Arc Technical Architecture: A Guide for Ethereum Developers

The expensive mistake in an Arc migration is treating it like a new RPC URL. Arc is designed around a different economic center: stablecoin finance. That changes what developers should optimize, even when familiar EVM tooling remains useful.

For an Ethereum developer, the encouraging part is that the application layer does not need to be reinvented. Arc is EVM-compatible, so Solidity contracts, standard transaction concepts, and much of the existing developer workflow remain relevant. The architectural work is elsewhere: understand the consensus assumptions, make USDC the native fee asset in your product model, and avoid depending on Ethereum-specific operating assumptions that Arc does not promise.

This guide maps the important layers without inventing chain IDs, RPC URLs, contract addresses, or undocumented APIs. Treat the current Arc documentation as the source of truth for network configuration and deployment instructions.

Arc’s architecture in one view

A useful mental model is to separate Arc into five layers:

1. Execution: EVM-compatible smart-contract execution for Solidity and familiar transaction semantics.
2. Consensus: Malachite-based Byzantine fault-tolerant consensus, intended to provide deterministic, sub-second finality under the network’s validator assumptions.
3. Validator set: A permissioned validator model rather than an open, permissionless proof-of-stake set.
4. Fee asset: USDC gas, which makes transaction costs denominated in the stablecoin most relevant to the network’s financial use cases.
5. Application roadmap: Privacy and MEV-oriented capabilities are staged or roadmap areas, not blanket guarantees that every deployment already has private ordering or confidential execution.

That last point matters. “Built for stablecoin finance” describes the design direction; it is not a reason to infer an undocumented API, privacy primitive, or production feature.

What EVM compatibility means in practice

EVM compatibility gives an Ethereum team a familiar starting point:

• Solidity and common EVM languages remain the natural contract languages.
• Contract calls, event logs, ABI encoding, and transaction receipts should be approached with standard EVM abstractions.
• Existing tooling can often be reused, provided the tool supports the network configuration you obtain from Arc’s official docs.
• Wallet and custody integrations still need an explicit network review. EVM-compatible does not mean every wallet, indexer, bridge, or RPC provider supports Arc automatically.

Compatibility is not identical to equivalence. Do not hard-code assumptions about block timing, fee volatility, validator decentralization, reorg behavior, precompiles, supported opcodes, or ecosystem infrastructure until you verify them. A good migration starts by converting assumptions into test cases.

Ethereum versus Arc: the engineering surface

Consensus and finality: design for a known answer

Arc uses a Malachite-based BFT consensus design. The practical implication for builders is not merely “blocks are fast.” It is that the network is designed around deterministic finality under its consensus assumptions, with a target of sub-second finality described in Arc’s materials.

That changes application logic. On a chain where teams wait for a probabilistic confirmation policy, a deposit service may count blocks and set a risk threshold. On Arc, a better pattern is to use the network’s documented finality and receipt behavior, then define what your own business process considers settled.

Do not write code that assumes every observed block is final, and do not write code that assumes a generic Ethereum confirmation count transfers unchanged. Instead:

• Separate included from finalized in your database.
• Persist the transaction hash, block reference, and finality status.
• Make settlement idempotent.
• Reconcile against the official network or indexer data available to your system.
• Define a timeout and an operator review path for unavailable or ambiguous infrastructure.

Illustrative pseudocode, intentionally using no undocumented endpoint:

submit transfer
store {tx_hash, status: "submitted"}

while status != "finalized":
    receipt = read_standard_evm_receipt(tx_hash)

    if receipt is missing:
        retry_with_backoff()
        continue

    if receipt indicates execution failure:
        mark_failed_once()
        stop

    if arc_finality_signal_is_confirmed(receipt, documented_network_rules):
        mark_finalized_once(tx_hash, receipt.block_reference)
        release_business_action()
        stop

    mark_included_but_unfinalized(receipt.block_reference)
    wait()

The function name arc_finality_signal_is_confirmed is a placeholder for your integration’s documented implementation. It is not an Arc endpoint.

USDC gas changes product architecture

USDC gas is more than a fee-setting detail. It can simplify a stablecoin application because users do not need to acquire a second asset solely to pay for transactions. It also introduces operational questions that Ethereum teams sometimes leave to the wallet layer.

Your product should decide:

• Who supplies the user’s USDC for gas?
• Is the displayed price in USDC fixed, estimated, or refreshed before signing?
• How are gas limits and fee parameters represented in the UI?
• What happens when a user has enough USDC for the payment but not enough for gas?
• Can a relayer or paymaster model be used, and is that capability documented for the deployment you target?
• How do treasury, accounting, and risk systems reconcile gas expense in USDC?

