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Swap

The Swap tab converts between XLM, USDC, and EURC using the live Stellar testnet DEX order book. The rate you see is whatever the network's market makers are quoting — not an oracle, not a CEX feed.

How a swap runs​

  1. You type an amount in the You pay panel.
  2. Pesalo debounces ~350 ms and asks Horizon for the best strict-send path from your source asset to the destination asset. Horizon returns the best destination_amount across all available paths (direct or via intermediate hops).
  3. The You receive panel fills with that amount, the Rate line shows 1 SRC ≈ X DST.
  4. We apply a 1% slippage floor to destMin so the order doesn't fail under churn.
  5. On Swap, we build a pathPaymentStrictSend op, sign it, and POST to Horizon.

Auto-trustline​

Stellar requires a trustline for any non-native asset before an account can hold it. If you swap XLM → USDC and your account doesn't trust USDC yet, Pesalo runs a change_trust op first, then the swap, in the same user action. You'll see two signed transactions in the loading overlay, then a single success.

Quick-percent chips​

The You pay panel has 25% / 50% / MAX chips that prefill your current balance share. MAX uses the full free balance — be aware that the 2 XLM reserve floor still applies if you're swapping native XLM out, so a true 100% will get rejected with op_underfunded.

Common failures​

  • "No swap route available right now." — Horizon's path-finder couldn't get from source to destination at this size. Try a smaller amount, the other direction, or a different pair.
  • "Price moved against you past the slippage limit. Try again." — order book moved more than 1% during build. The rate updates on the next keystroke.
  • "Stellar rejected the transaction (op_too_few_offers)." — not enough cumulative liquidity in the path. Use a smaller amount.

EURC liquidity caveat​

XLM ↔ EURC swaps frequently return "No swap route available" on testnet because Circle's testnet EURC issuer (GB3Q6QDZYTHWT7E5PVS3W7FUT5GVAFC5KSZFFLPU25GO7VTC3NM2ZTVO) has essentially zero DEX liquidity. That's a real testnet ecosystem state, not a bug. Mainnet EURC books are deep. See Limitations.