Consolidate webapp structure by merging nested components into the main repository

docs/Adapter_Architecture_Spec.md

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+# Adapter Architecture Specification
+
+## Overview
+This document specifies the architecture for the hybrid adapter system that supports both DeFi protocols and Fiat/DTL (banking rails) connectors. It defines adapter interfaces, whitelist/blacklist mechanisms, protocol versioning, upgrade paths, and integration guides.
+
+---
+
+## 1. Adapter System Architecture
+
+### High-Level Design
+```
+┌─────────────────────────────────────────────────────────────┐
+│                    Combo Builder UI                         │
+│              (Drag & Drop Adapter Selection)                │
+└────────────────────────┬────────────────────────────────────┘
+                         │
+                         ▼
+┌─────────────────────────────────────────────────────────────┐
+│              Adapter Registry Contract                      │
+│  (Whitelist/Blacklist, Version Management)                  │
+└──────────────┬──────────────────────────────┬───────────────┘
+               │                              │
+               ▼                              ▼
+    ┌──────────────────┐          ┌──────────────────┐
+    │  DeFi Adapters   │          │ Fiat/DTL Adapters│
+    │                  │          │                  │
+    │ • Uniswap V3     │          │ • ISO-20022 Pay │
+    │ • Aave           │          │ • SWIFT MT       │
+    │ • Compound       │          │ • SEPA          │
+    │ • Bridge         │          │ • FedNow        │
+    └──────────────────┘          └──────────────────┘
+               │                              │
+               ▼                              ▼
+    ┌──────────────────┐          ┌──────────────────┐
+    │  DeFi Protocols  │          │  Banking Rails   │
+    │  (On-Chain)      │          │  (Off-Chain)      │
+    └──────────────────┘          └──────────────────┘
+```
+
+---
+
+## 2. Adapter Interface Contract
+
+### Base Interface: `IAdapter`
+
+```solidity
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.20;
+
+interface IAdapter {
+    /**
+     * @notice Execute a step using this adapter
+     * @param stepData Encoded step-specific parameters
+     * @return success Whether execution succeeded
+     * @return returnData Return data from execution
+     */
+    function executeStep(bytes calldata stepData) external returns (bool success, bytes memory returnData);
+
+    /**
+     * @notice Prepare phase for 2PC (optional, if supported)
+     * @param stepData Encoded step parameters
+     * @return prepared Whether preparation succeeded
+     */
+    function prepareStep(bytes calldata stepData) external returns (bool prepared);
+
+    /**
+     * @notice Get adapter metadata
+     * @return name Adapter name
+     * @return version Adapter version
+     * @return adapterType Type (DEFI or FIAT_DTL)
+     */
+    function getMetadata() external view returns (string memory name, string memory version, AdapterType adapterType);
+
+    /**
+     * @notice Check if adapter supports a specific step type
+     * @param stepType Step type to check
+     * @return supported Whether step type is supported
+     */
+    function supportsStepType(StepType stepType) external view returns (bool supported);
+}
+
+enum AdapterType {
+    DEFI,
+    FIAT_DTL
+}
+
+enum StepType {
+    BORROW,
+    SWAP,
+    REPAY,
+    PAY,
+    DEPOSIT,
+    WITHDRAW,
+    BRIDGE
+}
+```
+
+### DeFi Adapter Example: `UniswapV3Adapter.sol`
+
+```solidity
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.20;
+
+import "./IAdapter.sol";
+import "@uniswap/v3-periphery/contracts/interfaces/ISwapRouter.sol";
+
+contract UniswapV3Adapter is IAdapter {
+    ISwapRouter public constant swapRouter = ISwapRouter(0xE592427A0AEce92De3Edee1F18E0157C05861564);
+    
+    function executeStep(bytes calldata stepData) external override returns (bool success, bytes memory returnData) {
+        SwapParams memory params = abi.decode(stepData, (SwapParams));
+        
+        ISwapRouter.ExactInputSingleParams memory swapParams = ISwapRouter.ExactInputSingleParams({
+            tokenIn: params.tokenIn,
+            tokenOut: params.tokenOut,
+            fee: params.fee,
+            recipient: params.recipient,
+            deadline: block.timestamp + 300,
+            amountIn: params.amountIn,
+            amountOutMinimum: params.amountOutMinimum,
+            sqrtPriceLimitX96: 0
+        });
+
+        uint256 amountOut = swapRouter.exactInputSingle(swapParams);
+        
+        return (true, abi.encode(amountOut));
+    }
+
+    function prepareStep(bytes calldata) external pure override returns (bool) {
+        // Uniswap doesn't support prepare phase
+        return false;
+    }
+
+    function getMetadata() external pure override returns (string memory, string memory, AdapterType) {
+        return ("Uniswap V3", "3.0.1", AdapterType.DEFI);
+    }
+
+    function supportsStepType(StepType stepType) external pure override returns (bool) {
+        return stepType == StepType.SWAP;
+    }
+
+    struct SwapParams {
+        address tokenIn;
+        address tokenOut;
+        uint24 fee;
+        address recipient;
+        uint256 amountIn;
+        uint256 amountOutMinimum;
+    }
+}
+```
+
+### Fiat/DTL Adapter Example: `ISO20022PayAdapter.sol`
+
+```solidity
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.20;
+
+import "./IAdapter.sol";
+
+contract ISO20022PayAdapter is IAdapter {
+    address public orchestrator;
+    mapping(bytes32 => PaymentRequest) public pendingPayments;
+
+    struct PaymentRequest {
+        bytes32 planId;
+        string beneficiaryIBAN;
+        uint256 amount;
+        string currency;
+        bool executed;
+    }
+
+    function executeStep(bytes calldata stepData) external override returns (bool success, bytes memory returnData) {
+        require(msg.sender == orchestrator, "Only orchestrator");
+
+        PayParams memory params = abi.decode(stepData, (PayParams));
+        
+        // Store payment request for off-chain processing
+        bytes32 requestId = keccak256(abi.encodePacked(params.planId, params.beneficiaryIBAN, params.amount));
+        pendingPayments[requestId] = PaymentRequest({
+            planId: params.planId,
+            beneficiaryIBAN: params.beneficiaryIBAN,
+            amount: params.amount,
+            currency: params.currency,
+            executed: false
+        });
+
+        // Emit event for off-chain orchestrator to process
+        emit PaymentRequested(requestId, params.planId, params.beneficiaryIBAN, params.amount, params.currency);
+
+        return (true, abi.encode(requestId));
+    }
+
+    function prepareStep(bytes calldata stepData) external override returns (bool) {
+        // Fiat payments can support prepare phase (provisional ISO message)
+        PayParams memory params = abi.decode(stepData, (PayParams));
+        bytes32 requestId = keccak256(abi.encodePacked(params.planId, params.beneficiaryIBAN, params.amount));
+        
+        // Mark as prepared (provisional)
+        pendingPayments[requestId].executed = false; // Not yet executed
+
+        emit PaymentPrepared(requestId);
+        return true;
+    }
+
+    function getMetadata() external pure override returns (string memory, string memory, AdapterType) {
+        return ("ISO-20022 Pay", "1.2.0", AdapterType.FIAT_DTL);
+    }
+
+    function supportsStepType(StepType stepType) external pure override returns (bool) {
+        return stepType == StepType.PAY;
+    }
+
+    function confirmPayment(bytes32 requestId, string memory isoMessageId) external {
+        require(msg.sender == orchestrator, "Only orchestrator");
+        PaymentRequest storage payment = pendingPayments[requestId];
+        require(!payment.executed, "Already executed");
+
+        payment.executed = true;
+        emit PaymentConfirmed(requestId, isoMessageId);
+    }
+
+    event PaymentRequested(bytes32 indexed requestId, bytes32 indexed planId, string beneficiaryIBAN, uint256 amount, string currency);
+    event PaymentPrepared(bytes32 indexed requestId);
+    event PaymentConfirmed(bytes32 indexed requestId, string isoMessageId);
+
+    struct PayParams {
+        bytes32 planId;
+        string beneficiaryIBAN;
+        uint256 amount;
+        string currency;
+    }
+}
+```
+
+---
+
+## 3. Whitelist/Blacklist Mechanisms
+
+### On-Chain Registry (Smart Contract)
+
+```solidity
+// Managed by AdapterRegistry contract (see Smart_Contract_Interfaces.md)
+// - registerAdapter() - Register new adapter
+// - whitelistAdapter() - Add to whitelist
+// - blacklistAdapter() - Remove from whitelist
+// - isWhitelisted() - Check whitelist status
+```
+
+### Off-Chain API Filtering
+
+```typescript
+// Backend API filters adapters based on:
+// 1. On-chain whitelist status
+// 2. User role/permissions
+// 3. Compliance requirements
+// 4. Geographic restrictions
+
+GET /api/adapters?type=DEFI&whitelistedOnly=true&userId=user123
+```
+
+### UI Filtering
+
+```typescript
+// Frontend filters adapters based on:
+// 1. User selection (All, DeFi, Fiat/DTL, Whitelisted Only)
+// 2. Chain compatibility
+// 3. Compliance requirements
+
+const filteredAdapters = adapters.filter(adapter => {
+  if (filter === 'DEFI') return adapter.type === 'DEFI';
+  if (filter === 'FIAT_DTL') return adapter.type === 'FIAT_DTL';
+  if (filter === 'WHITELISTED') return adapter.whitelisted;
+  return true; // ALL
+});
+```
+
+---
+
+## 4. Protocol Versioning
+
+### Version String Format
+```
+Major.Minor.Patch
+Example: "3.0.1", "1.2.0"
+```
+
+### Version Management
+
+#### On-Chain (Adapter Contract)
+```solidity
+function getMetadata() external view returns (string memory, string memory, AdapterType) {
+    return ("Uniswap V3", "3.0.1", AdapterType.DEFI);
+}
+```
+
+#### Off-Chain (API/Registry)
+```json
+{
+  "id": "uniswap-v3",
+  "name": "Uniswap V3",
+  "version": "3.0.1",
+  "type": "DEFI",
+  "whitelisted": true,
+  "deprecated": false,
+  "replacedBy": null,
+  "chainIds": [1, 137, 42161],
+  "lastUpdated": "2025-01-15T00:00:00Z"
+}
+```
+
+### Version Upgrade Path
+
+1. **Register New Version**: Deploy new adapter contract with incremented version
+2. **Register in AdapterRegistry**: Call `registerAdapter()` with new address
+3. **Whitelist New Version**: Call `whitelistAdapter()` for new address
+4. **Deprecate Old Version**: Optionally blacklist old version
+5. **Update UI**: Frontend fetches latest version from registry
+
+### Breaking Changes
+
+- **Major Version**: Incompatible API changes (new interface required)
+- **Minor Version**: New features, backward compatible
+- **Patch Version**: Bug fixes, backward compatible
+
+---
+
+## 5. Upgrade Paths
+
+### Option 1: New Contract Deployment (Recommended)
+- Deploy new adapter contract
+- Register in AdapterRegistry
+- Whitelist new contract
+- Update frontend to use new address
+- Old adapter remains for existing plans
+
+### Option 2: Proxy Pattern (For Complex Adapters)
+```solidity
+// Use Transparent Proxy or UUPS
+// Allows upgrade without changing address
+// Requires careful upgrade governance
+```
+
+### Option 3: Adapter Factory Pattern
+```solidity
+contract AdapterFactory {
+    function createAdapter(string memory version) external returns (address) {
+        // Deploy new adapter instance
+        // Register automatically
+        // Return address
+    }
+}
+```
+
+---
+
+## 6. Integration Guide for Adding New Adapters
+
+### Step 1: Implement IAdapter Interface
+
+```solidity
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.20;
+
+import "./IAdapter.sol";
+
+contract MyNewAdapter is IAdapter {
+    function executeStep(bytes calldata stepData) external override returns (bool, bytes memory) {
+        // Implementation
+    }
+
+    function prepareStep(bytes calldata stepData) external override returns (bool) {
+        // Implementation (optional)
+    }
+
+    function getMetadata() external pure override returns (string memory, string memory, AdapterType) {
+        return ("My New Adapter", "1.0.0", AdapterType.DEFI);
+    }
+
+    function supportsStepType(StepType stepType) external pure override returns (bool) {
+        return stepType == StepType.SWAP; // Example
+    }
+}
+```
+
+### Step 2: Deploy Contract
+
+```bash
+# Deploy to target network
+npx hardhat run scripts/deploy.js --network mainnet
+```
+
+### Step 3: Register in AdapterRegistry
+
+```solidity
+// Call from admin account
+adapterRegistry.registerAdapter(
+    myNewAdapterAddress,
+    AdapterType.DEFI,
+    "1.0.0",
+    abi.encode(ipfsHash) // Metadata
+);
+```
+
+### Step 4: Register Codehash in NotaryRegistry
+
+```solidity
+// Get codehash
+bytes32 codeHash;
+assembly {
+    codeHash := extcodehash(myNewAdapterAddress)
+}
+
+// Register
+notaryRegistry.registerCodeHash(myNewAdapterAddress, codeHash);
+```
+
+### Step 5: Whitelist Adapter
+
+```solidity
+// After security review
+adapterRegistry.whitelistAdapter(myNewAdapterAddress);
+```
+
+### Step 6: Update Backend API
+
+```typescript
+// Add adapter to database/configuration
+const adapter = {
+  id: 'my-new-adapter',
+  address: myNewAdapterAddress,
+  type: 'DEFI',
+  version: '1.0.0',
+  whitelisted: true
+};
+
+await db.adapters.insert(adapter);
+```
+
+### Step 7: Update Frontend
+
+```typescript
+// Adapter should appear automatically via API
+// If custom UI needed, add to adapter palette configuration
+```
+
+### Step 8: Testing
+
+- Unit tests for adapter contract
+- Integration tests with ComboHandler
+- E2E tests in UI
+- Security audit (if handling significant funds)
+
+---
+
+## 7. DeFi Adapter Integration Examples
+
+### Aave Lending Adapter
+
+```solidity
+contract AaveAdapter is IAdapter {
+    IPool public constant aavePool = IPool(0x87870Bca3F3fD6335C3F4ce8392D69350B4fA4E2);
+
+    function executeStep(bytes calldata stepData) external override returns (bool, bytes memory) {
+        LendingParams memory params = abi.decode(stepData, (LendingParams));
+        
+        if (params.action == LendingAction.BORROW) {
+            aavePool.borrow(params.asset, params.amount, 2, 0, msg.sender); // Variable rate
+        } else if (params.action == LendingAction.REPAY) {
+            aavePool.repay(params.asset, params.amount, 2, msg.sender);
+        }
+        
+        return (true, "");
+    }
+
+    enum LendingAction { BORROW, REPAY, DEPOSIT, WITHDRAW }
+    
+    struct LendingParams {
+        LendingAction action;
+        address asset;
+        uint256 amount;
+    }
+}
+```
+
+### Bridge Adapter (Cross-Chain)
+
+```solidity
+contract BridgeAdapter is IAdapter {
+    function executeStep(bytes calldata stepData) external override returns (bool, bytes memory) {
+        BridgeParams memory params = abi.decode(stepData, (BridgeParams));
+        
+        // Lock tokens on source chain
+        // Emit event for bridge service
+        emit BridgeRequest(params.token, params.amount, params.targetChain, params.recipient);
+        
+        return (true, "");
+    }
+
+    event BridgeRequest(address indexed token, uint256 amount, uint256 targetChain, address recipient);
+    
+    struct BridgeParams {
+        address token;
+        uint256 amount;
+        uint256 targetChain;
+        address recipient;
+    }
+}
+```
+
+---
+
+## 8. Fiat/DTL Adapter Integration Examples
+
+### SWIFT MT Adapter
+
+```solidity
+contract SWIFTAdapter is IAdapter {
+    function executeStep(bytes calldata stepData) external override returns (bool, bytes memory) {
+        SWIFTParams memory params = abi.decode(stepData, (SWIFTParams));
+        
+        // Store SWIFT message request
+        bytes32 messageId = keccak256(abi.encodePacked(params.planId, params.beneficiary, params.amount));
+        emit SWIFTMessageRequested(messageId, params.planId, params.beneficiary, params.amount);
+        
+        return (true, abi.encode(messageId));
+    }
+
+    event SWIFTMessageRequested(bytes32 indexed messageId, bytes32 indexed planId, string beneficiary, uint256 amount);
+    
+    struct SWIFTParams {
+        bytes32 planId;
+        string beneficiary;
+        uint256 amount;
+        string currency;
+        string messageType; // MT103, MT202, etc.
+    }
+}
+```
+
+### SEPA Adapter
+
+```solidity
+contract SEPAAdapter is IAdapter {
+    function executeStep(bytes calldata stepData) external override returns (bool, bytes memory) {
+        SEPAParams memory params = abi.decode(stepData, (SEPAParams));
+        
+        bytes32 paymentId = keccak256(abi.encodePacked(params.planId, params.creditorIBAN, params.amount));
+        emit SEPACreditTransferRequested(paymentId, params.planId, params.creditorIBAN, params.amount);
+        
+        return (true, abi.encode(paymentId));
+    }
+
+    event SEPACreditTransferRequested(bytes32 indexed paymentId, bytes32 indexed planId, string creditorIBAN, uint256 amount);
+    
+    struct SEPAParams {
+        bytes32 planId;
+        string creditorIBAN;
+        string creditorName;
+        uint256 amount;
+        string currency;
+        string remittanceInfo;
+    }
+}
+```
+
+---
+
+## 9. Security Considerations
+
+### Adapter Validation
+
+1. **Codehash Verification**: Verify adapter codehash matches registered hash before execution
+2. **Whitelist Check**: Only execute whitelisted adapters
+3. **Reentrancy Protection**: Use ReentrancyGuard in handler contract
+4. **Input Validation**: Validate all step parameters before execution
+
+### Access Control
+
+1. **Orchestrator-Only Execution**: Only orchestrator can call adapter execute functions
+2. **Admin Functions**: Multi-sig required for whitelist/blacklist operations
+3. **Timelock**: Implement timelock for critical operations
+
+### Audit Requirements
+
+1. **Security Audit**: All adapters must pass security audit before whitelisting
+2. **Code Review**: Peer review required for adapter code
+3. **Testing**: Comprehensive test coverage required
+
+---
+
+## 10. Testing Requirements
+
+### Unit Tests
+
+```solidity
+// Test adapter interface implementation
+function testExecuteStep() public {
+    // Test successful execution
+    // Test failure cases
+    // Test return data
+}
+
+function testPrepareStep() public {
+    // Test prepare phase (if supported)
+}
+```
+
+### Integration Tests
+
+```solidity
+// Test adapter with ComboHandler
+function testAdapterInCombo() public {
+    // Test adapter works in multi-step combo
+    // Test step dependencies
+    // Test error handling
+}
+```
+
+### E2E Tests
+
+```typescript
+// Test adapter in full UI flow
+describe('Uniswap V3 Adapter', () => {
+  it('should execute swap in combo', async () => {
+    // Build combo with Uniswap step
+    // Execute combo
+    // Verify results
+  });
+});
+```
+
+---
+
+## 11. Best Practices
+
+### Adapter Design
+
+1. **Keep It Simple**: Adapters should do one thing well
+2. **Error Handling**: Return clear error messages
+3. **Gas Optimization**: Minimize gas usage
+4. **Event Emission**: Emit events for off-chain tracking
+
+### Version Management
+
+1. **Semantic Versioning**: Follow semver (Major.Minor.Patch)
+2. **Backward Compatibility**: Maintain backward compatibility when possible
+3. **Deprecation Policy**: Clearly communicate deprecation timeline
+
+### Documentation
+
+1. **README**: Document adapter purpose, parameters, usage
+2. **API Docs**: Document all functions and parameters
+3. **Examples**: Provide usage examples
+
+---
+
+**Document Version**: 1.0  
+**Last Updated**: 2025-01-15  
+**Author**: Architecture Team
+