A safe configuration should keep network-specific values outside application code:

network:
  name: arc
  chain_id: "LOAD_FROM_OFFICIAL_ARC_DOCUMENTATION"
  rpc_url: "LOAD_FROM_OFFICIAL_ARC_DOCUMENTATION"
  explorer_url: "LOAD_FROM_OFFICIAL_ARC_DOCUMENTATION"
fees:
  asset: USDC
  quote_policy: "refresh-before-signing"
  max_fee_policy: "use-values-supported-by-network-documentation"

The placeholders are deliberate. Never copy a chain ID, RPC URL, explorer URL, or token address from an unofficial post into production.

Permissioned validators and reliability assumptions

A permissioned validator set can support predictable operations and coordinated infrastructure, but it is also a different trust and governance model from a permissionless network. Your threat model should document both the benefits and the assumptions.

For application teams, the practical checklist includes:

• Identify the validator and governance information published by Arc.
• Ask which failures the consensus design tolerates and what operators monitor.
• Define how your service behaves during validator maintenance, network halt, or degraded finality.
• Avoid claiming that permissioned means centralized in every operational sense, or that BFT means failure-proof.
• Keep an emergency pause or withdrawal policy at the application layer where the business risk justifies it.

This is especially important for custody, treasury, and settlement products. A fast finality target is valuable only if your service can detect when the network is outside normal conditions.

Deployment workflow for an Ethereum team

1. Inventory assumptions

List every Ethereum-specific dependency: native asset balances, confirmation counts, chain ID allowlists, bridge contracts, block explorers, gas oracle logic, RPC methods, indexer support, and wallet network metadata.

2. Compile and test against the target environment

Use the compiler version, libraries, and deployment method supported by your existing stack, then test against Arc’s documented environment. Include contract deployment, event decoding, revert handling, and fee estimation. Do not assume a green local test proves network compatibility.

3. Build fee-aware UX

Show USDC gas clearly. Test insufficient-gas states, stale quotes, rejected transactions, and users who hold application funds but cannot pay the fee.

4. Separate inclusion from settlement

Update your indexing schema and queues. A receipt can indicate execution while your business rule waits for the documented finality condition.

5. Threat-model visibility and ordering

Treat ordinary on-chain data as public unless the relevant Arc documentation explicitly says otherwise. Do not market a contract as private because privacy features appear on a roadmap.

6. Operate with observability

Track failed transactions, fee estimates, receipt latency, finality latency, RPC errors, and reconciliation mismatches. Alert on behavior, not just infrastructure uptime.

Teams building automation systems should make these states first-class workflow inputs rather than burying them in a retry loop.

What not to assume

Several common migration shortcuts create avoidable risk:

• “EVM-compatible means Ethereum-identical.” It does not establish identical infrastructure, precompiles, fees, or finality semantics.
• “Sub-second finality means zero latency.” Wallet signing, RPC propagation, indexing, and application processing still take time.
• “USDC gas means users never need fee management.” They still need a sufficient balance and a valid transaction configuration.
• “Permissioned validators are automatically safer.” They change the trust and operational model; they do not remove the need for controls.
• “Roadmap privacy is available today.” Verify the exact release and deployment before relying on it.

Developer checklist

Before mainnet launch, confirm:

• Arc’s official docs provide the exact network identifiers used by your deployment.
• No chain ID, RPC URL, token address, or endpoint is hard-coded from an unofficial source.
• Contracts compile and pass integration tests in the target environment.
• Wallet, custody, indexer, and explorer support is verified.
• USDC gas is represented in quotes, balances, accounting, and support playbooks.
• Included, failed, and finalized states are distinct in storage and code.
• Retry logic is idempotent and has an operator escalation path.
• Validator, outage, and degraded-finality assumptions are in the threat model.
• Privacy and MEV claims are limited to documented, deployed capabilities.
• A staging deployment has been reconciled independently.

The practical takeaway

Arc gives Ethereum developers a familiar execution model with a different network thesis: stablecoin-native fees, BFT-oriented deterministic finality, and a validator model designed for a purpose-built financial network. The best migration is not a blind port. It is an assumption audit.

Start with a small contract and one settlement workflow. Verify the official network configuration, model USDC gas end to end, separate inclusion from finality, and test failure states before expanding. For teams that need help turning this into a launch plan, Hangryfeed’s Web3 services and contact page are the natural next steps.

Official sources

• Arc documentation
• Circle: Introducing Arc
• Arc Litepaper (PDF)