“One of the pioneering firms in web3 solutions, digital assets and tokenization, recognized for its innovation and solid reputation across Spain and Latin America.”
Jorge CorredorLawyer, Rincón Cuéllar & Asociados
Crypto wallet development. Clear signing, planned recovery.
We are a crypto wallet development company. We build custodial and self-custodial wallets with access recovery and signing flows users understand before they approve.
They trust Metlabs with their blockchain projects
Wallets
Which wallet does your product need?
It depends on who controls the keys. With custody, your company signs for the user and takes on a custodian's obligations. With self-custody, the user keeps control and your product designs how they recover access. In between, MPC and ERC-4337 smart accounts split or program that responsibility.
158,000
personal wallet compromises in 2025
Chainalysis · 2025
80,000+
victims of personal wallet theft
Chainalysis · 2025
$713M
stolen from personal wallets in 2025
Chainalysis · 2025
What's included
What our crypto wallet development services include.
A wallet is judged at its worst moment, when a user loses their phone or signs something they do not understand. Every piece is built for that moment.
Custody model
Custodial, MPC or smart account, chosen for your license, your users and the risk you take on.
Key management
Keys in the device's secure enclave, an HSM or institutional custodians such as Fireblocks and BitGo, integrated through their APIs. Never in plain text.
Access recovery
Guardians, backup keys or identity checks, depending on the custody model you choose.
Readable signing
EIP-712 typed data and transaction simulation, so users see what they approve before signing.
Sponsored gas
ERC-4337 paymasters so users can transact without buying the network token first.
Mobile and web apps
Interfaces with balances, history and alerts for every operation, built into your product.
Custody decision
Custodial, MPC or smart account wallet?
This decision sets your legal obligations and the user experience. The real question is who can move the funds and how access comes back when a device is lost.
| Criterion | Custodial | MPC | Smart account (ERC-4337) |
|---|---|---|---|
| Who controls the key | Your company, signing on the user's behalf. | Nobody holds it whole. It is split into shares. | The user, under the contract's validation rules. |
| Access recovery | Through support, after verifying the user's identity. | The lost share is regenerated from the others. | Guardians or backup keys defined in the contract. |
| EU framework | Custody on behalf of clients requires a CASP license. | Depends on whether your company can sign alone. | Self-custody if your company cannot move funds. |
| Typical fit | Exchanges, neobanks and non-technical users. | Corporate treasury and apps without a seed phrase. | Consumer products with sponsored gas. |
How each model fits under MiCA is confirmed with legal counsel for each product and jurisdiction before development starts.
Methodology
How we develop your crypto wallet.
Four phases, each with a deliverable. Custody is decided before any screen is designed, and access recovery is tested before launch.
A document covering who signs, how access is recovered and which parts of the wallet live on-chain.
Sign-up, balance, send and signing screens designed for users who have never signed a transaction.
App, signing service and account contracts, with every change reviewed in a pull request.
Contract and access recovery tests on testnet before the wallet opens to real users.
Tools for wallets that live inside your product.
TypeScript and React in the app, viem and wagmi to talk to the network, and the EVM networks where the accounts are deployed.
- TypeScript
Types for blockchain interfaces, SDKs and services, with fewer errors in production.
- React
Components and state management for Web3 application interfaces.
- Viem
A TypeScript client for EVM networks, modular and strictly typed by design.
- Wagmi
Hooks for EVM wallets and contracts in React, Vue and other frontends.
- Ethereum
EVM contracts, tokens and final settlement on an open Proof of Stake network.
- Base
An EVM layer 2 on the OP Stack with tools for building applications.
Use cases
Where we build crypto wallets.
Your own wallet makes sense when users move value inside your product and you do not want to send them to a third-party app.
Stablecoin accounts
Tokenized euro or dollar balances inside a banking app, with the custody its license requires.
Blockchain for Banking & Finance
In-game wallets
Accounts created at sign-up with sponsored gas, so players never see a seed phrase.
Blockchain for Gaming & Entertainment
Certificates of authenticity
Buyers receive the item's digital certificate in a wallet they open with their email.
Blockchain for Fashion & Luxury
Digital season tickets
Season tickets in the fan's wallet, with transfers the club controls to curb scalping.
Blockchain for Pro Sports
Reviews
What do our clients think of Metlabs?
“We structured the tokenization of real estate projects with them, and I value the team's ability to understand our corporate needs and genuinely solve them.”
Joan MejíaManager, GLOBYNE
“They advised us on the feasibility of tokenizing real estate assets in Uruguay with direct, cordial treatment. A professional team, responsive and always available.”
Álvaro Silva SantamaríaCEO, Sp Inmuebles
“Great professionals at structuring tokenized projects, with technical command and attention to detail that inspire full confidence at every stage of the work.”
Francisco BetancourtVerified Google review
“As a blockchain lawyer, I value their experience and professionalism in consulting and executing tokenization projects. Technology partners you can fully trust.”
