Model Context Protocol (MCP) has emerged as a de facto industry standard for communication of foundation models and AI agents with external resources and with each other. This led us to introduce it as another method of integration (on top of the TypeScript SDK, Woocommerce/Dokan plugin, and native web3 calls).

The MCP server supports both legacy SSE and Streamable HTTP connections at their respective endpoints:

• HTTP(S): mcp.unicrow.ai/mcp
• SSE: mcp.unicrow.ai/sse

The functions currently supported are:

• pay
• refund
• release
• claim
• arbitrate

Unicrow currently runs on Base and Arbitrum One and each of these tools take chainId parameter so that they can return a contract address for the desired chain.

Below example calls for pay, refund, and arbitrate

Pay

{
  "tool": "pay",
  "arguments": {
    "chainId": 42161,
    "sender": "0x742d35Cc6631C0532925a3b8D4Fd23c83e4C9B1A",
    "buyer": "0x742d35Cc6631C0532925a3b8D4Fd23c83e4C9B1A", 
    "seller": "0x8ba1f109551bD432803012645Hac136c74a13EcE",
    "currency": "0xFd086bC7CD5C481DCC9C85ebE478A1C0b69FCbb9",
    "amount": "100000000",
    "challengePeriod": 86400,
    "challengeExtension": 43200,
    "marketplace": "0x123456789aBcDeFgHiJkLmNoP123456789AbCdEf",
    "marketplaceFee": 9.5,
    "arbitrator": "0xAbCdEf123456789aBcDeFgHiJkLmNoP123456789", 
    "arbitratorFee": 4.5,
    "paymentReference": "ORDER-12345"
  }
}

The tool returns serialized transaction and contract address

{
  data: '0x0...',
  contractAddress: '0xDb815D9bEaAa8d3bdc714Be3a17dCBA5eCbe876B'
}

The smart contract’s Pay function returns escrowId which is then used in any of the subsequent calls to identify the escrow.

Refund

{
  "tool": "refund",
  "arguments": {
    "chainId": 42161,
    "escrowId": "123456"
  }
}

Release and Claim follow the same pattern

Arbitrate

{
  "tool": "arbitrate",
  "arguments": {
    "chainId": 42161,
    "escrowId": "123456789", 
    "buyerSplit": 75.0,
    "sellerSplit": 25.0
  }
}

Limitations and prerequisites

The server only returns transactions that need to be signed and broadcasted. It is therefore assumed that the agent has key infrastructure available and is connected to one of the supported chains.

Also, while reading escrowId and using it in all subsequent calls is all the agent needs for the full escrow lifecycle, staying updated about escrow updates executed by other parties requires blockchain indexing, which we plan to introduce in a separate MCP server.

We’d love to hear about how we can further support the agents in their secured transaction needs.

On-prem deployment

We will open source the server code so anyone can run it locally if desired. Stay tuned and contact us for any suggestions, feedback, or questions

Integration into an upcoming multi-agent platform

The MCP server will be integrated into an upcoming multi-agent platform. To be announced here and on our X

Introduction

Unicrow open-source SDK already provides two ways for marketplaces and platforms to easily facilitate cryptocurrency payments — by either embedding the payment process into the marketplace’s frontend, or by reusing the built-in UI components.

Now we’re introducing a 3rd method (in fact, also 4th but more on that below), a native integration into WooCommerce and Dokan, Wordpress’ most popular e-commerce and multi-vendor plugins.

This provides arguably the quickest, the most secure, and completely permissionless way to process payments between buyers and sellers on a WooCommerce/Dokan marketplace (which itself is arguably the quickest and easiest way to build a marketplace).

Overview

There are a few things important to understand before we get into the actual (and actually very simple) setup.

Unicrow 101

To better grasp the potential that Unicrow brings to marketplace operators, it is good to understand the protocol basics. For that, we recommend our introduction post (TODO: add link), but let us briefly highlight key points here:

• Unicrow runs on Ethereum’s Layer 2s Arbitrum One and Base and supports ETH and any ERC20 token, e.g. stablecoins like USDT or USDC
• Each individual escrow has the following parameters: seller (supposed to receive the funds), marketplace (optional, gets a fee), arbitrator (optional, decides a dispute), and what’s the challenge (escrow) period.
• Buyer can release funds to the seller at any time
• Funds can be claimed to the seller after the challenge period ends
• Marketplace and/or arbitrator fees will be sent out when the funds are claimed or released from the escrow.