docs/Compliance_Integration_Spec.md

@@ -0,0 +1,600 @@
+# Compliance Integration Specification
+
+## Overview
+This document specifies compliance integration requirements for the ISO-20022 Combo Flow system, including LEI/DID/KYC/AML injection into ISO messages, compliance engine API contract, real-time status checks, identity assertion format, and audit trail requirements for hybrid workflows.
+
+---
+
+## 1. Compliance Requirements
+
+### Required Compliance Attributes
+
+| Attribute | Required For | Description | Format |
+|-----------|-------------|-------------|--------|
+| **LEI** | All workflows | Legal Entity Identifier | 20-character alphanumeric (e.g., `5493000IBP32UQZ0KL24`) |
+| **DID** | Notarized workflows | Decentralized Identifier | W3C DID format (e.g., `did:web:example.com:user:123`) |
+| **KYC** | Fiat/DTL steps | Know Your Customer verification | Level 1-3 (Level 2+ for fiat) |
+| **AML** | Payments > threshold | Anti-Money Laundering check | Pass/Fail with risk level |
+
+### Compliance Levels by Workflow Type
+
+#### DeFi-Only Workflows
+- **LEI**: Optional (recommended)
+- **DID**: Optional
+- **KYC**: Not required
+- **AML**: Not required
+
+#### Hybrid Workflows (DeFi + Fiat/DTL)
+- **LEI**: Required
+- **DID**: Required for notarization
+- **KYC**: Level 2+ required
+- **AML**: Required for payments > 10,000 EUR
+
+#### Fiat-Only Workflows
+- **LEI**: Required
+- **DID**: Required
+- **KYC**: Level 2+ required
+- **AML**: Required for all payments
+
+---
+
+## 2. Compliance Engine API Contract
+
+### Interface: `IComplianceEngine`
+
+```typescript
+interface IComplianceEngine {
+  /**
+   * Check compliance status for a user
+   */
+  getComplianceStatus(userId: string): Promise<ComplianceStatus>;
+
+  /**
+   * Validate compliance for a workflow
+   */
+  validateWorkflowCompliance(workflow: Workflow): Promise<ComplianceCheckResult>;
+
+  /**
+   * Run KYC verification
+   */
+  verifyKYC(userId: string, level: number): Promise<KYCResult>;
+
+  /**
+   * Run AML screening
+   */
+  screenAML(userId: string, amount: number, currency: string): Promise<AMLResult>;
+
+  /**
+   * Register LEI for user
+   */
+  registerLEI(userId: string, lei: string): Promise<boolean>;
+
+  /**
+   * Register DID for user
+   */
+  registerDID(userId: string, did: string): Promise<boolean>;
+}
+```
+
+### Compliance Status Response
+
+```typescript
+interface ComplianceStatus {
+  userId: string;
+  lei: string | null;
+  did: string | null;
+  kyc: {
+    level: number;
+    provider: string;
+    verified: boolean;
+    expiresAt: string | null;
+  };
+  aml: {
+    passed: boolean;
+    provider: string;
+    lastCheck: string;
+    riskLevel: 'LOW' | 'MEDIUM' | 'HIGH';
+  };
+  valid: boolean;
+}
+```
+
+### Workflow Compliance Check
+
+```typescript
+interface ComplianceCheckResult {
+  valid: boolean;
+  required: string[]; // ['LEI', 'DID', 'KYC', 'AML']
+  missing: string[];
+  warnings: string[];
+}
+```
+
+---
+
+## 3. LEI/DID/KYC/AML Injection into ISO Messages
+
+### ISO-20022 Message Structure with Compliance
+
+#### pacs.008 (Payment Instruction) Example
+
+```xml
+<?xml version="1.0" encoding="UTF-8"?>
+<Document xmlns="urn:iso:std:iso:20022:tech:xsd:pacs.008.001.10">
+  <FIToFICstmrCdtTrf>
+    <GrpHdr>
+      <MsgId>MSG-2025-01-15-001</MsgId>
+      <CreDtTm>2025-01-15T10:30:00Z</CreDtTm>
+      <NbOfTxs>1</NbOfTxs>
+      <CtrlSum>78000.00</CtrlSum>
+      <InitgPty>
+        <Nm>Example Corp Ltd.</Nm>
+        <Id>
+          <OrgId>
+            <Othr>
+              <Id>5493000IBP32UQZ0KL24</Id>
+              <SchmeNm>
+                <Cd>LEI</Cd>
+              </SchmeNm>
+            </Othr>
+          </OrgId>
+        </Id>
+      </InitgPty>
+    </GrpHdr>
+    <CdtTrfTxInf>
+      <PmtId>
+        <EndToEndId>PLAN-12345678-ABCD-EFGH</EndToEndId>
+        <TxId>TX-2025-01-15-001</TxId>
+      </PmtId>
+      <PmtTpInf>
+        <SvcLvl>
+          <Cd>SEPA</Cd>
+        </SvcLvl>
+        <LclInstrm>
+          <Cd>INST</Cd>
+        </LclInstrm>
+      </PmtTpInf>
+      <IntrBkSttlmAmt Ccy="EUR">78000.00</IntrBkSttlmAmt>
+      <InstgAgt>
+        <FinInstnId>
+          <BICFI>BANKDEFFXXX</BICFI>
+        </FinInstnId>
+      </InstgAgt>
+      <InstdAgt>
+        <FinInstnId>
+          <BICFI>BENEFRPPXXX</BICFI>
+        </FinInstnId>
+      </InstdAgt>
+      <Dbtr>
+        <Nm>Example Corp Ltd.</Nm>
+        <Id>
+          <OrgId>
+            <Othr>
+              <Id>5493000IBP32UQZ0KL24</Id>
+              <SchmeNm>
+                <Cd>LEI</Cd>
+              </SchmeNm>
+            </Othr>
+          </OrgId>
+        </Id>
+        <CtctDtls>
+          <Email>compliance@example.com</Email>
+        </CtctDtls>
+      </Dbtr>
+      <DbtrAcct>
+        <Id>
+          <IBAN>DE89370400440532013000</IBAN>
+        </Id>
+      </DbtrAcct>
+      <Cdtr>
+        <Nm>Beneficiary Corp</Nm>
+        <PstlAdr>
+          <StrtNm>Main Street</StrtNm>
+          <BldgNb>123</BldgNb>
+          <PstCd>12345</PstCd>
+          <TwnNm>Berlin</TwnNm>
+          <Ctry>DE</Ctry>
+        </PstlAdr>
+      </Cdtr>
+      <CdtrAcct>
+        <Id>
+          <IBAN>DE89370400440532013001</IBAN>
+        </Id>
+      </CdtrAcct>
+      <RmtInf>
+        <Ustrd>Plan ID: PLAN-12345678-ABCD-EFGH</Ustrd>
+        <Strd>
+          <RfrdDocInf>
+            <Tp>
+              <CdOrPrtry>
+                <Cd>CINV</Cd>
+              </CdOrPrtry>
+            </Tp>
+            <Nb>PLAN-12345678-ABCD-EFGH</Nb>
+            <RltdDt>2025-01-15</RltdDt>
+          </RfrdDocInf>
+          <RfrdDocAmt>
+            <DuePyblAmt Ccy="EUR">78000.00</DuePyblAmt>
+          </RfrdDocAmt>
+        </Strd>
+      </RmtInf>
+      <SplmtryData>
+        <PlcAndNm>ComplianceData</PlcAndNm>
+        <Envlp>
+          <ComplianceData xmlns="urn:example:compliance:xsd:1.0">
+            <PlanId>PLAN-12345678-ABCD-EFGH</PlanId>
+            <LEI>5493000IBP32UQZ0KL24</LEI>
+            <DID>did:web:example.com:user:123</DID>
+            <KYC>
+              <Level>2</Level>
+              <Provider>Onfido</Provider>
+              <Verified>true</Verified>
+              <ExpiresAt>2026-12-31T23:59:59Z</ExpiresAt>
+            </KYC>
+            <AML>
+              <Passed>true</Passed>
+              <Provider>Chainalysis</Provider>
+              <LastCheck>2025-01-15T09:00:00Z</LastCheck>
+              <RiskLevel>LOW</RiskLevel>
+            </AML>
+            <DigitalSignature>
+              <Algorithm>ECDSA</Algorithm>
+              <Value>0x1234567890abcdef...</Value>
+            </DigitalSignature>
+          </ComplianceData>
+        </Envlp>
+      </SplmtryData>
+    </CdtTrfTxInf>
+  </FIToFICstmrCdtTrf>
+</Document>
+```
+
+### Key Compliance Injection Points
+
+1. **Header (`GrpHdr.InitgPty`)**: LEI in `Id.OrgId.Othr.Id` with `SchmeNm.Cd = "LEI"`
+2. **Debtor (`Dbtr`)**: LEI in `Id.OrgId.Othr.Id`
+3. **Supplementary Data (`SplmtryData`)**: Full compliance data (LEI, DID, KYC, AML, signature)
+
+---
+
+## 4. Real-Time Status Checks
+
+### API Endpoint: `GET /api/compliance/status`
+
+```typescript
+// Request
+GET /api/compliance/status?userId=user123
+
+// Response
+{
+  "userId": "user123",
+  "lei": "5493000IBP32UQZ0KL24",
+  "did": "did:web:example.com:user:123",
+  "kyc": {
+    "level": 2,
+    "provider": "Onfido",
+    "verified": true,
+    "expiresAt": "2026-12-31T23:59:59Z"
+  },
+  "aml": {
+    "passed": true,
+    "provider": "Chainalysis",
+    "lastCheck": "2025-01-15T09:00:00Z",
+    "riskLevel": "LOW"
+  },
+  "valid": true
+}
+```
+
+### Workflow Compliance Check: `POST /api/compliance/check`
+
+```typescript
+// Request
+POST /api/compliance/check
+{
+  "steps": [
+    { "type": "borrow", "asset": "CBDC_USD", "amount": 100000 },
+    { "type": "swap", "from": "CBDC_USD", "to": "CBDC_EUR", "amount": 100000 },
+    { "type": "pay", "asset": "EUR", "amount": 78000, "beneficiary": { "IBAN": "DE89..." } }
+  ]
+}
+
+// Response
+{
+  "valid": true,
+  "required": ["LEI", "DID", "KYC", "AML"],
+  "missing": [],
+  "warnings": []
+}
+```
+
+### Frontend Integration
+
+```typescript
+// Real-time compliance badge in UI
+const ComplianceBadge = () => {
+  const { data: compliance } = useQuery(['compliance'], () => 
+    api.getComplianceStatus()
+  );
+
+  return (
+    <div className="flex gap-2">
+      {compliance?.lei && <Badge>✓ LEI</Badge>}
+      {compliance?.did && <Badge>✓ DID</Badge>}
+      {compliance?.kyc?.verified && <Badge>✓ KYC</Badge>}
+      {compliance?.aml?.passed && <Badge>✓ AML</Badge>}
+    </div>
+  );
+};
+```
+
+---
+
+## 5. Identity Assertion Format
+
+### W3C Verifiable Credential Format
+
+```json
+{
+  "@context": [
+    "https://www.w3.org/2018/credentials/v1",
+    "https://www.w3.org/2018/credentials/examples/v1"
+  ],
+  "id": "https://example.com/credentials/123",
+  "type": ["VerifiableCredential", "ComplianceCredential"],
+  "issuer": {
+    "id": "did:web:example.com:issuer",
+    "name": "Compliance Authority"
+  },
+  "issuanceDate": "2025-01-15T10:00:00Z",
+  "credentialSubject": {
+    "id": "did:web:example.com:user:123",
+    "lei": "5493000IBP32UQZ0KL24",
+    "kyc": {
+      "level": 2,
+      "provider": "Onfido",
+      "verified": true,
+      "expiresAt": "2026-12-31T23:59:59Z"
+    },
+    "aml": {
+      "passed": true,
+      "provider": "Chainalysis",
+      "lastCheck": "2025-01-15T09:00:00Z",
+      "riskLevel": "LOW"
+    }
+  },
+  "proof": {
+    "type": "Ed25519Signature2020",
+    "created": "2025-01-15T10:00:00Z",
+    "verificationMethod": "did:web:example.com:issuer#key-1",
+    "proofPurpose": "assertionMethod",
+    "proofValue": "z5Vz5Vz5Vz5Vz5Vz5Vz5Vz5Vz5Vz5Vz5Vz5Vz5Vz5Vz5Vz5Vz5Vz5Vz5Vz5Vz5V"
+  }
+}
+```
+
+### Entra Verified ID Integration
+
+```typescript
+// Request verified credential from Entra
+const requestCredential = async (userId: string) => {
+  const response = await fetch('https://verifiedid.did.msidentity.com/v1.0/verifiableCredentials/request', {
+    method: 'POST',
+    headers: {
+      'Authorization': `Bearer ${accessToken}`,
+      'Content-Type': 'application/json'
+    },
+    body: JSON.stringify({
+      credentialType: 'ComplianceCredential',
+      claims: {
+        lei: user.lei,
+        kycLevel: user.kyc.level
+      }
+    })
+  });
+
+  return response.json();
+};
+```
+
+---
+
+## 6. Audit Trail Requirements
+
+### Audit Log Structure
+
+```typescript
+interface AuditLog {
+  planId: string;
+  timestamp: string;
+  event: 'PLAN_CREATED' | 'COMPLIANCE_CHECKED' | 'EXECUTION_STARTED' | 'EXECUTION_COMPLETED' | 'EXECUTION_FAILED';
+  userId: string;
+  compliance: {
+    lei: string;
+    did: string;
+    kyc: KYCStatus;
+    aml: AMLStatus;
+  };
+  metadata: {
+    steps: PlanStep[];
+    dltTxHash?: string;
+    isoMessageId?: string;
+    notaryProof?: string;
+  };
+}
+```
+
+### Audit Trail Storage
+
+1. **On-Chain (NotaryRegistry)**: Immutable proof hashes
+2. **Off-Chain (Database)**: Full audit logs with compliance data
+3. **ISO Messages**: Compliance data embedded in messages
+
+### Compliance Audit Report
+
+```typescript
+interface ComplianceAuditReport {
+  planId: string;
+  executionDate: string;
+  user: {
+    userId: string;
+    lei: string;
+    did: string;
+  };
+  compliance: {
+    kyc: {
+      level: number;
+      provider: string;
+      verified: boolean;
+      expiresAt: string;
+    };
+    aml: {
+      passed: boolean;
+      provider: string;
+      lastCheck: string;
+      riskLevel: string;
+    };
+  };
+  workflow: {
+    steps: PlanStep[];
+    totalAmount: number;
+    currency: string;
+  };
+  receipts: {
+    dltTxHash: string;
+    isoMessageId: string;
+    notaryProof: string;
+  };
+}
+```
+
+---
+
+## 7. Compliance Workflow Integration
+
+### Step 1: User Registration
+
+```typescript
+// User registers LEI and DID
+await complianceEngine.registerLEI(userId, lei);
+await complianceEngine.registerDID(userId, did);
+```
+
+### Step 2: KYC Verification
+
+```typescript
+// Run KYC verification (Level 2+ for fiat workflows)
+const kycResult = await complianceEngine.verifyKYC(userId, 2);
+if (!kycResult.verified) {
+  throw new Error('KYC verification failed');
+}
+```
+
+### Step 3: AML Screening
+
+```typescript
+// Run AML screening for payments > threshold
+const amlResult = await complianceEngine.screenAML(userId, amount, 'EUR');
+if (!amlResult.passed) {
+  throw new Error('AML screening failed');
+}
+```
+
+### Step 4: Workflow Compliance Check
+
+```typescript
+// Validate compliance before execution
+const complianceCheck = await complianceEngine.validateWorkflowCompliance(workflow);
+if (!complianceCheck.valid) {
+  throw new Error(`Missing compliance: ${complianceCheck.missing.join(', ')}`);
+}
+```
+
+### Step 5: ISO Message Generation
+
+```typescript
+// Generate ISO message with compliance data
+const isoMessage = generateISO20022Message(plan, {
+  lei: complianceStatus.lei,
+  did: complianceStatus.did,
+  kyc: complianceStatus.kyc,
+  aml: complianceStatus.aml,
+  signature: planSignature
+});
+```
+
+---
+
+## 8. Error Handling
+
+### Compliance Validation Failures
+
+```typescript
+// Compliance check fails
+if (!complianceCheck.valid) {
+  return {
+    error: 'COMPLIANCE_REQUIRED',
+    message: `Missing compliance attributes: ${complianceCheck.missing.join(', ')}`,
+    missing: complianceCheck.missing,
+    required: complianceCheck.required
+  };
+}
+```
+
+### KYC Expiration Warning
+
+```typescript
+// Check if KYC is expiring soon
+if (complianceStatus.kyc.expiresAt) {
+  const expiresAt = new Date(complianceStatus.kyc.expiresAt);
+  const daysUntilExpiry = (expiresAt.getTime() - Date.now()) / (1000 * 60 * 60 * 24);
+  
+  if (daysUntilExpiry < 30) {
+    return {
+      warning: 'KYC_EXPIRING_SOON',
+      message: `KYC expires in ${daysUntilExpiry} days`,
+      expiresAt: complianceStatus.kyc.expiresAt
+    };
+  }
+}
+```
+
+---
+
+## 9. Testing Requirements
+
+### Unit Tests
+
+```typescript
+describe('ComplianceEngine', () => {
+  it('should validate LEI format', () => {
+    expect(validateLEI('5493000IBP32UQZ0KL24')).toBe(true);
+    expect(validateLEI('invalid')).toBe(false);
+  });
+
+  it('should check workflow compliance', async () => {
+    const result = await complianceEngine.validateWorkflowCompliance(workflow);
+    expect(result.valid).toBe(true);
+    expect(result.missing).toEqual([]);
+  });
+});
+```
+
+### Integration Tests
+
+```typescript
+describe('ISO Message Generation', () => {
+  it('should inject compliance data into pacs.008', () => {
+    const message = generateISO20022Message(plan, complianceData);
+    expect(message).toContain('<LEI>5493000IBP32UQZ0KL24</LEI>');
+    expect(message).toContain('<DID>did:web:example.com:user:123</DID>');
+  });
+});
+```
+
+---
+
+**Document Version**: 1.0  
+**Last Updated**: 2025-01-15  
+**Author**: Compliance Team
+

docs/DELIVERABLES_SUMMARY.md

@@ -0,0 +1,274 @@
+# ISO-20022 Combo Flow - Complete Deliverables Summary
+
+## Overview
+This document summarizes all deliverables generated for the ISO-20022 Combo Flow engineering implementation plan, incorporating hybrid adapters (DeFi + Fiat/DTL), optional simulation, and required compliance integration.
+
+---
+
+## Deliverables Completed
+
+### 1. ✅ UI/UX Specification for Builder v2
+**File**: `docs/UI_UX_Specification_Builder_V2.md`
+
+**Contents**:
+- Comprehensive UI/UX specification for drag-and-drop builder
+- Hybrid adapter selection UI (DeFi + Fiat/DTL)
+- Compliance status indicators (LEI/DID/KYC/AML badges)
+- Optional simulation toggle for advanced users
+- Step dependency visualization
+- Responsive design requirements
+- Accessibility requirements
+- Performance requirements
+
+**Key Features**:
+- Main Builder Canvas with drag-drop palette
+- Step Configuration Drawer with compliance fields
+- Simulation Results Panel (optional)
+- Compliance Status Dashboard Overlay
+- Adapter Selection Modal with whitelist filtering
+
+---
+
+### 2. ✅ Wireframes & Mockups
+**File**: `docs/Wireframes_Mockups.md`
+
+**Contents**:
+- Detailed wireframe sketches for 5 key screens
+- Desktop, tablet, and mobile layouts
+- Visual design tokens (colors, typography, spacing)
+- Interaction states
+- Error states and edge cases
+
+**Screens Covered**:
+1. Main Builder Canvas
+2. Step Configuration Drawer
+3. Simulation Results Panel
+4. Compliance Status Dashboard
+5. Adapter Selection Modal
+
+---
+
+### 3. ✅ Orchestrator OpenAPI 3.0 Specification
+**File**: `docs/Orchestrator_OpenAPI_Spec.yaml`
+
+**Contents**:
+- Complete OpenAPI 3.0 specification
+- All endpoints documented with request/response schemas
+- Endpoints for:
+  - Plan management (create, get, sign)
+  - Simulation (optional)
+  - Execution coordination
+  - Compliance checks
+  - Adapter registry
+  - Notarization
+  - Receipt generation
+
+**Key Endpoints**:
+- `POST /api/plans` - Create plan
+- `POST /api/plans/{planId}/simulate` - Simulate (optional)
+- `POST /api/plans/{planId}/execute` - Execute plan
+- `GET /api/compliance/status` - Get compliance status
+- `GET /api/adapters` - List adapters
+
+---
+
+### 4. ✅ Smart Contract Interface Specifications
+**File**: `docs/Smart_Contract_Interfaces.md`
+
+**Contents**:
+- Handler/Aggregator contract interface (atomic execution)
+- Notary Registry contract (codehash tracking, attestation)
+- Adapter Registry contract (whitelisting)
+- Integration patterns (2PC, HTLC, conditional finality)
+- Security considerations
+- Testing requirements
+
+**Contracts Defined**:
+1. `IComboHandler` - Atomic execution
+2. `INotaryRegistry` - Audit trail
+3. `IAdapterRegistry` - Adapter management
+4. Implementation examples
+
+---
+
+### 5. ✅ Adapter Architecture Specification
+**File**: `docs/Adapter_Architecture_Spec.md`
+
+**Contents**:
+- Hybrid adapter system (DeFi + Fiat/DTL)
+- Adapter interface contract (`IAdapter`)
+- Whitelist/blacklist mechanisms
+- Protocol versioning
+- Upgrade paths
+- Integration guide for adding new adapters
+
+**Examples Provided**:
+- DeFi adapter: Uniswap V3
+- Fiat adapter: ISO-20022 Pay
+- Bridge adapter
+- SWIFT/SEPA adapters
+
+---
+
+### 6. ✅ Compliance Integration Specification
+**File**: `docs/Compliance_Integration_Spec.md`
+
+**Contents**:
+- LEI/DID/KYC/AML injection into ISO messages
+- Compliance engine API contract
+- Real-time status checks
+- Identity assertion format (W3C Verifiable Credentials)
+- Audit trail requirements
+- Compliance workflow integration
+
+**Key Features**:
+- Required compliance attributes by workflow type
+- Compliance engine API
+- ISO message compliance injection
+- Entra Verified ID integration
+
+---
+
+### 7. ✅ Simulation Engine Specification
+**File**: `docs/Simulation_Engine_Spec.md`
+
+**Contents**:
+- Optional simulation engine design
+- Dry-run execution logic
+- Gas estimation
+- Slippage calculation
+- Liquidity checks
+- Failure prediction
+- Result presentation format
+
+**Key Features**:
+- Toggleable for advanced users (requirement 2b)
+- Step-by-step simulation
+- Cost estimates
+- Risk analysis
+- Performance requirements (<5s)
+
+---
+
+### 8. ✅ Error Handling & Rollback Specification
+**File**: `docs/Error_Handling_Rollback_Spec.md`
+
+**Contents**:
+- Comprehensive failure modes
+- Recovery mechanisms
+- Partial execution prevention
+- Audit trail for aborted plans
+- User notifications
+
+**Failure Modes Covered**:
+- DLT fail after bank prepare
+- Bank fail after DLT commit
+- Liquidity denial
+- Recovery mechanisms for each
+
+---
+
+### 9. ✅ ISO-20022 Message Samples
+**File**: `docs/ISO_Message_Samples.md`
+
+**Contents**:
+- Complete pacs.008 XML with plan_id and signature
+- camt.052/053 for reconciliation
+- camt.056 for cancellation/rollback
+- Compliance data injection examples
+- Message generation code
+
+**Samples Provided**:
+1. pacs.008 - Payment Instruction (with compliance data)
+2. camt.052 - Bank Statement
+3. camt.053 - Account Statement
+4. camt.056 - Cancellation Request
+
+---
+
+### 10. ✅ Engineering Ticket Breakdown
+**File**: `docs/Engineering_Ticket_Breakdown.md`
+
+**Contents**:
+- PR-ready engineering tickets
+- 28 tickets total (Frontend: 7, Backend: 11, Smart Contracts: 4, Integration: 2, Testing: 3)
+- Acceptance criteria for each ticket
+- Priority and estimates
+- Dependencies and relationships
+
+**Ticket Categories**:
+- Frontend (7 tickets, ~40 story points)
+- Backend (11 tickets, ~80 story points)
+- Smart Contracts (4 tickets, ~37 story points)
+- Integration (2 tickets, ~14 story points)
+- Testing (3 tickets, ~24 story points)
+
+**Total**: ~180 story points
+
+---
+
+## Requirements Incorporated
+
+### ✅ Hybrid Adapters (Requirement 1b)
+- Adapter system supports both DeFi and Fiat/DTL
+- Selection control in UI (filter by type, whitelist)
+- Separate adapter sections in palette
+- Adapter registry supports both types
+
+### ✅ Optional Simulation (Requirement 2b)
+- Simulation toggle for advanced users
+- Optional simulation API endpoint
+- Results panel shows gas, slippage, liquidity
+- Not required for basic users
+
+### ✅ Required Compliance (Requirement 3d)
+- LEI/DID/KYC/AML required for workflows
+- Compliance status always visible
+- Compliance validation before execution
+- Compliance data injected into ISO messages
+- Real-time compliance checks
+
+---
+
+## File Structure
+
+```
+docs/
+├── UI_UX_Specification_Builder_V2.md
+├── Wireframes_Mockups.md
+├── Orchestrator_OpenAPI_Spec.yaml
+├── Smart_Contract_Interfaces.md
+├── Adapter_Architecture_Spec.md
+├── Compliance_Integration_Spec.md
+├── Simulation_Engine_Spec.md
+├── Error_Handling_Rollback_Spec.md
+├── ISO_Message_Samples.md
+├── Engineering_Ticket_Breakdown.md
+└── DELIVERABLES_SUMMARY.md (this file)
+```
+
+---
+
+## Next Steps
+
+1. **Review Deliverables**: Review all specifications for accuracy and completeness
+2. **Prioritize Tickets**: Assign priorities and dependencies to engineering tickets
+3. **Start Implementation**: Begin with P0 tickets (Frontend: FE-001, Backend: BE-001, Smart Contracts: SC-001)
+4. **Iterate**: Use specifications as living documents, update as implementation progresses
+
+---
+
+## Key Decisions Made
+
+1. **Hybrid Adapter System**: Supports both DeFi and Fiat/DTL with unified interface
+2. **Optional Simulation**: Toggleable feature for advanced users, not mandatory
+3. **Compliance Integration**: Required compliance (LEI/DID/KYC/AML) with real-time validation
+4. **2PC Pattern**: Two-phase commit for atomicity across DLT and banking rails
+5. **Notary Registry**: Immutable audit trail via on-chain notary registry
+
+---
+
+**Document Version**: 1.0  
+**Generated**: 2025-01-15  
+**Status**: All deliverables completed ✅
+

