OpenChainGraph · Circle Arc L1 · 6 Tools · 8 Chains

Circle Arc Network: ChainGraph Workflow Guide

Verifiable economics and compliance chains for Circle Arc L1, the EVM-compatible blockchain with USDC-as-native-gas, Malachite BFT (~350ms finality), StableFX 24/7 on-chain FX, CPN global payment rail, xReserve/USYC, ERC-4337 Paymaster, and CCTP v2 cross-chain bridging. Public testnet Oct 2025; mainnet 2026. Eight chains covering the full Arc use-case surface area from CPN corridor economics to GENIUS Act §4 compliance to CCTP v2 transfer validation.

8 Chains · 6 Tools Circle Arc L1 CPN · StableFX · xReserve GENIUS Act §4 MiCA Art. 54 ERC-4337 · Paymaster CCTP v2 · v1 Sunset 31 Jul 2026

Start here: Run the Arc Fit Diagnostic (ART-42), a 12-question A–F diagnostic that grades your organization across CPN, StableFX, DvP, and agentic commerce dimensions and routes you to the right chain. The CCTP v2 branch fires when ≥2 dimensions score >0.

⬡ Open ART-42: Arc Fit Diagnostic →

Circle Arc L1 · Technology Facts

What is Arc?

Arc is Circle's EVM-compatible Layer 1 blockchain, purpose-built for financial use cases. It uses USDC as the native gas token, so agents and users never need ETH on Arc. Consensus is Malachite BFT with ~350ms finality. Public testnet launched Oct 2025; mainnet expected 2026.

Arc's key primitives: Circle Payments Network (CPN) for global USDC settlement corridors, StableFX for 24/7 on-chain FX (atomic Payment-versus-Payment, PFMI P12 compliant), xReserve for on-chain USDC/USYC reserve management, ERC-4337 Paymaster for USDC-as-gas account abstraction, and CCTP v2 for cross-chain USDC bridging (13 domains, Fast Transfer ~30s). USYC (Hashnote, US T-bill backed) is Circle's first native yield-bearing asset on Arc.

Consensus

Malachite BFT ~350ms finality

Native gas

USDC · no ETH required

Testnet

Oct 2025 (public)

Mainnet

2026

FX settlement

StableFX 24/7 PvP · PFMI P12

CCTP v2

13 domains · Fast Transfer ~30s

Yield asset

USYC (Hashnote) · US T-bill backed

Paymaster

ERC-4337 · Circle-sponsored gas

8 Chains · Start with the entry point

Arc Workflow Chains

Run ART-42 first. Its scores route you to one or more of the seven downstream chains. The CCTP v2 branch activates automatically when ≥2 dimensions score >0, indicating cross-chain flows are needed.

Entry Point

Arc Fit Diagnostic

12-question A–F scoring across CPN, StableFX, DvP, and agentic commerce. Routes to the right Arc chain. CCTP v2 branch fires when ≥2 dims >0.

1 Node · ART-42

→ chains/arc-fit.html

CPN Payment

CPN Corridor Economics

Model CPN vs SWIFT/ACH/SEPA/card for cross-border USD flows. 3-year NPV, per-payment cost savings, migration verdict. WorldBank Q4 2024 benchmarks.

2 Nodes · ART-42 → ART-43

→ chains/arc-cpn-payment.html

StableFX

StableFX Risk Elimination

Quantify Herstatt risk and FX spread savings from Arc StableFX 24/7 atomic PvP vs non-CLS bilateral settlement. BIS methodology. PFMI P12.

2 Nodes · ART-42 → ART-44

→ chains/arc-stablefx.html

xReserve

xReserve Issuance Compliance

8-check A–F linter: GENIUS §4 eligible assets, §4(a)(11) yield prohibition, MiCA Art. 54, USYC limits, CCTP domains, attestation, mint/burn segregation.

2 Nodes · ART-42 → ART-45

→ chains/arc-xreserve-issuance.html

DvP Settlement

DvP Atomic Settlement

StableFX PvP risk model + ERC-4337 Paymaster economics for atomic DvP on Arc. PFMI P12 atomicity. USDC-as-gas, no ETH bootstrap.

