Colossus Docs Index

As of March 13, 2026, the new Colossus docs make the system much clearer.

Colossus is not just another crypto card wrapper on top of Visa or Mastercard rails. The docs describe a stablecoin-native card network on an Ethereum L2 (Chain ID 951) that keeps the familiar EMV card and terminal flow while moving settlement, issuer/acquirer configuration, and auditability onchain.

What It Is

• Network model: a vertically integrated card network with issuer, processor, and settlement layers tied together on ColossusNet.
• User experience: same card-present EMV tap flow and existing terminals, but settlement runs through ColossusNet rather than legacy card-network rails.
• Credit model: three modes are documented:
  • Direct Debit
  • Consumer Credit
  • Premium Credit
• Who owns credit policy: the issuer. ColossusNet provides the network, validation, settlement, gas sponsorship, and onchain audit trail.
• Core timing + identifiers: RID A000000951, Chain ID 951, 1 second block time, 100ms preconfirmation, and 172ms measured end-to-end authorization latency in the architecture docs.

Product Docs

• Overview
  • What Colossus is, how it works, fee structure, settlement tiers, and network identifiers.
• Frequently Asked Questions
  • Common questions around compatibility, regulation, and product boundaries.

Technical Docs

• System Architecture
  • L2 parameters, account abstraction, middleware timing, and the 172ms authorization budget.
• Card Architecture
  • JavaCard applets, EMV interfaces, dual issuance, cryptographic design, and card registration.
• Transaction Flow
  • Contact/contactless flows, issuer-mediated settlement, GENERATE AC, and offline terminal behavior.
• Smart Contracts
  • EMVValidator, EMVSettlement, AcquirerConfig, and token/currency mapping.
• Cross-Chain Architecture
  • Stablecoin bridging and source-chain module design.
• ISO 8583 Middleware
  • Message parsing, API endpoints, UserOperation construction, and gas sponsorship.

Integration Guides

• For Merchants
  • Fees, settlement, chargeback handling, wire liquidation, and why merchants do not carry traditional representment/arbitration burden.
• For Issuers
  • Dual issuance, collateral pools, issuer hooks, interchange tiers, and the split between issuer credit policy and ColossusNet settlement.
• For Acquirers
  • ISO 8583 integration, onchain merchant/terminal registry, settlement export, wire liquidation, and gas sponsorship.
• For Cardholders
  • Wallet setup, card registration, funding, and payment flow.

API Reference

• Endpoints
  • API index.
• Schemas
  • Data models and type definitions.
• Service Information
  • Root service metadata.
• Health Check
  • Liveness/health endpoint.
• Process ARQC Message
  • Authorization request processing.
• Prometheus Metrics
  • Metrics endpoint.

Repos Referenced In Docs

• github.com/colossus-credit
• emv-validator
• emv-card-sim
• emvpt
• kernel
• devnet
• rollup-boost
• builder-playground

Why It Matters For attn

• Colossus is not a direct attn Credit comparator.
• It is closer to card-network + issuer/acquirer settlement infrastructure.
• The relevant overlap is strategic:
  • cards
  • issuer-funded credit
  • merchant settlement
  • same-terminal stablecoin acceptance
• That makes it useful context for attn partnerships and market mapping, especially where credit engines may sit behind card or payment surfaces rather than owning the front-end network.