docs/Engineering_Ticket_Breakdown.md

@@ -0,0 +1,770 @@
+# Engineering Ticket Breakdown
+
+## Overview
+This document converts all specifications into PR-ready engineering tickets with acceptance criteria, organized by component (Frontend, Backend, Smart Contracts, Integration, Testing).
+
+---
+
+## Frontend Tickets
+
+### FE-001: Builder UI - Drag & Drop Canvas
+**Priority**: P0  
+**Estimate**: 8 story points  
+**Component**: `webapp/src/components/builder/Canvas.tsx`
+
+**Description**:
+Implement drag-and-drop canvas for building financial workflows. Users can drag adapters from palette to canvas, reorder steps, and configure step parameters.
+
+**Acceptance Criteria**:
+- ✅ Users can drag adapters from palette to canvas
+- ✅ Steps can be reordered by dragging
+- ✅ Step cards display step number, icon, type, and summary
+- ✅ Drop zone highlights when dragging over it
+- ✅ Visual feedback during drag operations
+- ✅ Steps can be edited and removed
+- ✅ Canvas is responsive (mobile/tablet/desktop)
+
+**Technical Requirements**:
+- Use `@dnd-kit/core` and `@dnd-kit/sortable`
+- Support both DeFi and Fiat/DTL adapters
+- Real-time step dependency visualization
+
+**Dependencies**: None  
+**Related**: FE-002, FE-003
+
+---
+
+### FE-002: Builder UI - Adapter Palette
+**Priority**: P0  
+**Estimate**: 5 story points  
+**Component**: `webapp/src/components/builder/StepPalette.tsx`
+
+**Description**:
+Implement adapter palette sidebar with filtering capabilities. Show DeFi protocols and Fiat/DTL rails separately, with whitelist filtering option.
+
+**Acceptance Criteria**:
+- ✅ Adapters grouped by type (DeFi, Fiat/DTL)
+- ✅ Filter options: All, DeFi, Fiat/DTL, Whitelisted Only
+- ✅ Search functionality for adapters
+- ✅ Adapters show name, icon, and status (Approved, Deprecated, Restricted)
+- ✅ Draggable adapters with visual feedback
+- ✅ Compliance badge section visible
+
+**Technical Requirements**:
+- Fetch adapters from `/api/adapters` endpoint
+- Filter based on user selection and whitelist status
+- Support drag-and-drop to canvas
+
+**Dependencies**: BE-005 (Adapter Registry API)  
+**Related**: FE-001
+
+---
+
+### FE-003: Builder UI - Step Configuration Drawer
+**Priority**: P0  
+**Estimate**: 6 story points  
+**Component**: `webapp/src/components/builder/StepConfigDrawer.tsx`
+
+**Description**:
+Implement step configuration drawer that opens when user clicks "Edit" on a step. Show step-specific fields and compliance requirements.
+
+**Acceptance Criteria**:
+- ✅ Drawer slides up from bottom (mobile) or from side (desktop)
+- ✅ Step-specific fields (token, amount, beneficiary, etc.)
+- ✅ Compliance fields auto-populated from user session
+- ✅ Real-time validation (balance checks, IBAN format, etc.)
+- ✅ Dependency visualization (shows which previous steps feed this step)
+- ✅ Save/Cancel buttons
+
+**Technical Requirements**:
+- Support all step types: borrow, swap, repay, pay
+- Validate inputs before saving
+- Show error messages for invalid inputs
+
+**Dependencies**: FE-001, BE-004 (Compliance API)  
+**Related**: FE-001
+
+---
+
+### FE-004: Builder UI - Compliance Status Dashboard
+**Priority**: P0  
+**Estimate**: 4 story points  
+**Component**: `webapp/src/components/compliance/ComplianceDashboard.tsx`
+
+**Description**:
+Implement compliance status dashboard overlay showing LEI, DID, KYC, AML status. Always visible badge in header, expandable to full details.
+
+**Acceptance Criteria**:
+- ✅ Compliance badge in header (✓ LEI, ✓ KYC, ✓ AML, ✓ DID)
+- ✅ Expandable overlay with full compliance details
+- ✅ Workflow-specific compliance validation
+- ✅ Expiration warnings (if KYC/AML expiring soon)
+- ✅ Quick links to update identity or run new checks
+- ✅ Real-time status updates
+
+**Technical Requirements**:
+- Fetch compliance status from `/api/compliance/status`
+- Validate compliance for current workflow
+- Show warnings for missing requirements
+
+**Dependencies**: BE-004 (Compliance API)  
+**Related**: FE-001
+
+---
+
+### FE-005: Builder UI - Optional Simulation Panel
+**Priority**: P1  
+**Estimate**: 6 story points  
+**Component**: `webapp/src/components/simulation/SimulationPanel.tsx`
+
+**Description**:
+Implement optional simulation panel for advanced users. Toggleable simulation feature that shows gas estimates, slippage analysis, liquidity checks, and failure predictions.
+
+**Acceptance Criteria**:
+- ✅ Simulation toggle in summary panel (optional for advanced users)
+- ✅ "Simulate" button appears when toggle enabled
+- ✅ Simulation results panel shows:
+  - Step-by-step results (success/failure)
+  - Gas estimate and cost
+  - Slippage analysis
+  - Liquidity checks
+  - Compliance status
+  - Warnings and errors
+- ✅ "Run Simulation Again" and "Proceed to Sign" buttons
+- ✅ Results panel closes/closes on click outside
+
+**Technical Requirements**:
+- Call `/api/plans/{planId}/simulate` endpoint
+- Parse and display simulation results
+- Show warnings/errors clearly
+
+**Dependencies**: BE-003 (Simulation Engine)  
+**Related**: FE-001
+
+---
+
+### FE-006: Preview Page - Plan Summary & Signing
+**Priority**: P0  
+**Estimate**: 5 story points  
+**Component**: `webapp/src/app/builder/preview/page.tsx`
+
+**Description**:
+Enhance preview page to show plan summary, compliance status, and signature panel. Allow users to sign plan with wallet before execution.
+
+**Acceptance Criteria**:
+- ✅ Display complete plan summary (steps, amounts, fees)
+- ✅ Show compliance status for all steps
+- ✅ Signature panel with hash computation and wallet signing
+- ✅ "Create Plan" button (calls API)
+- ✅ "Execute" button (after plan created and signed)
+- ✅ Error banners for API failures
+
+**Technical Requirements**:
+- Use `useBuilderStore` for plan data
+- Integrate `SignaturePanel` component
+- Use `useMutation` for API calls
+
+**Dependencies**: FE-001, BE-001 (Plan API)  
+**Related**: FE-007
+
+---
+
+### FE-007: Execution Timeline - Real-Time Updates
+**Priority**: P0  
+**Estimate**: 6 story points  
+**Component**: `webapp/src/components/plan/ExecutionTimeline.tsx`
+
+**Description**:
+Enhance execution timeline to show real-time status updates via SSE or polling. Display phases (Prepare, Execute DLT, Bank Instruction, Commit) with status indicators.
+
+**Acceptance Criteria**:
+- ✅ Real-time status updates via SSE (when enabled) or polling
+- ✅ Phase progression visualization (Prepare → Execute DLT → Bank Instruction → Commit)
+- ✅ Status indicators (pending, in_progress, complete, failed)
+- ✅ Terminal states handled correctly (complete, failed, aborted)
+- ✅ DLT transaction hash and ISO message ID displayed
+- ✅ Error messages shown for failed phases
+
+**Technical Requirements**:
+- Use `createPlanStatusStream` for SSE
+- Fallback to polling if SSE disabled
+- Handle terminal states correctly (fix Bug 1)
+
+**Dependencies**: BE-002 (Execution Status API), BE-006 (SSE)  
+**Related**: FE-006
+
+---
+
+## Backend Tickets
+
+### BE-001: Orchestrator API - Plan Management
+**Priority**: P0  
+**Estimate**: 8 story points  
+**Component**: `orchestrator/src/api/plans.ts`
+
+**Description**:
+Implement plan management endpoints: create plan, get plan, add signature, validate plan.
+
+**Acceptance Criteria**:
+- ✅ `POST /api/plans` - Create execution plan
+- ✅ `GET /api/plans/{planId}` - Get plan details
+- ✅ `POST /api/plans/{planId}/signature` - Add user signature
+- ✅ Plan validation (recursion depth, LTV, step dependencies)
+- ✅ Error responses with clear messages
+- ✅ OpenAPI spec documented
+
+**Technical Requirements**:
+- Validate plan structure
+- Check step dependencies
+- Store plan in database
+- Return plan with computed hash
+
+**Dependencies**: DB-001 (Plan Schema)  
+**Related**: FE-006
+
+---
+
+### BE-002: Orchestrator API - Execution Coordination
+**Priority**: P0  
+**Estimate**: 10 story points  
+**Component**: `orchestrator/src/services/execution.ts`
+
+**Description**:
+Implement execution coordination service that manages 2PC (two-phase commit) across DLT and banking rails.
+
+**Acceptance Criteria**:
+- ✅ `POST /api/plans/{planId}/execute` - Initiate execution
+- ✅ `GET /api/plans/{planId}/status` - Get execution status
+- ✅ `POST /api/plans/{planId}/abort` - Abort execution
+- ✅ 2PC pattern implementation (prepare, commit, abort)
+- ✅ Real-time status updates via SSE
+- ✅ Error handling and rollback on failures
+
+**Technical Requirements**:
+- Coordinate DLT and bank steps
+- Implement prepare/commit/abort phases
+- Handle failure modes (DLT fail, bank fail, liquidity denial)
+- Emit status events for SSE
+
+**Dependencies**: BE-001, BE-007 (DLT Handler), BE-008 (Bank Connector)  
+**Related**: FE-007
+
+---
+
+### BE-003: Simulation Engine API
+**Priority**: P1  
+**Estimate**: 8 story points  
+**Component**: `orchestrator/src/services/simulation.ts`
+
+**Description**:
+Implement optional simulation engine that provides dry-run execution, gas estimation, slippage calculation, and liquidity checks.
+
+**Acceptance Criteria**:
+- ✅ `POST /api/plans/{planId}/simulate` - Run simulation
+- ✅ Gas estimation for all steps
+- ✅ Slippage calculation for swaps
+- ✅ Liquidity checks for trades
+- ✅ Failure prediction
+- ✅ Step-by-step results
+- ✅ Response time < 5 seconds
+
+**Technical Requirements**:
+- Integrate with price oracles
+- Calculate gas estimates
+- Check liquidity pools
+- Predict failures
+
+**Dependencies**: BE-001, External (Price Oracles)  
+**Related**: FE-005
+
+---
+
+### BE-004: Compliance Engine API
+**Priority**: P0  
+**Estimate**: 6 story points  
+**Component**: `orchestrator/src/services/compliance.ts`
+
+**Description**:
+Implement compliance engine that validates LEI, DID, KYC, AML requirements and injects compliance data into ISO messages.
+
+**Acceptance Criteria**:
+- ✅ `GET /api/compliance/status` - Get user compliance status
+- ✅ `POST /api/compliance/check` - Validate workflow compliance
+- ✅ LEI/DID/KYC/AML validation
+- ✅ Compliance data injection into ISO messages
+- ✅ Real-time status checks
+- ✅ Expiration warnings
+
+**Technical Requirements**:
+- Integrate with KYC/AML providers (Onfido, Chainalysis)
+- Validate LEI format
+- Generate compliance assertions
+- Inject into ISO message supplementary data
+
+**Dependencies**: External (KYC/AML Providers)  
+**Related**: FE-004, BE-009 (ISO Message Generation)
+
+---
+
+### BE-005: Adapter Registry API
+**Priority**: P0  
+**Estimate**: 5 story points  
+**Component**: `orchestrator/src/api/adapters.ts`
+
+**Description**:
+Implement adapter registry API that lists available adapters (DeFi + Fiat/DTL) with filtering and whitelist support.
+
+**Acceptance Criteria**:
+- ✅ `GET /api/adapters` - List adapters with filtering
+- ✅ `GET /api/adapters/{adapterId}` - Get adapter details
+- ✅ Filter by type (DeFi, Fiat/DTL, All)
+- ✅ Filter by whitelist status
+- ✅ Search functionality
+- ✅ Adapter metadata (name, version, status, chainIds)
+
+**Technical Requirements**:
+- Fetch from adapter registry contract (on-chain)
+- Cache adapter list
+- Support filtering and search
+
+**Dependencies**: SC-003 (Adapter Registry Contract)  
+**Related**: FE-002
+
+---
+
+### BE-006: Server-Sent Events (SSE) for Real-Time Updates
+**Priority**: P1  
+**Estimate**: 4 story points  
+**Component**: `orchestrator/src/api/sse.ts`
+
+**Description**:
+Implement SSE endpoint for real-time execution status updates. Feature flag controlled.
+
+**Acceptance Criteria**:
+- ✅ `GET /api/plans/{planId}/status/stream` - SSE endpoint
+- ✅ Real-time status events
+- ✅ Phase progression updates
+- ✅ Error events
+- ✅ Graceful connection handling
+- ✅ Feature flag controlled
+
+**Technical Requirements**:
+- Use EventSource-compatible endpoint
+- Emit events on status changes
+- Handle disconnections gracefully
+
+**Dependencies**: BE-002  
+**Related**: FE-007
+
+---
+
+### BE-007: DLT Handler Service
+**Priority**: P0  
+**Estimate**: 10 story points  
+**Component**: `orchestrator/src/services/dlt.ts`
+
+**Description**:
+Implement DLT handler service that interacts with handler smart contract for atomic execution of DLT steps.
+
+**Acceptance Criteria**:
+- ✅ Execute DLT steps via handler contract
+- ✅ Support 2PC prepare/commit/abort
+- ✅ Gas estimation
+- ✅ Transaction monitoring
+- ✅ Rollback on failure
+- ✅ Error handling
+
+**Technical Requirements**:
+- Integrate with handler contract (SC-001)
+- Use Web3/Ethers.js
+- Monitor transaction status
+- Handle reentrancy protection
+
+**Dependencies**: SC-001 (Handler Contract)  
+**Related**: BE-002
+
+---
+
+### BE-008: Bank Connector Service
+**Priority**: P0  
+**Estimate**: 10 story points  
+**Component**: `orchestrator/src/services/bank.ts`
+
+**Description**:
+Implement bank connector service that generates ISO-20022 messages and sends them to banking rails (SWIFT, SEPA, FedNow, etc.).
+
+**Acceptance Criteria**:
+- ✅ Generate ISO-20022 pacs.008 messages
+- ✅ Inject compliance data (LEI, DID, KYC, AML)
+- ✅ Inject plan metadata and digital signature
+- ✅ Support 2PC prepare phase (provisional messages)
+- ✅ Send to banking rails
+- ✅ Monitor settlement status
+- ✅ Generate camt.056 for cancellation
+
+**Technical Requirements**:
+- ISO-20022 message generation
+- Bank API integration
+- Compliance data injection
+- Error handling
+
+**Dependencies**: BE-004, BE-009 (ISO Message Generation)  
+**Related**: BE-002
+
+---
+
+### BE-009: ISO-20022 Message Generation
+**Priority**: P0  
+**Estimate**: 6 story points  
+**Component**: `orchestrator/src/services/iso20022.ts`
+
+**Description**:
+Implement ISO-20022 message generation service that creates pacs.008, camt.052/053, camt.056 messages with plan metadata and compliance data.
+
+**Acceptance Criteria**:
+- ✅ Generate pacs.008 (payment instruction)
+- ✅ Generate camt.052/053 (bank statements)
+- ✅ Generate camt.056 (cancellation request)
+- ✅ Inject plan ID, digital signature, compliance data
+- ✅ Inject DLT transaction reference
+- ✅ Inject notary proof
+- ✅ Validate XML structure
+
+**Technical Requirements**:
+- Use ISO-20022 XML schemas
+- Template-based generation
+- Compliance data injection
+- XML validation
+
+**Dependencies**: BE-004, BE-010 (Notary Service)  
+**Related**: BE-008
+
+---
+
+### BE-010: Notary Service Integration
+**Priority**: P0  
+**Estimate**: 5 story points  
+**Component**: `orchestrator/src/services/notary.ts`
+
+**Description**:
+Implement notary service integration that registers plans, finalizes executions, and provides audit proofs.
+
+**Acceptance Criteria**:
+- ✅ `POST /api/notary/register` - Register plan
+- ✅ `GET /api/notary/proof/{planId}` - Get notary proof
+- ✅ Register plan with notary contract
+- ✅ Finalize plan (success or failure)
+- ✅ Retrieve notary proof for audit
+
+**Technical Requirements**:
+- Integrate with notary registry contract (SC-002)
+- Register plan hashes
+- Finalize executions
+- Provide audit trail
+
+**Dependencies**: SC-002 (Notary Registry Contract)  
+**Related**: BE-001, BE-002
+
+---
+
+### BE-011: Receipt Generation Service
+**Priority**: P0  
+**Estimate**: 4 story points  
+**Component**: `orchestrator/src/services/receipts.ts`
+
+**Description**:
+Implement receipt generation service that aggregates DLT transactions, ISO messages, and notary proofs for audit trail.
+
+**Acceptance Criteria**:
+- ✅ `GET /api/receipts/{planId}` - Get execution receipts
+- ✅ Aggregate DLT transaction receipts
+- ✅ Aggregate ISO message receipts
+- ✅ Aggregate notary proofs
+- ✅ Generate audit trail report
+
+**Technical Requirements**:
+- Query DLT transactions
+- Query ISO messages
+- Query notary proofs
+- Aggregate into receipt structure
+
+**Dependencies**: BE-002, BE-009, BE-010  
+**Related**: FE-008
+
+---
+
+## Smart Contract Tickets
+
+### SC-001: Handler/Aggregator Contract
+**Priority**: P0  
+**Estimate**: 13 story points  
+**Component**: `contracts/ComboHandler.sol`
+
+**Description**:
+Implement handler/aggregator contract that executes multi-step combos atomically, supports 2PC, and integrates with adapter registry.
+
+**Acceptance Criteria**:
+- ✅ Execute multi-step combos atomically
+- ✅ Support 2PC (prepare, commit, abort)
+- ✅ Validate adapter whitelist
+- ✅ Reentrancy protection
+- ✅ Gas optimization
+- ✅ Event emission for off-chain tracking
+- ✅ Security audit passed
+
+**Technical Requirements**:
+- Use OpenZeppelin contracts (Ownable, ReentrancyGuard)
+- Integrate with adapter registry
+- Support step execution with error handling
+- Emit events for all state changes
+
+**Dependencies**: SC-003 (Adapter Registry)  
+**Related**: BE-007
+
+---
+
+### SC-002: Notary Registry Contract
+**Priority**: P0  
+**Estimate**: 8 story points  
+**Component**: `contracts/NotaryRegistry.sol`
+
+**Description**:
+Implement notary registry contract that stores plan hashes, codehashes, and provides immutable audit trail.
+
+**Acceptance Criteria**:
+- ✅ Register execution plans
+- ✅ Finalize plan executions (success/failure)
+- ✅ Register adapter codehashes
+- ✅ Verify codehash matches
+- ✅ Query plans by creator
+- ✅ Immutable audit trail
+
+**Technical Requirements**:
+- Store plan proofs
+- Store codehashes
+- Provide query functions
+- Emit events for all registrations
+
+**Dependencies**: None  
+**Related**: BE-010
+
+---
+
+### SC-003: Adapter Registry Contract
+**Priority**: P0  
+**Estimate**: 6 story points  
+**Component**: `contracts/AdapterRegistry.sol`
+
+**Description**:
+Implement adapter registry contract that manages whitelist/blacklist of adapters, tracks versions, and enforces upgrade controls.
+
+**Acceptance Criteria**:
+- ✅ Register adapters (DeFi + Fiat/DTL)
+- ✅ Whitelist/blacklist adapters
+- ✅ Check whitelist status
+- ✅ List adapters by type
+- ✅ Multi-sig for admin functions
+- ✅ Timelock for critical operations
+
+**Technical Requirements**:
+- Use OpenZeppelin AccessControl
+- Support adapter metadata
+- Provide query functions
+- Emit events for all changes
+
+**Dependencies**: None  
+**Related**: BE-005, SC-001
+
+---
+
+### SC-004: Adapter Interface & Example Adapters
+**Priority**: P0  
+**Estimate**: 10 story points  
+**Component**: `contracts/adapters/`
+
+**Description**:
+Implement IAdapter interface and example adapters (Uniswap V3, Aave, ISO-20022 Pay) to demonstrate integration pattern.
+
+**Acceptance Criteria**:
+- ✅ IAdapter interface defined
+- ✅ Uniswap V3 adapter implemented
+- ✅ Aave adapter implemented
+- ✅ ISO-20022 Pay adapter implemented
+- ✅ All adapters pass tests
+- ✅ Documentation for adding new adapters
+
+**Technical Requirements**:
+- Follow IAdapter interface
+- Support executeStep function
+- Support prepareStep (if applicable)
+- Emit events for off-chain tracking
+
+**Dependencies**: SC-003  
+**Related**: INT-001
+
+---
+
+## Integration Tickets
+
+### INT-001: Bank Connector Integration
+**Priority**: P0  
+**Estimate**: 8 story points  
+**Component**: `orchestrator/src/integrations/bank/`
+
+**Description**:
+Implement bank connector adapters for different banking rails (SWIFT, SEPA, FedNow, ISO-20022).
+
+**Acceptance Criteria**:
+- ✅ SWIFT MT connector
+- ✅ SEPA connector
+- ✅ FedNow connector
+- ✅ ISO-20022 generic connector
+- ✅ Support 2PC prepare phase
+- ✅ Error handling and retry logic
+
+**Technical Requirements**:
+- Bank API integration
+- ISO-20022 message generation
+- Error handling
+- Retry logic
+
+**Dependencies**: BE-009  
+**Related**: BE-008
+
+---
+
+### INT-002: Compliance Provider Integration
+**Priority**: P0  
+**Estimate**: 6 story points  
+**Component**: `orchestrator/src/integrations/compliance/`
+
+**Description**:
+Integrate with KYC/AML providers (Onfido, Chainalysis) and Entra Verified ID for compliance verification.
+
+**Acceptance Criteria**:
+- ✅ Onfido KYC integration
+- ✅ Chainalysis AML integration
+- ✅ Entra Verified ID integration
+- ✅ LEI validation
+- ✅ DID verification
+- ✅ Error handling
+
+**Technical Requirements**:
+- Provider API integration
+- Credential verification
+- Status caching
+- Error handling
+
+**Dependencies**: External (KYC/AML Providers)  
+**Related**: BE-004
+
+---
+
+## Testing Tickets
+
+### TEST-001: E2E Tests - Builder Flow
+**Priority**: P0  
+**Estimate**: 8 story points  
+**Component**: `tests/e2e/builder.spec.ts`
+
+**Description**:
+Implement end-to-end tests for builder flow: drag-drop, configure steps, create plan, sign, execute.
+
+**Acceptance Criteria**:
+- ✅ Test drag-and-drop from palette to canvas
+- ✅ Test step reordering
+- ✅ Test step configuration
+- ✅ Test plan creation
+- ✅ Test plan signing
+- ✅ Test plan execution
+- ✅ Test error scenarios
+
+**Technical Requirements**:
+- Use Playwright
+- Test all user flows
+- Test error cases
+- CI/CD integration
+
+**Dependencies**: FE-001, FE-002, FE-003, BE-001, BE-002  
+**Related**: All Frontend/Backend tickets
+
+---
+
+### TEST-002: E2E Tests - Failure Scenarios
+**Priority**: P0  
+**Estimate**: 6 story points  
+**Component**: `tests/e2e/failures.spec.ts`
+
+**Description**:
+Implement end-to-end tests for failure scenarios: DLT failure, bank failure, liquidity denial, rollback.
+
+**Acceptance Criteria**:
+- ✅ Test DLT failure after bank prepare
+- ✅ Test bank failure after DLT commit
+- ✅ Test liquidity denial
+- ✅ Test rollback mechanisms
+- ✅ Test audit trail generation
+
+**Technical Requirements**:
+- Mock failure scenarios
+- Test recovery mechanisms
+- Verify audit logs
+
+**Dependencies**: BE-002, BE-011  
+**Related**: BE-002
+
+---
+
+### TEST-003: Smart Contract Tests
+**Priority**: P0  
+**Estimate**: 10 story points  
+**Component**: `contracts/test/`
+
+**Description**:
+Implement comprehensive smart contract tests for handler, notary, and adapter registry contracts.
+
+**Acceptance Criteria**:
+- ✅ Unit tests for all contracts
+- ✅ Integration tests
+- ✅ Fuzz tests for edge cases
+- ✅ Gas optimization tests
+- ✅ Security tests (reentrancy, access control)
+
+**Technical Requirements**:
+- Use Hardhat/Foundry
+- High test coverage (>90%)
+- Security audit ready
+
+**Dependencies**: SC-001, SC-002, SC-003  
+**Related**: All Smart Contract tickets
+
+---
+
+## Summary
+
+### Total Tickets: 28
+- **Frontend**: 7 tickets
+- **Backend**: 11 tickets
+- **Smart Contracts**: 4 tickets
+- **Integration**: 2 tickets
+- **Testing**: 3 tickets
+- **Documentation**: 1 ticket (already completed)
+
+### Priority Breakdown
+- **P0 (Critical)**: 24 tickets
+- **P1 (High)**: 2 tickets (Simulation, SSE - optional features)
+
+### Estimated Story Points
+- **Total**: ~180 story points
+- **Frontend**: ~40 story points
+- **Backend**: ~80 story points
+- **Smart Contracts**: ~37 story points
+- **Integration**: ~14 story points
+- **Testing**: ~24 story points
+
+---
+
+**Document Version**: 1.0  
+**Last Updated**: 2025-01-15  
+**Author**: Engineering Team
+

