XRPL Swap API

curl -X POST 'https://api.xrpl.to/v1/dex/quote' \
  -H 'Content-Type: application/json' \
  -d '{
  "source_account": "rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh",
  "source_token": "84e5efeb89c4eae8f68188982dc290d8",
  "source_value": "10",
  "destination_token": "0dd550278b74cb6690fdae351e8e0df3"
}'

{
  "status": "success",
  "requiresTrustline": {
    "currency": "524C555344000000000000000000000000000000",
    "issuer": "rMxCKbEDwqr76QuheSUMdEGf4B9xJ8m5De",
    "limit": "13.101899999999997"
  },
  "quote": {
    "source_amount": {
      "currency": "XRP",
      "value": "10.000000"
    },
    "destination_amount": {
      "currency": "524C555344000000000000000000000000000000",
      "issuer": "rMxCKbEDwqr76QuheSUMdEGf4B9xJ8m5De",
      "value": "13.101899999999997"
    },
    "execution_rate": "0.76324808",
    "price_impact": {
      "percent": "-0.06%",
      "xrp": "0.01 XRP"
    },
    "suggested_slippage": 0.6,
    "route": "xrp",
    "paths": [],
    "warnings": []
  }
}

• Exact input or exact output: send source_value (what you give) or destination_value (what you want).
• suggested_slippage is the tolerance, in percent, this trade needs; use it rather than a fixed figure.
• paths must go into the Payment for token-to-token routes; it is empty when one side is XRP.

import { PaymentFlags, xrpToDrops } from 'xrpl'

// The quote writes XRP as drops (a string) or as { currency: 'XRP', value };
// a token as { currency, issuer, value }.
const isXrp = (a) => typeof a === 'string' || a.currency === 'XRP'
const valueOf = (a) => (typeof a === 'string' ? Number(a) / 1e6 : Number(a.value))
const amount = (a, v) => isXrp(a)
  ? xrpToDrops(v.toFixed(6))
  : { currency: a.currency, issuer: a.issuer, value: v.toPrecision(15) }

function buildSwap(account, quote) {
  const give = quote.source_amount, get = quote.destination_amount
  const out = valueOf(get)
  return {
    TransactionType: 'Payment',
    Account: account,
    Destination: account,                         // paying yourself is a swap
    SendMax: amount(give, valueOf(give)),         // the most you give
    Amount: amount(get, out * 2),                 // a ceiling; DeliverMin is the real limit
    DeliverMin: amount(get, out * (1 - quote.suggested_slippage / 100)),
    Flags: PaymentFlags.tfPartialPayment,
    ...(quote.paths?.length ? { Paths: quote.paths } : {}),
  }
}

With the partial-payment flag, the ledger delivers as much as your SendMax buys, and refuses the whole trade if that would be less than DeliverMin. Both directions of this builder were dry-run on Mainnet with rippled’s simulate and came back tesSUCCESS. To tell your app’s trades apart on the ledger, add a SourceTag of your own.

import { Client, Wallet } from 'xrpl'

const client = new Client('wss://xrplcluster.com')
await client.connect()
const wallet = Wallet.fromSeed(seed)                      // on the user's device
const tx = await client.autofill(buildSwap(wallet.address, quote))
const { tx_blob, hash } = wallet.sign(tx)

const res = await fetch('https://api.xrpl.to/v1/submit', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({ tx_blob }),
}).then((r) => r.json())                                  // res.engine_result is provisional

// later: final once validated
const done = await fetch(`https://api.xrpl.to/v1/tx/${hash}`).then((r) => r.json())
// done.validated === true, done.meta.TransactionResult === 'tesSUCCESS'

The result from /submit is the server’s first opinion; only the validated ledger is final. Or let xrpl.js do steps 3 and 4 at once with client.submitAndWait(tx, { wallet }) (xrpl.js guide).

• tecPATH_PARTIAL (“Path could not send full amount”): the price moved past your DeliverMin. Quote again.
• tecPATH_DRY (“Path could not send partial amount”): no route at all, often a missing trust line for what you are buying; the quote’s requiresTrustline says which to open, with NoRipple set.
• tecUNFUNDED_PAYMENT: not enough to send once the reserve is kept back.

Quoted messages are rippled’s own (TER.cpp).

Quotes run the heaviest routing the API does, so they have their own limit: 1/min anonymous, 3/min free, 45/min partner (10 credits/call). Higher limits come with a key (plans). Any app, website, bot, or dashboard that displays xrpl.to data must show a visible, clickable credit to xrpl.to on the same screen as that data — not buried in an about page.

Is there a swap API for the XRP Ledger?

Yes. xrpl.to’s POST /v1/dex/quote returns the best price for a swap across every order book and AMM pool on the ledger, with the paths and slippage to use; your app then signs and submits the Payment.

Does the swap API hold or sign anything?

No. It only quotes. The transaction is built and signed on the user’s side and can be submitted to any XRP Ledger server.

How many quotes can I request?

Per the API’s own documentation: 1/min anonymous, 3/min free, 45/min partner (10 credits/call). A key raises the limit.