[Crypto projects](https://revain.org/projects/) › Kleros

# Kleros (PNK): how it works, supply and reviews

## In short

- **Type**: Dispute-resolution protocol made of smart contracts; Court V1 runs on Ethereum, V2 on Arbitrum.
- **Maximum supply**: 915,528,222.07931277 PNK; supply changes only by Kleros DAO governance vote.
- **Risks and caveats**: Jurors who vote against the final decision lose part of their staked PNK.
- **Checked**: 1 November 2026

## Key facts

- **Ticker**: PNK
- **Official site**: [kleros.io](https://kleros.io/)

Key facts checked on 1 November 2026 against official sources.

## What is Kleros

Kleros is a decentralised arbitration protocol: jurors who stake the PNK token are drawn to decide disputes, and the ruling is enforced on-chain. It is used by Web3 apps, businesses and governments to resolve disputes such as escrow, insurance claims and listing curation.

## Network and consensus

| Parameter | Details |
|---|---|
| Type | Dispute-resolution protocol made of smart contracts; Court V1 runs on Ethereum, V2 on Arbitrum. |
| Launched | Court V1 launched on Ethereum mainnet in 2018. |
| Smart contracts | V1's core contract is KlerosLiquid, combining staking, juror selection, voting and dispute management. |
| Runs on | On Arbitrum (V2 home chain) PNK uses the standard bridged token. |
| Status of V2 | Kleros V2 is in beta and undergoing internal review and external audits. |
| Use cases | Dispute resolution for business and government, e.g. chargebacks and fraud cases in finance. |

## Supply and issuance

| Parameter | Details |
|---|---|
| Maximum supply | 915,528,222.07931277 PNK; supply changes only by Kleros DAO governance vote. |
| Total supply | The tokenomics page gives a total supply of 764,626,704 PNK (conflicts with the 915,528,222 maximum on the PNK token page). |
| Staking rewards | Coherent jurors earn arbitration fees and PNK from incoherent jurors, who lose part of their stake. |

## What PNK is used for

- Staking: PNK is staked in a court to be eligible for juror selection; more stake means higher selection probability.
- Governance: PNK holders vote on Kleros Improvement Proposals (KIPs), court parameters and upgrades.
- Attack resistance: the cost of acquiring a majority of PNK is a defence against 51% (Sybil) attacks.

## Who develops and governs Kleros

- **Developer**: Developed by Coopérative Kleros, a French cooperative society.
- **Legal entity**: Coopérative Kleros, SCIC SAS, Paris Trade and Companies Register no. 841 671 902.
- **Governance**: PNK holders vote on proposals to create courts, set parameters and guide the protocol.
- **Company**: The cooperative publishes annual, monthly treasury and risk reports.
- **Governance process**: Proposals (KIPs) are drafted on the Kleros Forum, voted on Snapshot by PNK holders and enacted on-chain through Kleros Governor.
- **Open source**: Kleros publishes its code on GitHub; GitHub shows the organisation has verified the kleros.io domain.

## History

| Date | Event |
|---|---|
| 2018 | Kleros Court V1 launched on Ethereum mainnet. |
| 11 January 2024 | Kleros announced that it had blocked an attempted attack on the Proof of Humanity DAO governor. |
| 28 May 2026 | The legal notice was revised; Coopérative Kleros is the publisher. |

## Security and audits

- PNK staking is designed to make a 51% (Sybil) attack costly; the docs list market scarcity, price impact and forking as defences.
- Kleros V2 is in beta and undergoing internal review and external audits.
- In January 2024 Kleros reported that a malicious list submitted to the Proof of Humanity DAO governor was challenged and blocked through a Kleros court case.

## Security incidents

Incidents are reported by third parties (press, incident databases) but are not confirmed in the company’s own channels, so none is listed here.

## Official PNK contracts

| Network | Contract address |
|---|---|
| Ethereum | [0x93ED3FBe21207Ec2E8f2d3c3de6e058Cb73Bc04d](https://etherscan.io/token/0x93ED3FBe21207Ec2E8f2d3c3de6e058Cb73Bc04d) |

PNK token contract on Ethereum mainnet as listed in the Kleros V1 deployment addresses.

## Risks and caveats

- Jurors who vote against the final decision lose part of their staked PNK.
- Kleros V2 is still in beta and under external audits.
- The website is informational only and is not financial advice or an offer of PNK.

## Official links

- Website: [kleros.io](https://kleros.io/)
- Docs: [docs.kleros.io](https://docs.kleros.io/)
- Whitepaper: [kleros.io/static/whitepaper.pdf](https://kleros.io/static/whitepaper.pdf)
- Source code: [github.com/kleros](https://github.com/kleros)
- Blog: [blog.kleros.io](https://blog.kleros.io/)
- Governance forum: [forum.kleros.io](https://forum.kleros.io/)

## Questions and answers

**What is Kleros?**

Kleros is a decentralised arbitration protocol where jurors who stake PNK decide disputes; Court V1 has run on Ethereum since 2018.

**What is PNK used for?**

PNK is staked to qualify as a juror and is used to vote on governance proposals; staking also makes 51% attacks costly.

**What is the supply of PNK?**

Kleros docs give two figures: a maximum supply of 915,528,222.07931277 PNK (PNK token page) and a total supply of 764,626,704 PNK (tokenomics page); supply changes only by DAO governance vote.

**Who is behind Kleros?**

Coopérative Kleros, a French cooperative (SCIC SAS) registered in Paris under RCS 841 671 902.

**Has Kleros been hacked?**

In January 2024 Kleros reported blocking an attempted attack on the Proof of Humanity DAO governor; it says the DAO's funds were saved.

## Sources

- [Kleros - Home](https://kleros.io/)
- [Kleros - PNK token](https://kleros.io/pnk-token)
- [Kleros - Cooperative](https://kleros.io/cooperative)
- [Kleros - Legal notice](https://kleros.io/legal-notice)
- [Kleros - Become a juror](https://kleros.io/earn-become-a-juror)
- [Kleros docs - PNK token](https://docs.kleros.io/concepts/pnk-token)
- [Kleros docs - Tokenomics](https://docs.kleros.io/concepts/tokenomics)
- [Kleros docs - V1 deployment addresses](https://docs.kleros.io/reference/contracts/deployment-addresses-v1)
- [Kleros docs - Court overview](https://docs.kleros.io/court/overview)
- [Kleros docs - Governance overview](https://docs.kleros.io/governance/overview)
- [Kleros on X - PoH governor exploit attempt (11 January 2024)](https://x.com/Kleros_io/status/1745430493519286782)
- [Etherscan - PNK token contract](https://etherscan.io/token/0x93ED3FBe21207Ec2E8f2d3c3de6e058Cb73Bc04d)
- [Kleros on GitHub](https://github.com/kleros)

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Page updated: 2026-11-01

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Source: https://revain.org/projects/kleros/