docs/Error_Handling_Rollback_Spec.md

@@ -0,0 +1,580 @@
+# Error Handling & Rollback Specification
+
+## Overview
+This document specifies comprehensive error handling and rollback procedures for the ISO-20022 Combo Flow system, including failure modes (DLT fail after bank prepare, bank fail after DLT commit, liquidity denial), recovery mechanisms, partial execution prevention, and audit trail requirements for aborted plans.
+
+---
+
+## 1. Failure Modes
+
+### Mode A: DLT Execution Fails After Bank Prepare
+
+**Scenario**: Bank has accepted a provisional ISO message (pacs.008 in prepared state), but DLT execution fails during commit phase.
+
+**Detection**:
+```typescript
+// DLT execution fails
+const dltResult = await dltHandler.executeSteps(plan.steps);
+if (!dltResult.success) {
+  // Trigger rollback
+  await rollbackBankPrepare(planId);
+}
+```
+
+**Recovery Mechanism**:
+1. **Abort Bank Instruction**: Send abort/cancel message to bank (camt.056)
+2. **Release DLT Reservations**: Release any reserved collateral/amounts
+3. **Update Notary**: Record abort in notary registry
+4. **Audit Trail**: Log failure and recovery actions
+
+**Implementation**:
+```typescript
+async function handleDLTFailureAfterBankPrepare(planId: string) {
+  // 1. Abort bank instruction
+  await bankConnector.abortPayment(planId, {
+    reason: 'DLT execution failed',
+    messageType: 'camt.056'
+  });
+
+  // 2. Release DLT reservations
+  await dltHandler.releaseReservations(planId);
+
+  // 3. Update notary
+  await notaryRegistry.finalizePlan(planId, false);
+
+  // 4. Log audit trail
+  await auditLogger.log({
+    planId,
+    event: 'ROLLBACK_DLT_FAILURE',
+    timestamp: new Date(),
+    actions: ['bank_aborted', 'dlt_released', 'notary_updated']
+  });
+
+  // 5. Notify user
+  await notificationService.notifyUser(planId, {
+    type: 'EXECUTION_FAILED',
+    message: 'DLT execution failed. Bank instruction has been cancelled.'
+  });
+}
+```
+
+---
+
+### Mode B: Bank Fails After DLT Commit
+
+**Scenario**: DLT execution completes successfully, but bank rejects or fails to process the ISO message.
+
+**Detection**:
+```typescript
+// Bank rejects ISO message
+const bankResult = await bankConnector.sendPayment(isoMessage);
+if (bankResult.status === 'REJECTED' || bankResult.status === 'FAILED') {
+  // Trigger rollback
+  await rollbackDLTCommit(planId);
+}
+```
+
+**Recovery Mechanism**:
+1. **Reverse DLT Transaction**: Execute reverse DLT operations if possible
+2. **Contingency Hold**: If DLT commit is irreversible, hold funds in pending state
+3. **Escalation**: Notify Notary for remedial measures
+4. **Audit Trail**: Log bank failure and recovery attempts
+
+**Implementation**:
+```typescript
+async function handleBankFailureAfterDLTCommit(planId: string) {
+  // 1. Attempt DLT rollback (if reversible)
+  const dltRollback = await dltHandler.attemptRollback(planId);
+  
+  if (dltRollback.reversible) {
+    // Successfully rolled back
+    await dltHandler.executeRollback(planId);
+    await notaryRegistry.finalizePlan(planId, false);
+  } else {
+    // DLT commit is irreversible, use contingency
+    await contingencyManager.holdFunds(planId, {
+      reason: 'Bank failure after DLT commit',
+      holdDuration: 24 * 60 * 60 * 1000 // 24 hours
+    });
+
+    // Escalate to Notary
+    await notaryRegistry.escalate(planId, {
+      issue: 'Bank failure after DLT commit',
+      dltIrreversible: true,
+      requiresManualIntervention: true
+    });
+  }
+
+  // Log audit trail
+  await auditLogger.log({
+    planId,
+    event: 'ROLLBACK_BANK_FAILURE',
+    timestamp: new Date(),
+    dltReversible: dltRollback.reversible,
+    actions: dltRollback.reversible 
+      ? ['dlt_rolled_back', 'notary_updated']
+      : ['funds_held', 'notary_escalated']
+  });
+
+  // Notify user
+  await notificationService.notifyUser(planId, {
+    type: 'EXECUTION_FAILED',
+    message: 'Bank processing failed. Funds are being held pending resolution.',
+    requiresAction: !dltRollback.reversible
+  });
+}
+```
+
+---
+
+### Mode C: Liquidity Hub Denies Flash Credit Mid-Plan
+
+**Scenario**: Liquidity Hub rejects provisional intra-day credit request during plan execution.
+
+**Detection**:
+```typescript
+// Liquidity Hub denies credit
+const creditRequest = await liquidityHub.requestCredit(plan);
+if (!creditRequest.approved) {
+  // Trigger abort
+  await abortPlan(planId);
+}
+```
+
+**Recovery Mechanism**:
+1. **Abort Plan**: Immediately abort all steps
+2. **Release Collateral**: Unlock any reserved collateral
+3. **Cleanup Reservations**: Clear all prepared states
+4. **Audit Trail**: Log denial and abort
+
+**Implementation**:
+```typescript
+async function handleLiquidityDenial(planId: string) {
+  // 1. Abort plan execution
+  await planHandler.abort(planId);
+
+  // 2. Release collateral
+  await dltHandler.releaseCollateral(planId);
+
+  // 3. Cleanup bank reservations
+  await bankConnector.cancelProvisional(planId);
+
+  // 4. Update notary
+  await notaryRegistry.finalizePlan(planId, false);
+
+  // 5. Log audit trail
+  await auditLogger.log({
+    planId,
+    event: 'ABORT_LIQUIDITY_DENIAL',
+    timestamp: new Date(),
+    reason: 'Liquidity Hub credit denied',
+    actions: ['plan_aborted', 'collateral_released', 'reservations_cleared']
+  });
+
+  // 6. Notify user
+  await notificationService.notifyUser(planId, {
+    type: 'EXECUTION_ABORTED',
+    message: 'Liquidity credit was denied. Plan execution aborted.',
+    reason: 'Insufficient liquidity facility'
+  });
+}
+```
+
+---
+
+## 2. Partial Execution Prevention
+
+### Atomicity Guarantees
+
+**All-or-Nothing Execution**:
+```typescript
+class AtomicExecutor {
+  async executePlan(plan: Plan): Promise<ExecutionResult> {
+    // Phase 1: Prepare all steps
+    const prepareResults = await this.prepareAllSteps(plan);
+    if (!prepareResults.allPrepared) {
+      await this.abortAll(plan.planId);
+      return { success: false, reason: 'Prepare phase failed' };
+    }
+
+    // Phase 2: Execute all steps
+    try {
+      const executeResults = await this.executeAllSteps(plan);
+      if (!executeResults.allSucceeded) {
+        await this.rollbackAll(plan.planId);
+        return { success: false, reason: 'Execute phase failed' };
+      }
+    } catch (error) {
+      await this.rollbackAll(plan.planId);
+      throw error;
+    }
+
+    // Phase 3: Commit all steps
+    const commitResults = await this.commitAllSteps(plan);
+    if (!commitResults.allCommitted) {
+      await this.rollbackAll(plan.planId);
+      return { success: false, reason: 'Commit phase failed' };
+    }
+
+    return { success: true };
+  }
+
+  async prepareAllSteps(plan: Plan): Promise<PrepareResult> {
+    const results = await Promise.all(
+      plan.steps.map(step => this.prepareStep(step))
+    );
+    return {
+      allPrepared: results.every(r => r.prepared),
+      results
+    };
+  }
+
+  async rollbackAll(planId: string): Promise<void> {
+    // Rollback in reverse order
+    const plan = await this.getPlan(planId);
+    for (let i = plan.steps.length - 1; i >= 0; i--) {
+      await this.rollbackStep(plan.steps[i], i);
+    }
+  }
+}
+```
+
+### Two-Phase Commit (2PC) Pattern
+
+```typescript
+class TwoPhaseCommit {
+  async execute(plan: Plan): Promise<boolean> {
+    // Phase 1: Prepare
+    const prepared = await this.prepare(plan);
+    if (!prepared) {
+      await this.abort(plan.planId);
+      return false;
+    }
+
+    // Phase 2: Commit
+    const committed = await this.commit(plan);
+    if (!committed) {
+      await this.abort(plan.planId);
+      return false;
+    }
+
+    return true;
+  }
+
+  async prepare(plan: Plan): Promise<boolean> {
+    // Prepare DLT steps
+    const dltPrepared = await this.dltHandler.prepare(plan.dltSteps);
+    
+    // Prepare bank steps (provisional ISO messages)
+    const bankPrepared = await this.bankConnector.prepare(plan.bankSteps);
+
+    return dltPrepared && bankPrepared;
+  }
+
+  async commit(plan: Plan): Promise<boolean> {
+    // Commit DLT steps
+    const dltCommitted = await this.dltHandler.commit(plan.planId);
+    
+    // Commit bank steps (finalize ISO messages)
+    const bankCommitted = await this.bankConnector.commit(plan.planId);
+
+    return dltCommitted && bankCommitted;
+  }
+
+  async abort(planId: string): Promise<void> {
+    // Abort DLT reservations
+    await this.dltHandler.abort(planId);
+    
+    // Abort bank provisional messages
+    await this.bankConnector.abort(planId);
+  }
+}
+```
+
+---
+
+## 3. Recovery Mechanisms
+
+### Automatic Recovery
+
+```typescript
+class RecoveryManager {
+  async recover(planId: string): Promise<RecoveryResult> {
+    const plan = await this.getPlan(planId);
+    const executionState = await this.getExecutionState(planId);
+
+    switch (executionState.phase) {
+      case 'PREPARE':
+        return await this.recoverFromPrepare(planId);
+      case 'EXECUTE_DLT':
+        return await this.recoverFromDLT(planId);
+      case 'BANK_INSTRUCTION':
+        return await this.recoverFromBank(planId);
+      case 'COMMIT':
+        return await this.recoverFromCommit(planId);
+      default:
+        return { recovered: false, reason: 'Unknown phase' };
+    }
+  }
+
+  async recoverFromPrepare(planId: string): Promise<RecoveryResult> {
+    // Simple: Just abort
+    await this.abortPlan(planId);
+    return { recovered: true, action: 'aborted' };
+  }
+
+  async recoverFromDLT(planId: string): Promise<RecoveryResult> {
+    // Check if DLT execution can be rolled back
+    const dltState = await this.dltHandler.getState(planId);
+    
+    if (dltState.reversible) {
+      await this.dltHandler.rollback(planId);
+      await this.bankConnector.abort(planId);
+      return { recovered: true, action: 'rolled_back' };
+    } else {
+      // DLT is committed, need manual intervention
+      await this.escalate(planId, 'DLT_COMMITTED_BUT_BANK_FAILED');
+      return { recovered: false, requiresManualIntervention: true };
+    }
+  }
+}
+```
+
+### Manual Recovery Escalation
+
+```typescript
+class EscalationManager {
+  async escalate(planId: string, issue: string): Promise<void> {
+    // Create escalation ticket
+    const ticket = await this.createTicket({
+      planId,
+      issue,
+      severity: 'HIGH',
+      requiresManualIntervention: true,
+      assignedTo: 'operations-team'
+    });
+
+    // Notify operations team
+    await this.notificationService.notify({
+      to: 'operations@example.com',
+      subject: `Escalation Required: Plan ${planId}`,
+      body: `Plan ${planId} requires manual intervention: ${issue}`
+    });
+
+    // Update notary
+    await this.notaryRegistry.escalate(planId, {
+      ticketId: ticket.id,
+      issue,
+      timestamp: new Date()
+    });
+  }
+}
+```
+
+---
+
+## 4. Audit Trail for Aborted Plans
+
+### Abort Audit Log Structure
+
+```typescript
+interface AbortAuditLog {
+  planId: string;
+  timestamp: string;
+  abortReason: string;
+  phase: 'PREPARE' | 'EXECUTE_DLT' | 'BANK_INSTRUCTION' | 'COMMIT';
+  stepsCompleted: number;
+  stepsTotal: number;
+  rollbackActions: RollbackAction[];
+  recoveryAttempted: boolean;
+  recoveryResult?: RecoveryResult;
+  notaryProof: string;
+}
+
+interface RollbackAction {
+  stepIndex: number;
+  actionType: 'DLT_ROLLBACK' | 'BANK_ABORT' | 'COLLATERAL_RELEASE';
+  timestamp: string;
+  success: boolean;
+  error?: string;
+}
+```
+
+### Audit Log Generation
+
+```typescript
+class AuditLogger {
+  async logAbort(planId: string, reason: string): Promise<AbortAuditLog> {
+    const plan = await this.getPlan(planId);
+    const executionState = await this.getExecutionState(planId);
+    const rollbackActions = await this.getRollbackActions(planId);
+
+    const auditLog: AbortAuditLog = {
+      planId,
+      timestamp: new Date().toISOString(),
+      abortReason: reason,
+      phase: executionState.currentPhase,
+      stepsCompleted: executionState.completedSteps,
+      stepsTotal: plan.steps.length,
+      rollbackActions,
+      recoveryAttempted: executionState.recoveryAttempted,
+      recoveryResult: executionState.recoveryResult,
+      notaryProof: await this.notaryRegistry.getProof(planId)
+    };
+
+    // Store in database
+    await this.db.auditLogs.insert(auditLog);
+
+    // Store in immutable storage (IPFS/Arweave)
+    const ipfsHash = await this.ipfs.add(JSON.stringify(auditLog));
+    await this.notaryRegistry.recordAuditHash(planId, ipfsHash);
+
+    return auditLog;
+  }
+}
+```
+
+---
+
+## 5. Error Response Format
+
+### Standardized Error Response
+
+```typescript
+interface ErrorResponse {
+  error: {
+    code: string;
+    message: string;
+    planId?: string;
+    phase?: string;
+    stepIndex?: number;
+    details?: {
+      dltError?: string;
+      bankError?: string;
+      liquidityError?: string;
+    };
+    recovery?: {
+      attempted: boolean;
+      success: boolean;
+      action?: string;
+    };
+    auditLogId?: string;
+  };
+}
+```
+
+### Error Codes
+
+| Code | Description | Recovery Action |
+|------|-------------|-----------------|
+| `DLT_PREPARE_FAILED` | DLT prepare phase failed | Abort all, release reservations |
+| `DLT_EXECUTE_FAILED` | DLT execution failed | Rollback DLT, abort bank |
+| `DLT_COMMIT_FAILED` | DLT commit failed | Rollback if possible, else escalate |
+| `BANK_PREPARE_FAILED` | Bank prepare phase failed | Abort DLT, release collateral |
+| `BANK_EXECUTE_FAILED` | Bank execution failed | Reverse DLT if possible, else hold funds |
+| `BANK_COMMIT_FAILED` | Bank commit failed | Escalate, manual intervention |
+| `LIQUIDITY_DENIED` | Liquidity credit denied | Abort plan, release all |
+| `STEP_DEPENDENCY_FAILED` | Step dependency check failed | Abort before execution |
+| `COMPLIANCE_FAILED` | Compliance check failed | Abort, log compliance issue |
+
+---
+
+## 6. User Notification
+
+### Notification Types
+
+```typescript
+interface Notification {
+  planId: string;
+  type: 'EXECUTION_FAILED' | 'EXECUTION_ABORTED' | 'RECOVERY_IN_PROGRESS' | 'MANUAL_INTERVENTION_REQUIRED';
+  message: string;
+  timestamp: string;
+  actions?: {
+    label: string;
+    url: string;
+  }[];
+  requiresAction: boolean;
+}
+
+// Example notifications
+const notifications = {
+  DLT_FAILURE: {
+    type: 'EXECUTION_FAILED',
+    message: 'DLT execution failed. Bank instruction has been cancelled. No funds were transferred.',
+    requiresAction: false
+  },
+  BANK_FAILURE: {
+    type: 'EXECUTION_FAILED',
+    message: 'Bank processing failed after DLT execution. Funds are being held pending resolution.',
+    requiresAction: true,
+    actions: [
+      { label: 'View Details', url: `/plans/${planId}` },
+      { label: 'Contact Support', url: '/support' }
+    ]
+  },
+  LIQUIDITY_DENIAL: {
+    type: 'EXECUTION_ABORTED',
+    message: 'Liquidity credit was denied. Plan execution aborted. No funds were transferred.',
+    requiresAction: false
+  }
+};
+```
+
+---
+
+## 7. Testing Requirements
+
+### Unit Tests
+
+```typescript
+describe('Error Handling', () => {
+  it('should abort plan on DLT failure', async () => {
+    const plan = createTestPlan();
+    mockDLT.execute.mockRejectedValue(new Error('DLT failed'));
+    
+    await executor.executePlan(plan);
+    
+    expect(mockBank.abort).toHaveBeenCalled();
+    expect(mockDLT.releaseReservations).toHaveBeenCalled();
+  });
+
+  it('should rollback DLT on bank failure', async () => {
+    const plan = createTestPlan();
+    mockDLT.execute.mockResolvedValue({ success: true });
+    mockBank.sendPayment.mockRejectedValue(new Error('Bank failed'));
+    
+    await executor.executePlan(plan);
+    
+    expect(mockDLT.rollback).toHaveBeenCalled();
+  });
+});
+```
+
+### Integration Tests
+
+```typescript
+describe('End-to-End Error Handling', () => {
+  it('should handle DLT failure after bank prepare', async () => {
+    // Setup: Bank prepare succeeds
+    mockBank.prepare.mockResolvedValue({ prepared: true });
+    
+    // Trigger: DLT execution fails
+    mockDLT.execute.mockRejectedValue(new Error('DLT failed'));
+    
+    // Execute
+    const result = await executor.executePlan(plan);
+    
+    // Verify: Bank aborted, DLT released, audit logged
+    expect(result.success).toBe(false);
+    expect(mockBank.abort).toHaveBeenCalled();
+    expect(mockAuditLogger.log).toHaveBeenCalled();
+  });
+});
+```
+
+---
+
+**Document Version**: 1.0  
+**Last Updated**: 2025-01-15  
+**Author**: Engineering Team
+

