Registry

What is a registry?

A registry is the system that issues environmental credits, assigns each credit a unique identifier, tracks ownership changes, and records retirements. Its core function is preventing double counting — ensuring the same environmental benefit cannot be claimed by more than one buyer.

For how the registry relates to standards, methodologies, digital Measurement, Reporting and Verification (dMRV), independent assurance, and buyers, see Credit Ecosystem Roles.

How Carrot's registry works

Credits on Carrot are issued as digital assets in the public registry. Each credit carries a tamper-evident record that links the physical event that originated it — a verified mass of material collected, sorted, or processed — through issuance and purchase to its eventual retirement.

This record is publicly accessible: anyone can confirm a credit's issuance, ownership history, and retirement on the public ledger without Carrot's cooperation, and open the provenance document behind a recorded MassID, certificate or receipt in the Metadata Viewer. Participant identities in the provenance record are published as hashes rather than names. The Carrot Registry shows these records alongside every issued certificate, including those not yet recorded on the public ledger, and the verification results behind each one.

What the registry covers

The registry is the home for the credit lifecycle once verified environmental outcomes are ready to become market-facing assets. It covers:

• Credit issuance — RecycledID and GasID certificates back fungible credits such as Recycling Credits and Carbon Credits, respectively.
• Fungible credit tracking — Credit balances are tracked by certificate so available, purchased, and retired amounts cannot exceed the verified backing amount.
• Purchase records — Credit purchases create permanent records that connect buyers, payment, certificates, and purchased amounts.
• Retirement records — Credit retirement permanently removes the claimed credit amount from circulation and creates a permanent receipt for the environmental claim.
• Account and custody flows — Buyer and participant accounts interact with credit balances, receipts, and settlement flows while non-transferable records stay in the registry's custody.
• Settlement layer — Purchase and retirement flows connect payment, inventory allocation, rewards distribution, and permanent audit records.

The registry does not decide whether a physical activity qualifies for credit issuance. That decision comes from approved methodology framework criteria executed through dMRV. The registry records the resulting credit lifecycle: issuance, ownership-related activity, purchase, retirement, and the receipts that make those actions auditable.

Why is the registry built this way?

The registry runs on blockchain infrastructure. Three properties of that design matter directly to credit buyers:

• Public and permanent — Credit records exist on a public ledger, not a private database controlled by a single organization. The data persists regardless of what happens to any individual company or service.
• Independently verifiable — Any auditor, regulator, or buyer can confirm the integrity of a credit — its issuance, ownership history, and retirement status — without requiring Carrot's cooperation or access to proprietary systems.
• Programmable — Smart contracts hold credit sale proceeds and release each supply chain participant's share against a cryptographic proof of their committed allocation. What each participant is owed is fixed on-chain at the moment of sale, not decided afterwards.

For why Carrot builds this as digital public infrastructure, see the Network section.

Registry, Standard, and Third-Party Verification

Three distinct functions make up the ecosystem. The registry issues and tracks credits. The standard governs the program and methodologies that determine how environmental benefits are measured and which activities qualify for credit issuance. Third-party verification gives independent assurance over facilities and, where a methodology, program, or market requires it, over methodology frameworks and the evidence that automated dMRV execution produces; the execution itself is deterministic software, with recorded human decisions where a rule cannot be settled by code.

These functions are complementary but separate. The registry is infrastructure — it must be reliable, transparent, and tamper-resistant. The standard is governance — it must be scientifically rigorous and operationally enforceable. Third-party verification is assurance — it must be performed by parties independent from Carrot's operations. Carrot operates the registry and governs methodology quality through the Carrot dMRV Standard; third-party verification is conducted by external, independent auditors and Validation/Verification Bodies (VVBs).