Platform

One passport platform, from first part to final recycling.

EVstring brings product types, registration, lifecycle tracking, document integrity, public QR passports, recovery records, credentials and analytics into one platform shared by every organisation in the value chain. EV batteries first; chargers, solar panels, electronics and textiles on the same engine.

Book a demo Sign in

Delivery status:AvailableIn developmentRoadmap

Available

Configurable product types

Each kind of product is a versioned definition: its fields, lifecycle states, who may take each step, the documents it carries and the records kept about it. The definition is compiled into on-chain rules, so a new product type needs no new smart contract.

Five templates today: EV batteries, EV chargers, solar panels, consumer electronics and textiles.
Rules stored in the AssetTypeRegistry contract, with a fingerprint proving they match the definition.
New versions never change products already registered: each keeps the rules it was born with.
Role names per type (for example "Installer / EPC" for solar), so every screen speaks the industry's language.

Available

Product registration & identity

Manufacturers register each product once through a guided form generated from its type. EVstring issues a passport ID such as EVS-{maker}-{year}-{serial} for a battery or SPV-… for a solar panel, a QR code and an ERC-721 passport token held by the manufacturer.

Specifications stored off-chain; public and restricted fields set per product type.
SHA-256 fingerprint of the registered data anchored on-chain at mint time.
Passport ID is unique on-chain: duplicates are rejected by the contract.
QR payload designed for later GS1 Digital Link compatibility.

Available

Lifecycle & custody

Every product type has its own lifecycle, from manufactured to recycled: seven states for a battery, a similar path for a charger or a panel. The AssetLifecycle contract allows only the transitions its type defines, for the roles it names. Custody follows the product as its passport token moves between organisations.

Role-aware dashboards show each user only the steps they may take, for every product type.
Every event records actor, timestamp, transaction hash and a fingerprint of supporting data.
Custody moves with the steps that hand a product over; history is append-only.
Service visits, second life (reuse, refurbishment, resale) and recycling supported.

Available

Public passport & QR

Every QR code opens a fast, server-rendered public passport page that works on any phone. It shows the public tier of information and a live "data matches its on-chain fingerprint" check, and never exposes personal data.

Identity, key specifications, manufacturer and current state at a glance.
Lifecycle timeline with on-chain references.
No VINs, owner names or restricted fields, in the page or in its data.
Light and dark mode, readable on small screens.

Available

Material recovery & records

Records capture what happens to a product: material recovered at recycling, repairs, refurbishment grades, performance tests. Each is fingerprinted and anchored by the RecordRegistry contract, so recycled content can be traced back to real products.

Materials per product type: lithium, cobalt and nickel for batteries; glass, silicon and silver for panels; fibre-to-fibre for textiles.
Values stay off-chain; their hash is anchored against the product's passport.
Totals visible publicly; detail available to regulators.
Closing a passport by recycling requires a valid licensed-recycler credential.

Available

Verifiable credentials

Organisations hold W3C verifiable credentials signed by their issuer: a recycling licence, a carbon-footprint audit, an ISO 14001 certificate. Anyone can verify one, and its revocation, without an account.

Each organisation has a decentralised identifier (did:ethr) tied to its wallet and anchored on-chain.
A licensed-recycler credential gates recycling and material-recovery records.
An audit credential adds an "Audited" badge to carbon declarations.
Revocation takes effect immediately and is visible on a public status endpoint.

Available

Regulator analytics

Read-only access for regulators and auditors to complete audit trails and market-wide views, across every product type, without requesting spreadsheets from each company.

Products by lifecycle phase, by type and by manufacturer.
Recovered material totals per product type.
Recycled content against legal minimums where a product type has them.
No write permissions: auditors observe, they do not alter.

Available

Organisations, roles & the owner panel

Every user belongs to an organisation, and every organisation has exactly one on-chain role. The platform owner has a dedicated panel: organisations and their users, product types, credentials, and a dashboard of what the network achieved.

Roles: manufacturer, OEM / installer, owner, service centre, second-life operator, recycler, regulator / auditor.
Permissions enforced twice: in the API and in the smart contracts.
Onboard, suspend, archive or remove organisations; manage users and their access.
Impact by category: traceability, circularity, carbon transparency, trust.

Available

Documents & integrity verification

Certificates, composition reports, dismantling guides and service photos are fingerprinted, encrypted when restricted, stored in content-addressed storage and anchored by the DocumentRegistry contract. Which documents a product carries, and who may add them, comes from its type.

AES-256-GCM encryption with a per-document key for restricted and regulator tiers.
Verify any file: verified, tampered or not found, with block and timestamp.
Every access to a restricted document written to an audit log.
Downloadable PDF passport certificate with on-chain references.

Available

Telemetry & state of health

For product types with live data, such as batteries, management data (voltage, current, temperature, state of charge, state of health) is ingested, stored as time series, and anchored by Merkle root per time window.

