Smart contracts and Web3 features, built carefully

A blockchain earns its place when several parties who don't trust a single operator need to agree on a record, when users hold assets they can take elsewhere, or when the public has to be able to verify what happened. If one company controls the data and nothing needs to be transferable, a normal database is cheaper, faster and far easier to change. Loyalty points, internal records and most marketplaces fall into the second group. We'll tell you which group your idea is in before you spend anything.

We write automated tests for every function and every way it can fail, run static analysis, and build on OpenZeppelin's audited contracts rather than writing token or access-control code from scratch. Every contract is deployed to a testnet first, where you can use it with test funds.

For any contract that will hold real value, we recommend an independent audit before mainnet, by a firm whose job that is. We are developers, not auditors: we'll help you brief the auditor and fix what they find, but we don't certify our own work.

Since 8 October 2023 the FCA's financial promotions regime has applied to cryptoassets. Promoting a qualifying cryptoasset to UK consumers is a criminal offence unless the promotion is made or approved by an FCA-authorised firm, or falls within an exemption, and approved promotions carry prescribed risk warnings and a cooling-off period for first-time investors. That covers websites, apps and social posts.

We build the software. You are responsible for the regulatory position of anything you promote or sell through it, and we don't advise on that: speak to a solicitor who specialises in financial regulation before you launch.

App Store Review Guideline 3.1.5 sets out what a crypto app may do: wallets may store virtual currency only if the developer is enrolled as an organisation; apps may not mine on the device; exchange features are allowed only through an approved exchange and only in regions where the app has the licences to offer them; ICOs, crypto futures and similar must come from established banks, securities firms or other approved financial institutions; and apps may not pay out cryptocurrency for tasks such as downloading other apps or posting to social networks.

Separately, an app may show NFTs a person owns, but owning one can't unlock features in the app, and selling NFTs or NFT services inside the app goes through In-App Purchase. We design iPhone features around these rules from the start so the version you build is the version Apple approves.