Vanessa RivasBlockchain lawyer, El Salvador
“Great professionals, very attentive to their clients and always mindful of every detail. Working with their team has been a genuine pleasure from start to finish.”
CriptorentVerified Google review
“A very professional yet approachable company that empathizes with your doubts and needs. Highly recommended for entrepreneurs with a tokenization project.”
Javier EspasaTokenization entrepreneur
“Exceptional in every sense. From legal support I value their rigor and transparency: working with Metlabs means professionalism, innovation and security.”
Pedro A. Agúndez MéndezGoogle Local Guide
“Excellent service across blockchain development, asset tokenization and consulting. A very professional team that I recommend wholeheartedly, without reservation.”
José Luis DíazVerified Google review
“I have worked with them on several projects and they are very professional. A guarantee that everything turns out perfectly. Without a doubt, 100% recommended.”
Ignacio Fernández JiménezVerified Google review
“One of the pioneering firms in web3 solutions, digital assets and tokenization, recognized for its innovation and solid reputation across Spain and Latin America.”
Jorge CorredorLawyer, Rincón Cuéllar & Asociados
“Great professionals at structuring tokenized projects, with technical command and attention to detail that inspire full confidence at every stage of the work.”
Francisco BetancourtVerified Google review
“A very professional yet approachable company that empathizes with your doubts and needs. Highly recommended for entrepreneurs with a tokenization project.”
Javier EspasaTokenization entrepreneur
“I have worked with them on several projects and they are very professional. A guarantee that everything turns out perfectly. Without a doubt, 100% recommended.”
Ignacio Fernández JiménezVerified Google review
“We structured the tokenization of real estate projects with them, and I value the team's ability to understand our corporate needs and genuinely solve them.”
Joan MejíaManager, GLOBYNE
“As a blockchain lawyer, I value their experience and professionalism in consulting and executing tokenization projects. Technology partners you can fully trust.”
Vanessa RivasBlockchain lawyer, El Salvador
“Exceptional in every sense. From legal support I value their rigor and transparency: working with Metlabs means professionalism, innovation and security.”
Pedro A. Agúndez MéndezGoogle Local Guide
“They advised us on the feasibility of tokenizing real estate assets in Uruguay with direct, cordial treatment. A professional team, responsive and always available.”
Álvaro Silva SantamaríaCEO, Sp Inmuebles
“Great professionals, very attentive to their clients and always mindful of every detail. Working with their team has been a genuine pleasure from start to finish.”
CriptorentVerified Google review
“Excellent service across blockchain development, asset tokenization and consulting. A very professional team that I recommend wholeheartedly, without reservation.”
José Luis DíazVerified Google review
Team
In-house blockchain development team
Metlabs is a blockchain development company based in A Coruña, Spain. An in-house team covers every part of the project, from product and engineering to infrastructure and legal fit. The people who design your architecture write, test and deploy the code.
Meet the team- Projects in production
- +30
- In tokenized assets
- +$40M
- In‑house development
- 100%
Isaac González
Head of Innovation
Carlos Peña
Full Stack Engineer
Pablo Castro
DevOps Engineer
Helena Ramos
Product Designer
Javier Yáñez
Legal
Security
Security in wallet development
Every delivery goes through the same checklist before it reaches mainnet. What changes between projects is the depth of each control, because an MVP does not carry the same risk as a contract that holds third-party funds.
Before mainnet
- Roles and permissions defined for every critical function
- Unit and invariant tests, and fuzzing on the logic that moves value
- Static analysis and peer review of every change
- Multisig and timelock on administration when the risk justifies it
- Custody and rotation of the deployment keys agreed
- External audit when the value at risk requires it
We work with leading audit firms
FAQ
Crypto wallet development questions
It depends on your license and your users. A custodial wallet gives the simplest recovery but makes you a custodian, which in the EU means CASP authorization under MiCA. A non-custodial wallet leaves the keys with the user, so you have to design recovery through MPC shares, guardians or backup keys.
We start by choosing the custody model and the recovery flow, then design the sign-up, balance, send and signing screens. The app talks to the network through viem or wagmi, keys live in the secure enclave or an HSM, and every flow is tested on testnet, including recovery, before launch.
It depends on scope. The main drivers are the custody model, the number of networks and assets, whether you need native mobile apps as well as web, integrations with KYC or payment providers and whether gas is sponsored. We quote a fixed scope after the custody and recovery decisions are made.
That depends on the custody model chosen at the start. In a custodial wallet, support restores access after an identity check. With MPC, the missing key share is regenerated from the others. A smart account can rotate its signing key through guardians or a backup key defined in the contract.
Blockchain development
More blockchain development services.
Connect your operations
Represent assets and rights
Blog
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Let's build the rails for your product.
Tell us who will use the wallet and which license you hold. We start with the custody model and access recovery.
