# Ethereum Classic (ETC)

> Ethereum Classic is immutable infrastructure for global finance — the only mature Proof-of-Work blockchain with native smart contracts, permissionless, censorship-resistant, and secured by dedicated mining infrastructure operating continuously since 2015.

Full context for AI agents: https://ethereumclassic.com/llms-full.txt

## About

Ethereum Classic (ETC) is a decentralized, open-source blockchain platform that runs smart contracts. It is the original Ethereum chain, maintaining the principle of "Code is Law" after the 2016 DAO fork. ETC uses Proof-of-Work consensus with the ETCHash mining algorithm and has a fixed monetary policy with a capped supply of ~210.7 million ETC.

ETC sits at the intersection of two distinct regulatory trajectories: the commodity classification path that Bitcoin established (Proof-of-Work, no issuer, no pre-mine) and the programmable finance frameworks that Ethereum established (EVM, Solidity, DeFi). Bitcoin has PoW without programmability. Ethereum has the EVM without PoW. ETC has both.

## Key Facts

- Ticker: ETC
- Chain ID: 61 (mainnet), 63 (Mordor testnet)
- Consensus: Proof-of-Work (ETCHash)
- Block time: ~13 seconds
- Supply cap: ~210.7 million ETC
- Current block reward: 1.6384 ETC (Era 6, blocks 25M–30M)
- Block reward reduction: 20% every 5 million blocks ("fifthing")
- Smart contracts: EVM-compatible (Solidity, Vyper)

## Sections

- [About](https://ethereumclassic.com/about) — Site overview, institutional positioning (PoW Security, Institutional Infrastructure, Regulatory Clarity), PoW/EVM intersection, community
- [Investment Products](https://ethereumclassic.com/investment-products) — Grayscale Ethereum Classic Trust (ETCG): fund facts, Grayscale product lifecycle (3-stage trust-to-ETF path, GBTC Jan 2024 → ETHE Jul 2024 precedent), brokerage access, investment thesis
- [Wallet](https://ethereumclassic.com/wallet) — Download wallets and manage ETC
- [Buy ETC](https://ethereumclassic.com/buy) — Purchase ETC on exchanges
- [Exchanges](https://ethereumclassic.com/exchanges) — Compare and filter exchanges by fees, KYC, and region
- [Apps](https://ethereumclassic.com/apps) — Discover DeFi, infrastructure, and dApps on ETC
- [Learn](https://ethereumclassic.com/learn) — Educational resources about Ethereum Classic
- [FAQ](https://ethereumclassic.com/faq) — Frequently asked questions for users, investors, miners, developers, and community
- [Why Classic](https://ethereumclassic.com/why-classic) — Philosophy: genesis, code is law, decentralism, proof of work, sound money
- [Mining](https://ethereumclassic.com/mining) — Mining pools, hardware, and profitability
- [Build](https://ethereumclassic.com/build) — Developer documentation and tools
- [News](https://ethereumclassic.com/news) — Latest Ethereum Classic news and updates
- [Research](https://ethereumclassic.com/research) — Network analytics, supply data, and reports
- [Emission Schedule](https://ethereumclassic.com/research/emission-schedule) — Supply reduction countdown, S2F charts, and era history
- [Ethereum 2014 ICO](https://ethereumclassic.com/research/ethereum-ico) — Original Ethereum presale data: $18.5M raised, 72M ETH issued — the genesis supply ETC carries today
- [2016 DAO Fork](https://ethereumclassic.com/research/dao-fork) — How the Ethereum Foundation forked the original chain and applied the ETH name to the new chain; how Ethereum Classic got its name
- [Block Reward Countdown](https://ethereumclassic.com/block-reward-countdown) — Live countdown to the next fifthing, emission curve, inflation rate, era history table, and the ECIP-1017 explainer
- [Price](https://ethereumclassic.com/price) — Live ETC price and market data
- [Community](https://ethereumclassic.com/community) — Social channels and events
- [Olympia Upgrade](https://ethereumclassic.com/olympia) — Olympia network upgrade hub
- [Upgrade Your Node](https://ethereumclassic.com/olympia/upgrade) — Client upgrade guides
- [Miners & Fee Market](https://ethereumclassic.com/olympia/miners) — How EIP-1559 affects miners under Olympia
- [Core-Geth v1.12.2x Security Audit](https://ethereumclassic.com/build/clients/core-geth-security-audit) — Six unpatched CVEs in etclabscore/core-geth v1.12.x (21-month maintenance gap, Go 1.21 EOL), actively exploited against ETC mainnet bootnodes March 2026. Full CVE detail, postmortem PR trail, and migration guide. All issues patched in ethereumclassic/core-geth by White B0x, pending release as v1.13.0. Migrate to Fukuii — Ethereum Classic's first native client (Scala 3 LTS on Pekko Typed Actors, by The Fukuii Authors).
- [Olympia Governance](https://ethereumclassic.com/olympia/governance) — Treasury and governance contracts
- [Fork History](https://ethereumclassic.com/upgrades) — Network upgrade history (Atlantis → Olympia)

## Emission Schedule ("Fifthing")

ETC reduces its block reward by 20% every 5 million blocks under ECIP-1017. This event is called a "fifthing" (not "halving"). The 5th fifthing reduced the reward from 2.048 ETC to 1.6384 ETC per block at block 25,000,000. The 6th will reduce it to 1.31072 ETC at block 30,000,000.

