V1 Overview

Overview of Kleros Court V1 architecture, contracts, and deployment status.

Status

Kleros Court V1 is deployed on Ethereum Mainnet, Gnosis Chain, and Polygon. It remains operational for existing integrations. New integrations should use Kleros V2 on Arbitrum One.

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Architecture

V1 uses a single KlerosLiquid contract that combines arbitration, staking, juror drawing, voting, and appeal logic:

Contract	Role
KlerosLiquid	Core court contract handling disputes, juror selection, and ruling enforcement
PNK	ERC-20 token used for staking and juror incentives
PolicyRegistry	Stores court policies describing juror guidelines
Arbitrable Contracts	Implement ERC-792 to interact with KlerosLiquid

V1 vs V2 Differences

Feature	V1	V2
Home chain	Ethereum Mainnet	Arbitrum One
Arbitration standard	ERC-792	IArbitratorV2 (no appeal in interface)
Evidence standard	ERC-1497	Dispute Templates + cross-chain evidence
Dispute kits	None (monolithic)	Modular (DisputeKitClassic, specialized kits)
Voting	Commit-reveal	Commit-reveal (default); Shutter encryption available in testing
Cross-chain	Limited (xDAI bridge)	Vea bridge (Ethereum, Gnosis, extensible)
Staking	Direct in KlerosLiquid	SortitionModule (sortition tree)

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V1 Deployment Addresses

Ethereum Mainnet

Contract	Address
KlerosLiquid	0x988b3A538b618C7A603e1c11Ab82Cd16dbE28069
PNK	0x93ED3FBe21207Ec2E8f2d3c3de6e058Cb73Bc04d

Gnosis Chain

Contract	Address
xKlerosLiquid	See the kleros-v2 repository for current addresses

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V1 Standards

V1 integrations use two ERC standards:

• ERC-792: Arbitration Standard defining the IArbitrable and IArbitrator interfaces
• ERC-1497: Evidence Standard defining MetaEvidence, Evidence, and Dispute events for sharing dispute context

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Migration

If you have an existing V1 integration and want to migrate to V2, see the Migration Guide.