A browser extension wallet is the most direct way for users to connect to web3 applications: it sits in the browser, holds the user's keys and answers connection and signing requests from websites. MetaMask, Rabby and Phantom are the best-known examples. Companies build their own extension when they need a wallet for their own ecosystem, specific chains, an enterprise setting with policies, or a better user experience than generic wallets offer. Our general extension work is described under browser extension development; this page covers wallets.
Core of a Wallet Extension
- Secure key storage: keys encrypted with a key derived from the user's password, decrypted only in memory, with auto-lock. Optional hardware wallet support.
- dApp connection standards: the EIP-1193 provider that websites talk to, and EIP-6963 so the wallet works alongside other installed wallets without conflicts.
- Readable signing: transactions and EIP-712 messages decoded into plain actions, never raw hex.
- Simulation and warnings: expected balance changes before signing, and warnings for unlimited approvals and known malicious sites. See blind signing prevention.
- Multi-chain: EVM networks and, where needed, Solana, with reliable RPC connections and token detection.
Built for Today's Browsers
Extensions now run on Manifest V3, where the background code is a service worker that can be stopped at any time. Wallet state, pending requests and locks must survive that. We build for Chrome, Edge, Brave and Firefox from one codebase in TypeScript, keep the permissions the extension asks for minimal, and prepare it for the store review process, which looks closely at crypto wallets.
Beyond the Basics
- Smart account support with passkeys, recovery and gasless transactions.
- Enterprise policies: allowed contracts, spending limits and approval flows for teams.
- Connection to mobile through WalletConnect.
Frequently Asked Questions
How long does store approval take?
It varies per store and per update. Wallets get extra scrutiny, so we keep permissions minimal and document why each is needed.
Can we start from an open-source wallet?
Sometimes. Forking saves time but brings someone else's design decisions and licence terms; we review both before advising.
How are keys protected?
Encrypted at rest with a password-derived key, decrypted only while unlocked, never sent to any server, and optionally kept on a hardware device.
Who owns the code?
Ownership of the source code is set out in the contract, and the code can be fully yours, including documentation and tests.
Part of our crypto wallet development, alongside desktop and mobile wallets.
Build Your Wallet Extension
Tell us which chains, users and features your wallet needs. We will build an extension that is secure, fast and ready for store review.