- Era 1 (0–5M): 5 ETC
- Era 2 (5M–10M): 4 ETC
- Era 3 (10M–15M): 3.2 ETC
- Era 4 (15M–20M): 2.56 ETC
- Era 5 (20M–25M): 2.048 ETC
- Era 6 (25M–30M): 1.6384 ETC ← current
- Era 7 (30M–35M): 1.31072 ETC ← next fifthing

## Olympia Network Upgrade

Olympia is Ethereum Classic's next hard fork: the most significant upgrade in the network's history. It introduces EIP-1559 dynamic fee market, a protocol-controlled treasury funded by basefee revenue (block rewards remain untouched), on-chain governance with soulbound NFT voting, and EVM alignment that advances the execution layer through Glamsterdam.

Olympia deploys in five stages. Only Stages 1 and 5 are hard forks; Stages 2, 3 and 4 are contract deployments and governance actions on a chain whose consensus rules are already settled.

- Stage 1 — Consensus Upgrades (HARD FORK): ECIP-1111 (Execution Client Basefee Specification Alignment), ECIP-1112 (Long-term Sustainability Basefee Treasury Contract Specification), ECIP-1121 (Execution Client Specification Alignment), ECIP-1122 (Olympia ETC Network Security Client Configuration). All four activate at the same block; the Treasury deploys and begins accumulating basefee.
- Stage 2 — Core Governance (contract deployment): ECIP-1113 (Olympia DAO Governance Framework), ECIP-1114 (Olympia Funding Proposal Process), ECIP-1119 (Treasury Sanctions Compliance Oracle). The governance suite that spends the Stage 1 vault.
- Stage 3 — Prediction Markets (contract deployment): ECIP-1117 (Futarchy Child-DAO Governance), ECIP-1118 (Futarchy Funding and Streaming Disbursements), plus ECIP-1119, which applies here too because funds move. Seeded by a funding proposal from the Stage 2 DAO. Futarchy is an open signal layer and a Child-DAO under ECIP-1113 section 6 — it informs decisions and is never binding; binding allocation stays with the Olympia DAO.
- Stage 4 — Treasury Distribution (governance activation): ECIP-1115 (Olympia L-Curve Smoothing for Long-Term Network Security). Runs as a configured experiment on Treasury-held revenue, adjustable through governance without a hard fork. Supersedes ECIP-1120, which is excluded.
- Stage 5 — Protocol Integration (HARD FORK): ECIP-1116 (Consensus-Layer L-Curve Hardening for Base Fee Miner Distribution). Embeds the curve ECIP-1115 demonstrated into block finalization, paid by the protocol rather than disbursed from the treasury.

**ECIP-1121 — EVM Compatibility:** Advances the ETC execution layer through Dencun (Cancun-Deneb), Pectra (Prague-Electra), Fusaka (Fulu-Osaka), and Glamsterdam (Gloas-Amsterdam). ETC implemented partial London EIPs in Mystique (2022) and partial Shanghai EIPs in Spiral (2024), deferring the EIP-1559 fee market for independent governance design. ECIP-1111 delivers those deferred London fee market EIPs (EIP-1559 + EIP-3198). ECIP-1121 delivers the remaining execution-layer EIPs from Dencun, Pectra, and Fusaka that are independent of Proof-of-Stake and blob data availability, and carries that work into Glamsterdam.

From Glamsterdam, ECIP-1121 specifies two EIPs: EIP-7975 (eth/70) and EIP-7997 (deterministic CREATE2 factory). Glamsterdam's other execution-layer EIPs depend on EIP-7928 (Block-Level Access Lists) or EIP-4788 (beacon block root), neither of which is in scope for ECIP-1121. The accurate description is therefore "Dencun, Pectra and Fusaka complete, Glamsterdam opened" rather than parity with all of Glamsterdam.

