Trusted peer-to-peer transactions on any platform.

A protocol for decentralized payments & reputation on Ethereum.

Use XNK today on the Listia marketplace with over 10M users!

Millions of items listed. Thousands of transactions per day.

Ink Protocol Decentralizes P2P Payments


Remove uncertainty. View any seller’s global reputation, pay with escrow, and leave feedback for completed transactions.


Reputation is decentralized, independent, and public, so it is available anywhere. Bring it with you and never worry about rebuilding it from scratch.

Any marketplace platform

Ink Protocol can be integrated into new or existing platforms and can also be used in marketplaces that don’t directly handle payments.

Any transaction

Ink Protocol doesn’t require a marketplace. It can be used for any peer-to-peer transaction, regardless of where it happens.

The Listia Marketplace

Ink Protocol is the new reputation and payment system within the Listia marketplace.

  • Launched 2009

  • 10M registered users

  • 100M items sold

  • Use XNK to buy items

Buy and sell anything on Listia using XNK, like clothing, collectibles, electronics, toys, gadgets, jewelry, and much more! Millions of items have already been listed, with thousands of daily transactions.

Listia Inc. Investors

and others…

Replin: Seller Reputation App

Built on top of Ink Protocol, Replin helps marketplace sellers drive more sales by building trust and reputation everywhere they sell. Use your existing PayPal account and create a single public reputation to use on any p2p marketplace, forum, or classifieds site.

  • Build decentralized reputation

  • A single profile for all your sales

  • Payments processed via PayPal

All ratings are tied to actual payments, which are stored on the Ethereum blockchain.

Available on iOS, Android, and at

Ink Pay: DeFi Payments via XNK

The Ink Pay dApp allows buyers and sellers to make and receive cryptocurrency payment for items on any third-party platform or marketplace like Craigslist, Facebook Marketplace, OfferUp, and more.

  • Sellers can accept cryptocurrency payments with Ink Pay and build their reputation.
  • Buyers can check a seller’s reputation before buying and also leave feedback once a transaction is complete.
  • Optionally add a mediator and decentralized escrow for a higher level of safety. Coming soon…

Available at

Marketplace and E-commerce Partnerships

Coinbase Wallet
DApp Browser and Mobile Wallet
for the Ink Pay App

Create your own peer-to-peer marketplace
using Ink Protocol for Reputation

Dai stablecoin integration
on the Ink Pay App

Decentralized bounty hunting platform
using Ink Protocol for Reputation

Cross-border P2P loans ecosystem using Ink Protocol for Reputation

Universal Crypto Wallet and fiat payment solution for Ink Protocol

Blockchain-based e-commerce platform
using Ink Protocol for Reputation

Automated Supply Chain and Payments
using Ink Protocol for Reputation

Everyday Carry
Men’s Accessories E-Commerce Site
using Ink Protocol and XNK

Blockchain-powered secondary ticket
seller using Ink Protocol for Reputation

The Ink Protocol Token (XNK)

Ink Protocol is a decentralized finance and reputation and payment protocol powered by the Ethereum blockchain and XNK, an ERC20 compatible token.

XNK is the underlying currency used in all Ink Protocol transactions. As a result, all transactions and feedback are backed by proof of payment on the blockchain.

XNK is also earned by mediators for the mediation services that they provide on transactions.

XNK is already used on the Listia marketplace as a virtual currency for transactions.


Ink Protocol Features

Decentralized reputation and feedback

Ink Protocol helps users safely send and receive payments in P2P transactions and marketplaces while earning public reputation for every completed transaction.

Sellers can take their earned reputation with them from marketplace to marketplace.

To ensure sellers’ reputations are credible, feedback may only be given on completed transactions.

Third party mediation and escrow

Ink Protocol’s built-in dispute resolution allows a mediator to be assigned to a transaction. Mediators exist as independent Smart Contracts and are jointly agreed upon by the buyer and seller.

With mediation, payment is held in escrow until the buyer confirms the transaction. In the event of a dispute, the mediator works with both parties to decide on an outcome.

The Ink Protocol Ecosystem

Marketplaces, payment apps, and mediation services can all use Ink Protocol. Listia will integrate the Ink Protocol into its existing marketplace and immediately begin development of the Ink Pay app. Developers can build their own marketplaces, payment apps, and other services to leverage the Ink Protocol platform.


Ink Protocol Whitepaper

Transaction State Diagram

Milestones / Roadmap

June 2009 – Listia Inc. is founded and receives funding from Y Combinator
August 2009 – The Listia marketplace launches
October 2009 – Listia announces $400K angel round
April 2011 – Listia launches iOS app, announces $1.75MM seed round led by A16Z
January 2012 – Listia reaches 1M registered users, launches Android app
January 2013 – Listia partners with Best Buy to power the Listia Rewards Store
October 2013 – Listia announces $9MM series A led by General Catalyst
February 2014 – Listia allows Bitcoin to be bought and sold in the marketplace
November 2014 – Listia first experiments with creating a cryptocurrency
December 2015 – Listia launches the Credit Exchange, allowing sellers to earn USD
April 2016 – Listia launches Credits + Cash feature
June 2016 – Listia launches Listia Plus
September 2016 – Listia integrates shipping labels and tracking
May 2017 – Listia hits 10M registered users
June 2017 – Listia begins work on Ink Protocol design and whitepaper
September 2017 – Listia publishes website and Ink Protocol whitepaper
November 2017 – Listia introduces the Ink Protocol project publicly

February 2018 – Ink Protocol network goes live and ready for everyone to use!
February 2018 – Launch XNK integration
March 2018 – Kleros partnership announcement
March 2018 – Bounty0x partnership announcement
March 2018 – Sharetribe partnership announcement
March 2018 – Developer Portal launch (
Q2 2018
  • Launch Ink Pay App and Ink Pay partnerships
  • Marketplace partnerships
  • Consumer app partnerships
  • Shipping and logistics partnerships
  • Launch first live integration with consumer app partners
  • Create a developer community around the Ink Developer Portal and Gitter

Q3 2018

  • Start work on enabling additional cryptocurrency payments
  • Launch easy reputation viewer / browser
  • Start feedback and reputation importer for existing marketplaces
  • Start work on fiat payments integration

Q4 2018

  • Launch Ink Pay Checkouts feature
  • Start work on marketplace plugins for forums and message boards
  • Start work on marketplace plugins for online stores
  • Integrate local marketplaces and other marketplace verticals into Ink Pay


  • Launch fiat marketplace payments through Replin via PayPal partnership
  • Build out a platform for selling on Twitter, Instagram, FB Marketplace via Replin
  • Integrate Replin into new marketplaces, forums, message boards, classifieds, consumer apps
  • Create a widget for 3rd party marketplaces to display Replin reputation for their users
  • Add support for additional currencies in Replin to support international usage
  • Focus on perfecting user engagement, and find product-market fit in Q2/Q3
  • Focus on growth and scaling of Replin users and transaction volume in Q3/Q4
  • Build Replin integrations for open e-commerce platforms that support Apps and Plug-ins

Goals for 2020 and beyond

  • Ink Protocol will be partnering with Props to push the vision of a large-scale consumer token economy together! Read more

Listia Press

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