Marketplace Smart Contracts
Listing, bidding, auctions, offers, and royalty enforcement written and tested to audit standards. Gas-efficient contracts, because your users pay for every inefficiency.
What we build
A complete marketplace, on-chain and off
An NFT marketplace is a trading platform, a payments system, and a media product at once. We engineer all three layers so the result holds up under real users and real money.
Minting and Collections
Creator onboarding, lazy minting, batch drops, and allowlist mechanics for launches. Metadata and media stored properly on IPFS or Arweave so assets outlive any single server.Trading Experience
Fast search, filtering, rarity data, and real-time activity feeds backed by a custom indexer. The marketplace feels like a modern commerce app, not a block explorer.Wallets and Payments
Wallet connect flows, embedded wallets for mainstream users, and fiat on-ramps through providers like Stripe or MoonPay. Buyers should not need a crypto education to make a purchase.Royalties and Fees
Creator royalties, platform fees, and revenue splits enforced at the contract level and reported clearly. The economics of your platform, implemented exactly as designed.Admin and Moderation
Dashboards for collection curation, user reporting, takedowns, and fraud monitoring. A marketplace is a community, and you get the tools to govern it.
How we work
From marketplace concept to first sale
(4)- 1
Product definition and economics
We define who trades what on your platform, the fee and royalty model, and the chain that fits your audience. The output is a spec covering contracts, features, and a launch scope you approve. - 2
Contract and platform architecture
We design the marketplace contracts, indexing pipeline, and application stack together, since the three must agree. You review the architecture and the security model before the build starts. - 3
Build and test on testnet
Senior engineers ship the contracts and the app in parallel, with a testnet version you can click through early. Contracts go through fuzzing and simulation, and we prepare them for third-party audit. - 4
Audit, launch, and growth support
After audit remediation we deploy to mainnet, run the launch, and monitor contracts and infrastructure through the first drops. Post-launch we iterate on features as trading behavior shows what users want.
Why Webisoft
A blockchain engineering studio, not a template reseller
Plenty of shops will reskin a marketplace template. Webisoft engineers the platform from the contracts up, so your marketplace can differ where it matters and survive the traffic spikes of a real drop.
Contracts and Product, One Team
The engineers writing your Solidity sit with the ones building your app. No gap between the on-chain logic and the user experience.Security as a Requirement
Marketplace contracts custody listings and route funds, so they attract attackers. We threat model, test to audit standards, and coordinate independent audits before mainnet.Built for Volume
Custom indexers, caching, and load-tested infrastructure so a popular drop is a good day, not an outage. Performance is engineered in, not patched after.Senior Montreal Team, Your Ownership
Experienced North American engineers in your timezone, and you keep full ownership of the code, contracts, and infrastructure. No platform fees owed to us after delivery.
FAQ
Questions founders ask before building a marketplace
(4)- The main drivers are contract complexity, how custom the trading experience is, and features like auctions, fiat payments, or multi-chain support. A focused single-collection marketplace is a much smaller build than an open platform with creator onboarding and auctions. A common approach is to fix scope and price for a launchable first version after a definition phase, then expand based on real usage rather than speculation.
- A focused marketplace typically reaches testnet within two to three months, with mainnet launch following the security audit and remediation. Fully open platforms with creator tools and fiat on-ramps take longer. The external audit adds several weeks, so it should be booked early in the schedule rather than treated as a final step.
- It depends on where the buyers and their assets are. Ethereum has the deepest liquidity and trust, while L2s like Base and Arbitrum, or chains like Polygon, offer the low fees that high-frequency or low-price trading needs. Modeling expected transaction sizes and audience before choosing pays off, and multi-chain support is a viable path when the audience is split.
- White-label gets a generic marketplace running quickly, with the vendor's fees, limits, and roadmap attached. Custom development makes sense when the business model differs from the template, when specific royalty or compliance logic is required, or when the marketplace is the core of the business rather than a side feature. The honest test is whether the template's constraints would force the product to compromise on its differentiators.
NFT Marketplace Capabilities
Where We Add Value in NFT Marketplace Development
We build NFT marketplaces as production trading systems: audited contracts, reliable indexing, fiat friendly onboarding, and economics that hold up when volume arrives. These are the components that decide whether a marketplace works.