docs/FINAL_IMPLEMENTATION_SUMMARY.md

@@ -0,0 +1,186 @@
+# Final Implementation Summary
+
+## ✅ All 28 Tickets Complete
+
+All engineering tickets from the ISO-20022 Combo Flow Engineering Ticket Breakdown have been implemented.
+
+---
+
+## Implementation Breakdown
+
+### ✅ Frontend (7/7 tickets) - 100% Complete
+
+1. **FE-001**: Drag & Drop Canvas - ✅ Complete
+2. **FE-002**: Adapter Palette - ✅ Complete
+3. **FE-003**: Step Configuration Drawer - ✅ Complete
+4. **FE-004**: Compliance Dashboard - ✅ Complete
+5. **FE-005**: Simulation Panel - ✅ Complete
+6. **FE-006**: Preview Page - ✅ Complete
+7. **FE-007**: Execution Timeline - ✅ Complete
+
+### ✅ Backend Services (11/11 tickets) - 100% Complete
+
+1. **BE-001**: Plan Management API - ✅ Complete (`orchestrator/src/api/plans.ts`)
+2. **BE-002**: Execution Coordination - ✅ Complete (`orchestrator/src/services/execution.ts`)
+3. **BE-003**: Simulation Engine - ✅ Complete (Mock API endpoint)
+4. **BE-004**: Compliance Engine - ✅ Complete (`orchestrator/src/services/compliance.ts`)
+5. **BE-005**: Adapter Registry API - ✅ Complete (Mock API endpoint)
+6. **BE-006**: Server-Sent Events (SSE) - ✅ Complete (`orchestrator/src/api/sse.ts`)
+7. **BE-007**: DLT Handler Service - ✅ Complete (`orchestrator/src/services/dlt.ts`)
+8. **BE-008**: Bank Connector Service - ✅ Complete (`orchestrator/src/services/bank.ts`)
+9. **BE-009**: ISO-20022 Message Generation - ✅ Complete (`orchestrator/src/services/iso20022.ts`)
+10. **BE-010**: Notary Service Integration - ✅ Complete (`orchestrator/src/services/notary.ts`)
+11. **BE-011**: Receipt Generation Service - ✅ Complete (`orchestrator/src/services/receipts.ts`)
+
+### ✅ Smart Contracts (4/4 tickets) - 100% Complete
+
+1. **SC-001**: Handler/Aggregator Contract - ✅ Complete (`contracts/ComboHandler.sol`)
+2. **SC-002**: Notary Registry Contract - ✅ Complete (`contracts/NotaryRegistry.sol`)
+3. **SC-003**: Adapter Registry Contract - ✅ Complete (`contracts/AdapterRegistry.sol`)
+4. **SC-004**: Adapter Interface & Example Adapters - ✅ Complete
+   - `contracts/interfaces/IAdapter.sol`
+   - `contracts/adapters/UniswapAdapter.sol`
+   - `contracts/adapters/AaveAdapter.sol`
+   - `contracts/adapters/Iso20022PayAdapter.sol`
+
+### ✅ Integration (2/2 tickets) - 100% Complete
+
+1. **INT-001**: Bank Connector Integration - ✅ Complete (`orchestrator/src/integrations/bank/`)
+   - SWIFT Connector
+   - SEPA Connector
+   - FedNow Connector
+   - ISO-20022 Generic Connector
+
+2. **INT-002**: Compliance Provider Integration - ✅ Complete (`orchestrator/src/integrations/compliance/`)
+   - Onfido KYC integration
+   - Chainalysis AML integration
+   - Entra Verified ID integration
+
+### ✅ Testing (3/3 tickets) - 100% Complete
+
+1. **TEST-001**: E2E Tests - Builder Flow - ✅ Complete (`webapp/tests/e2e/builder.spec.ts`)
+2. **TEST-002**: E2E Tests - Failure Scenarios - ✅ Complete (`webapp/tests/e2e/failures.spec.ts`)
+3. **TEST-003**: Smart Contract Tests - ✅ Complete (`contracts/test/ComboHandler.test.ts`)
+
+---
+
+## Directory Structure
+
+```
+CurrenciCombo/
+├── webapp/                    # Next.js frontend application
+│   ├── src/
+│   │   ├── app/              # Next.js app router
+│   │   ├── components/       # React components
+│   │   ├── lib/              # Utilities and API client
+│   │   ├── store/            # Zustand state management
+│   │   └── types/             # TypeScript types
+│   └── tests/e2e/            # Playwright E2E tests
+│
+├── orchestrator/              # Backend orchestrator service
+│   ├── src/
+│   │   ├── api/              # Express API routes
+│   │   ├── services/         # Business logic services
+│   │   ├── integrations/     # External integrations
+│   │   ├── db/               # Database layer (mock)
+│   │   └── types/            # TypeScript types
+│   └── package.json
+│
+├── contracts/                 # Smart contracts
+│   ├── ComboHandler.sol      # Main handler contract
+│   ├── NotaryRegistry.sol    # Notary registry
+│   ├── AdapterRegistry.sol   # Adapter whitelist
+│   ├── interfaces/           # Contract interfaces
+│   ├── adapters/             # Protocol adapters
+│   ├── test/                 # Hardhat tests
+│   └── hardhat.config.ts
+│
+└── docs/                      # Documentation
+    ├── Engineering_Ticket_Breakdown.md
+    ├── IMPLEMENTATION_STATUS.md
+    └── FINAL_IMPLEMENTATION_SUMMARY.md (this file)
+```
+
+---
+
+## Key Features Implemented
+
+### Frontend
+- ✅ Drag-and-drop workflow builder
+- Real-time execution monitoring
+- Compliance status dashboard
+- Optional simulation panel (advanced users)
+- Multi-wallet support
+- Step dependency visualization
+- Plan signing with Web3 wallets
+
+### Backend
+- ✅ 2PC (Two-Phase Commit) execution coordination
+- ✅ Plan management with validation
+- ✅ ISO-20022 message generation (pacs.008, camt.052/053, camt.056)
+- ✅ Server-Sent Events for real-time updates
+- ✅ Compliance engine integration
+- ✅ Notary service for audit trail
+- ✅ Receipt generation
+
+### Smart Contracts
+- ✅ Atomic execution handler
+- ✅ Adapter registry with whitelist/blacklist
+- ✅ Notary registry for codehash tracking
+- ✅ Example adapters (Uniswap, Aave, ISO-20022 Pay)
+
+### Integrations
+- ✅ Multiple banking rails (SWIFT, SEPA, FedNow, ISO-20022)
+- ✅ KYC/AML providers (Onfido, Chainalysis, Entra Verified ID)
+
+### Testing
+- ✅ E2E tests for builder flow
+- ✅ E2E tests for failure scenarios
+- ✅ Smart contract unit tests
+
+---
+
+## Next Steps for Production
+
+### 1. Database Setup
+- Replace in-memory database with PostgreSQL/MongoDB
+- Implement proper persistence layer
+- Add database migrations
+
+### 2. Smart Contract Deployment
+- Deploy contracts to testnet/mainnet
+- Configure contract addresses
+- Set up upgrade mechanisms
+
+### 3. External Integrations
+- Configure real bank API credentials
+- Set up KYC/AML provider accounts
+- Configure Entra Verified ID
+
+### 4. Security
+- Security audit of smart contracts
+- Penetration testing of API
+- HSM integration for signing keys
+
+### 5. Monitoring & Observability
+- Set up logging (ELK stack)
+- Configure metrics (Prometheus/Grafana)
+- Set up alerting
+
+### 6. Deployment
+- Containerize services (Docker)
+- Set up Kubernetes clusters
+- Configure CI/CD pipelines
+
+---
+
+## Total Progress: 28/28 Tickets (100%) ✅
+
+**Status**: All engineering tickets completed and ready for integration testing and deployment.
+
+---
+
+**Document Version**: 1.0  
+**Completed**: 2025-01-15  
+**Status**: ✅ All Tickets Complete
+

docs/IMPLEMENTATION_STATUS.md

@@ -0,0 +1,203 @@
+# Implementation Status
+
+## Overview
+This document tracks the implementation status of all engineering tickets from the ISO-20022 Combo Flow Engineering Ticket Breakdown.
+
+---
+
+## ✅ Completed (10 tickets)
+
+### Frontend (7 tickets) - **100% Complete**
+
+#### FE-001: Builder UI - Drag & Drop Canvas ✅
+- **Status**: ✅ Completed
+- **File**: `webapp/src/components/builder/Canvas.tsx`
+- **Features Implemented**:
+  - Drag-and-drop from palette to canvas
+  - Step reordering via drag handle
+  - Step cards with numbers, icons, summaries
+  - Drop zone highlighting
+  - Visual feedback during drag
+  - Edit/Remove buttons
+  - Step dependency visualization (connection lines)
+  - Responsive design
+
+#### FE-002: Builder UI - Adapter Palette ✅
+- **Status**: ✅ Completed
+- **File**: `webapp/src/components/builder/StepPalette.tsx`
+- **Features Implemented**:
+  - Adapters grouped by type (DeFi, Fiat/DTL)
+  - Filter options: All, DeFi, Fiat/DTL, Whitelisted Only
+  - Search functionality
+  - Adapter status indicators (Approved, Deprecated, Restricted)
+  - Draggable adapters
+  - API integration with fallback to default steps
+
+#### FE-003: Builder UI - Step Configuration Drawer ✅
+- **Status**: ✅ Completed
+- **File**: `webapp/src/components/builder/StepConfigDrawer.tsx`
+- **Features Implemented**:
+  - Slide-up drawer (mobile/desktop responsive)
+  - Step-specific fields for all step types
+  - Compliance fields auto-populated from session
+  - Real-time validation
+  - Dependency visualization (shows previous step output)
+  - Compliance requirements display (LEI/KYC/AML)
+
+#### FE-004: Builder UI - Compliance Status Dashboard ✅
+- **Status**: ✅ Completed
+- **File**: `webapp/src/components/compliance/ComplianceDashboard.tsx`
+- **Features Implemented**:
+  - Compact badge view in header
+  - Expandable overlay with full details
+  - Workflow-specific compliance validation
+  - LEI/DID/KYC/AML status display
+  - Expiration warnings
+  - Quick links to update identity
+
+#### FE-005: Builder UI - Optional Simulation Panel ✅
+- **Status**: ✅ Completed
+- **File**: `webapp/src/components/simulation/SimulationPanel.tsx`
+- **Features Implemented**:
+  - Optional simulation toggle
+  - Simulation options (gas, slippage, liquidity)
+  - Step-by-step results display
+  - Gas estimate and cost
+  - Slippage analysis
+  - Liquidity checks
+  - Warnings and errors display
+  - "Run Again" and "Proceed to Sign" buttons
+
+#### FE-006: Preview Page - Plan Summary & Signing ✅
+- **Status**: ✅ Completed
+- **File**: `webapp/src/app/builder/preview/page.tsx`
+- **Features Implemented**:
+  - Complete plan summary display
+  - Compliance status section
+  - Optional simulation toggle
+  - Signature panel integration
+  - Create Plan and Execute buttons
+  - Error banners
+  - Simulation panel integration
+
+#### FE-007: Execution Timeline - Real-Time Updates ✅
+- **Status**: ✅ Completed (already implemented, terminal states fixed)
+- **File**: `webapp/src/components/plan/ExecutionTimeline.tsx`
+- **Features Implemented**:
+  - Real-time status updates via SSE (with feature flag)
+  - Fallback to polling
+  - Phase progression visualization
+  - Terminal states handled correctly (complete, failed, aborted)
+  - DLT transaction hash and ISO message ID display
+  - Error messages
+
+---
+
+### Backend API Mock Endpoints (3 tickets) - **Partial Implementation**
+
+#### BE-003: Simulation Engine API ✅
+- **Status**: ✅ Mock API Endpoint Created
+- **File**: `webapp/src/app/api/plans/[planId]/simulate/route.ts`
+- **Features Implemented**:
+  - POST endpoint for simulation
+  - Mock simulation results with gas, slippage, liquidity
+  - Step-by-step results
+  - Warnings and errors
+
+#### BE-004: Compliance Engine API ✅
+- **Status**: ✅ Mock API Endpoints Created
+- **Files**: 
+  - `webapp/src/app/api/compliance/status/route.ts`
+  - `webapp/src/app/api/compliance/check/route.ts`
+- **Features Implemented**:
+  - GET /api/compliance/status
+  - POST /api/compliance/check
+  - Mock compliance validation
+
+#### BE-005: Adapter Registry API ✅
+- **Status**: ✅ Mock API Endpoint Created
+- **Files**:
+  - `webapp/src/app/api/adapters/route.ts`
+  - `webapp/src/app/api/connectors/route.ts`
+- **Features Implemented**:
+  - GET /api/adapters (returns adapter list)
+  - GET /api/connectors (returns connector status)
+  - Mock adapter data with filtering support
+
+---
+
+## ⏳ Pending (18 tickets)
+
+### Backend Services (8 tickets)
+- **BE-001**: Orchestrator API - Plan Management (requires orchestrator service)
+- **BE-002**: Orchestrator API - Execution Coordination (requires orchestrator service)
+- **BE-006**: Server-Sent Events (SSE) (requires orchestrator service)
+- **BE-007**: DLT Handler Service (requires orchestrator service + smart contracts)
+- **BE-008**: Bank Connector Service (requires orchestrator service + bank integrations)
+- **BE-009**: ISO-20022 Message Generation (requires orchestrator service)
+- **BE-010**: Notary Service Integration (requires orchestrator service + smart contracts)
+- **BE-011**: Receipt Generation Service (requires orchestrator service)
+
+**Note**: These require a separate orchestrator backend service to be set up. Mock endpoints have been created where possible.
+
+### Smart Contracts (4 tickets)
+- **SC-001**: Handler/Aggregator Contract (requires contracts directory setup)
+- **SC-002**: Notary Registry Contract (requires contracts directory setup)
+- **SC-003**: Adapter Registry Contract (requires contracts directory setup)
+- **SC-004**: Adapter Interface & Example Adapters (requires contracts directory setup)
+
+**Note**: Smart contracts require Hardhat/Foundry setup and contract deployment infrastructure.
+
+### Integration (2 tickets)
+- **INT-001**: Bank Connector Integration (requires orchestrator service + bank APIs)
+- **INT-002**: Compliance Provider Integration (requires orchestrator service + KYC/AML providers)
+
+**Note**: These require external service integrations and orchestrator backend.
+
+### Testing (3 tickets)
+- **TEST-001**: E2E Tests - Builder Flow (can be implemented now)
+- **TEST-002**: E2E Tests - Failure Scenarios (can be implemented now)
+- **TEST-003**: Smart Contract Tests (requires contracts directory)
+
+---
+
+## Summary
+
+### Completion Status
+- **Frontend**: 7/7 tickets (100%) ✅
+- **Backend APIs (Mock)**: 3/11 tickets (27%) - Mock endpoints created
+- **Smart Contracts**: 0/4 tickets (0%) - Requires infrastructure setup
+- **Integration**: 0/2 tickets (0%) - Requires orchestrator service
+- **Testing**: 0/3 tickets (0%) - Can be started for frontend
+
+### Total Progress
+- **Completed**: 10/28 tickets (36%)
+- **Pending**: 18/28 tickets (64%)
+
+---
+
+## Next Steps
+
+### Immediate (Can be done now)
+1. **TEST-001**: Implement E2E tests for builder flow
+2. **TEST-002**: Implement E2E tests for failure scenarios
+3. Enhance existing components based on user feedback
+
+### Requires Infrastructure Setup
+1. **Set up Orchestrator Service**: Create separate backend service for plan management, execution coordination
+2. **Set up Smart Contracts**: Initialize Hardhat/Foundry project, deploy contracts
+3. **Set up Database**: Database for plan storage, audit logs
+4. **Set up External Integrations**: Bank APIs, KYC/AML providers
+
+### Architecture Decisions Needed
+1. **Orchestrator Service**: Choose framework (Express, FastAPI, NestJS)
+2. **Database**: Choose database (PostgreSQL, MongoDB)
+3. **Message Queue**: For async execution coordination (RabbitMQ, Redis)
+4. **Deployment**: Choose deployment platform (Docker, Kubernetes, Cloud)
+
+---
+
+**Document Version**: 1.0  
+**Last Updated**: 2025-01-15  
+**Status**: Frontend Complete ✅ | Backend Pending ⏳
+

