Fixed-scope offer
Smart contract and Web3 integration
- Price
- From £6,000
- Time
- 3 to 5 weeks
- Payment
- 50% deposit to book, balance on launch; monthly plans billed in advance.
Smart contracts written in Solidity, tested and deployed to a testnet, and wallet connection added to the web or mobile app you already have, in three to five weeks.
We reply within one working day.
What happens after you get in touch
We reply within one working day.
Step 1
We reply within one working day
We read what you sent and come back with questions, a rough view of cost, or a time to talk.
Step 2
A 20-minute call
We talk through what you need and tell you honestly whether we're the right team. No charge and no obligation.
Step 3
A written, fixed-price proposal
Scope, price and timeline in writing. Nothing starts until you've signed it off.
Who it's for
Teams with a live product who want to add an on-chain feature, such as a token, NFT, membership or payment, without rebuilding the product around it.
What you get: Tested contracts on a testnet, wallet connection working in your app, and a clear path and cost list for going to mainnet.
What's included
- A scoping call that confirms what belongs on-chain and what doesn't. If the honest answer is nothing, we say so and stop there at no charge.
- Solidity contracts for Ethereum or an EVM chain (Base, Arbitrum, Optimism, Polygon), built on OpenZeppelin's audited libraries.
- An automated test suite covering every function and failure case, and static analysis.
- Deployment to a testnet, with a script you can rerun, so you can try everything with test funds.
- Wallet connection in your existing app: WalletConnect and browser wallets, and Sign-In with Ethereum if people should use their wallet as their account.
- A written mainnet checklist: deployment steps, estimated gas, what an auditor will need, and what to monitor.
- The contracts, tests, scripts and documentation in your repository.
Not included
- Mainnet deployment costs, gas, RPC or indexer hosting, and the fee for an independent audit. These are paid by you, and we recommend an audit before mainnet for any contract holding value.
- A security audit. We write the tests and use audited libraries; an independent firm should audit before mainnet.
- Regulatory advice. UK cryptoasset promotions are regulated by the FCA; you are responsible for the regulatory position of what you offer.
- Non-EVM chains such as Solana.
How it runs
- Week 1Scoping: what goes on-chain, which chain, the contract design and the mainnet cost list, signed off by you.
- Weeks 2 to 4Contracts, tests and testnet deployment, then wallet connection in your app, with a demo each week.
- Week 5Your review on the testnet, fixes, documentation and the mainnet checklist. Mainnet deployment is a separate step, after any audit.
Why trust us with it
We have no shipped blockchain client work to show, so we're not going to pretend otherwise. What you can check is how we build: our own apps on the App Store and this site, and the process on this page, which is tests for every function, audited libraries, a testnet you can try, and an independent audit before mainnet for anything that holds value.
After launch
Keep it working after launch
Websites and apps need looking after once they're live. Ongoing development is the plan most people choose after this, at from £1,500 a month.
Already have an app or site that needs looking after?2 reserved build days a month, more if you need themFits after this
Ongoing development
From £1,500 a month
From £1,500 a month for 2 reserved build days to keep improving your app or web product, with a backlog we prioritise together and a release each month.
What's coveredin Ongoing developmentUp to 1 hour of small edits a month
Website care
£95 a month
We keep your website online, up to date and secure, and make the small changes you need each month.
What's coveredin Website careUp to 3 hours of changes a month
Website care Plus
£195 a month
Everything in Website care, with three hours of changes a month for sites that need new pages, offers or content most months.
What's coveredin Website care PlusUp to 4 hours of changes a month
App care
£450 a month
We keep your app working on each new iOS or Android, passing App Review or Play policy and looking current in the store, with time each month for changes.
What's coveredin App care
Month to month, billed in advance. Cancel with 30 days' notice. Pay yearly for two months free. Prices exclude VAT.
Questions we get asked
That's the first thing we check, and if a database does the job we'll tell you. On-chain makes sense when several parties who don't trust one operator need a shared record, when users hold assets they can take elsewhere, or when the public has to be able to verify what happened.
Ethereum and EVM-compatible chains such as Base, Arbitrum, Optimism and Polygon. We don't take on Solana or other non-EVM chains at the moment.
It includes everything up to and including the testnet and a mainnet checklist. Mainnet deployment itself is a short, separate step after you've decided on an audit, and the gas, hosting and audit fees are paid by you. Nothing that holds value should go to mainnet without an independent audit.
Because an audit is only worth something when it's independent. We write the tests, use audited libraries and run static analysis, then help you brief an audit firm and fix what they find.
Since 8 October 2023, promoting cryptoassets to UK consumers has fallen under the FCA's financial promotions regime, and doing so without an authorised firm's approval or an exemption is a criminal offence. We build the software; you're responsible for the regulatory position of what you promote or sell, and we don't advise on it. Speak to a specialist solicitor before launch.
A 50% deposit to book the start date and the balance on launch of the testnet release. Prices exclude VAT.
Read before you start
- After launch
- Plan your budget
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- App Store launch package£1,500, 5 working days
- On-device AI featureFrom £4,000, 3 to 6 weeks
- iPhone Duo readiness reviewFrom £2,500, 2 weeks
- App broken, rejected or abandoned?One place to start
- Something bigger or differentAll services
Start with a 20-minute call with our team.
Tell us where you are and what you need. We'll tell you honestly whether this offer fits, or what would. We reply within one working day.
We reply within one working day. Or call 020 3540 5048