For Issuers

Colossus gives banks and fintechs a new way to issue payment cards. Dual-issue with Colossus alongside your existing Visa or Mastercard program to earn higher interchange with instant settlement.

Dual issuance

Your existing card program stays exactly as it is. Colossus is added as an additional network on your cards. When a cardholder transacts at a merchant that accepts Colossus, the transaction routes through ColossusNet at higher interchange with instant settlement. When they transact anywhere else, the card falls back to the primary network.

New cards are issued with both networks enabled on your natural reissuance cycle. There is no requirement to reissue your entire portfolio at once.

The Durbin Amendment requires by law that every debit card carry at least two unaffiliated payment networks. Adding Colossus as the second network on a debit card is doing exactly what the law already mandates. For credit cards, the Credit Card Competition Act would extend dual-network requirements to credit. By dual-issuing with Colossus now, you are positioned ahead of potential regulation.

Colossus transactions are purely incremental. At zero Colossus merchant acceptance, your card is exactly what it was yesterday. At any level of Colossus acceptance, you are earning more.

Revenue

Issuers earn the full interchange on every ColossusNet transaction. No network assessments, no per-authorization fees, no settlement fees.

On a $100 Consumer Credit transaction, the issuer nets approximately $1.699. On Visa, after network deductions (assessments, per-auth fees, settlement fees), the net is approximately $1.55-$1.65. The network fee on ColossusNet trends downward over time as the underlying infrastructure gets cheaper, improving margins year over year.

Interchange is settled instantly. On legacy networks, the issuer authorizes a transaction on Monday but does not receive the interchange payment until Wednesday. On ColossusNet, the interchange is settled in seconds.

How the collateral model works

Rather than funding transactions through traditional banking rails, ColossusNet uses an on-chain collateral model:

1. Post collateral: Deposit stablecoins into a ColossusNet collateral pool. This pool covers transactions for your cardholders.
2. Fund transactions: When a cardholder taps their card, ColossusNet forwards the card's cryptographic proof to you. You validate the transaction and return a signed funding authorization.
3. Dual-signature settlement: ColossusNet verifies both the card's EMV signature (ECDSA P-256) and your funding signature, then draws from your collateral pool to settle with the merchant instantly.
4. Top up as needed: Periodically replenish your collateral balance. Transactions that would exceed available collateral are declined automatically by on-chain enforcement.

The merchant is paid instantly from your collateral pool. You then independently retrieve the settlement amount from the cardholder on the source chain. The cardholder's source chain account has the ColossusNet ERC-7579 modules installed, enabling you to noncustodially retrieve settlement amounts. See Cross-Chain Architecture for the full flow.

Consumer Credit

Consumer Credit issuance is permissionless with a $100,000 refundable deposit. Any bank, fintech, credit union, or lending platform can issue Consumer Credit cards by posting the deposit. KYC is optional for Consumer Credit issuers.

The $100K deposit is held by the protocol and covers dispute resolution for chargebacks and fraud. The full deposit is returned if you leave the network.

2026 Launch Incentive: The $100,000 deposit is waived for the first 10 issuers.

Premium Credit

Premium Credit requires permission from the network. Colossus grants Premium status based on the issuer's demonstrated ability to deliver a genuinely differentiated card product: travel benefits, concierge services, lounge access, elevated insurance, and reward structures that justify the higher interchange rate.

• KYC/AML mandatory for all Premium Credit issuers.
• Deposit amount set by request based on projected volume and risk profile.
• 20% issuance cap: Premium Credit cards will never exceed 20% of total ColossusNet card issuance, preventing the portfolio migration problem seen on legacy networks where issuers steadily moved their entire card base into premium tiers to capture higher interchange.

Premium status is reviewed periodically. If an issuer reduces their benefits package while continuing to charge Premium interchange, Colossus can revoke the designation and move the issuer's cards to the Consumer tier at 1.70%.

Issuer hooks

When cards are registered on ColossusNet, they are bound to your issuer hook, a smart contract you deploy on ColossusNet. The hook executes within the transaction context and validates that txn.origin matches your stored issuer address. This ensures only your authorized systems can draw against your collateral pool.

The hook is registered during the card registration process and is invoked automatically after the card's EMV signature is validated.

Signing API

To participate in transaction authorization, you host a WebSocket signing endpoint:

/api/v1/eth_signRawTransactionSync

The endpoint receives a raw byte stream containing the transaction to be funded. Your system validates the transaction (checking cardholder balance, credit limits, risk parameters, and any other criteria you define) and returns a signed response synchronously.

The WebSocket design is intentional: ColossusNet's measured authorization latency is 172ms, and the synchronous round-trip ensures your authorization decision fits within that window.

Credit limit enforcement

Credit limits and available credit calculations are managed entirely by you through the signing API. When a transaction arrives at your signing endpoint, you evaluate cardholder creditworthiness and balance before returning a signed funding authorization. ColossusNet does not enforce or calculate credit limits; that authority remains with the issuer.

This means you can implement whatever credit policy you choose: traditional credit limits, dynamic risk scoring, real-time fraud checks, or any other logic your business requires.

Card registration flow

Registering a cardholder with an issuer follows a four-step process:

1. Account setup: The cardholder creates an ERC-4337 account with a standard Ethereum key pair (secp256k1 root signer).
2. Card tap: The cardholder taps their ColossusNet card on their phone. The mobile app reads the card via NFC and retrieves the secp256r1 public key and tokenized PAN.
3. On-chain registration: The cardholder submits a transaction registering the PAN, secp256r1 public key, and your issuer hook on ColossusNet. This binds the card to your collateral pool.
4. Source chain module installation: The cardholder installs the EMVValidator and EMVSettlement modules on their source chain ERC-4337 account, enabling you to noncustodially retrieve settlement amounts.

See Card Registration for the full technical flow.

What ColossusNet provides

You focus on credit policy, risk management, and cardholder relationships. ColossusNet handles the rest:

• Settlement infrastructure: Instant stablecoin settlement with merchants from your collateral pool.
• On-chain signature verification: Card EMV signatures validated via the RIP-7212 P-256 precompile.
• Cross-chain bridging: Cardholders and issuers can fund accounts from any EVM chain via LayerZero OFT V2.
• Gas sponsorship: All transaction gas is covered by ColossusNet. Neither you nor your cardholders pay gas fees.
• Immutable audit trail: Every transaction is recorded on-chain for compliance and reconciliation.