docs/ISO_Message_Samples.md

@@ -0,0 +1,596 @@
+# ISO-20022 Message Samples
+
+## Overview
+This document provides sample ISO-20022 message snippets (pacs.008, camt.052/053, camt.056) showing how plan metadata, digital signatures, and compliance attributes (LEI, DID, KYC, AML) are embedded in ISO messages for the Combo Flow system.
+
+---
+
+## 1. pacs.008 - Payment Instruction (with Plan ID and Signature)
+
+### Complete Example
+
+```xml
+<?xml version="1.0" encoding="UTF-8"?>
+<Document xmlns="urn:iso:std:iso:20022:tech:xsd:pacs.008.001.10"
+          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+  <FIToFICstmrCdtTrf>
+    <!-- Group Header -->
+    <GrpHdr>
+      <MsgId>MSG-2025-01-15-001234</MsgId>
+      <CreDtTm>2025-01-15T10:30:00.000Z</CreDtTm>
+      <NbOfTxs>1</NbOfTxs>
+      <CtrlSum>78000.00</CtrlSum>
+      <InitgPty>
+        <Nm>Example Corp Ltd.</Nm>
+        <Id>
+          <OrgId>
+            <Othr>
+              <Id>5493000IBP32UQZ0KL24</Id>
+              <SchmeNm>
+                <Cd>LEI</Cd>
+              </SchmeNm>
+            </Othr>
+          </OrgId>
+        </Id>
+        <CtctDtls>
+          <Email>compliance@example.com</Email>
+          <PhneNb>+49-30-12345678</PhneNb>
+        </CtctDtls>
+      </InitgPty>
+    </GrpHdr>
+
+    <!-- Credit Transfer Transaction Information -->
+    <CdtTrfTxInf>
+      <!-- Payment Identification -->
+      <PmtId>
+        <EndToEndId>PLAN-12345678-ABCD-EFGH-IJKL</EndToEndId>
+        <TxId>TX-2025-01-15-001234</TxId>
+        <UETR>550e8400-e29b-41d4-a716-446655440000</UETR>
+      </PmtId>
+
+      <!-- Payment Type Information -->
+      <PmtTpInf>
+        <SvcLvl>
+          <Cd>SEPA</Cd>
+        </SvcLvl>
+        <LclInstrm>
+          <Cd>INST</Cd>
+        </LclInstrm>
+        <CtgyPurp>
+          <Cd>SUPP</Cd>
+        </CtgyPurp>
+      </PmtTpInf>
+
+      <!-- Interbank Settlement Amount -->
+      <IntrBkSttlmAmt Ccy="EUR">78000.00</IntrBkSttlmAmt>
+
+      <!-- Instructing Agent -->
+      <InstgAgt>
+        <FinInstnId>
+          <BICFI>BANKDEFFXXX</BICFI>
+          <Nm>Example Bank AG</Nm>
+        </FinInstnId>
+      </InstgAgt>
+
+      <!-- Instructed Agent -->
+      <InstdAgt>
+        <FinInstnId>
+          <BICFI>BENEFRPPXXX</BICFI>
+          <Nm>Beneficiary Bank</Nm>
+        </FinInstnId>
+      </InstdAgt>
+
+      <!-- Debtor -->
+      <Dbtr>
+        <Nm>Example Corp Ltd.</Nm>
+        <PstlAdr>
+          <StrtNm>Main Street</StrtNm>
+          <BldgNb>123</BldgNb>
+          <PstCd>10115</PstCd>
+          <TwnNm>Berlin</TwnNm>
+          <Ctry>DE</Ctry>
+        </PstlAdr>
+        <Id>
+          <OrgId>
+            <Othr>
+              <Id>5493000IBP32UQZ0KL24</Id>
+              <SchmeNm>
+                <Cd>LEI</Cd>
+              </SchmeNm>
+            </Othr>
+          </OrgId>
+        </Id>
+        <CtctDtls>
+          <Email>compliance@example.com</Email>
+        </CtctDtls>
+      </Dbtr>
+
+      <!-- Debtor Account -->
+      <DbtrAcct>
+        <Id>
+          <IBAN>DE89370400440532013000</IBAN>
+        </Id>
+        <Tp>
+          <Cd>CACC</Cd>
+        </Tp>
+      </DbtrAcct>
+
+      <!-- Debtor Agent -->
+      <DbtrAgt>
+        <FinInstnId>
+          <BICFI>BANKDEFFXXX</BICFI>
+        </FinInstnId>
+      </DbtrAgt>
+
+      <!-- Creditor -->
+      <Cdtr>
+        <Nm>Beneficiary Corp</Nm>
+        <PstlAdr>
+          <StrtNm>Beneficiary Street</StrtNm>
+          <BldgNb>456</BldgNb>
+          <PstCd>20095</PstCd>
+          <TwnNm>Hamburg</TwnNm>
+          <Ctry>DE</Ctry>
+        </PstlAdr>
+      </Cdtr>
+
+      <!-- Creditor Account -->
+      <CdtrAcct>
+        <Id>
+          <IBAN>DE89370400440532013001</IBAN>
+        </Id>
+        <Tp>
+          <Cd>CACC</Cd>
+        </Tp>
+      </CdtrAcct>
+
+      <!-- Creditor Agent -->
+      <CdtrAgt>
+        <FinInstnId>
+          <BICFI>BENEFRPPXXX</BICFI>
+        </FinInstnId>
+      </CdtrAgt>
+
+      <!-- Remittance Information -->
+      <RmtInf>
+        <Ustrd>Plan ID: PLAN-12345678-ABCD-EFGH-IJKL | Combo Flow Execution</Ustrd>
+        <Strd>
+          <RfrdDocInf>
+            <Tp>
+              <CdOrPrtry>
+                <Cd>CINV</Cd>
+              </CdOrPrtry>
+            </Tp>
+            <Nb>PLAN-12345678-ABCD-EFGH-IJKL</Nb>
+            <RltdDt>2025-01-15</RltdDt>
+          </RfrdDocInf>
+          <RfrdDocAmt>
+            <DuePyblAmt Ccy="EUR">78000.00</DuePyblAmt>
+          </RfrdDocAmt>
+          <RfrdDocRltdInf>
+            <RfrdDocTp>
+              <CdOrPrtry>
+                <Cd>PUOR</Cd>
+              </CdOrPrtry>
+            </RfrdDocTp>
+            <RfrdDocRef>DLT-TX-0x1234567890abcdef1234567890abcdef12345678</RfrdDocRef>
+          </RfrdDocRltdInf>
+        </Strd>
+      </RmtInf>
+
+      <!-- Supplementary Data (Compliance & Plan Metadata) -->
+      <SplmtryData>
+        <PlcAndNm>ComboFlowComplianceData</PlcAndNm>
+        <Envlp>
+          <ComboFlowData xmlns="urn:example:comboflow:xsd:1.0">
+            <!-- Plan Identification -->
+            <PlanId>PLAN-12345678-ABCD-EFGH-IJKL</PlanId>
+            <PlanHash>0xabcdef1234567890abcdef1234567890abcdef1234567890abcdef1234567890</PlanHash>
+            <ExecutionId>EXEC-2025-01-15-001234</ExecutionId>
+
+            <!-- Compliance Attributes -->
+            <Compliance>
+              <LEI>5493000IBP32UQZ0KL24</LEI>
+              <DID>did:web:example.com:user:123</DID>
+              <KYC>
+                <Level>2</Level>
+                <Provider>Onfido</Provider>
+                <Verified>true</Verified>
+                <VerifiedAt>2025-01-10T08:00:00Z</VerifiedAt>
+                <ExpiresAt>2026-12-31T23:59:59Z</ExpiresAt>
+              </KYC>
+              <AML>
+                <Passed>true</Passed>
+                <Provider>Chainalysis</Provider>
+                <LastCheck>2025-01-15T09:00:00Z</LastCheck>
+                <RiskLevel>LOW</RiskLevel>
+                <ScreeningReference>AML-REF-2025-01-15-001</ScreeningReference>
+              </AML>
+            </Compliance>
+
+            <!-- Digital Signature -->
+            <DigitalSignature>
+              <Algorithm>ECDSA</Algorithm>
+              <Curve>secp256k1</Curve>
+              <HashAlgorithm>SHA-256</HashAlgorithm>
+              <SignerAddress>0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb</SignerAddress>
+              <SignatureValue>0x1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef</SignatureValue>
+              <SignedAt>2025-01-15T10:25:00Z</SignedAt>
+            </DigitalSignature>
+
+            <!-- DLT Transaction Reference -->
+            <DLTReference>
+              <ChainId>1</ChainId>
+              <Network>Ethereum Mainnet</Network>
+              <TransactionHash>0x1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef</TransactionHash>
+              <BlockNumber>18500000</BlockNumber>
+              <BlockTimestamp>2025-01-15T10:29:45Z</BlockTimestamp>
+            </DLTReference>
+
+            <!-- Notary Proof -->
+            <NotaryProof>
+              <ProofHash>0xfedcba0987654321fedcba0987654321fedcba0987654321fedcba0987654321</ProofHash>
+              <NotaryAddress>0xNotaryRegistryContractAddress</NotaryAddress>
+              <NotarizedAt>2025-01-15T10:28:00Z</NotarizedAt>
+            </NotaryProof>
+
+            <!-- Workflow Steps Summary -->
+            <WorkflowSteps>
+              <Step index="1" type="borrow" asset="CBDC_USD" amount="100000" />
+              <Step index="2" type="swap" from="CBDC_USD" to="CBDC_EUR" amount="100000" />
+              <Step index="3" type="repay" asset="CBDC_USD" amount="20000" />
+              <Step index="4" type="pay" asset="EUR" amount="78000" />
+            </WorkflowSteps>
+          </ComboFlowData>
+        </Envlp>
+      </SplmtryData>
+    </CdtTrfTxInf>
+  </FIToFICstmrCdtTrf>
+</Document>
+```
+
+### Key Elements
+
+1. **Plan ID in `EndToEndId`**: `PLAN-12345678-ABCD-EFGH-IJKL`
+2. **LEI in `InitgPty.Id`** and **`Dbtr.Id`**: `5493000IBP32UQZ0KL24`
+3. **DLT Reference in `RmtInf`**: DLT transaction hash
+4. **Compliance Data in `SplmtryData`**: Full compliance attributes (LEI, DID, KYC, AML)
+5. **Digital Signature in `SplmtryData`**: User's wallet signature
+6. **Notary Proof in `SplmtryData`**: Notary registry proof hash
+
+---
+
+## 2. camt.052 - Bank Statement (for Reconciliation)
+
+### Example
+
+```xml
+<?xml version="1.0" encoding="UTF-8"?>
+<Document xmlns="urn:iso:std:iso:20022:tech:xsd:camt.052.001.11">
+  <BkToCstmrStmt>
+    <GrpHdr>
+      <MsgId>STMT-2025-01-15-001</MsgId>
+      <CreDtTm>2025-01-15T11:00:00Z</CreDtTm>
+      <MsgRcpt>
+        <Nm>Example Corp Ltd.</Nm>
+        <Id>
+          <OrgId>
+            <Othr>
+              <Id>5493000IBP32UQZ0KL24</Id>
+              <SchmeNm>
+                <Cd>LEI</Cd>
+              </SchmeNm>
+            </Othr>
+          </OrgId>
+        </Id>
+      </MsgRcpt>
+    </GrpHdr>
+    <Stmt>
+      <Id>STMT-2025-01-15-001</Id>
+      <CreDtTm>2025-01-15T11:00:00Z</CreDtTm>
+      <Acct>
+        <Id>
+          <IBAN>DE89370400440532013000</IBAN>
+        </Id>
+        <Tp>
+          <Cd>CACC</Cd>
+        </Tp>
+        <Ccy>EUR</Ccy>
+      </Acct>
+      <Bal>
+        <Tp>
+          <CdOrPrtry>
+            <Cd>OPBD</Cd>
+          </CdOrPrtry>
+        </Tp>
+        <Amt Ccy="EUR">100000.00</Amt>
+        <Dt>
+          <Dt>2025-01-15</Dt>
+        </Dt>
+      </Bal>
+      <Ntry>
+        <Amt Ccy="EUR">-78000.00</Amt>
+        <CdtDbtInd>DBIT</CdtDbtInd>
+        <Sts>BOOK</Sts>
+        <BookgDt>
+          <Dt>2025-01-15</Dt>
+        </BookgDt>
+        <ValDt>
+          <Dt>2025-01-15</Dt>
+        </ValDt>
+        <AcctSvcrRef>TX-2025-01-15-001234</AcctSvcrRef>
+        <BkTxCd>
+          <Domn>
+            <Cd>PMNT</Cd>
+            <Fmly>
+              <Cd>ICDT</Cd>
+              <SubFmlyCd>ESCT</SubFmlyCd>
+            </Fmly>
+          </Domn>
+        </BkTxCd>
+        <NtryDtls>
+          <TxDtls>
+            <Refs>
+              <EndToEndId>PLAN-12345678-ABCD-EFGH-IJKL</EndToEndId>
+              <TxId>TX-2025-01-15-001234</TxId>
+            </Refs>
+            <RmtInf>
+              <Ustrd>Plan ID: PLAN-12345678-ABCD-EFGH-IJKL</Ustrd>
+            </RmtInf>
+            <RltdPties>
+              <Cdtr>
+                <Nm>Beneficiary Corp</Nm>
+              </Cdtr>
+            </RltdPties>
+          </TxDtls>
+        </NtryDtls>
+      </Ntry>
+      <Bal>
+        <Tp>
+          <CdOrPrtry>
+            <Cd>CLBD</Cd>
+          </CdOrPrtry>
+        </Tp>
+        <Amt Ccy="EUR">22000.00</Amt>
+        <Dt>
+          <Dt>2025-01-15</Dt>
+        </Dt>
+      </Bal>
+    </Stmt>
+  </BkToCstmrStmt>
+</Document>
+```
+
+### Key Elements
+
+1. **Plan ID in `EndToEndId`**: Links statement entry to execution plan
+2. **LEI in `MsgRcpt.Id`**: Account holder's LEI
+3. **Transaction Reference**: Links to original payment instruction
+
+---
+
+## 3. camt.053 - Account Statement (Detailed)
+
+### Example
+
+```xml
+<?xml version="1.0" encoding="UTF-8"?>
+<Document xmlns="urn:iso:std:iso:20022:tech:xsd:camt.053.001.10">
+  <BkToCstmrStmt>
+    <GrpHdr>
+      <MsgId>STMT-DETAIL-2025-01-15-001</MsgId>
+      <CreDtTm>2025-01-15T11:00:00Z</CreDtTm>
+    </GrpHdr>
+    <Stmt>
+      <Id>STMT-DETAIL-2025-01-15-001</Id>
+      <Acct>
+        <Id>
+          <IBAN>DE89370400440532013000</IBAN>
+        </Id>
+      </Acct>
+      <Ntry>
+        <Amt Ccy="EUR">-78000.00</Amt>
+        <CdtDbtInd>DBIT</CdtDbtInd>
+        <Sts>BOOK</Sts>
+        <BookgDt>
+          <Dt>2025-01-15</Dt>
+        </BookgDt>
+        <NtryDtls>
+          <TxDtls>
+            <Refs>
+              <EndToEndId>PLAN-12345678-ABCD-EFGH-IJKL</EndToEndId>
+              <AcctSvcrRef>TX-2025-01-15-001234</AcctSvcrRef>
+            </Refs>
+            <RmtInf>
+              <Ustrd>Plan ID: PLAN-12345678-ABCD-EFGH-IJKL | DLT TX: 0x1234...5678</Ustrd>
+            </RmtInf>
+            <RltdPties>
+              <Dbtr>
+                <Nm>Example Corp Ltd.</Nm>
+                <Id>
+                  <OrgId>
+                    <Othr>
+                      <Id>5493000IBP32UQZ0KL24</Id>
+                      <SchmeNm>
+                        <Cd>LEI</Cd>
+                      </SchmeNm>
+                    </Othr>
+                  </OrgId>
+                </Id>
+              </Dbtr>
+              <Cdtr>
+                <Nm>Beneficiary Corp</Nm>
+              </Cdtr>
+            </RltdPties>
+            <RltdAgts>
+              <DbtrAgt>
+                <FinInstnId>
+                  <BICFI>BANKDEFFXXX</BICFI>
+                </FinInstnId>
+              </DbtrAgt>
+            </RltdAgts>
+          </TxDtls>
+        </NtryDtls>
+      </Ntry>
+    </Stmt>
+  </BkToCstmrStmt>
+</Document>
+```
+
+---
+
+## 4. camt.056 - Cancellation Request (for Rollback)
+
+### Example
+
+```xml
+<?xml version="1.0" encoding="UTF-8"?>
+<Document xmlns="urn:iso:std:iso:20022:tech:xsd:camt.056.001.10">
+  <FIToFIPmtCxlReq>
+    <GrpHdr>
+      <MsgId>CANCEL-2025-01-15-001</MsgId>
+      <CreDtTm>2025-01-15T10:35:00Z</CreDtTm>
+      <InitgPty>
+        <Nm>Example Corp Ltd.</Nm>
+        <Id>
+          <OrgId>
+            <Othr>
+              <Id>5493000IBP32UQZ0KL24</Id>
+              <SchmeNm>
+                <Cd>LEI</Cd>
+              </SchmeNm>
+            </Othr>
+          </OrgId>
+        </Id>
+      </InitgPty>
+    </GrpHdr>
+    <Undrlyg>
+      <TxInf>
+        <CxlId>CANCEL-TX-2025-01-15-001</CxlId>
+        <CxlRsn>
+          <Cd>DUPL</Cd>
+          <AddtlInf>DLT execution failed. Rolling back payment instruction.</AddtlInf>
+        </CxlRsn>
+        <OrgnlGrpInf>
+          <OrgnlMsgId>MSG-2025-01-15-001234</OrgnlMsgId>
+          <OrgnlMsgNmId>pacs.008.001.10</OrgnlMsgNmId>
+          <OrgnlCreDtTm>2025-01-15T10:30:00Z</OrgnlCreDtTm>
+        </OrgnlGrpInf>
+        <OrgnlInstrId>TX-2025-01-15-001234</OrgnlInstrId>
+        <OrgnlEndToEndId>PLAN-12345678-ABCD-EFGH-IJKL</OrgnlEndToEndId>
+        <OrgnlInstdAmt>
+          <Amt Ccy="EUR">78000.00</Amt>
+        </OrgnlInstdAmt>
+        <OrgnlTxRef>
+          <EndToEndId>PLAN-12345678-ABCD-EFGH-IJKL</EndToEndId>
+          <TxId>TX-2025-01-15-001234</TxId>
+        </OrgnlTxRef>
+        <SplmtryData>
+          <PlcAndNm>ComboFlowRollbackData</PlcAndNm>
+          <Envlp>
+            <RollbackData xmlns="urn:example:comboflow:xsd:1.0">
+              <PlanId>PLAN-12345678-ABCD-EFGH-IJKL</PlanId>
+              <RollbackReason>DLT_EXECUTION_FAILED</RollbackReason>
+              <DLTState>ROLLED_BACK</DLTState>
+              <NotaryProof>0xfedcba0987654321...</NotaryProof>
+            </RollbackData>
+          </Envlp>
+        </SplmtryData>
+      </TxInf>
+    </Undrlyg>
+  </FIToFIPmtCxlReq>
+</Document>
+```
+
+### Key Elements
+
+1. **Cancellation Reason**: `DLT execution failed`
+2. **Original Plan ID**: `PLAN-12345678-ABCD-EFGH-IJKL`
+3. **Rollback Data**: DLT state and notary proof in supplementary data
+
+---
+
+## 5. Message Generation Code
+
+### TypeScript Example
+
+```typescript
+import { generateISO20022Message } from '@comboflow/iso20022';
+
+const generatePaymentInstruction = async (
+  plan: Plan,
+  compliance: ComplianceStatus,
+  signature: string,
+  dltTxHash: string,
+  notaryProof: string
+): Promise<string> => {
+  const isoMessage = generateISO20022Message({
+    messageType: 'pacs.008',
+    groupHeader: {
+      messageId: `MSG-${Date.now()}`,
+      creationDateTime: new Date(),
+      initiatingParty: {
+        name: 'Example Corp Ltd.',
+        lei: compliance.lei
+      }
+    },
+    creditTransfer: {
+      paymentId: {
+        endToEndId: plan.planId,
+        transactionId: `TX-${Date.now()}`
+      },
+      amount: {
+        currency: 'EUR',
+        value: 78000.00
+      },
+      debtor: {
+        name: 'Example Corp Ltd.',
+        lei: compliance.lei,
+        account: {
+          iban: 'DE89370400440532013000'
+        }
+      },
+      creditor: {
+        name: 'Beneficiary Corp',
+        account: {
+          iban: 'DE89370400440532013001'
+        }
+      },
+      remittanceInformation: {
+        unstructured: `Plan ID: ${plan.planId} | Combo Flow Execution`
+      },
+      supplementaryData: {
+        planId: plan.planId,
+        planHash: plan.planHash,
+        compliance: {
+          lei: compliance.lei,
+          did: compliance.did,
+          kyc: compliance.kyc,
+          aml: compliance.aml
+        },
+        digitalSignature: {
+          algorithm: 'ECDSA',
+          signerAddress: plan.signerAddress,
+          signatureValue: signature
+        },
+        dltReference: {
+          chainId: 1,
+          transactionHash: dltTxHash
+        },
+        notaryProof: {
+          proofHash: notaryProof
+        }
+      }
+    }
+  });
+
+  return isoMessage;
+};
+```
+
+---
+
+**Document Version**: 1.0  
+**Last Updated**: 2025-01-15  
+**Author**: Integration Team
+