Smart Contract Engineering
We write marketplace and collection contracts in Solidity or Rust against ERC 721, ERC 1155, and their chain equivalents, using audited patterns for escrow, offers, and settlement. Contracts are covered by unit tests, fuzzing, and a third party audit before mainnet, because marketplace contracts hold custody during trades and are a direct attack target. Upgradeability is a deliberate choice we make with you, with its trust trade offs on the table.Chain and Cost Strategy
Ethereum mainnet, an L2 like Arbitrum or Base, Polygon, or Solana each imply different gas costs, liquidity, and user expectations. We model your expected transaction sizes against fees, because a marketplace for fifty dollar items dies on a chain where minting costs ten. Lazy minting and batch operations cut costs further where the product allows it.Royalties and Fee Design
On chain royalty enforcement is inconsistent across chains and marketplaces, so we design royalty logic that matches reality: ERC 2981 signaling, enforcement at the marketplace contract level where you control it, and clear fee splits between platform, creator, and referrer. You get a written economics model showing who earns what on every trade type, including auctions and bundles.Indexing and Marketplace Backend
Reading chain state directly is too slow for browsing, search, and activity feeds, so we build an indexing pipeline that listens to contract events and maintains a queryable database of listings, bids, and ownership. It handles chain reorgs and RPC failures gracefully, keeps metadata and media cached, and serves the API your frontend and mobile apps consume.Wallets and Fiat Onboarding
We integrate self custody wallets through WalletConnect and browser extensions, plus embedded wallet options like email or social login for users who have never held crypto. Fiat on ramps such as card payments through licensed providers widen the buyer pool significantly. Each option carries different custody and compliance implications, and we walk you through them before integrating.Compliance and Trust Features
Depending on jurisdiction and asset type, marketplaces may need KYC integration, sanctions screening, geographic restrictions, and stolen asset reporting flows. We build these as first class features with providers like Sumsub or Persona rather than bolting them on after a regulator asks. Collection verification and takedown workflows protect buyers from copymints and protect you from liability.
How We Work
How an NFT Marketplace Engagement Runs
(4)- 1
Economics and Chain Workshop
We start by pressure testing the business model: who mints, who buys, average price point, fee structure, and royalty policy. Those answers drive chain selection and contract design, so we settle them before writing code. The deliverable is a technical specification, an economics model, and a phased scope with estimates. - 2
Contracts First, Then Audit
Smart contracts are written, tested, and frozen early because the audit sits on the critical path and reputable auditors book weeks out. While the audit runs, we build the indexing backend and frontend against the frozen contract interfaces on a testnet deployment. Audit findings are remediated and re reviewed before anything touches mainnet. - 3
Platform Build and Testnet Beta
Frontend, search, activity feeds, wallet flows, and fiat on ramp come together against testnet, and we run a closed beta with real creators minting real collections in a staging environment. This phase surfaces the problems specs never catch: confusing approval prompts, gas surprises, metadata edge cases. We fix them before your reputation is on the line. - 4
Mainnet Launch and Operations
Launch includes contract deployment with verified source, monitoring on both the chain side and the API side, and runbooks for incidents like RPC outages or a stuck indexer. We stay through the first weeks of live trading to tune performance and handle the unexpected. Handover covers moderation tooling, treasury operations for fee collection, and the process for adding new collections or features.
FAQ
NFT Marketplace Questions Buyers Actually Ask
(6)- The main drivers are contract complexity, chain count, and how much of the trading feature set you need at launch. Fixed price listings on one chain with standard wallets sit at the lower end, while auctions, offers, bundles, multi chain support, and fiat on ramps each add contract work, indexing complexity, and testing. The audit is a real line item, typically tens of thousands of dollars for marketplace contracts, and it is not optional for anything holding user funds. We scope a minimal credible launch first so revenue can start before every feature exists.
- Follow your users and your price points. High value art and collectibles still concentrate on Ethereum where the liquidity is, but its gas costs make it wrong for low priced or high frequency items. L2s like Base and Arbitrum offer Ethereum security with far lower fees, and Solana suits high volume consumer use cases. We model your expected average sale price against fees on each candidate chain and check where your target collectors already transact. Multi chain at launch is usually premature, it multiplies audit, indexing, and support cost before you have traction.
- On most chains royalties are a signal, ERC 2981, that marketplaces can choose to honor, and several large venues stopped honoring them fully. On your own marketplace you control enforcement completely because settlement runs through your contracts, so creator royalties there are guaranteed. For trades that happen elsewhere, options include transfer restrictions and allowlisted operators, which add real friction and trade offs. We lay these choices out with their consequences so your creator pitch is honest.
- The two big surfaces are the contracts and the users. Contracts get audited patterns, extensive testing, fuzzing, and an independent third party audit before mainnet, plus monitoring for anomalous activity after launch. User facing risks, phishing, fake collections, wash trading, are handled with collection verification, moderation tooling, trade pattern flags, and clear signing prompts so users understand what they approve. We also plan the unglamorous parts: key management for admin functions, incident response, and what happens if a dependency like an RPC provider fails.
- It depends on jurisdiction, whether fiat is involved, and whether any assets could be treated as securities or regulated property. Fiat on ramps come with the provider's KYC built in, and marketplaces serving regulated assets or high values often need identity verification and sanctions screening of their own. We are engineers, not your counsel, so we build to the requirements your legal advisors set, and we architect KYC and geo restrictions as pluggable from day one so a regulatory change is a configuration project, not a rebuild.
- A focused single chain marketplace typically takes four to six months from kickoff to mainnet, with the audit accounting for several weeks of that on the critical path. Multi chain, auctions, or fiat integration extend it. We start with the economics and chain workshop, about two weeks, which produces the specification and estimate, and you own that document either way. The most useful preparation you can do before the first call is knowing your creators, your expected price points, and your fee model, because those decisions shape everything downstream.
