Credit Purchase
How credit purchases work in the Carrot Network — atomic on-chain transactions, certificate allocation, and integrated retirement.
The credit buyer
The Carrot Network is a demand-side market — most of the value comes from credit buyers. Credit buyers are typically organizations — producers, manufacturers, importers, distributors, and their representatives (such as Producer Responsibility Organizations) — but individuals may also purchase credits to offset waste and carbon footprints.
Credit buyers purchase Tokenized Recycling Credits (TRC) and Tokenized Carbon Credits (TCC) to:
- Meet ESG commitments — Demonstrate verifiable environmental action to employees, customers, shareholders, and regulators.
- Comply with EPR mandates — Extended Producer Responsibility laws increasingly require producers to fund the recovery and recycling of their products and packaging.
- Offset carbon footprints — Retire carbon credits to permanently claim the greenhouse gas emissions avoided through recycling.
The purchase flow
The six-step atomic purchase flow: from buyer signature through smart-contract settlement to on-chain receipt.
Credits are purchased only through Carrot interfaces — buyers do not purchase directly on-chain. When a buyer uses a Carrot interface (e.g. the Carrot Store for individuals, or Carrot-provided interfaces for organizations), the platform executes the following atomic on-chain flow:
| Step | Action | Description |
|---|---|---|
| 1 | Purchase order signed | The buyer (or an authorized operator) signs a purchase order using an EIP-712 typed data signature, authorizing the transaction with the credit type, amount, and payment details. |
| 2 | Payment transferred | USDC is transferred from the payer to the RewardsVault smart contract, where it becomes available for rewards distribution to participants. |
| 3 | Certificate updated | The purchased amounts are recorded on the backing certificates, reducing the available inventory for each allocated certificate. |
| 4 | Credits transferred | Credit tokens (e.g. C-BIOW, C-CARB.CH4) are transferred from the Vault to the buyer's wallet. |
| 5 | Receipt minted | A CreditPurchaseReceipt NFT is minted as immutable, on-chain proof of the purchase transaction. |
| 6 | Rewards recorded | A Merkle root is committed on-chain for the rewards distribution, enabling participants to claim their share. |
All purchases and receipts are publicly verifiable through the Carrot Explorer or any blockchain block explorer (e.g. PolygonScan).
Certificate allocation
Every credit is backed by a certificate — either a RecycledID (for recycling credits) or a GasID (for carbon credits). When a purchase is created, the platform allocates certificates from available inventory to fulfill the order. Certificates are allocated on a first-available basis, drawing from the oldest eligible certificates first.
A single purchase may span multiple certificates if no single certificate has enough available balance to fill the order. The purchase receipt records each certificate allocation, maintaining a clear audit trail from purchased credits back to the underlying verified recycling work and MassIDs.
Integrated retirement
Buyers can purchase and retire credits in a single atomic transaction. When the integrated retirement flag is enabled, credits are bought and immediately burned within the same on-chain operation. Both a CreditPurchaseReceipt and a CreditRetirementReceipt NFT are minted in the same transaction.
This is the most common path for compliance buyers — organizations and individuals that need to claim the environmental offset immediately upon purchase. It simplifies the process to a single step and reduces transaction costs.
For buyers who prefer to hold credits and retire them later, standalone retirement is available as a separate transaction. See Credit Retirement for details on both retirement paths.
Fiat payment methods
The Carrot Network recognizes that many credit buyers lack blockchain infrastructure. To address this, the platform supports fiat payment methods — including credit card and wire transfer — for buyers that prefer traditional payment flows. The platform handles the conversion so that the smart contracts always settle in USDC, regardless of how the buyer pays.
Credits · Rewards Distribution · Smart Contracts · Credit Retirement