Reviews and Ratings

UMP uses a secure review system that ensures only real buyers can leave reviews. This helps build trust in the marketplace and helps other buyers make informed decisions.

Review scores help you evaluate sellers and listings

How Reviews Work

For Buyers

When you buy an item:

• After receiving your item, wait for the seller to confirm the sale
• Once confirmed, you can leave a review with:
  • Star ratings for different aspects of your purchase
  • Confirmation that the item matched its description
  • Written feedback about your experience
• Your review is permanently stored on-chain using Ethereum Attestation Service (EAS)

Leaving a review on UMP

For Sellers

As a seller:

• You must first confirm valid sales through an attestation
• This attestation allows the buyer to leave a review
• Your overall rating is calculated from all verified reviews
• Reviews help build your reputation in the marketplace
• Currently, it costs 1 wei (1e-18 ETH) to make a sale attestation. However, this fee may be increased in the future as an anti-sibyl measure.

Technical Details

UMP's review system uses several features to ensure trust:

Attestation Process

• Uses Ethereum Attestation Service (EAS) for all reviews
• Links each review to a specific purchase
• Verifies the authenticity of sales
• Creates permanent, tamper-proof records

What is EAS?

The Ethereum Attestation Service (EAS) is a system that lets anyone create verified statements about anything on the blockchain. Think of it like a digital notary - when someone makes a statement (called an attestation), EAS records it in a way that proves who made it and ensures it can't be changed later. This makes it useful for things like reviews, credentials, identity verification, or any situation where you need to prove something is true.

You can learn more about EAS on the EAS website.

Review Components

Reviews help build trust in our marketplace. Each review includes:

• Star ratings to rate your experience
• Written feedback
• Purchase verification
• Timestamp

Security Features

• Only confirmed buyers can leave reviews
• Reviews cannot be edited after submission
• All reviews are stored on-chain for transparency
• Seller attestations prevent fake reviews