Mezo veNFT Marketplace
An escrowless, peer-to-peer secondary marketplace for trading veBTC and veMEZO vote-escrowed NFTs on the Mezo Network. Sellers retain full custody until atomic purchase.
Table of Contents
- Overview
- Architecture
- Contract Addresses
- Quick Start
- Deployment Guide
- Environment Variables
- Security & Audit Diff
- Bounty Compliance
- Maintenance Plan
Overview
The Mezo veNFT Marketplace provides a secondary liquidity layer for locked Bitcoin and MEZO governance positions. Users can:
- List veBTC and veMEZO positions for sale at any price in BTC, MEZO, or MUSD
- Browse all active listings with real-time intrinsic value, voting power, lock expiry, and discount percentage
- Buy listed positions with a single atomic transaction — NFT and payment swap simultaneously
- Bid — make an offer on any veNFT; the owner accepts it on-chain. Your funds stay in your wallet (only an approval is held) until a bid is accepted
- Pay in any token — buy a listing priced in one currency using another; the swap routes automatically through Mezo's Velodrome DEX
- Cancel listings at any time with no penalty
- View full position details: locked amount, voting weight (with decay), time remaining, price-to-value ratio
Key Design Properties
| Property | Detail |
|---|
| Escrowless | NFT stays in seller's wallet until purchase — no custodial risk |
| Atomic swap | NFT transfer happens before payment — buyer cannot lose funds if NFT moved |
| Multi-token | Native BTC, MEZO governance token, MUSD stablecoin |
| Protocol fee | Default 2%, hardcapped at 5%, 48-hour timelock on changes |
| Emergency pause | Admin can halt marketplace instantly |
Architecture
Four modular smart contracts — adapted from the OpenXSwap audited pattern for Mezo's dual-token system:
v2 Modules
Additive contracts deployed on top of the core marketplace (the core is unchanged):
| Contract | Role | Mainnet |
|---|
VeNFTBidding | On-chain offers/bids — escrowless; acceptBid settles the fee split directly | 0xef35dc538b50549e95687a51e8aa542D485ea384 |
SwapPaymentRouter | Pay-with-any-token — swaps via Mezo's Velodrome DEX, then buyNFT | 0x638Bab65738bA7BcD47D3c1d6Cb4eaf6CC872617 |
Bidding flow: bidder approves the bidding contract → createBid (funds stay in wallet) → the NFT owner calls acceptBid, which atomically transfers the NFT and pulls payment, routing the protocol fee to the treasury. No escrow.
Swap flow: buyer calls swapAndBuy → the router swaps their token → the listing's quote token through the Velodrome BTC/MUSD pool (pool-direct, no oracle), then calls the marketplace's buyNFT and forwards the NFT. Single transaction. (MEZO has no DEX pool, so MEZO-priced listings are paid in MEZO directly.)
Listings & activity are served by a Goldsky subgraph indexer (subgraph/) when SUBGRAPH_URL is configured, with an automatic on-chain fallback.
Deployment Order
1. MezoVeNFTAdapter(veBTC, veMEZO)
2. PaymentRouter(feeRecipient, admin, MUSD, feeBps)
3. MarketplaceAdmin(admin, isTestnet)
4. VeNFTMarketplace(adapter, router, admin)
5. router.setMarketplace(marketplace) ← security: restrict routePayment caller (one-time)
6. admin.setPaymentRouter(router) ← governance: link fee control
7. router.transferAdmin(adminContract) ← propose admin transfer to MarketplaceAdmin
8. admin.acceptRouterAdmin() ← accept: enforce 48h timelock on fee changes
Contract Addresses
Mezo Testnet (Chain ID: 31611)
| Contract | Address |
|---|
| BTC (native) | 0x7b7c000000000000000000000000000000000000 |
| MEZO | 0x7b7c000000000000000000000000000000000001 |
| MUSD | 0x118917a40FAF1CD7a13dB0Ef56C86De7973Ac503 |
| veBTC (ERC-721) | 0x38E35d92E6Bfc6787272A62345856B13eA12130a |
| veMEZO (ERC-721) | 0xaCE816CA2bcc9b12C59799dcC5A959Fb9b98111b |
| VeNFTMarketplace | 0xF18016FbadfA732c58814b6341054484FcDBF26f |
| MezoVeNFTAdapter | 0x526A542F7B2809376391CD7f884Daf4967fFEb14 |
| PaymentRouter | 0x157ed850E41e0f220549005da8b55bBE2AE32d7D |
| MarketplaceAdmin | 0xdBBc692828866ab0ee8BC8C2e6B7d911F7B89Ed4 |
| RPC | https://rpc.test.mezo.org |
| Explorer | https://explorer.test.mezo.org |
| Faucet | https://faucet.test.mezo.org |
This is the beginning of the README. Read the rest at the original. Read the full README ↗
