair config.
Signed transaction fails for ESDT input	Client used `txData` as the full data field.	Use the full `transaction` object, or wrap `txData` in the ESDT transfer prefix.

Aggregator

Prerequisites

1. Validate The Pair

2. Request A Quote

3. Request Transaction Data

Verify

Common Failure

Next Steps

​Prerequisites

​1. Validate The Pair

​2. Request A Quote

​3. Request Transaction Data

​Verify

​Common Failure

​Next Steps

Prerequisites

1. Validate The Pair

2. Request A Quote

3. Request Transaction Data

Verify

Common Failure

Next Steps