Any single reading provable against its on-chain root.
State-of-health trend per battery, with retirement alerts below 80%.
Constant on-chain footprint regardless of fleet size.
Ingestion over MQTT (or HTTP), Merkle roots anchored on a schedule, alerts for heat and low SoH.

Available

Carbon footprint & recycled content

Manufacturers declare the carbon footprint per lifecycle stage and the recycled share of each material their product type tracks. The declaration is hashed and anchored, and shown on the public passport with a live integrity check.

Per unit of the product type: kg CO₂e per kWh for a battery, per kWp for a solar panel.
Battery recycled shares compared with the EU minimums for 2031 and 2036 (Art. 8).
Closed loop: recycled content linked to the recycled products it came from, with their on-chain recovery records.
Regulator view of recycled content across the market, per product type.

In development

Field app (Android)

A Flutter app for the workshop, the installation site and the recycling yard. It talks only to the API, never to the chain, so no keys live on the phone. It reads each product type from its passport, so new types need no app update.

Scan the QR label to open the passport with its live integrity check.
Field steps follow the product type's rules: start and complete service, retire, recycle.
Attach photos; every action shows its transaction status.
Tokens kept in the platform keystore; refresh tokens rotate on use.

Lifecycle

Lifecycle rules, enforced on-chain.

Each product type has its own state machine, registered in the AssetTypeRegistry contract and enforced by AssetLifecycle. Once registered, a version cannot be quietly changed. Shown here: the EV battery.

1
MANUFACTURED
Manufacturer registers the battery; passport token minted
2
INSTALLED
Vehicle OEM installs it (VIN kept off-chain, salted hash on-chain)
3
IN_USE
OEM or current owner puts it into service
4
UNDER_SERVICE ⇄ IN_USE
Service centre opens and closes service visits
5
RETIRED
Owner or service centre retires it, with the latest state-of-health reading
6
SECOND_LIFE ⇄ RETIRED
Second-life operator repurposes it, e.g. stationary storage
7
RECYCLED
Licensed recycler dismantles it and records recovered materials (terminal)
Any other transition is rejected by the contract.

Want the detail? How the contract enforces it.

Data model

Built on Annex XIII of the EU Battery Regulation.

The passport's information categories and access tiers follow Annex XIII of Regulation (EU) 2023/1542 and industry content guidance, so the data you capture today maps to what will be required.

Passport data categories and access tiers
Category	Examples	Access tier
General information	Passport ID, manufacturer, date and place of manufacture, category, chemistry, weight, rated capacity	Public
Carbon footprint	kg CO₂e per kWh, by lifecycle stage, with audit certificate	Public
Material composition	Cathode, anode, electrolyte, critical raw materials, hazardous substances	Public summary · restricted detail
Recycled content	Recycled shares of cobalt, lithium, nickel and lead	Public
Performance & durability	Capacity, voltage range, power, expected lifetime, state of health, efficiency	Public summary · restricted detail
Due diligence	Supplier reports, origin certificates, third-party verification	Restricted
Dismantling & safety	Disassembly guide, safety instructions, extinguishing agent, part numbers	Restricted
Lifecycle events	Every state change with actor, timestamp and transaction	Public summary · regulator full
Material recovery	Recovered Li, Co, Ni, Mn, Cu, Al and graphite	Public totals · regulator detail

See the compliance mapping for requirement-by-requirement coverage, including what is not yet covered.

Roadmap

What comes next.

Planned capabilities, in rough order. Timelines depend on pilot partner priorities; we will not describe these as available until they are.

Roadmap

Multi-validator network & explorer

Validator nodes run by consortium members instead of one operator, and a public block explorer for every passport reference.

Roadmap

Remaining-useful-life prediction

Machine-learning estimates of remaining life from anchored telemetry, to support second-life grading.

Roadmap

Public-chain anchoring

Optional periodic anchoring of ledger checkpoints to a public network for extra external verifiability.

Deployment

Run it the way your consortium needs.

EVstring is container-based and does not depend on a public cloud or a public blockchain.

Managed

We operate the platform and validator nodes; your teams use the web app and integrate through the API.

Consortium

Industry partners each run a validator node, so no single company controls the ledger.

Private

Deployment in your own data centre or region for organisations with strict residency requirements.

Beyond batteries

Available

One trust layer for every regulated product.

The EU's Ecodesign for Sustainable Products Regulation extends the digital product passport idea well beyond batteries. In EVstring each product type is a versioned definition (fields, lifecycle, who may do what, documents, recovery records) that the smart contracts enforce. The prototype ships five templates; more types are added as data, not code.

EV batteries
EV chargers
Solar panels
Consumer electronics
Textiles & apparel

Get started

See a battery passport end to end.

We will walk you through registration, lifecycle events, the public QR passport and tamper-evident verification, using your own battery categories as the example.

Book a demo Try the public passport