🧠 Use Case

Design a transparent, blockchain-based Payment for Ecosystem Services (PES) program.

The goal is to reward verified ecological actions (e.g., tree planting, soil restoration) with programmable payments in ADA or stablecoins using Verifiable Credentials (VCs), smart contracts, and metadata NFTs — implemented using Cardano-native tools with no dependency on external oracle-based systems or deprecated identity frameworks.

1. Functional Flow

  1. A farmer performs an ecological activity (e.g., tree planting).
  2. A verifier (e.g., NGO or cooperative agent) inspects and validates the activity.
  3. A Verifiable Credential (VC) is issued to confirm the ecological action.
  4. A CIP-68 NFT is minted, embedding:
  5. A smart contract validates the hash and disburses funds to the farmer’s wallet.

2. Architecture Diagram

[Farmer] → [Verifier Mobile App] → [VC Issued]

↓

[NFT Minted w/ CIP-68 Metadata + VC Hash]

↓

[Smart Contract Validates VC Hash → Pays ADA]

↓

[Farmer Wallet (Lace, Eternl, Typhon)]

3. Tools & Libraries

Layer Toolset Description
Identity VC Hashing (W3C JSON-LD) Attestation of verified ecosystem action
Metadata CIP-68 + IPFS Anchor VC hash and location metadata on-chain
Smart Contracts Aiken Payout contract verifying credential hash match
UI / Wallets Mesh SDK + Lucid Evolution Wallet interaction, NFT minting, verifier/farmer dashboards
Storage IPFS or GitHub Off-chain storage of VC files, photos, geodata, logs

4. Credential Format (VC Example)

{

"@context": [

"<https://www.w3.org/2018/credentials/v1>"

],

"id": "vc:climate:12345",

"type": ["VerifiableCredential", "ClimateActivity"],

"issuer": "did:cardano:verifier123",

"issuanceDate": "2025-07-03T00:00:00Z",

"credentialSubject": {

"id": "did:cardano:farmer987",

"activityType": "TreePlanting",

"treeSpecies": "Acacia Senegal",

"location": {

"lat": "15.8921",

"lng": "35.1831"

},

"timestamp": "2025-07-01T13:00:00Z"

},

"proof": {

"type": "Ed25519Signature2020",

"created": "2025-07-03T01:00:00Z",

"proofPurpose": "assertionMethod",

"verificationMethod": "did:cardano:verifier123#keys-1",

"jws": "eyJhbGciOiJFZERTQSJ9.."

}

}

5. CIP-68 NFT Metadata (Example)

{

"name": "TreePlanting #12345",

"description": "Verified climate action - Acacia planting",

"image": "ipfs://QmExampleHash/photo.jpg",

"vc_hash": "0x9f2a38...d21b7a",

"lat": "15.8921",

"lng": "35.1831",

"tree_species": "Acacia Senegal",

"verified_by": "did:cardano:verifier123",

"timestamp": "2025-07-01T13:00:00Z"

}