Kleros (PNK — Pinakion, named after the ancient Athenian citizen selection token) is a decentralized dispute resolution protocol launched in 2018 that functions as a “decentralized judge” for any digitally expressible conflict — from DeFi insurance claims and token list curation disputes to freelance contract disagreements and NFT authenticity verification — by drawing on a pool of jurors who stake PNK tokens in subject-matter-specific “courts” and are then randomly selected (weighted by PNK staked) to review evidence and cast votes, with the economic design ensuring that jurors who rule with the majority earn ETH fees while jurors who rule against the majority lose a portion of their staked PNK, creating a Schelling point equilibrium where honest, accurate rulings are individually rational.
| Stat | Value |
|---|---|
| Ticker | PNK |
| Price | $0.01 |
| Market Cap | $10.07M |
| 24h Change | +1.6% |
| Circulating Supply | 724.19M PNK |
| All-Time High | $0.38 |
| Contract (Ethereum) | 0x93ed...c04d |
| Contract (Xdai) | 0x37b6...f7b3 |
| Contract (Arbitrum One) | 0x330b...cae5 |
How It Works
- Court specialization — Kleros organizes disputes into specialized “courts” (e.g., “Blockchain (Non-Technical)”, “Token Listing”, “Insurance”, “Marketing Services”). Jurors stake PNK specifically in the court(s) where they have expertise.
- Random juror selection — When a dispute is raised, jurors are randomly selected from the staking pool of the relevant court. The probability of being selected is proportional to the amount of PNK staked. This random selection is activated by a commit-reveal scheme.
- Evidence submission — Both disputing parties submit evidence in defined evidence files (JSON-LD format submitted to IPFS). Jurors review this evidence within the dispute window.
- Ruling and enforcement — Jurors cast votes within the ruling period. The majority ruling wins and is returned to the requesting contract to enforce (e.g., Kleros tells an insurance contract to pay out a claim). Jurors who voted with the majority receive fees (ETH/ERC-20 arbitration fees paid by the disputing parties). Jurors who voted against the majority lose some staked PNK (penalized) as a coherence incentive.
- Appeals — Losing parties can appeal decisions by paying an increasing appeal fee. Appeals escalate the dispute to a larger jury. In extreme appeals, disputes escalate to the Kleros General Court.
- Policy documents — Each court has publicly posted policy rules defining what a correct ruling means. This reduces subjectivity and anchors the Schelling point.
Tokenomics
| Parameter | Value |
|---|---|
| Ticker | PNK (Pinakion) |
| Chain | Ethereum ERC-20 |
| Contract | 0x93ED3FBe21207Ec2E8f2d3c3de6e058Cb73Bc04d |
| Total Supply | ~764,626,704 PNK (no hard cap; initial mint) |
| Token function | Staking in courts (juror eligibility + penalty collateral) |
| Juror rewards | Paid in ETH or the token of the dispute |
| Kleros DAO | PNK holders vote on court parameters and policy |
Use Cases
- DeFi insurance — Unslashed Finance, Cover Protocol, Nexus Mutual–adjacent applications use Kleros to resolve insurance claim disputes.
- Token list curation — The Kleros T2CR (Token² Curated Registry) maintains a community-curated list of legitimate Ethereum tokens (used by Uniswap to display token metadata for many years).
- Content moderation — The Proof of Humanity DAO uses Kleros to adjudicate challenges to humanity proof submissions.
- Freelance disputes — Platforms like Linguo (translation freelancing) use Kleros to resolve disputes between requester and translator over quality.
- NFT authenticity — Kleros can resolve challenges to NFT authenticity and copyright claims.
- Cross-chain bridges and DeFi protocols — As an oracle/judgment layer for any smart-contract-integrated dispute.
History
- 2017 — Clément Lesaege (co-founder/CTO) and Federico Ast (co-founder/CEO) publish the Kleros whitepaper describing decentralized arbitration using Schelling point game theory. The project wins the ETHCC Paris hackathon.
- 2018-07-31 — PNK token sale concludes. Kleros raises approximately $1.2M via a DAICO-style token sale (where refunds were possible if investors approved). PNK distributed to token sale participants.
- 2018 — Kleros MVP court deployed on Ethereum mainnet. First courts are General and Token Listing courts.
- 2019 — Kleros Curate (formerly T2CR) used by Uniswap for its default token list. This is one of Kleros’s highest-visibility integrations; Uniswap’s interface pulls from the Kleros-curated token list to display token names and metadata.
- 2020 — Proof of Humanity project integrates Kleros. PoH is a sybil-resistant registry of verified humans; any challenge to a profile’s legitimacy is resolved by Kleros courts.
- 2021 — Kleros deploys on Gnosis Chain (formerly xDai) for cheaper dispute resolution. Linguo translation platform uses Kleros. Kleros Escrow enables trustless milestone-payment contracts for freelancers.
- 2022 — Kleros DAO governance becomes more active. Kleros is used as an oracle-of-last-resort for Decentralized Autonomous Organizations in internal governance disputes (e.g., between DAO contributors over deliverable quality).
- 2023 — Kleros integrates with Realitio (oracle for prediction markets) to serve as the final arbitrator for unresolved Realitio questions. This makes Kleros part of prediction market stacks including Omen on Gnosis Chain and some Polymarket architecture.
- 2024 — Kleros Arbitrum integration expands. The protocol has resolved tens of thousands of disputes across multiple courts. PNK staking activity remains active across specialized courts.
Common Misconceptions
“Kleros jurors are legal professionals or arbitration experts.”
Jurors are anonymous token stakers — anyone in the world who stakes PNK in a specific court. The incentive to rule honestly comes from the economic penalty for incoherent rulings, not from being vetted professionals. Policy documents help non-experts apply consistent standards.
“PNK is used to pay for dispute resolution.”
Dispute fees (paid by the disputing parties) are denominated in ETH or the relevant token — not PNK. PNK is used only for staking (juror eligibility) and is at risk of loss if a juror votes incoherently. PNK is the stake, ETH is the reward/fee.
“Kleros replaces legal contracts.”
Kleros resolves digitally expressible disputes within smart contract contexts. It cannot enforce outcomes in the physical world without the counterparty’s cooperation or involvement of traditional law. It is most powerful for on-chain disputes where the smart contract has programmatic enforcement.
Social Media Sentiment
Kleros occupies a respected niche within the Ethereum infrastructure ecosystem and is widely cited in academic papers on decentralized justice systems. Practitioners who have integrated it (particularly Uniswap’s token list usage and Proof of Humanity) speak positively of its reliability. Criticism historically focused on the relative centralization of PNK staking concentration among a few large stakers, who could potentially dominate juror selection in smaller courts. The project is seen as technically rigorous and principled but somewhat complex for mainstream adoption.
Last updated: 2026-04