On-chain · Verifiable provenance · Methodology v1.0

carbon credit tokens.
Fully on-chain.

Blockchain is not the source of truth — our verified accounting is. The chain is the transparency layer: immutable ownership, transfers, retirement, and pro-rata revenue distribution.

Standard
On-chain
Network
EVM L2
Layer
Settlement
Settlement
USDC
stablecoin
Why blockchain (and why not)

The chain is a transparency layer, not the science.

Our carbon accounting is the source of truth, validated by methodology and auditors. The blockchain just makes ownership, transfer, retirement, and revenue distribution publicly verifiable — and impossible to silently rewrite.

Provenance

Every batch's audit hash, methodology version, and tokenization tx are publicly verifiable on-chain.

Immutable retirement

Once retired, credits are burned. No silent resale, no double-counting, no rug-pulls.

Pro-rata payouts

Revenue distribution contract splits sale proceeds across drivers by verified net contribution.

Smart contracts deployed

Four contracts. One purpose: trustless transparency.

Token
CarbonCreditToken

Mint, transfer, retire batches with metadata URI. Token ID = batch ID hash. Prevents transfer of retired credits.

Solidity
Marketplace

List tokenized credits, escrow payment, transfer to buyer. Routes platform fee + driver reward pool.

Solidity
Retirement

Burns the token amount. Emits Retirement event with reason, certificate ID, timestamp. Resale impossible.

Solidity
RevenueDistribution

Receives sale proceeds. Computes per-driver pro-rata share by verified net CO₂e. Stablecoin payout.

Token metadata

Every token, fully described.

Each credit batch has an IPFS-pinnable metadata URI containing the full accounting story — gross savings, every deduction, methodology version, audit hash, and registry reference. Auditors can verify directly from chain data.

Sample metadata.json
{
  "batch_id": "65f3a2…",
  "vintage": "2026-Q1",
  "geography": "US-CA",
  "methodology_version": "v1.0",
  "total_net_co2e_kg": 7050,
  "gross_co2_avoided_kg": 10000,
  "ev_grid_emissions_kg": 2500,
  "tire_penalty_kg": 350,
  "other_penalties_kg": 100,
  "verification_status": "verified",
  "registry_reference": null,
  "audit_hash": "0x9c…ff21",
  "contributors": 4128,
  "issued_at": "2026-02-27T18:42:00Z"
}
Data architecture

What lives on-chain. What never does.

Privacy by design: GPS routes, KYC, and payment details remain encrypted off-chain. Only what needs to be verifiable goes on-chain.

On-chain
  • Token ID + batch hash
    Permanent batch identifier
  • Ownership transfers
    Every transfer publicly logged
  • Retirement events
    Burn proof with certificate ID
  • Revenue distribution
    Pro-rata payout transactions
  • Metadata URI
    IPFS pointer to disclosure JSON
  • Audit hash
    Tamper-evident batch fingerprint
Off-chain · encrypted
  • Raw GPS routes
    Polylines never leave secure backend
  • User identity / KYC
    Encrypted PII, GDPR-ready
  • Vehicle & tire profiles
    Linked to user, not to chain
  • Payment details
    Stripe-tokenized, PCI-DSS scope
  • Driver wallet balance
    USD ledger in Mongo
  • Fraud-flag evidence
    Admin-only audit logs
Smart contract security

Built on OpenZeppelin. Audited patterns only.

ReentrancyGuard

All payable functions wrapped to block reentrancy attacks.

AccessControl

Role-based mint/list/retire/distribute permissions. Multisig-ready.

Pausable

Emergency pause on Marketplace and RevenueDistribution.

Events for everything

Mint, transfer, retire, distribute all emit indexed events for off-chain indexing.

No PII on-chain

Contracts handle batch IDs and tons only — never user identity or GPS.

Unit-tested

Hardhat suite covers mint, transfer, retire, fee routing, reentrancy guards.

Live contracts

Verifiable on blockchain explorer.

Network
EVM L2 Blockchain
Mode · simulation
CarbonCreditToken
0x046ec54c7290cbce1ad6da298963a09b8ba2129c
Marketplace
0xd0ef1907a083f0b2f5316a287e250fdba1a5fc8c
Retirement
0x1bea2678e13e00839a2ee5023f11c9a8c2bfaf1b
RevenueDistribution
0x768ba6b1fb4e39b95258c1bd74d19119ee7941ce

Verify it yourself.

Browse live tokenized credit batches, read the methodology each batch is bound to, or see every environmental deduction we apply.