3 Nodes · ART-42 → ART-44 → ART-46

→ chains/arc-dvp-settlement.html

Agentic Commerce

ERC-4337 Paymaster gas abstraction + CPN settlement for autonomous agent payment flows on Arc. Sponsorship break-even. 3-year NPV for agent commerce.

3 Nodes · ART-42 → ART-46 → ART-43

→ chains/arc-agentic-commerce.html

Reserve

Reserve Compliance

Full reserve compliance workflow: xReserve GENIUS/MiCA linter + StableFX risk quantification for Arc stablecoin issuers who also hold FX exposures.

2 Nodes · ART-45 → ART-44

→ chains/arc-reserve-compliance.html

CCTP v2 · Deadline 31 Jul 2026

CCTP v2 Transfer

Validate CCTP v2 cross-chain USDC transfer: domain eligibility, Fast Transfer LP, Hook safety, v1 sunset migration. Fires when ≥2 Arc dims >0.

2 Nodes · ART-42 → ART-47

→ chains/arc-cctp-transfer.html

Regulatory Framework

Regulatory Citations

All Arc tools cite primary-source regulatory material. No fabricated figures. All numerical estimates (CPN fee, Arc gas price, StableFX spread) are clearly labeled as estimates and user-adjustable.

GENIUS §4

Payment Stablecoin Act (S.394, 119th Congress, signed 18 Jul 2025). Requires 1:1 eligible-asset backing: demand deposits, T-bills <93d, overnight repo on T-bills, Fed reserves. §4(a)(11) prohibits PPSIs from paying yield to holders.

MiCA Art. 54

EU Markets in Crypto-Assets Regulation Art. 54: reserve asset requirements for EU Electronic Money Token (EMT) issuers. Minimum liquid reserve; asset segregation; custody rules.

PFMI P12

CPSS-IOSCO Principles for Financial Market Infrastructures, Principle 12: Exchange-of-value settlement systems. Atomicity: final settlement of both legs simultaneously, or neither. Arc StableFX satisfies P12 for FX settlement.

BIS FX Code P35

BIS FX Global Code Principle 35: Market participants should seek to reduce settlement risk, preferring netting, PvP, and CLS-equivalent settlement where available. Arc StableFX provides PvP alternative for non-CLS pairs.

BIS Herstatt

Allsopp, Bhalla, Hackworth & Jeffery (1996): Quantifying principal risk in FX settlement. Herstatt exposure = notional × (exposure hours / 24). Used in ART-44 Herstatt credit-cost proxy calculation.

ERC-4337

Account Abstraction standard. Allows smart contract wallets as first-class users; Paymaster can sponsor or accept ERC-20 tokens (USDC on Arc) for gas. Circle Paymaster live on Arc testnet Oct 2025.

CCTP v2

Circle Cross-Chain Transfer Protocol v2. 13 domains as of Oct 2025. Fast Transfer: ~30s via LP-backed instant minting. Hooks: arbitrary execution on destination post-mint. CCTP v1 manual relay phase-out: 31 Jul 2026.

OpenChainGraph v0.3.1 · What These Tools Produce

Verifiable Execution Artifacts

Every Arc tool produces an OpenChainGraph §4 artifact: a JSON document anchored by a WebCrypto SHA-256 execution_hash over the sorted-key canonical preimage of policy_parameters + output_payload. The hash is independently verifiable by any tool that re-runs the same inputs.

chaingraph_version 0.3.1 · compatible with all OCG v0.3.x consumers
execution_hash WebCrypto SHA-256 · RFC 8785 / JCS canonical preimage · independently verifiable
chain block parent_hashes, parent_tool_ids, chain_depth · full DAG traceability
semantic_profile ISO 20022 aligned: pacs.008 (CPN/Paymaster), fxtr.008 (StableFX), acmt.023 (xReserve), pacs.009 (CCTP)
compliance_flags Machine-readable compliance verdict: ARC_FIT_DIAGNOSTIC_COMPLETE, CCTP_V2_VALIDATED, etc.
AP2 export All tools export JSON artifact + Markdown memo for direct LLM/agent consumption
zero PII All computations are fully client-side; no data transmitted. Verified by audit_signature in each artifact.