Supported tokens

The plugin supports ETH, USDC, and USDT and Arbitrum One network. We will extend the support for Base soon and for additional tokens based on feedback and eventually make it easier for admins to add support for any tokens. In the meantime, the admins can extend support in the source code directly (see Advanced Setup below)

Supported functionality

Woocommerce
Unicrow plugin extends Wooommerce (WC) in the following ways:

• It is added to a list of payment methods in WC’s settings and on the checkout page
• It adds an optional seller address attribute to product settings — this technically allows operating a multi-vendor marketplace even without Dokan, simply by adding different seller address to different products.
• It adds a link to the transaction in Unicrow web3 app to admin emails and to the order notes.

Dokan
The plugin further adds or reuses the following to Dokan settings:

• It uses Dokan’s admin commission as a marketplace fee parameter in Unicrow transactions
• It adds seller address parameter to vendor settings and if set, uses it in the transactions (in that case, setting seller address in product settings is not necessary)
• It adds a note with a link to the transaction in Unicrow web3 app to email sent to the vendor

Limitations

• Unicrow currently requires exactly one seller address per escrow, therefore plugin will throw an error if the order contains different seller ethereum addresses (e.g. if different addresses are set in the products or if products from different vendors with unique addresses are in the order)
• Supported currencies: ETH, USDT, USDC
• Supported network: Arbitrum One

Prerequisites

Wordpress plugins:

• Woocommerce is a required and technically sufficient pre-requisite since Unicrow plugin hooks into its functions for setting up and for payment processing.
  While Woocommerce itself doesn’t support multi-seller setup, Unicrow extends product settings for seller address attribute. That means if an admin doesn’t want to complicate things with multiple sellers and an additional plugin such as Dokan, but wants to be able to process payments to different addresses for different products, the combination of WC and Unicrow allows for this.
• (Optional) Dokan for full multi-vendor functionality.

Other/Crypto-related prerequisites for different actors:

• Marketplace operator
  - A secure wallet able to receive fees (if applicable) on the supported network
  - An online web3 wallet to provide arbitration service loaded with a little bit bit of ETH to pay for gas costs
  - (optional) An online web3 wallet that would regularly claim payments to sellers as a service to them (for simplification it can be done also from the Arbitrator wallet)
• Buyer
  - A web3 wallet with sufficient balance to pay the purchase and a little bit of ETH on the supported network
• Seller
  - An Ethereum address to receive the supported tokens on the supported network

Setup

If any of this is not working for you or if you want to provide any feedback to this process or the plugin itself, please contact us at hello@unicrow.io

Follow these steps to set up Unicrow with WooCommerce and, optionally, Dokan

1. Open Wordpress Admin Console
2. Install and activate WooCommerce, Unicrow plugin, and optionally Dokan
3. Open Woocommerce → Settings → Payments and press Manage next to Unicrow
4. Enter the values per your preference:

• Unicrow Environment URL: Leave to default for production setup. Contact us at devs@unicrow.io or at our Discord to use our staging area with the private testnet for testing
• Default Seller Address: If you plan to receive all payments to one address, paste that address here. Leave it empty if you plan to set seller address per product or (in Dokan) per vendor
• Marketplace Address: If you plan to collect a commission directly from Unicrow to your wallet, paste its address here. This can be a cold wallet or even an exchange address as long as it supports receiving the tokens you chose on the supported network (currently Arbitrum One TODO: add link to arbitrum guide).
• Marketplace Commission: Leave empty if you want the plugin to reuse Dokan commission settings or if you don’t plan to charge a commission.
• Challenge Period: How long a buyer can challenge the payment. After this, the seller can claim the payment.
• Arbitrator address: An address of a wallet account from which you will resolve disputes. The address should be funded with a little bit of ETH for gas fees and easy to access and make transactions from, e.g. a browser or even a mobile wallet. It won’t hold customer funds at any point so it can be “hot”.
• Arbitrator fee: Arbitrator fee in %. If the marketplace operator is an arbitrator too, can leave this at 0.
• Accepted tokens: Currently supporting ETH, USDT, USDC. We’d like your feedback which ones we should prioritize and will eventually let you manage a custom list (which you of course can still do by opening the plugin code and editing config.php :-)

