Onchain payables & accounting · Built on Arc

Pay. Close the books. Retire the key.optional

Contrapay pays your vendors in USDC and EURC from your own Safe and writes the journal entry in the same step. Turn on bunker mode, and every key that signs retires in that same transaction.

Become a design partner Try bunker mode
0 keysheld by Contrapay that can move your funds
1×Each key signs once on chain in bunker mode, then it retires
≈0.5 sCCTP attestation for transfers from Arc
Optional · watch the rotation
The problem

Month-end should not be archaeology.

Today37unmatched
With Contrapay0unmatched
USDC on five chains Hashes matched by hand Bridges that look like expenses EUR invoices in spreadsheets
Payment and entry in one flow

The entry is born with the payment.

Payment run PR-0187

2/3
Acme Ltd12,000.00 USDC INV-104 · Arc queuedpaid on Arcburned · in transitminted on Base
Beta GmbH4,500.00 EURC 2026-88 · Arc · EUR queuedpaid on Arcburned · in transitminted on Base
Gamma Labs3,000.00 USDC G-17 · Base · CCTP queuedpaid on Arcburned · in transitminted on Base
Safe 2 of 3 signed · relayer executed tx 0x7c3e…a91f · 3 × InvoicePaid

Journal entries posted

Example data
AccountDebitCredit
R03JE-1041 · INV-104 settled on Arc
Accounts payable · USD12,000.00
Holdings · USDC · Arc12,000.00
R04JE-1042 · 2026-88, EUR 4,500.00
Accounts payable · EUR4,878.00
Realized FX gain/loss18.90
Holdings · EURC · Arc4,896.90
R06JE-1043 · G-17 burned on Arc
Transfers in transit3,000.00
Holdings · USDC · Arc3,000.00
R07JE-1044 · G-17 minted on Base
Accounts payable · USD3,000.00
Transfers in transit3,000.00
Total22,896.9022,896.90
Balanced · holdings = chain
Bunker mode · optional

Sign once. Retire the key.

Every signature reveals a public key. In bunker mode, that key loses control in the same transaction.

Mode AFor Safe treasuries

Owner rotation

The owners who sign are replaced in the same transaction.

Same Safe addressk-of-n staysCold owner never signs
Mode BFor single-signer treasuries

Address rotation

Your funds always sit on an address that has never signed.

EIP-7702 batchRelayer pays the gasOne treasury in the books
Spare owner required
Key proofs stay in your browser
A second admin turns it on

Status: optional, per treasury, after the pilot. Mode A comes first. It protects your keys. It does not change how USDC or CCTP sign.

How it works

Six steps. One Safe transaction.

  1. Capture the invoicePDF SHA-256
  2. Approve by policy2 approvals above 5,000 USD
  3. Batch up to 25MultiSend → pay()
  4. Sign in your walletEIP-712 · safeTxHash
  5. Settle or routeArc <1 s · CCTP
  6. Post and syncJE → Xero
Built on Arc

Arc at the center. Every chain at the edge.

Final on Arc in under a second. Paid out to five chains with CCTP. Vendors get the full amount.

Payment routes from Arc Arc, CCTP domain 26, sits at the center. Routes go to Ethereum (domain 0), OP Mainnet (2), Arbitrum (3), Base (6) and Polygon PoS (7). Arc domain 26 Ethereumdomain 0 OP Mainnetdomain 2 Arbitrumdomain 3 Basedomain 6 Polygon PoSdomain 7
<1 sfinality on Arc
≈0.001USDC gas per transfer
0.5 sCCTP attestation from Arc
0 bpsCCTP fee from Arc
What you get

Built for the controller and the signers.

Non-custodial

Your Safe, your signers. We never hold funds.

Onchain proof

InvoicePaid carries the invoice and PDF hash.

Hourly reconciliation

Holdings = chain, to 18 decimals.

EUR without spreadsheets

ECB rates. Realized FX posts with the payment.

Xero sync

Bills, payments and files. The bill shows as paid.

Fraud controls

New payout address: second approver and 24 h wait.

Security

We prepare. You sign.

Signers see every payment in plain terms, and the same hash on their hardware wallet.

Contrapay · signing screenPR-0187
  • Acme Ltd12,000.00 USDCArc
  • Beta GmbH4,500.00 EURCArc
  • Gamma Labs3,000.00 USDCBase
safeTxHash0x8f3a 91c2 … 7d04 c21e
Immutable router 7-day deadline per run Relayer holds only gas Second view in Safe{Wallet} Signing only on app.contrapay3.com

Want more? Turn on bunker modeOptional
Scope

Pilot first. Then the rest.

In the pilotPhase 1
Safe + EOA on ArcUSDC + EURCCCTP to 5 chainsDouble-entry ledgerECB FX ratesXero + CSV
Next
ReceivablesCircle Gateway balanceBank payoutsQuickBooks · NetSuiteBunker modeFireblocks · BitGo
Operations enter Approvers approve Signers sign Accountants close

For protocols, DAOs, Web3 studios and crypto-native companies.

Design partners

Looking for 2–3 teams building on Arc.

Contact: hello@contrapay3.com

Free during the pilot
A direct line to the builder
A say in the roadmap
Fit: a Safe on Arc and recurring vendor payments
FAQ

Questions teams ask first.

Does Contrapay hold our funds?

No. Payments leave your own Safe, signed by your own signers. Our relayer only submits them and holds only gas.

What if Contrapay is down?

Your funds stay in your Safe, and Safe{Wallet} still works. When Contrapay returns, it reads the chain from where it stopped.

Which chains can vendors use?

Arc, plus Base, Arbitrum, OP Mainnet, Polygon PoS and Ethereum through CCTP. Vendors get the full invoice amount.

Can an auditor check a payment without Contrapay?

Yes. The auditor recomputes the invoice hash and compares it with the InvoicePaid event on Arc.

Why is bunker mode optional?

It adds steps. In Mode A, each signer registers a next key and the Safe Transaction Service mirror is off. Mode B uses a single key. A good multisig is enough for most teams today.