“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
Decentralized identity. Share only what is needed.
We issue and verify credentials so your users can prove who they are or what they are allowed to do without handing over the whole document, and with no personal data on-chain.
They trust Metlabs with their blockchain projects
Decentralized identity
How do you add verifiable credentials to a product?
Your product acts as a credential issuer, a verifier or both. It asks the user for one specific claim, such as being over 18 or a verified customer. Their wallet, such as the EUDI Wallet, presents it signed, and your backend checks the issuer's signature and whether the credential is still valid. No personal data is written on-chain.
2026
deadline for every EU state's EUDI Wallet
EU Commission · 2026
36 months
for banks to accept the EUDI Wallet
eIDAS 2 · 2024
100%
of EU citizens with secure eID, 2030 target
Digital Decade · 2022
What's included
What our verifiable credentials development includes.
Every piece covers what a digital identity needs in production. Who signs each credential, how it is checked and which data never leaves the user's device.
Credential issuance
SD-JWT VC or W3C credentials, signed with your keys and published with a revocation status.
Verification
A service that requests the exact claim from the wallet and checks signature, issuer and status.
Selective disclosure
Users prove one attribute, such as their age, without showing the whole document.
EUDI Wallet support
Presentation flows that work with the European wallet and with other identity wallets.
Keys and DIDs
Management and rotation of issuer keys, published as a DID or as a certificate.
Privacy by design
Personal data kept off-chain, data minimization and consent records under the GDPR.
Architecture decision
Which credential format should you choose?
The format decides who can verify and what they see. SD-JWT VC is one of the formats the EUDI Wallet adopts. W3C VCs lead in open ecosystems. An on-chain attestation fits when the verifier is a smart contract.
| Criterion | SD-JWT VC | W3C VC with DID | On-chain attestation |
|---|---|---|---|
| Where the data lives | In the user's wallet. The issuer does not see each use. | In the wallet. The issuer's key resolves through a DID. | A public flag in a contract, with no personal data. |
| Selective disclosure | Built in, with a salted hash per attribute. | With BBS proofs, or by presenting the whole credential. | Not applicable. The contract only reads yes or no. |
| Who verifies | A backend that checks signature and revocation. | A backend that resolves the DID and checks the proof. | A smart contract, in the same transaction. |
| Typical fit | EUDI Wallet and reusable KYC. | Degrees, diplomas and industry credentials. | Allowlists for regulated tokens and dApps. |
Only attestations without personal data go on-chain. The GDPR requires that data can be erased, and what is written on-chain cannot be.
Methodology
How we build your digital identity system.
Four phases, each with a concrete deliverable. We decide which attributes each flow requests before writing code, and no personal data reaches the network at any point.
Which credentials you issue or verify, which attributes each flow requests and what stays off-chain.
Issuers, verifiers, key custody and the point where verification reaches your contracts.
Issuance and verification services and, when needed, the contract that only accepts verified addresses.
Every presentation and rejection flow tested, with Foundry and Slither on the on-chain side.
Tools for an identity you can verify.
Issuance and verification services in TypeScript and, when verification reaches the network, Solidity contracts on audited libraries.
- TypeScript
Types for blockchain interfaces, SDKs and services, with fewer errors in production.
- Node.js
A JavaScript runtime for backends, indexers and server-side Web3 services.
- Solidity
The smart contract language for verifiable rules on EVM networks.
- OpenZeppelin
Audited Solidity contracts for tokens, access control and upgradeable systems.
- Ethereum
EVM contracts, tokens and final settlement on an open Proof of Stake network.
- Polygon
Polygon PoS: EVM contracts secured by its own validators, with low fees.
Use cases
Where we apply decentralized identity.
A verifiable credential adds value when the same claim is checked many times, in different places, and handing over the full document each time is a risk.
Reusable KYC
A customer verified once presents the credential to other institutions without repeating the process.
Blockchain for Banking & Finance
Verifiable degrees
Diplomas and certificates an employer checks instantly, without calling the university.
Blockchain for Education
Healthcare credentials
Professionals who prove their license or specialty to another provider without paperwork.
Blockchain for Digital Health
Public services with EUDI
Public services that accept the European wallet to identify citizens from other countries.
Blockchain for Public Sector
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 digital identity
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
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 what your users need to prove and to whom. We start with the attributes each flow requests and what stays off-chain.
