• Author: Brennan Mulligan (General Manager, RareDAO Foundation), Charles Crain (CTO, SuperRare Labs; RareDAO Council Member)
• Status: Proposed
• Type: Protocol Development
• Implementer: RareDAO Foundation
• Sponsors: John Crain
• Created Date: May 6, 2025

Summary

This proposal introduces new batch listing and auction contracts that allow creators to launch large drops with a single transaction. It also includes reusable approval managers that simplify token approvals and reduce friction as Rare Protocol continues to expand.

Background & Motivation

Creators and collectors currently face high friction when launching multi-piece drops. Each listing or reserve auction must be created individually, requiring a separate transaction and approval. This increases gas costs and adds unnecessary overhead to the process.

Recent protocol upgrades have improved the collector experience—most notably the Batch Offers SIP, which allowed prospective buyers to send several offers in a single transaction. However, an equivalent sell-side improvement is still missing.

This proposal introduces two new marketplace contracts:

• RareBatchListingMarketplace for fixed-price listings (link)
• RareBatchAuctionHouse for reserve auctions (link)

These contracts allow creators to set up many listings or auctions in a single transaction. This dramatically reduces the number of transactions required when launching large drops.

To support this flow and reduce approval fatigue, we also propose two reusable approval manager contracts:

• ERC20ApprovalManager (link)
• ERC721ApprovalManager (link)

These contracts allow users to grant a single approval that can be reused across future Rare Protocol modules, instead of repeating approval transactions for each new contract.

Bundling these contracts into a single SIP ensures the batch listing and auction flows are fully functional at launch, with the necessary approvals infrastructure in place.

Specification

The proposed contracts will be deployed to Ethereum mainnet and include two marketplace modules and two approval managers. The RareBatchListingMarketplace and RareBatchAuctionHouse will each be deployed behind upgradeable proxies. The ERC20ApprovalManager and ERC721ApprovalManager are standalone contracts.

In the fixed-price flow, a creator stores a single Merkle root that specifies the currency and price. When a buyer calls buyWithMerkleProof, the contract verifies the token’s inclusion in the root, transfers funds using the ERC20 approval manager, transfers the NFT using the ERC721 approval manager, and completes the sale. Additionally, the seller will have the option to enforce a whitelist of addresses allowed to purchase artworks included in the batch allowing substantially more control around private and pre-sales in addition to standard bulk listing formats.

In the reserve-auction flow, a creator stores a Merkle root defining the currency, starting bid, and auction duration. A buyer may submit the first bid using bidWithAuctionMerkleProof, which verifies inclusion, creates the auction, and escrows the NFT. The auction proceeds using standard mechanics and is settled using settleAuction.

The approval managers allow users to authorize token transfers once and reuse that approval across multiple Rare Protocol modules. Initially, only the two new batch marketplace modules will use them, but future proposals may extend this model to additional Rare Protocol contracts. If necessary, the Council may permanently disable transfers by calling a one-way disable() function.

Contract deployment, ownership, & auditing

All contracts will be deployed by the RareDAO Foundation. Ownership and proxy-admin rights will be transferred to the RareDAO Council multisig immediately after deployment. A third-party security audit must be completed, and all findings must be addressed prior to deployment.

Benefits

• Improved seller experience: Enables sellers to configure many listings or auctions with a single low-cost transaction, supporting larger drops and more flexible release strategies.
• Unified token approval system: Introduces a reusable token approval model that simplifies onboarding and reduces user friction as new modules are added.
• Gradual implementation: Creates a path to unify token approvals across all protocol modules, including existing contracts, reducing cognitive overhead and improving security over time.

Drawbacks

• Shared configuration constraints: Each bulk auction or listing only supports a single configuration (e.g. price, duration). The generation of multiple merkle roots are needed for varied pricing, which could eventually be accommodated at the UI layer.

• New approval model introduces trust assumptions: Centralizing permissions improves UX but increases reliance on proper role management when deploying contracts.

Implementation

Upon execution of this proposal, the following steps shall be taken for implementation:

1. RareDAO Foundation and SuperRare Labs will coordinate to resolve any audit feedback not accounted for prior to completion of proposal voting.
2. RareDAO Foundation will deploy all of the contracts necessary for the deployment of this functionality, as described in the Specification section.
3. Once the contracts are deployed and tested, ownership and proxy-admin rights will be transferred to the RareDAO Council multisig for ongoing community ownership.