4. If you use Dokan, you can adjust the following settings:

• Admin commission in Dokan → Settings → Selling Options (Unicrow technically supports percentage commission only, if flat commission is used, the plugin will convert it to percentage using total price)
  - Note: If Admin commission is also set in Vendor settings, that value will take precedence.
• Vendor’s seller address in Users → All Users → Edit → Unicrow Vendor Options (at the very bottom)
  - If this is left empty and neither product nor Woocommerce default seller address is set up, Unicrow payment option will not be available for the seller

Users’ experience

Once things are set up properly (i.e. all required values are set), Unicrow will show up for the buyer as a payment option in the checkout.

Token selection

If multiple tokens are enabled, the user will be able to choose one. If only one token is set in the admin options, it will be explicitly mentioned in the payment method title.

Currency conversion

If the user selects ETH or if the shop’s currency is other than USD, the plugin will read read the current price or the rate of the shop’s currency vs. the selected stablecoin from CoinGecko API. If the shop is in USD and USDT or USDC is selected, 1:1 rate is always used.

Payment

When the user confirms Unicrow payment and presses Place Order, they will be redirected to Unicrow where they can pay.

Confirmation

After the payment, the user will be redirected back to the shop’s checkout confirmation page.

Both the admin and the seller will receive an email with a link to Unicrow app’s payment screen where they can verify that the payment was made as per the checkout. The same link is added to the order dashboard in WP admin.

Dispute resolution

If the admin needs to step in as an arbitrator, they can open the same link with their arbitrator wallet connected.

Claim

When the challenge period ends, either the seller, or the admin can follow the same link to release the payment from the escrow. The fees (if defined) are sent in the same transaction to the arbitrator and the marketplace addresses and the remaining amount to the seller.

This ability for the marketplace (or, technically, anyone) to release the funds on behalf of the seller securely (because the smart contract makes sure they’re sent only where they belong) creates a great user experience for the sellers who potentially don’t need to claim the payments manually (and can even have them sent to a fiat off-ramp).

Currently, this claim must be called manually by someone. Please contact us if you ere interested in having an automated service calling the claim for your marketplace users.

How-to Guides

Admins who want to post how-to guides to their website are more then welcome to reuse the text and images from this post and from the guides on our docs page: guide for buyers, guide for sellers, and also an overview of basic concepts

Unicrow’s escrow smart contracts are now deployed to Base as well as Arbitrum One where the protocol has been running from its day 1.

This support extends to our full developer stack and to our web3 app. While it presented a very complex change in the development tooling architecture, we made sure to keep the developer experience sleek and the integration as simple as it was before.

The related changes are mainly:

• The SDK now must be initialized with a network configuration call
• The indexer needs to be configured with the selected networks when deployed
• Reading escrow data from the indexer requires chainId as a parameter if it indexes multiple networks

Network handling in the SDK

The best way to get a quick hands-on experience with Unicrow’s SDK is the step-by-step tutorial. However, below is an overview of the most important aspects of the integration and network handling.

Initial configuration

Whenever the app loads, the first call it needs to do before any Unicrow SDK calls are made is to configure the connected network, e.g.:

import Unicrow from "@unicrowio/sdk";

Unicrow.config({
  chainId: BigInt(42161),  // Arbitrum One chainId
});

Switching to a different network from the app

To ask user’s wallet to switch to a different network:

  Unicrow.wallet.switchNetwork(BigInt(42161));

Configuring network based on user’s wallet

If the user’s wallet is connected to one of the supported networks, this will configure the SDK with the connected network:

if (Unicrow.wallet.isWeb3WalletInstalled()) {
  if (await Unicrow.wallet.isSupportedNetworkConnected()) {
    const network = await Unicrow.wallet.getNetwork();
    Unicrow.config({
      chainId: network.chainId
    });
  }
}

Listening to user’s network change

To listen to when user changes network manually in their wallet, run the following

Unicrow.wallet.startListeningNetwork((chainId) => {
  // do something with the information
}); 

This function will change the SDK’s configuration automatically if the user switched to a supported network, but the callback provides an option to handle the situation in the app (e.g. informing the user if they switched to an unsupported network, or storing the chainId in a local context for easier access)

Indexer

The indexer can now fetch and store information from both supported mainnets and their respective Sepolia testnets.

