“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
Security token development. STOs with compliance built in.
We are an STO development company. We build the contracts and platform for your security token offering, so every transfer enforces the rules your legal structure defines.
They trust Metlabs with their blockchain projects
Security tokens
What does building a security token offering involve?
It means building the holder register of a security on a blockchain network. That covers the token contract, each investor's verified identity and the rules that decide who can receive it. The token represents a right against the issuer, defined by the offering's legal structure, and it remains subject to securities law.
$32B+
in assets tokenized with ERC-3643
ERC3643 Association · 2026
€1.6B
settled in Eurosystem DLT trials
ECB · 2025
$2T
in tokenized assets by 2030 (base case)
Forecast · McKinsey · 2024
What's included
What our security token development includes.
We build on the structure your legal team defines. Each piece turns one obligation of that structure into code or into the issuer's day-to-day operations.
ERC-3643 contract
An ERC-20 compatible token whose transfers depend on each investor's eligibility.
Investor identity
An identity registry with ONCHAINID and KYC claims signed by trusted issuers.
Compliance rules
Limits by country, investor type or number of holders, enforced on every transfer.
Issuer controls
Freezes, forced transfers and lost-wallet recovery, with roles and an on-chain record.
Investor portal
Onboarding, KYC, subscription and positions in an app that signs with the investor's wallet.
Holder register
Event indexing to reconcile the on-chain register with your systems and your reports.
Standard decision
ERC-3643, ERC-1400 or ERC-20 with an allowlist?
The standard decides where investor identity lives and what the issuer can do with the tokens. All three restrict transfers. They differ in maturity, interoperability and how much has to be custom-built.
| Criterion | ERC-3643 | ERC-1400 | ERC-20 with allowlist |
|---|---|---|---|
| Standard status | Final ERC, compatible with ERC-20. | A draft never finalized, with four sub-standards. | No compliance standard, custom logic. |
| Investor identity | On-chain registry with claims from trusted issuers. | Per-transfer validation with reason codes. | A list of addresses maintained by the issuer. |
| Issuer controls | Freeze, forced transfer and recovery. | Forced transfer and redemption by a controller. | Whatever is coded, with no common interface. |
| Typical fit | Securities with rules by investor and country. | Instruments with tranches or balance partitions. | Closed pilots with a few known investors. |
We default to ERC-3643. The final choice depends on the legal structure and on the infrastructure where the security is recorded or traded.
Methodology
How we build your security token offering.
Four phases, each with a deliverable. We start from a legal structure that is already defined and deploy nothing until every compliance rule has its test.
A diagram of the token, the identity registry, key custody and the chosen network.
We design in Figma the onboarding, subscription and portfolio each investor sees with their wallet.
The ERC-3643 token and its compliance modules in Solidity, reviewed function by function in pull requests.
Tests for every compliance rule, Slither analysis and deployment with roles held by a multisig.
Tools for an offering you can audit.
Solidity on OpenZeppelin libraries, testing with Foundry and Hardhat, and Ethereum or Polygon as the register network.
- Solidity
The smart contract language for verifiable rules on EVM networks.
- OpenZeppelin
Audited Solidity contracts for tokens, access control and upgradeable systems.
- Foundry
Solidity tests, invariant fuzzing and command-line tooling for EVM networks.
- Hardhat
An environment to compile, test and deploy contracts on EVM networks from Node.
- 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
Securities we issue as tokens.
Your legal structure defines the instrument. We build the on-chain register and the rules that come with it.
Real estate vehicle shares
Shares or bonds of the vehicle that owns the property, transferable only to eligible investors.
Blockchain for Real Estate
Digital bonds and notes
Debt recorded on-chain with its coupon and redemption schedule, and identified holders.
Blockchain for Banking & Finance
Renewable energy financing
Bonds or shares in energy projects, with periodic payments to each registered holder.
Blockchain for Energy & Sustainability
Rights in artworks
Economic rights against the vehicle that holds the work, with a verifiable holder register.
Blockchain for Art & Culture
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 security token issuance
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
Related articles
Security tokens in Spain: regulation and issuance steps
Security tokens in Spain: rights, documentation, DLT representation and responsible register operators before issuing securities.
What are the differences between security tokens and utility tokens?
How to distinguish financial rights from service access, what legal classification examines and why a token’s name does not determine its regulation.
OpenZeppelin and ERC-3643: how a security token is built
What OpenZeppelin libraries and ERC-3643 controls provide, and what a securities issuance also requires: rights, permissions, operations and review.
Let's build the rails for your offering.
Tell us which instrument you want to issue and in which jurisdiction. We start from your legal structure and take it into the contract.