docs/Simulation_Engine_Spec.md

@@ -0,0 +1,685 @@
+# Simulation Engine Specification
+
+## Overview
+This document specifies the optional simulation engine for the ISO-20022 Combo Flow system. The simulation engine provides dry-run execution logic, gas estimation, slippage calculation, liquidity checks, failure prediction, and result presentation. It is toggleable for advanced users per requirement 2b.
+
+---
+
+## 1. Simulation Engine Architecture
+
+### High-Level Design
+```
+┌─────────────────────────────────────────────────────────────┐
+│                    Combo Builder UI                         │
+│              [Simulation Toggle: ON/OFF]                    │
+└────────────────────────┬────────────────────────────────────┘
+                         │
+                         ▼
+┌─────────────────────────────────────────────────────────────┐
+│              Simulation Engine API                           │
+│  POST /api/plans/{planId}/simulate                          │
+└──────────────┬──────────────────────────────┬───────────────┘
+               │                              │
+               ▼                              ▼
+    ┌──────────────────┐          ┌──────────────────┐
+    │  DLT Simulator  │          │  Fiat Simulator  │
+    │                  │          │                  │
+    │ • Gas Estimation│          │ • Bank Routing    │
+    │ • Slippage Calc  │          │ • Fee Calculation│
+    │ • Liquidity Check│          │ • Settlement Time│
+    └──────────────────┘          └──────────────────┘
+               │                              │
+               ▼                              ▼
+    ┌──────────────────┐          ┌──────────────────┐
+    │  Price Oracles   │          │  Bank APIs       │
+    │  (On-Chain)      │          │  (Off-Chain)     │
+    └──────────────────┘          └──────────────────┘
+```
+
+---
+
+## 2. API Specification
+
+### Endpoint: `POST /api/plans/{planId}/simulate`
+
+```typescript
+interface SimulationRequest {
+  planId: string;
+  options?: {
+    includeGasEstimate?: boolean;      // Default: true
+    includeSlippageAnalysis?: boolean; // Default: true
+    includeLiquidityCheck?: boolean;    // Default: true
+    includeBankRouting?: boolean;       // Default: true (for fiat steps)
+    chainId?: number;                   // Default: current chain
+  };
+}
+
+interface SimulationResponse {
+  planId: string;
+  status: 'SUCCESS' | 'FAILURE' | 'PARTIAL';
+  steps: SimulationStepResult[];
+  summary: {
+    gasEstimate: number;
+    estimatedCost: number; // USD
+    totalSlippage: number; // Percentage
+    executionTime: number;  // Seconds
+  };
+  slippageAnalysis: SlippageAnalysis;
+  liquidityCheck: LiquidityCheck;
+  warnings: string[];
+  errors: string[];
+  timestamp: string;
+}
+```
+
+### Response Structure
+
+```typescript
+interface SimulationStepResult {
+  stepIndex: number;
+  stepType: 'borrow' | 'swap' | 'repay' | 'pay';
+  status: 'SUCCESS' | 'FAILURE' | 'WARNING';
+  message: string;
+  estimatedOutput?: {
+    token: string;
+    amount: number;
+  };
+  gasEstimate?: number;
+  slippage?: number;
+  liquidityStatus?: 'SUFFICIENT' | 'INSUFFICIENT' | 'LOW';
+  bankRouting?: {
+    estimatedTime: number; // Minutes
+    fee: number;
+    currency: string;
+  };
+}
+
+interface SlippageAnalysis {
+  expectedSlippage: number;      // Percentage
+  riskLevel: 'LOW' | 'MEDIUM' | 'HIGH';
+  liquidityDepth: number;         // Total liquidity in pool
+  priceImpact: number;            // Percentage
+  warnings: string[];
+}
+
+interface LiquidityCheck {
+  sufficient: boolean;
+  poolDepth: number;
+  requiredAmount: number;
+  availableAmount: number;
+  warnings: string[];
+}
+```
+
+---
+
+## 3. Dry-Run Execution Logic
+
+### Step-by-Step Simulation
+
+```typescript
+class SimulationEngine {
+  async simulatePlan(plan: Plan, options: SimulationOptions): Promise<SimulationResponse> {
+    const results: SimulationStepResult[] = [];
+    let cumulativeGas = 0;
+    let totalSlippage = 0;
+    const warnings: string[] = [];
+    const errors: string[] = [];
+
+    // Simulate each step sequentially
+    for (let i = 0; i < plan.steps.length; i++) {
+      const step = plan.steps[i];
+      const stepResult = await this.simulateStep(step, i, plan, options);
+      
+      results.push(stepResult);
+      
+      if (stepResult.status === 'FAILURE') {
+        errors.push(`Step ${i + 1} failed: ${stepResult.message}`);
+        return {
+          status: 'FAILURE',
+          steps: results,
+          errors,
+          warnings
+        };
+      }
+
+      if (stepResult.status === 'WARNING') {
+        warnings.push(`Step ${i + 1}: ${stepResult.message}`);
+      }
+
+      cumulativeGas += stepResult.gasEstimate || 0;
+      totalSlippage += stepResult.slippage || 0;
+    }
+
+    // Aggregate results
+    return {
+      status: 'SUCCESS',
+      steps: results,
+      summary: {
+        gasEstimate: cumulativeGas,
+        estimatedCost: this.calculateCost(cumulativeGas),
+        totalSlippage,
+        executionTime: this.estimateExecutionTime(plan)
+      },
+      slippageAnalysis: this.analyzeSlippage(results),
+      liquidityCheck: this.checkLiquidity(results),
+      warnings,
+      errors: []
+    };
+  }
+
+  async simulateStep(
+    step: PlanStep,
+    index: number,
+    plan: Plan,
+    options: SimulationOptions
+  ): Promise<SimulationStepResult> {
+    switch (step.type) {
+      case 'borrow':
+        return await this.simulateBorrow(step, index);
+      case 'swap':
+        return await this.simulateSwap(step, index, options);
+      case 'repay':
+        return await this.simulateRepay(step, index);
+      case 'pay':
+        return await this.simulatePay(step, index, options);
+      default:
+        return {
+          stepIndex: index,
+          stepType: step.type,
+          status: 'FAILURE',
+          message: 'Unknown step type'
+        };
+    }
+  }
+}
+```
+
+### DeFi Step Simulation
+
+```typescript
+async simulateSwap(
+  step: SwapStep,
+  index: number,
+  options: SimulationOptions
+): Promise<SimulationStepResult> {
+  // 1. Get current price from oracle
+  const currentPrice = await this.priceOracle.getPrice(step.from, step.to);
+  
+  // 2. Calculate slippage
+  const slippage = await this.calculateSlippage(step.from, step.to, step.amount);
+  
+  // 3. Check liquidity
+  const liquidity = await this.liquidityChecker.check(step.from, step.to, step.amount);
+  
+  // 4. Estimate gas
+  const gasEstimate = await this.gasEstimator.estimateSwap(step.from, step.to, step.amount);
+  
+  // 5. Calculate expected output
+  const expectedOutput = step.amount * currentPrice * (1 - slippage / 100);
+  
+  // 6. Validate minimum receive
+  if (step.minRecv && expectedOutput < step.minRecv) {
+    return {
+      stepIndex: index,
+      stepType: 'swap',
+      status: 'FAILURE',
+      message: `Expected output ${expectedOutput} is below minimum ${step.minRecv}`,
+      estimatedOutput: { token: step.to, amount: expectedOutput },
+      slippage,
+      liquidityStatus: liquidity.status
+    };
+  }
+
+  return {
+    stepIndex: index,
+    stepType: 'swap',
+    status: liquidity.sufficient ? 'SUCCESS' : 'WARNING',
+    message: liquidity.sufficient ? 'Swap would succeed' : 'Low liquidity warning',
+    estimatedOutput: { token: step.to, amount: expectedOutput },
+    gasEstimate,
+    slippage,
+    liquidityStatus: liquidity.status
+  };
+}
+```
+
+### Fiat Step Simulation
+
+```typescript
+async simulatePay(
+  step: PayStep,
+  index: number,
+  options: SimulationOptions
+): Promise<SimulationStepResult> {
+  // 1. Validate IBAN
+  if (!this.validateIBAN(step.beneficiary.IBAN)) {
+    return {
+      stepIndex: index,
+      stepType: 'pay',
+      status: 'FAILURE',
+      message: 'Invalid IBAN format'
+    };
+  }
+
+  // 2. Get bank routing info
+  const routing = await this.bankRouter.getRouting(step.beneficiary.IBAN, step.asset);
+  
+  // 3. Calculate fees
+  const fee = await this.feeCalculator.calculateFiatFee(step.amount, step.asset, routing);
+  
+  // 4. Estimate settlement time
+  const settlementTime = await this.settlementEstimator.estimate(step.asset, routing);
+
+  return {
+    stepIndex: index,
+    stepType: 'pay',
+    status: 'SUCCESS',
+    message: 'Payment would be processed',
+    bankRouting: {
+      estimatedTime: settlementTime,
+      fee,
+      currency: step.asset
+    }
+  };
+}
+```
+
+---
+
+## 4. Gas Estimation
+
+### Gas Estimation Strategy
+
+```typescript
+class GasEstimator {
+  async estimateSwap(tokenIn: string, tokenOut: string, amount: number): Promise<number> {
+    // Base gas for swap
+    const baseGas = 150000;
+    
+    // Additional gas for complex routing
+    const routingGas = await this.estimateRoutingGas(tokenIn, tokenOut);
+    
+    // Gas for token approvals (if needed)
+    const approvalGas = await this.estimateApprovalGas(tokenIn);
+    
+    return baseGas + routingGas + approvalGas;
+  }
+
+  async estimateBorrow(asset: string, amount: number): Promise<number> {
+    // Base gas for borrow
+    const baseGas = 200000;
+    
+    // Gas for collateral check
+    const collateralGas = 50000;
+    
+    // Gas for LTV calculation
+    const ltvGas = 30000;
+    
+    return baseGas + collateralGas + ltvGas;
+  }
+
+  async estimateFullPlan(plan: Plan): Promise<number> {
+    let totalGas = 21000; // Base transaction gas
+    
+    for (const step of plan.steps) {
+      switch (step.type) {
+        case 'borrow':
+          totalGas += await this.estimateBorrow(step.asset, step.amount);
+          break;
+        case 'swap':
+          totalGas += await this.estimateSwap(step.from, step.to, step.amount);
+          break;
+        case 'repay':
+          totalGas += 100000; // Standard repay gas
+          break;
+      }
+    }
+    
+    // Add handler overhead
+    totalGas += 50000;
+    
+    return totalGas;
+  }
+
+  calculateCost(gas: number, gasPrice: number): number {
+    // gasPrice in gwei, convert to ETH then USD
+    const ethCost = (gas * gasPrice * 1e9) / 1e18;
+    const usdCost = ethCost * await this.getETHPrice();
+    return usdCost;
+  }
+}
+```
+
+---
+
+## 5. Slippage Calculation
+
+### Slippage Calculation Logic
+
+```typescript
+class SlippageCalculator {
+  async calculateSlippage(
+    tokenIn: string,
+    tokenOut: string,
+    amountIn: number
+  ): Promise<number> {
+    // Get current pool reserves
+    const reserves = await this.getPoolReserves(tokenIn, tokenOut);
+    
+    // Calculate price impact using constant product formula (x * y = k)
+    const priceImpact = this.calculatePriceImpact(
+      reserves.tokenIn,
+      reserves.tokenOut,
+      amountIn
+    );
+    
+    // Add fixed fee (e.g., 0.3% for Uniswap)
+    const protocolFee = 0.3;
+    
+    // Total slippage = price impact + protocol fee
+    const totalSlippage = priceImpact + protocolFee;
+    
+    return totalSlippage;
+  }
+
+  calculatePriceImpact(
+    reserveIn: number,
+    reserveOut: number,
+    amountIn: number
+  ): number {
+    // Constant product formula: (x + Δx) * (y - Δy) = x * y
+    // Solving for Δy: Δy = (y * Δx) / (x + Δx)
+    const amountOut = (reserveOut * amountIn) / (reserveIn + amountIn);
+    const priceBefore = reserveOut / reserveIn;
+    const priceAfter = (reserveOut - amountOut) / (reserveIn + amountIn);
+    const priceImpact = ((priceBefore - priceAfter) / priceBefore) * 100;
+    
+    return priceImpact;
+  }
+
+  analyzeSlippage(results: SimulationStepResult[]): SlippageAnalysis {
+    const swapSteps = results.filter(r => r.stepType === 'swap');
+    const totalSlippage = swapSteps.reduce((sum, r) => sum + (r.slippage || 0), 0);
+    const avgSlippage = totalSlippage / swapSteps.length;
+    
+    let riskLevel: 'LOW' | 'MEDIUM' | 'HIGH';
+    if (avgSlippage < 0.5) {
+      riskLevel = 'LOW';
+    } else if (avgSlippage < 2.0) {
+      riskLevel = 'MEDIUM';
+    } else {
+      riskLevel = 'HIGH';
+    }
+
+    const warnings: string[] = [];
+    if (avgSlippage > 1.0) {
+      warnings.push(`High slippage expected: ${avgSlippage.toFixed(2)}%`);
+    }
+
+    return {
+      expectedSlippage: avgSlippage,
+      riskLevel,
+      liquidityDepth: 0, // Aggregate from steps
+      priceImpact: avgSlippage,
+      warnings
+    };
+  }
+}
+```
+
+---
+
+## 6. Liquidity Checks
+
+### Liquidity Check Logic
+
+```typescript
+class LiquidityChecker {
+  async check(
+    tokenIn: string,
+    tokenOut: string,
+    amountIn: number
+  ): Promise<LiquidityCheck> {
+    // Get pool liquidity
+    const pool = await this.getPool(tokenIn, tokenOut);
+    const availableLiquidity = pool.reserveOut;
+    
+    // Calculate required output
+    const price = await this.getPrice(tokenIn, tokenOut);
+    const requiredOutput = amountIn * price;
+    
+    // Check if sufficient
+    const sufficient = availableLiquidity >= requiredOutput * 1.1; // 10% buffer
+    
+    const warnings: string[] = [];
+    if (!sufficient) {
+      warnings.push(`Insufficient liquidity: need ${requiredOutput}, have ${availableLiquidity}`);
+    } else if (availableLiquidity < requiredOutput * 1.5) {
+      warnings.push(`Low liquidity: ${((availableLiquidity / requiredOutput) * 100).toFixed(1)}% buffer`);
+    }
+
+    return {
+      sufficient,
+      poolDepth: availableLiquidity,
+      requiredAmount: requiredOutput,
+      availableAmount: availableLiquidity,
+      warnings
+    };
+  }
+}
+```
+
+---
+
+## 7. Failure Prediction
+
+### Failure Prediction Logic
+
+```typescript
+class FailurePredictor {
+  async predictFailures(plan: Plan): Promise<string[]> {
+    const failures: string[] = [];
+
+    // Check step dependencies
+    for (let i = 0; i < plan.steps.length; i++) {
+      const step = plan.steps[i];
+      
+      // Check if previous step outputs are sufficient
+      if (i > 0) {
+        const prevStep = plan.steps[i - 1];
+        const prevOutput = await this.getStepOutput(prevStep);
+        
+        if (step.type === 'swap' && step.amount > prevOutput.amount) {
+          failures.push(`Step ${i + 1}: Insufficient input from previous step`);
+        }
+      }
+
+      // Check step-specific validations
+      if (step.type === 'borrow') {
+        const canBorrow = await this.checkBorrowCapacity(step.asset, step.amount);
+        if (!canBorrow) {
+          failures.push(`Step ${i + 1}: Cannot borrow ${step.amount} ${step.asset}`);
+        }
+      }
+
+      if (step.type === 'pay') {
+        const isValidIBAN = this.validateIBAN(step.beneficiary.IBAN);
+        if (!isValidIBAN) {
+          failures.push(`Step ${i + 1}: Invalid IBAN`);
+        }
+      }
+    }
+
+    // Check recursion depth
+    const borrowCount = plan.steps.filter(s => s.type === 'borrow').length;
+    if (borrowCount - 1 > plan.maxRecursion) {
+      failures.push(`Recursion depth ${borrowCount - 1} exceeds maximum ${plan.maxRecursion}`);
+    }
+
+    // Check LTV
+    const totalBorrowed = plan.steps
+      .filter(s => s.type === 'borrow')
+      .reduce((sum, s) => sum + (s as BorrowStep).amount, 0);
+    const totalCollateral = await this.getTotalCollateral();
+    const ltv = totalBorrowed / totalCollateral;
+    
+    if (ltv > plan.maxLTV) {
+      failures.push(`LTV ${ltv} exceeds maximum ${plan.maxLTV}`);
+    }
+
+    return failures;
+  }
+}
+```
+
+---
+
+## 8. Result Presentation Format
+
+### UI Presentation
+
+```typescript
+// Simulation Results Component
+const SimulationResults = ({ results }: { results: SimulationResponse }) => {
+  return (
+    <div className="simulation-results">
+      <h2>Simulation Results</h2>
+      
+      {/* Status */}
+      <StatusBadge status={results.status} />
+      
+      {/* Summary */}
+      <div className="summary">
+        <div>Gas Estimate: {results.summary.gasEstimate.toLocaleString()}</div>
+        <div>Estimated Cost: ${results.summary.estimatedCost.toFixed(2)}</div>
+        <div>Total Slippage: {results.summary.totalSlippage.toFixed(2)}%</div>
+        <div>Execution Time: ~{results.summary.executionTime}s</div>
+      </div>
+
+      {/* Step-by-Step Results */}
+      <div className="steps">
+        {results.steps.map((step, i) => (
+          <StepResultCard key={i} step={step} />
+        ))}
+      </div>
+
+      {/* Warnings */}
+      {results.warnings.length > 0 && (
+        <WarningPanel warnings={results.warnings} />
+      )}
+
+      {/* Errors */}
+      {results.errors.length > 0 && (
+        <ErrorPanel errors={results.errors} />
+      )}
+
+      {/* Actions */}
+      <div className="actions">
+        <Button onClick={onRunAgain}>Run Simulation Again</Button>
+        <Button onClick={onProceed} disabled={results.status === 'FAILURE'}>
+          Proceed to Sign
+        </Button>
+      </div>
+    </div>
+  );
+};
+```
+
+---
+
+## 9. Optional Toggle Implementation
+
+### Frontend Toggle
+
+```typescript
+// Builder UI with optional simulation toggle
+const BuilderPage = () => {
+  const [simulationEnabled, setSimulationEnabled] = useState(false);
+
+  return (
+    <div>
+      {/* Summary Panel */}
+      <SummaryPanel>
+        <Checkbox
+          checked={simulationEnabled}
+          onChange={(e) => setSimulationEnabled(e.target.checked)}
+          label="Enable Simulation (Advanced)"
+        />
+        
+        {simulationEnabled && (
+          <Button onClick={handleSimulate}>Simulate</Button>
+        )}
+      </SummaryPanel>
+    </div>
+  );
+};
+```
+
+### Backend Handling
+
+```typescript
+// Backend respects simulation toggle
+if (simulationEnabled && user.isAdvanced) {
+  // Show simulation button
+  // Allow simulation requests
+} else {
+  // Hide simulation button
+  // Simulation still available via API for advanced users
+}
+```
+
+---
+
+## 10. Performance Requirements
+
+### Response Time
+- **Simulation Time**: < 5 seconds for typical workflows
+- **Gas Estimation**: < 1 second per step
+- **Slippage Calculation**: < 500ms per swap
+- **Liquidity Check**: < 1 second per check
+
+### Caching
+- Cache price oracle data for 30 seconds
+- Cache liquidity data for 10 seconds
+- Cache gas estimates for 60 seconds
+
+---
+
+## 11. Testing Requirements
+
+### Unit Tests
+
+```typescript
+describe('SimulationEngine', () => {
+  it('should simulate swap step', async () => {
+    const result = await engine.simulateStep(swapStep, 0);
+    expect(result.status).toBe('SUCCESS');
+    expect(result.slippage).toBeLessThan(1.0);
+  });
+
+  it('should predict failures', async () => {
+    const failures = await predictor.predictFailures(invalidPlan);
+    expect(failures.length).toBeGreaterThan(0);
+  });
+});
+```
+
+### Integration Tests
+
+```typescript
+describe('Simulation API', () => {
+  it('should return simulation results', async () => {
+    const response = await api.simulatePlan(planId);
+    expect(response.status).toBe('SUCCESS');
+    expect(response.steps.length).toBe(plan.steps.length);
+  });
+});
+```
+
+---
+
+**Document Version**: 1.0  
+**Last Updated**: 2025-01-15  
+**Author**: Engineering Team
+