See Indexer Github repo for instruction on how to configure the networks

Smart Contracts

See our developer documentation for contract addresses

Arbius, a recently launched network for decentralized machine learning model execution is building a marketplace which will allow AI model to compete for customer jobs and to earn its own money.

The marketplace aims to be fully decentralized and trust-minimized and therefore will use Unicrow for payment settlement between the buyers and the sellers.

Read details in the Arbius announcement.

Hopscotch (hopscotch.trade) makes using web3 much more intuitive and user friendly by curating the most reliable services and integrating them with natural language user interface. Its mission is to make it easier for users to interact with each other and with businesses on-chain, a goal already supported by natively integrated address book functionality and end-to-end encrypted communication.

The functionality that the app already allows include sending balances between users, bridging and swapping tokens and native currencies, and on- and off-ramp from and to fiat currencies.

Some examples of this:

• Onramp 100 USD into ETH on Arbitrum
• Convert 10 MATIC into USDC on Polygon
• Bridge 1000 USDT from Avalanche to Arbitrum

For each of these, Hopscotch partnered up with the most trusted and liquid protocols so that new users don’t get lost in the sea of dApps. Hopscotch’s curation ensures the best price and user experience for the end users.

In its next upgrade, Hopscotch will integrate Unicrow to provide escrow between the users. Unicrow (unicrow.io) is a non-custodial and immutable escrow protocol supporting ETH and ERC20 tokens. Unicrow’s vision to enable real world commerce aligns well with Hopscotch functionality enabling communications and crypto-transactions between the users and businesses.

The integration will also support Unicrow’s arbitration functionality. In this example, Gary wants to send money to an escrow for Keir after they agreed on a judge:

• Escrow 1000 USDT for Keir for two weeks, with HAL as a judge

Unicrow’s immutable design and strict limitation of each party’s role in the process minimizes trust requirements while creating a much better user experience compared to e.g. multisig-based escrow because all the actions can be securely executed by a single party.

Therefore to release the funds, Gary can call: “Release the escrow to Keir”, or after the escrow period ends, Keir can prompt “Claim the payment from the escrow”.

If they have a dispute, HAL can decide on the despute but even if he goes rogue, he cannot freeze or steal the funds.

Follow Hopscotch and Unicrow at X to catch the announcement when the integration is live.

Morgan Culbertson, co-founder of Hopscotch: “Escrow has been on our roadmap from day one. Unicrow doing the heavy lifting in a beautifully designed developer experience saves us a lot of effort and gives trust and security assurances for our users”

Tomas Forgac, co-founder of Unicrow: “Our mission is to connect humans engaging in real world commerce in a secure and trusted way. We fell in love with Hopscotch’s user experience, which is about human crypto-connection in more than one way and it’s an honor to provide them with a small piece of the underlying infrastructure.”

Page Howe’s DomainOutlet.com, which lists thousands of high-quality domain names at wholesale prices, will add an option to pay for the domain purchases with USDT. The payments will be escrowed in Unicrow’s smart contracts.

The integration aligns well not only with Page’s strong belief in web3 ecosystem, but also with his long-term plans for the platform.

Read more here: https://domainoutlet.com/domain-outlet-starts-accepting-crypto-payments-for-domain-purchases/

The government of the aspiring micronation established on the principles of individual liberty and free trade, has endorsed using Unicrow’s escrow protocol for trades between businesses incorporated in Liberland.

From Liberland’s press release:

The shared commitment to free trade between the Liberland government and the Unicrow team makes this partnership a natural fit.

In addition

Liberland has stepped up to serve as an official arbitrator for individuals and entities wishing to use this service.

Read the full PR including a statement from the Liberland’s president here: https://liberland.org/en/news/458-liberland-endorses-unicrow-escrow-protocol-offers-arbitration-services

We asked GPT4 to list the challenges that marketplaces face when they want to integrate crypto. Turns out, Unicrow’s escrow platform solves all of them.

