Stablecoin with PoR, ACE & CCIP

What This Template Does

This repository demonstrates how financial institutions can build a secure, compliant, multi-chain stablecoin using Chainlink's complete service stack. The demo progresses through three phases:

Phase 1: Traditional banks trigger stablecoin minting and redemption using SWIFT-style messages via HTTP. CRE orchestrates the workflow, validates messages, and submits cryptographically-signed reports to mint or burn tokens on-chain.

Phase 2: Cross-chain stablecoin transfers using CCIP. Users can transfer tokens between Ethereum Sepolia and Avalanche Fuji testnets with automatic token burning on the source chain and minting on the destination.

Phase 3: Advanced multi-service integration (production requires additional audits and hardening) that combines:

1. Proof of Reserve (PoR) - Validates sufficient off-chain reserves before minting (prevents over-collateralization issues)
2. Automated Compliance Engine (ACE) - Enforces on-chain policies like address blacklisting for regulatory compliance
3. CCIP - Secure cross-chain transfers with compliance checks at both mint and transfer stages

Key Technologies:

• CRE (Chainlink Runtime Environment) - Orchestrates multi-service workflows with DON consensus
• PoR (Proof of Reserve) - External reserve validation
• ACE (Automated Compliance Engine) - On-chain policy enforcement
• CCIP (Cross-Chain Interoperability Protocol) - Secure token bridging

How It Works

Flow 1: Stablecoin Issuance with PoR + ACE

sequenceDiagram
    actor User
    participant CRE as CRE Workflow
    participant PoR as PoR API
    participant Forwarder as CRE Forwarder
    participant Consumer as MintingConsumerWithACE
    participant Stablecoin as Stablecoin Contract

    User->>CRE: HTTP Trigger (Deposit $1000 USD)
    CRE->>PoR: HTTP Capability (Fetch Reserves)
    PoR-->>CRE: Reserves: $500,000
    alt Sufficient Reserves
        CRE->>Forwarder: On Chain Write (Submit Mint Report)
        Forwarder->>Consumer: Call onReport()
        Consumer->>Consumer: Run PolicyEngine (BlacklistPolicy)
        alt Not Blacklisted
            Consumer->>Stablecoin: mint(user, 1000e18)
            Stablecoin-->>User: Tokens Minted
        else Blacklisted
            Consumer-->>User: Minting Failed
        end
    else Insufficient Reserves
        CRE-->>User: PoR Validation Failed
    end

Flow 2: Cross-Chain Transfer with ACE

sequenceDiagram
    actor Sender
    participant CRE as CRE Workflow
    participant Consumer as CCIPTransferConsumerWithACE
    participant Stablecoin as Stablecoin Contract
    participant Router as CCIP Router
    participant Destination as Destination Chain

    Sender->>CRE: HTTP Trigger (Transfer 500 tokens to Fuji)
    CRE->>Consumer: Call onReport()
    Consumer->>Consumer: Run PolicyEngine (VolumePolicy)
    alt Amount Within Limit
        Consumer->>Router: ccipSend(destinationChain, message)
        Router->>Stablecoin: Burn Tokens on Source
        Router->>Destination: Send CCIP Message (~10-20 min)
        CRE-->>Sender: Transfer Initiated
    else Amount Exceeds Limit
        CRE-->>Sender: Transfer Failed
    end

Repository Structure

Workflows Directory

Three progressive CRE workflows demonstrating increasing complexity:

• bank-stablecoin-workflow/ - Phase 1: Basic mint/redeem operations
• ccip-transfer-workflow/ - Phase 2: Cross-chain CCIP transfers
• bank-stablecoin-por-ace-ccip-workflow/ - Phase 3: PoR + ACE + CCIP integration

Contracts Directory

Smart contracts for stablecoin and ACE integration:

• StablecoinERC20.sol - Core stablecoin with mint/burn roles
• MintingConsumer.sol - Phase 1: Basic CRE consumer
• CCIPTransferConsumer.sol - Phase 2: CCIP consumer
• MintingConsumerWithACE.sol - Phase 3: ACE-protected mint consumer
• CCIPTransferConsumerWithACE.sol - Phase 3: ACE-protected CCIP consumer
• policies/AddressBlacklistPolicy.sol - ACE blacklist policy
• extractors/UnifiedExtractor.sol - ACE parameter extractor for both mint and CCIP operations

Prerequisites

To run this demo, you'll need:

Tools:

• Git
• Foundry (forge, cast, anvil)
• Bun (JavaScript runtime and package manager)
• Chainlink Runtime Environment CLI

Testnet Funds:

• ETH on Sepolia testnet (Chainlink Faucet)
• ETH on Fuji testnet
• LINK tokens

Getting Started

# Create configuration files
cp .env.example .env
cp secrets.yaml.example secrets.yaml

# Set project root
export CRE_PROJECT_ROOT=$(pwd)

# Install workflow dependencies
cd bank-stablecoin-por-ace-ccip-workflow && bun install && cd ..

# Dry run test (no wallet/gas needed)
cre workflow simulate bank-stablecoin-por-ace-ccip-workflow \
  --target local-simulation \
  --trigger-index 0 \
  --non-interactive \
  --http-payload @$CRE_PROJECT_ROOT/bank-stablecoin-por-ace-ccip-workflow/http_trigger_payload.json

CRE + PoR + ACE + CCIP Capabilities

This demo showcases the complete Chainlink service stack working together:

CRE Capabilities Demonstrated:

• ✅ HTTP Triggers - Banking system integration via REST API
• ✅ Node Mode - Fetch external data (PoR Mock Data) with DON consensus
• ✅ EVM Capabilities - Write signed reports on-chain
• ✅ Multi-Service Orchestration - Coordinate PoR → ACE → Mint → CCIP flows

ACE Capabilities Demonstrated:

• ✅ PolicyEngine - Central policy registry and execution
• ✅ Custom Extractors - Parse CRE's onReport(bytes,bytes) function
• ✅ Address Blacklist Policy - Block mints/transfers to sanctioned addresses
• ✅ Upgradeable Proxies - ERC-1967 pattern for all ACE components

Troubleshooting

Quick Tips:

• Workflow won't compile? → Run cd <workflow> && bun install
• ACE not blocking? → See the TROUBLESHOOTING.md in the repository
• CCIP not arriving? → Wait 10-20 min, check CCIP Explorer

Security Considerations

1. This is a demo project - Not production-ready
2. Verify PoR data sources - Demo uses mock data; real implementations should use live PoR feeds
3. ACE policies are examples - Customize policies for your compliance requirements
4. Use your own RPC for stability - For stable deployment and chainwrite operations it is advised to use your own private RPCs