Included EIPs (18, per ECIP-1121's Specification section):
- Gas Accounting and State Access: EIP-7702 (set EOA account code, chainId 61/63 replay protection), EIP-7623 (increase calldata cost), EIP-7825 (transaction gas limit cap, 2^24), EIP-7823 (MODEXP input bounds, 8192 bits), EIP-7883 (MODEXP gas cost increase), EIP-7935 (default gas limit 60M, network-authoritative on ETC per ECIP-1122)
- EVM Safety and Forward Compatibility: EIP-7934 (RLP block size limit, 8 MiB on ETC — no beacon-block margin), EIP-6780 (SELFDESTRUCT only in same tx), EIP-7910 (eth_config JSON-RPC method), EIP-7997 (deterministic CREATE2 factory at 0x4e59b44847b379578588920cA78FbF26c0B4956C, same address as every other EVM chain)
- Cryptographic and Precompile Enhancements: EIP-2537 (BLS12-381 precompile), EIP-7951 (secp256r1 / P256VERIFY for WebAuthn and passkeys)
- Execution Context Optimizations: EIP-5656 (MCOPY), EIP-2935 (historical block hashes in state), EIP-1153 (transient storage TSTORE/TLOAD), EIP-7939 (CLZ opcode, 0x1e)
- Networking (activates via devp2p capability negotiation, NOT a hard fork): EIP-7642 (eth/69 — retains total difficulty for PoW chain selection, drops receipt bloom filters), EIP-7975 (eth/70 — paginated receipts for blocks above the 10 MiB p2p limit)

Explicitly excluded: all blob-dependent EIPs (EIP-4844, EIP-7516, EIP-7691). Ethereum Classic is a pure Layer 1 execution chain.

Two client implementations at Olympia launch:
- Fukuii (fukuii.org) — Ethereum Classic's first native client, built ground-up for ETC rather than derived from an Ethereum client. An EVM execution client in Scala 3 LTS on Pekko Typed Actors, running on the JVM. One binary runs several networks at once in one JVM process, each isolated with its own state, metrics registry, and configuration; a further network is configuration, not a new client. Consensus is selected per deployment behind one interface: native Proof-of-Work for ETC mainnet and Mordor, or Proof-of-Stake with a built-in consensus layer, or an external client over the Engine API V1–V4. Ships an MCP server exposing node state to AI agents. Requires a current JDK LTS (25); the Docker image bundles one. Enterprise-grade by way of the JVM rather than a separate edition: JVM-native end to end with no foreign-language bridge, so JFR, async-profiler, JMX and heap dumps work as on any JVM process; Prometheus metrics, Grafana dashboards, and liveness and readiness endpoints ship in the binary, alongside concurrent multi-instance execution and external-signer/HSM custody integration. Apache 2.0, with Cosign-signed build provenance and a CycloneDX SBOM on releases. By The Fukuii Authors (Chippr Robotics LLC and White B0x Inc.). Repo: https://github.com/fukuii-project/fukuii-cli · Docs: https://docs.fukuii.org
- Core-Geth — A go-ethereum derivative maintained for Ethereum Classic, carried through Olympia for network continuity. Not native, and not a plugin.

ETC execution client plugins add Ethereum Classic support into existing Ethereum clients. A plugin is not a client implementation and carries no mining or Proof-of-Work consensus: Besu (https://github.com/besu-eth/besu), Erigon (https://github.com/erigontech/erigon), Ethrex (https://github.com/lambdaclass/ethrex), Go-Ethereum (https://github.com/ethereum/go-ethereum), Nethermind (https://github.com/NethermindEth/nethermind), Reth (https://github.com/paradigmxyz/reth).

Activation block: TBD (announced after CDC-23 community call).

## Networks

- Mainnet RPC: https://etc.rivet.link
- Mordor Testnet RPC: https://rpc.mordor.etccooperative.org
- Block Explorer: https://etc.blockscout.com

## Regulatory Positioning

- United States: digital commodity candidate under the CLARITY Act — Senate Banking Committee passed 15-9 (May 2026), Senate floor vote pending (CFTC spot jurisdiction upon enactment)
- United States: Proof-of-Work EVM platform for regulated stablecoin deployment under the GENIUS Act
- European Union: decentralized asset under MiCA (Markets in Crypto-Assets Regulation), exempt from issuer obligations as a fully decentralized protocol
- Japan: recognized crypto-asset on the FSA Green List (JVCEA), fast-track listing across all Japanese regulated exchanges

## Olympia Ecosystem Properties

- https://olympiadao.org — Governance landing page
- https://olympiatreasury.org — Treasury monitoring dashboard
- https://app.olympiadao.org — Proposal submission, voting, and execution
- https://ethereumclassicdao.org — Institutional (Ethereum Classic DAO LLC)
- https://github.com/olympiadao — Open-source governance repositories

## Contact

- Website: https://ethereumclassic.com
- GitHub: https://github.com/ethereumclassic-com

- /olympia/treasury — Olympia Treasury (ECIP-1112): how it is funded, what it can never do, staged deployment