There are undeniable advantages of allowing buyers and sellers on an online marketplace to settle in crypto. Even ChatGPT, when asked to focus on the challenges of integrating crypto, started by highlighting the benefits, which include global accessibility and low transaction costs. We also believe it’s worth for the new market segment that brings.

But getting back to what the famous AI bot warned about, here’s the list of the consideration and why we think Unicrow is uniquely capable of addressing all of them and removing many headaches for the marketplace operators and their users.

Note: we’re including only the headlines in bold and omit the details that GPT included and instead add our comments to each point:

1. Price Volatility: Oldie, but goodie. The answer is quite simple: stablecoins. They allow the users to reap the benefits of crypto’s permissionless nature, global access, and instant settlements, without the volatility. Unicrow supports any ERC20 tokens, which includes all stablecoins.
2. Regulatory Compliance: As mentioned in our recent announcement of the upcoming integration of Unicrow into Kriptonmarket, one of the advantages of the protocol is, that it is fully non-custodial and therefore minimizes the marketplaces’ regulatory exposure.
3. Transaction Validation Time: Very valid concern for the two most popular L1s: Bitcoin and Ethereum. Unicrow has been deployed to Ethereum’s L2 Arbitrum which has 1-second blocktimes and sufficient capacity for the current and anticipated demand.
4. Security Concerns: Since the integration of Unicrow removes the necessity for marketplaces to hold their users’ balances, the operators’ security risks drop dramatically, and along with those also the trust that users need to put into these platforms.
5. Technical Complexity: Our big inspiration has from the beginning been one particular online card payment processor famous for its beautiful and easy-to-use API. You know whom we’re talking about. We aimed to achieve the same level of developer-friendliness and ease of integration, making sure our SDK does all the web3 heavy lifting for the developers so that they can focus on the other parts of the user experience. Try our SDK tutorial to evaluate how close we’ve gotten.
6. User Experience: Crypto is famous for the necessity of trade-offs between user experience and security. Allow users to settle quickly via centralized and custodial escrow with all the risks that such a setup creates, or introduce a much more secure multisig setup which requires two parties to get together to release funds?
   How about having the best of both worlds, by relying on non-custodial smart contracts to deliver the security and therefore allowing unilateral and instant settlement actions?
7. Tax and Accounting Implications: These are also easily solved by integrating stablecoins and therefore removing any gains or losses that would need to be reflected in the marketplace’s or its users’ accounting and tax filing.

On top of the most obvious benefits already mentioned at the beginning, integrating crypto brings along the possibility of relying on smart contracts for the escrow processes, which in turn removes a lot of inefficiencies, trust assumptions and regulatory headaches of traditional escrow.

Learn more about how Unicrow escrow works in our documentation, try the SDK via an easy-to-follow tutorial, or reach out to us to discuss your possible use case.

Unicrow founders entered the world of Bitcoin and crypto a decade ago with the vision of improving economic freedom for everyone, especially those in the regions suffering from high and unpredictable inflation, capital controls, and difficulties engaging with global commerce.

Therefore we are proud to announce that Kriptonmarket, a pioneering peer-to-peer commerce platform that helps users across Latin America to trade more freely and to mitigate impacts of high inflation, will be integrating Unicrow escrow protocol.

The integration will deliver benefits to both Kriptonmarket’s users, who will enjoy increased transactional safety, transparency, and trust, and also to the nodes that operate the p2p marketplace for whom Unicrow’s non-custodial design will mitigate both the security risks and regulatory exposure related to handling customer funds.

For Kriptonmarket this will represent a major leap towards the team’s long-term vision of full decentralization of the platform.

In the run-up to the live integration, we will share further information about the background and details of this cooperation. Stay tuned as we contribute to reshaping the future of peer-to-peer markets. Together with Kriptonmarket, we are forging a path towards a more decentralized, secure, and user-centric future.

About Kriptonmarket

Kriptonmarket facilitates diverse peer-to-peer transactions including goods and services marketplace, crypto-OTC trading, and bill payments. Recently, Kriptonmarket announced a partnership with Tether to bring USDT to one of the world’s largest wholesale food markets: https://cointelegraph.com/news/tether-kriptonmarket-to-support-usdt-transactions-at-argentina-s-central-market