Dmytro Plavutskyi
Independent Founder & Product Builder

Case · Open on Arc Mainnet

Ryntra Guard

Stablecoin operations for teams on Arc

Role
My own product — strategy, design, engineering and release, done by me.
Status
Open on Arc Mainnet
Verified
2026-09-28
See it yourself
arc.ryntra.io ↗

The problem

Teams that pay in stablecoins need one way of paying: checked before the wallet signs, proven after Arc settles — without handing their keys or funds to anyone.

The approach

  • Request: who is paid, how much, in which stablecoin, on Arc — or a link the payer opens and pays
  • Check: the network, the recipient against sanctions lists, the balance and the fee — with a reason when it stops a payment
  • Approve: your own wallet approves the exact payment — change the amount or the recipient and it no longer applies
  • Settle: Arc settles it, and Ryntra reads the chain back to match what settled to what was approved
  • Receipt: every payment closes with a sealed receipt anyone can re-check against Arc, without trusting Ryntra

Who it's for

  • Teams paying contractors from their own wallet, with an approval on every payout
  • Companies whose finance team has to account for the treasury, payment by payment
  • Developers who request, check and prove payments from inside their own product

What it gives

  • A payment checked before anyone signs, with the approval bound to exactly what is signed
  • Your team's wallet signs every payment — Ryntra holds no keys and no funds
  • What settled matched to what was approved, read back from Arc
  • A sealed receipt anyone can verify with open-source code — no account, no key

What exists now

  • Live on Arc Mainnet: verify any Ryntra receipt — no account, no wallet
  • Open on Arc Mainnet: get paid with a link or QR; send, checked before you sign; payouts with an approval
  • Open on Arc Mainnet: send to your exchange account on Arc; top up Arc from another network
  • On testnet: exchange USDC ↔ EURC; export receipts for your books

What this case does not claim

Boundaries are part of the case. If it's not listed as existing, it isn't claimed.

  • Ryntra holds no keys and no funds, and nothing passes through its addresses
  • Payments are open on Arc Mainnet; the full app runs on testnet
  • Coming, not open: getting paid and paying out in EURC, a Safe treasury, batches, card or bank top-up, agent budgets and the payment intents API
  • Checks apply to payments prepared in Ryntra; wallet-level rules come with Safe
  • Amounts and addresses on Arc are public; Circle services only where Circle serves your country

What I build now.

My attention is on two products of one brand: Ryntra and Ryntra Guard. This page stays as a record of what came before.