Material record

MassID

The record of a batch of material.

Each MassID identifies a batch, its mass and the published collection, transport and treatment events.

This contract issues MassID records and makes them available for lookup on the Carrot network.

What a MassID records.

Three pieces of information follow the batch and give context to its journey.

Material: The type and subtype of material identified in the batch.
Mass: The quantity recorded for the batch, in kilograms.
Journey: Published events and the roles of those involved in collection, transport and treatment.

Participants appear in the record through identifiers and roles. Public names may appear too; wallet addresses are not part of the MassID’s public metadata.

From material to a certified outcome.

The MassID records the batch. Methodology verification determines whether its data meets the criteria for a certificate.

Can one batch support both credit types?

Yes, when it passes the respective verifications. Each certificate is linked to one MassID but records a different outcome: emission reductions or recycled mass.

Explore the frameworks

View the contract.

The address identifies the contract for this family. Each record it issues has its own number.

Network: Polygon Amoy · 80002
Symbol: MASS-ID

Contract address

0x3ad50e086878965212a2914d4330a1f807a081b8

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View transactions and issued records.

Standard, custody and metadata

Standard: ERC-721 · non-transferable records
Custody: Issued records are held by the Vault contract.
Issuance: The record is issued on the public network after digital measurement, reporting and verification (digital MRV) of its data.
Family metadata: This contract does not provide an IPFS reference.
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Can a MassID be revoked?

Yes. A network operator can revoke it if its underlying data is invalidated. Linked certificates must be revoked first; credits already sold prevent this revocation. The issuance and revocation history remains recorded on the network.

Read the revocation rules