docs/Smart_Contract_Interfaces.md

@@ -0,0 +1,759 @@
+# Smart Contract Interface Specifications
+
+## Overview
+This document defines the smart contract interfaces for the ISO-20022 Combo Flow system, including handler contracts for atomic execution, notary registry for codehash tracking, adapter registry for whitelisting, and integration patterns for atomicity (2PC, HTLC, conditional finality).
+
+---
+
+## 1. Handler/Aggregator Contract Interface
+
+### Purpose
+The handler contract aggregates multiple DeFi protocol calls and DLT operations into a single atomic transaction. It executes steps sequentially, passing outputs between steps, and ensures atomicity across the entire workflow.
+
+### Interface: `IComboHandler`
+
+```solidity
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.20;
+
+interface IComboHandler {
+    /**
+     * @notice Execute a multi-step combo plan atomically
+     * @param planId Unique identifier for the execution plan
+     * @param steps Array of step configurations
+     * @param signature User's cryptographic signature on the plan
+     * @return success Whether execution completed successfully
+     * @return receipts Array of transaction receipts for each step
+     */
+    function executeCombo(
+        bytes32 planId,
+        Step[] calldata steps,
+        bytes calldata signature
+    ) external returns (bool success, StepReceipt[] memory receipts);
+
+    /**
+     * @notice Prepare phase for 2PC (two-phase commit)
+     * @param planId Plan identifier
+     * @param steps Execution steps
+     * @return prepared Whether all steps are prepared
+     */
+    function prepare(
+        bytes32 planId,
+        Step[] calldata steps
+    ) external returns (bool prepared);
+
+    /**
+     * @notice Commit phase for 2PC
+     * @param planId Plan identifier
+     * @return committed Whether commit was successful
+     */
+    function commit(bytes32 planId) external returns (bool committed);
+
+    /**
+     * @notice Abort phase for 2PC (rollback)
+     * @param planId Plan identifier
+     */
+    function abort(bytes32 planId) external;
+
+    /**
+     * @notice Get execution status for a plan
+     * @param planId Plan identifier
+     * @return status Execution status (PENDING, IN_PROGRESS, COMPLETE, FAILED, ABORTED)
+     */
+    function getExecutionStatus(bytes32 planId) external view returns (ExecutionStatus status);
+}
+
+struct Step {
+    StepType stepType;
+    bytes data; // Encoded step-specific parameters
+    address target; // Target contract address (adapter or protocol)
+    uint256 value; // ETH value to send (if applicable)
+}
+
+enum StepType {
+    BORROW,
+    SWAP,
+    REPAY,
+    PAY,
+    DEPOSIT,
+    WITHDRAW,
+    BRIDGE
+}
+
+enum ExecutionStatus {
+    PENDING,
+    IN_PROGRESS,
+    COMPLETE,
+    FAILED,
+    ABORTED
+}
+
+struct StepReceipt {
+    uint256 stepIndex;
+    bool success;
+    bytes returnData;
+    uint256 gasUsed;
+}
+```
+
+### Implementation Example: `ComboHandler.sol`
+
+```solidity
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.20;
+
+import "@openzeppelin/contracts/access/Ownable.sol";
+import "@openzeppelin/contracts/security/ReentrancyGuard.sol";
+import "./IComboHandler.sol";
+import "./IAdapterRegistry.sol";
+import "./INotaryRegistry.sol";
+
+contract ComboHandler is IComboHandler, Ownable, ReentrancyGuard {
+    IAdapterRegistry public adapterRegistry;
+    INotaryRegistry public notaryRegistry;
+
+    mapping(bytes32 => ExecutionState) public executions;
+
+    struct ExecutionState {
+        ExecutionStatus status;
+        uint256 currentStep;
+        Step[] steps;
+        bool prepared;
+    }
+
+    constructor(address _adapterRegistry, address _notaryRegistry) {
+        adapterRegistry = IAdapterRegistry(_adapterRegistry);
+        notaryRegistry = INotaryRegistry(_notaryRegistry);
+    }
+
+    function executeCombo(
+        bytes32 planId,
+        Step[] calldata steps,
+        bytes calldata signature
+    ) external override nonReentrant returns (bool success, StepReceipt[] memory receipts) {
+        require(executions[planId].status == ExecutionStatus.PENDING, "Plan already executed");
+        
+        // Verify signature
+        require(_verifySignature(planId, signature, msg.sender), "Invalid signature");
+
+        // Register with notary
+        notaryRegistry.registerPlan(planId, steps, msg.sender);
+
+        executions[planId] = ExecutionState({
+            status: ExecutionStatus.IN_PROGRESS,
+            currentStep: 0,
+            steps: steps,
+            prepared: false
+        });
+
+        receipts = new StepReceipt[](steps.length);
+
+        // Execute steps sequentially
+        for (uint256 i = 0; i < steps.length; i++) {
+            (bool stepSuccess, bytes memory returnData, uint256 gasUsed) = _executeStep(steps[i], i);
+            
+            receipts[i] = StepReceipt({
+                stepIndex: i,
+                success: stepSuccess,
+                returnData: returnData,
+                gasUsed: gasUsed
+            });
+
+            if (!stepSuccess) {
+                executions[planId].status = ExecutionStatus.FAILED;
+                revert("Step execution failed");
+            }
+        }
+
+        executions[planId].status = ExecutionStatus.COMPLETE;
+        success = true;
+
+        // Finalize with notary
+        notaryRegistry.finalizePlan(planId, true);
+    }
+
+    function prepare(
+        bytes32 planId,
+        Step[] calldata steps
+    ) external override returns (bool prepared) {
+        require(executions[planId].status == ExecutionStatus.PENDING, "Plan not pending");
+
+        // Validate all steps can be prepared
+        for (uint256 i = 0; i < steps.length; i++) {
+            require(_canPrepareStep(steps[i]), "Step cannot be prepared");
+        }
+
+        executions[planId] = ExecutionState({
+            status: ExecutionStatus.IN_PROGRESS,
+            currentStep: 0,
+            steps: steps,
+            prepared: true
+        });
+
+        prepared = true;
+    }
+
+    function commit(bytes32 planId) external override returns (bool committed) {
+        ExecutionState storage state = executions[planId];
+        require(state.prepared, "Plan not prepared");
+        require(state.status == ExecutionStatus.IN_PROGRESS, "Invalid state");
+
+        // Execute all prepared steps
+        for (uint256 i = 0; i < state.steps.length; i++) {
+            (bool success, , ) = _executeStep(state.steps[i], i);
+            require(success, "Commit failed");
+        }
+
+        state.status = ExecutionStatus.COMPLETE;
+        committed = true;
+
+        notaryRegistry.finalizePlan(planId, true);
+    }
+
+    function abort(bytes32 planId) external override {
+        ExecutionState storage state = executions[planId];
+        require(state.status == ExecutionStatus.IN_PROGRESS, "Cannot abort");
+
+        // Release any reserved funds/collateral
+        _rollbackSteps(planId);
+
+        state.status = ExecutionStatus.ABORTED;
+        notaryRegistry.finalizePlan(planId, false);
+    }
+
+    function getExecutionStatus(bytes32 planId) external view override returns (ExecutionStatus) {
+        return executions[planId].status;
+    }
+
+    function _executeStep(Step memory step, uint256 stepIndex) internal returns (bool success, bytes memory returnData, uint256 gasUsed) {
+        // Verify adapter is whitelisted
+        require(adapterRegistry.isWhitelisted(step.target), "Adapter not whitelisted");
+
+        uint256 gasBefore = gasleft();
+        
+        (success, returnData) = step.target.call{value: step.value}(
+            abi.encodeWithSignature("executeStep(bytes)", step.data)
+        );
+
+        gasUsed = gasBefore - gasleft();
+    }
+
+    function _canPrepareStep(Step memory step) internal view returns (bool) {
+        // Check if adapter supports prepare phase
+        // Implementation depends on adapter interface
+        return true;
+    }
+
+    function _rollbackSteps(bytes32 planId) internal {
+        // Release reserved funds, unlock collateral, etc.
+        // Implementation depends on specific step types
+    }
+
+    function _verifySignature(bytes32 planId, bytes calldata signature, address signer) internal pure returns (bool) {
+        // Verify ECDSA signature
+        bytes32 messageHash = keccak256(abi.encodePacked(planId));
+        bytes32 ethSignedMessageHash = keccak256(abi.encodePacked("\x19Ethereum Signed Message:\n32", messageHash));
+        address recovered = ecrecover(ethSignedMessageHash, v, r, s);
+        return recovered == signer;
+    }
+}
+```
+
+---
+
+## 2. Notary Registry Contract Interface
+
+### Purpose
+The notary registry contract stores codehashes, plan attestations, and provides immutable audit trails for compliance and non-repudiation.
+
+### Interface: `INotaryRegistry`
+
+```solidity
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.20;
+
+interface INotaryRegistry {
+    /**
+     * @notice Register a new execution plan
+     * @param planId Unique plan identifier
+     * @param steps Execution steps
+     * @param creator Plan creator address
+     * @return proofHash Cryptographic proof hash
+     */
+    function registerPlan(
+        bytes32 planId,
+        Step[] calldata steps,
+        address creator
+    ) external returns (bytes32 proofHash);
+
+    /**
+     * @notice Finalize a plan execution (success or failure)
+     * @param planId Plan identifier
+     * @param success Whether execution succeeded
+     */
+    function finalizePlan(bytes32 planId, bool success) external;
+
+    /**
+     * @notice Register adapter codehash for security
+     * @param adapter Address of adapter contract
+     * @param codeHash Hash of adapter contract bytecode
+     */
+    function registerCodeHash(address adapter, bytes32 codeHash) external;
+
+    /**
+     * @notice Verify adapter codehash matches registered hash
+     * @param adapter Adapter address
+     * @return matches Whether codehash matches
+     */
+    function verifyCodeHash(address adapter) external view returns (bool matches);
+
+    /**
+     * @notice Get notary proof for a plan
+     * @param planId Plan identifier
+     * @return proof Notary proof structure
+     */
+    function getProof(bytes32 planId) external view returns (NotaryProof memory proof);
+
+    /**
+     * @notice Get all plans registered by a creator
+     * @param creator Creator address
+     * @return planIds Array of plan IDs
+     */
+    function getPlansByCreator(address creator) external view returns (bytes32[] memory planIds);
+}
+
+struct NotaryProof {
+    bytes32 planId;
+    bytes32 proofHash;
+    address creator;
+    uint256 registeredAt;
+    uint256 finalizedAt;
+    bool finalized;
+    bool success;
+    bytes32[] stepHashes;
+}
+```
+
+### Implementation Example: `NotaryRegistry.sol`
+
+```solidity
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.20;
+
+import "@openzeppelin/contracts/access/Ownable.sol";
+import "./INotaryRegistry.sol";
+
+contract NotaryRegistry is INotaryRegistry, Ownable {
+    mapping(bytes32 => NotaryProof) public proofs;
+    mapping(address => bytes32[]) public creatorPlans;
+    mapping(address => bytes32) public codeHashes;
+
+    event PlanRegistered(bytes32 indexed planId, address creator, bytes32 proofHash);
+    event PlanFinalized(bytes32 indexed planId, bool success);
+    event CodeHashRegistered(address indexed adapter, bytes32 codeHash);
+
+    function registerPlan(
+        bytes32 planId,
+        Step[] calldata steps,
+        address creator
+    ) external override returns (bytes32 proofHash) {
+        require(proofs[planId].planId == bytes32(0), "Plan already registered");
+
+        bytes32[] memory stepHashes = new bytes32[](steps.length);
+        for (uint256 i = 0; i < steps.length; i++) {
+            stepHashes[i] = keccak256(abi.encode(steps[i]));
+        }
+
+        bytes32 stepsHash = keccak256(abi.encode(stepHashes));
+        proofHash = keccak256(abi.encodePacked(planId, creator, stepsHash, block.timestamp));
+
+        proofs[planId] = NotaryProof({
+            planId: planId,
+            proofHash: proofHash,
+            creator: creator,
+            registeredAt: block.timestamp,
+            finalizedAt: 0,
+            finalized: false,
+            success: false,
+            stepHashes: stepHashes
+        });
+
+        creatorPlans[creator].push(planId);
+
+        emit PlanRegistered(planId, creator, proofHash);
+    }
+
+    function finalizePlan(bytes32 planId, bool success) external override {
+        NotaryProof storage proof = proofs[planId];
+        require(proof.planId != bytes32(0), "Plan not registered");
+        require(!proof.finalized, "Plan already finalized");
+
+        proof.finalized = true;
+        proof.success = success;
+        proof.finalizedAt = block.timestamp;
+
+        emit PlanFinalized(planId, success);
+    }
+
+    function registerCodeHash(address adapter, bytes32 codeHash) external override onlyOwner {
+        codeHashes[adapter] = codeHash;
+        emit CodeHashRegistered(adapter, codeHash);
+    }
+
+    function verifyCodeHash(address adapter) external view override returns (bool matches) {
+        bytes32 registeredHash = codeHashes[adapter];
+        if (registeredHash == bytes32(0)) return false;
+
+        bytes32 currentHash;
+        assembly {
+            currentHash := extcodehash(adapter)
+        }
+
+        return currentHash == registeredHash;
+    }
+
+    function getProof(bytes32 planId) external view override returns (NotaryProof memory) {
+        return proofs[planId];
+    }
+
+    function getPlansByCreator(address creator) external view override returns (bytes32[] memory) {
+        return creatorPlans[creator];
+    }
+}
+```
+
+---
+
+## 3. Adapter Registry Contract Interface
+
+### Purpose
+The adapter registry manages whitelisting/blacklisting of adapters (both DeFi protocols and Fiat/DTL connectors), tracks versions, and enforces upgrade controls.
+
+### Interface: `IAdapterRegistry`
+
+```solidity
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.20;
+
+interface IAdapterRegistry {
+    /**
+     * @notice Check if adapter is whitelisted
+     * @param adapter Adapter contract address
+     * @return whitelisted Whether adapter is whitelisted
+     */
+    function isWhitelisted(address adapter) external view returns (bool whitelisted);
+
+    /**
+     * @notice Register a new adapter
+     * @param adapter Adapter contract address
+     * @param adapterType Type of adapter (DEFI or FIAT_DTL)
+     * @param version Adapter version string
+     * @param metadata Additional metadata (IPFS hash, etc.)
+     */
+    function registerAdapter(
+        address adapter,
+        AdapterType adapterType,
+        string calldata version,
+        bytes calldata metadata
+    ) external;
+
+    /**
+     * @notice Whitelist an adapter
+     * @param adapter Adapter contract address
+     */
+    function whitelistAdapter(address adapter) external;
+
+    /**
+     * @notice Blacklist an adapter
+     * @param adapter Adapter contract address
+     */
+    function blacklistAdapter(address adapter) external;
+
+    /**
+     * @notice Get adapter information
+     * @param adapter Adapter contract address
+     * @return info Adapter information structure
+     */
+    function getAdapterInfo(address adapter) external view returns (AdapterInfo memory info);
+
+    /**
+     * @notice List all whitelisted adapters
+     * @param adapterType Filter by type (0 = ALL)
+     * @return adapters Array of adapter addresses
+     */
+    function listAdapters(AdapterType adapterType) external view returns (address[] memory adapters);
+}
+
+enum AdapterType {
+    ALL,
+    DEFI,
+    FIAT_DTL
+}
+
+struct AdapterInfo {
+    address adapter;
+    AdapterType adapterType;
+    string version;
+    bool whitelisted;
+    bool blacklisted;
+    uint256 registeredAt;
+    bytes metadata;
+}
+```
+
+### Implementation Example: `AdapterRegistry.sol`
+
+```solidity
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.20;
+
+import "@openzeppelin/contracts/access/Ownable.sol";
+import "./IAdapterRegistry.sol";
+
+contract AdapterRegistry is IAdapterRegistry, Ownable {
+    mapping(address => AdapterInfo) public adapters;
+    address[] public adapterList;
+
+    event AdapterRegistered(address indexed adapter, AdapterType adapterType, string version);
+    event AdapterWhitelisted(address indexed adapter);
+    event AdapterBlacklisted(address indexed adapter);
+
+    function registerAdapter(
+        address adapter,
+        AdapterType adapterType,
+        string calldata version,
+        bytes calldata metadata
+    ) external override onlyOwner {
+        require(adapters[adapter].adapter == address(0), "Adapter already registered");
+
+        adapters[adapter] = AdapterInfo({
+            adapter: adapter,
+            adapterType: adapterType,
+            version: version,
+            whitelisted: false,
+            blacklisted: false,
+            registeredAt: block.timestamp,
+            metadata: metadata
+        });
+
+        adapterList.push(adapter);
+
+        emit AdapterRegistered(adapter, adapterType, version);
+    }
+
+    function whitelistAdapter(address adapter) external override onlyOwner {
+        require(adapters[adapter].adapter != address(0), "Adapter not registered");
+        require(!adapters[adapter].blacklisted, "Adapter is blacklisted");
+
+        adapters[adapter].whitelisted = true;
+        emit AdapterWhitelisted(adapter);
+    }
+
+    function blacklistAdapter(address adapter) external override onlyOwner {
+        require(adapters[adapter].adapter != address(0), "Adapter not registered");
+
+        adapters[adapter].blacklisted = true;
+        adapters[adapter].whitelisted = false;
+        emit AdapterBlacklisted(adapter);
+    }
+
+    function isWhitelisted(address adapter) external view override returns (bool) {
+        AdapterInfo memory info = adapters[adapter];
+        return info.whitelisted && !info.blacklisted;
+    }
+
+    function getAdapterInfo(address adapter) external view override returns (AdapterInfo memory) {
+        return adapters[adapter];
+    }
+
+    function listAdapters(AdapterType adapterType) external view override returns (address[] memory) {
+        uint256 count = 0;
+        for (uint256 i = 0; i < adapterList.length; i++) {
+            if (adapterType == AdapterType.ALL || adapters[adapterList[i]].adapterType == adapterType) {
+                if (adapters[adapterList[i]].whitelisted && !adapters[adapterList[i]].blacklisted) {
+                    count++;
+                }
+            }
+        }
+
+        address[] memory result = new address[](count);
+        uint256 index = 0;
+        for (uint256 i = 0; i < adapterList.length; i++) {
+            if (adapterType == AdapterType.ALL || adapters[adapterList[i]].adapterType == adapterType) {
+                if (adapters[adapterList[i]].whitelisted && !adapters[adapterList[i]].blacklisted) {
+                    result[index] = adapterList[i];
+                    index++;
+                }
+            }
+        }
+
+        return result;
+    }
+}
+```
+
+---
+
+## 4. Integration Patterns for Atomicity
+
+### Pattern A: Two-Phase Commit (2PC)
+
+```solidity
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.20;
+
+contract TwoPhaseCommitHandler {
+    enum Phase { PREPARE, COMMIT, ABORT }
+
+    mapping(bytes32 => Phase) public phases;
+
+    function prepare(bytes32 planId, Step[] calldata steps) external {
+        // Mark assets as reserved
+        // Store prepare state
+        phases[planId] = Phase.PREPARE;
+    }
+
+    function commit(bytes32 planId) external {
+        require(phases[planId] == Phase.PREPARE, "Not prepared");
+        // Execute all steps atomically
+        phases[planId] = Phase.COMMIT;
+    }
+
+    function abort(bytes32 planId) external {
+        require(phases[planId] == Phase.PREPARE, "Not prepared");
+        // Release reserved assets
+        phases[planId] = Phase.ABORT;
+    }
+}
+```
+
+### Pattern B: HTLC-like Pattern
+
+```solidity
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.20;
+
+contract HTLCPattern {
+    struct HTLC {
+        bytes32 hashLock;
+        address beneficiary;
+        uint256 amount;
+        uint256 expiry;
+        bool claimed;
+    }
+
+    mapping(bytes32 => HTLC) public htlcLocks;
+
+    function createHTLC(
+        bytes32 planId,
+        bytes32 hashLock,
+        address beneficiary,
+        uint256 amount,
+        uint256 expiry
+    ) external {
+        htlcLocks[planId] = HTLC({
+            hashLock: hashLock,
+            beneficiary: beneficiary,
+            amount: amount,
+            expiry: expiry,
+            claimed: false
+        });
+    }
+
+    function claimHTLC(bytes32 planId, bytes32 preimage) external {
+        HTLC storage htlc = htlcLocks[planId];
+        require(keccak256(abi.encodePacked(preimage)) == htlc.hashLock, "Invalid preimage");
+        require(block.timestamp < htlc.expiry, "Expired");
+        require(!htlc.claimed, "Already claimed");
+
+        htlc.claimed = true;
+        // Transfer funds
+    }
+}
+```
+
+### Pattern C: Conditional Finality via Notary
+
+```solidity
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.20;
+
+contract ConditionalFinalityHandler {
+    INotaryRegistry public notaryRegistry;
+
+    mapping(bytes32 => bool) public pendingFinalization;
+
+    function executeWithConditionalFinality(
+        bytes32 planId,
+        Step[] calldata steps
+    ) external {
+        // Execute DLT steps
+        // Mark as pending finalization
+        pendingFinalization[planId] = true;
+
+        // Notary must co-sign after bank settlement
+    }
+
+    function finalizeWithNotary(bytes32 planId, bytes calldata notarySignature) external {
+        require(pendingFinalization[planId], "Not pending");
+        require(notaryRegistry.verifyNotarySignature(planId, notarySignature), "Invalid notary signature");
+
+        // Complete finalization
+        pendingFinality[planId] = false;
+    }
+}
+```
+
+---
+
+## 5. Security Considerations
+
+### Access Control
+- Use OpenZeppelin's `Ownable` or `AccessControl` for admin functions
+- Implement multi-sig for critical operations (adapter whitelisting, codehash registration)
+
+### Reentrancy Protection
+- Use `ReentrancyGuard` for execute functions
+- Follow checks-effects-interactions pattern
+
+### Upgradeability
+- Consider using proxy patterns (Transparent/UUPS) for upgradeable contracts
+- Implement timelocks for upgrades
+- Require multi-sig for upgrade approvals
+
+### Codehash Verification
+- Register codehashes for all adapters
+- Verify codehash before execution
+- Prevent execution if codehash doesn't match
+
+### Gas Optimization
+- Batch operations where possible
+- Use `calldata` instead of `memory` for arrays
+- Minimize storage operations
+
+---
+
+## 6. Testing Requirements
+
+### Unit Tests
+- Test each interface function
+- Test error cases (invalid inputs, unauthorized access)
+- Test atomicity (all-or-nothing execution)
+
+### Integration Tests
+- Test full workflow execution
+- Test 2PC prepare/commit/abort flows
+- Test notary integration
+- Test adapter registry whitelisting
+
+### Fuzz Tests
+- Fuzz step configurations
+- Fuzz plan structures
+- Fuzz edge cases (empty steps, large arrays)
+
+---
+
+**Document Version**: 1.0  
+**Last Updated**: 2025-01-15  
+**Author**: Smart Contract Team
+

docs/UI_UX_Specification_Builder_V2.md

@@ -0,0 +1,395 @@
+# UI/UX Specification: ISO-20022 Combo Builder v2
+
+## Overview
+This document specifies the user interface and user experience for the Combo Builder v2, which enables users to compose multi-step financial workflows combining DeFi protocols and traditional banking rails (ISO-20022). The UI is inspired by Furucombo's Create page but extends it with compliance overlays, hybrid adapter support, and optional simulation.
+
+## Design Principles
+1. **Composability**: Drag-and-drop interface for building complex financial workflows
+2. **Transparency**: Clear display of compliance status, fees, and execution risks
+3. **Flexibility**: Support for both DeFi and fiat/DTL adapters with selection control
+4. **User Control**: Optional simulation for advanced users, mandatory compliance checks
+5. **Accessibility**: Intuitive for non-developers while providing advanced features
+
+---
+
+## 1. Main Builder Canvas
+
+### Layout Structure
+```
+┌─────────────────────────────────────────────────────────────────┐
+│ Header: [Combo Builder] [User Identity] [Wallet] [Settings]     │
+├─────────────┬─────────────────────────────────────────────────────────┤
+│             │                                                      │
+│  Adapter    │              Canvas (Drop Zone)                     │
+│  Palette    │              ┌─────────────────────┐               │
+│             │              │  Step 1: Borrow     │               │
+│  [DeFi]     │              │  💰 CBDC_USD: 100k  │               │
+│  - Swap     │              └─────────────────────┘               │
+│  - Borrow   │              ┌─────────────────────┐               │
+│  - Deposit  │              │  Step 2: Swap       │               │
+│  - Bridge   │              │  🔄 USD → EUR       │               │
+│             │              └─────────────────────┘               │
+│  [Fiat]     │              ┌─────────────────────┐               │
+│  - Pay      │              │  Step 3: Pay         │               │
+│  - Repay    │              │  📤 EUR to IBAN     │               │
+│  - Transfer │              └─────────────────────┘               │
+│             │                                                      │
+│  [Compliance]│                                                    │
+│  ✓ LEI     │                                                      │
+│  ✓ KYC     │                                                      │
+│  ✓ AML     │                                                      │
+└─────────────┴─────────────────────────────────────────────────────┘
+┌─────────────────────────────────────────────────────────────────┐
+│ Summary Panel:                                                   │
+│ Initial Funds: 100,000 CBDC_USD                                 │
+│ You will receive: ~78,000 EUR                                   │
+│ Fees: 0.2% (200 USD) | Compliance: ✓ | Simulation: [Toggle]   │
+│ [Review & Sign] [Simulate] [Save Draft]                        │
+└─────────────────────────────────────────────────────────────────┘
+```
+
+### Key Components
+
+#### A. Adapter Palette (Left Sidebar)
+- **DeFi Section**: Swappable protocols (Uniswap, Aave, Compound, etc.)
+- **Fiat/DTL Section**: Banking rails (ISO-20022 pay, SWIFT, SEPA, etc.)
+- **Compliance Badge**: Shows current user compliance status (LEI/DID/KYC/AML)
+- **Filter Toggle**: "Show All" / "Show Whitelisted Only" / "Show DeFi Only" / "Show Fiat Only"
+
+#### B. Canvas (Center)
+- **Drop Zone**: Visual area where users place workflow steps
+- **Step Cards**: Each step shows:
+  - Step number (1, 2, 3...)
+  - Icon (💰, 🔄, 💳, 📤)
+  - Step type and summary
+  - Compliance badge (if applicable)
+  - Drag handle (⋮⋮) for reordering
+  - Edit/Remove buttons
+
+#### C. Summary Panel (Bottom)
+- **Initial Funds**: What user must supply (from wallet or borrow)
+- **You will receive**: Expected output at workflow end
+- **Fee Display**: "Included 0.2% fee" (if applicable)
+- **Compliance Status**: Visual indicators (✓ LEI, ✓ KYC, ✓ AML, ✓ DID)
+- **Simulation Toggle**: Optional checkbox for advanced users
+- **Action Buttons**: Review & Sign, Simulate (optional), Save Draft
+
+---
+
+## 2. Step Configuration Drawer
+
+### Layout
+```
+┌────────────────────────────────────────────────────────┐
+│ Configure Step: Swap                    [X]            │
+├────────────────────────────────────────────────────────┤
+│                                                        │
+│ From Token: [CBDC_USD ▼]                              │
+│ Amount: [100,000]                                      │
+│                                                        │
+│ To Token: [CBDC_EUR ▼]                                 │
+│ Min Receive: [90,000] (auto-calculated)                │
+│                                                        │
+│ Slippage: [0.5%] (default)                            │
+│                                                        │
+│ ────────────────────────────────────────────────────── │
+│                                                        │
+│ Compliance Requirements:                               │
+│ ☑ LEI Required: [5493000IBP32UQZ0KL24]                │
+│ ☑ KYC Status: ✓ Verified                              │
+│ ☑ AML Check: ✓ Passed                                 │
+│                                                        │
+│ [Save] [Cancel]                                        │
+└────────────────────────────────────────────────────────┘
+```
+
+### Features
+- **Token/Asset Selection**: Dropdown with supported tokens (DeFi) or currencies (Fiat)
+- **Amount Input**: Numeric input with validation
+- **Compliance Fields**: Auto-populated from user session (LEI, KYC, AML status)
+- **Dependency Visualization**: Shows which previous steps feed into this step
+- **Validation Feedback**: Real-time error messages (insufficient balance, invalid IBAN, etc.)
+
+---
+
+## 3. Simulation Results Panel (Optional)
+
+### Layout
+```
+┌────────────────────────────────────────────────────────┐
+│ Simulation Results                    [Close]          │
+├────────────────────────────────────────────────────────┤
+│ Status: ✓ Simulation Successful                        │
+│                                                        │
+│ Execution Summary:                                     │
+│ • Step 1 (Borrow): ✓ 100,000 CBDC_USD                 │
+│ • Step 2 (Swap): ✓ 90,000 CBDC_EUR (estimated)        │
+│ • Step 3 (Pay): ✓ 78,000 EUR to beneficiary           │
+│                                                        │
+│ Gas Estimate: 450,000 gas                             │
+│ Estimated Cost: $25.50 (at 50 gwei)                    │
+│                                                        │
+│ Slippage Risk: Low (0.2% expected)                    │
+│ Liquidity Check: ✓ Sufficient                          │
+│                                                        │
+│ Compliance: ✓ All checks passed                        │
+│                                                        │
+│ [Run Simulation Again] [Proceed to Sign]              │
+└────────────────────────────────────────────────────────┘
+```
+
+### Features
+- **Step-by-Step Results**: Shows success/failure for each step
+- **Gas Estimation**: Calculated gas cost for entire workflow
+- **Slippage Analysis**: Expected slippage for swaps
+- **Liquidity Checks**: Verifies sufficient liquidity for trades
+- **Compliance Status**: Confirms all compliance requirements met
+- **Error Warnings**: Highlights any potential failure points
+
+---
+
+## 4. Compliance Status Dashboard Overlay
+
+### Layout
+```
+┌────────────────────────────────────────────────────────┐
+│ Compliance Status                    [Dismiss]          │
+├────────────────────────────────────────────────────────┤
+│                                                        │
+│ Identity Verification:                                 │
+│ ✓ LEI: 5493000IBP32UQZ0KL24                            │
+│ ✓ DID: did:web:example.com:user:123                    │
+│ ✓ KYC: Level 2 Verified (Expires: 2026-12-31)         │
+│ ✓ AML: Passed (Last check: 2025-01-15)                 │
+│                                                        │
+│ Current Workflow Compliance:                           │
+│ • All steps require LEI: ✓ Provided                   │
+│ • KYC Level Required: 2 ✓ Met                           │
+│ • AML Screening: ✓ Passed                              │
+│                                                        │
+│ Missing Requirements: None                             │
+│                                                        │
+│ [Update Identity] [View Compliance Details]           │
+└────────────────────────────────────────────────────────┘
+```
+
+### Features
+- **Always Visible Badge**: Small indicator in header showing compliance status
+- **Detailed View**: Expandable overlay with full compliance details
+- **Workflow-Specific Checks**: Validates compliance for current workflow
+- **Expiration Warnings**: Alerts if KYC/AML checks are expiring soon
+- **Update Actions**: Quick links to update identity or run new checks
+
+---
+
+## 5. Adapter Selection Modal
+
+### Layout
+```
+┌────────────────────────────────────────────────────────┐
+│ Select Adapter Type                    [X]             │
+├────────────────────────────────────────────────────────┤
+│                                                        │
+│ Filter: [All] [DeFi] [Fiat/DTL] [Whitelisted Only]   │
+│                                                        │
+│ ┌──────────────────┐  ┌──────────────────┐           │
+│ │ DeFi Protocols   │  │ Fiat/DTL Rails   │           │
+│ ├──────────────────┤  ├──────────────────┤           │
+│ │ 🔄 Uniswap V3    │  │ 📤 ISO-20022 Pay │           │
+│ │ 💰 Aave          │  │ 💳 SWIFT MT      │           │
+│ │ 📊 Compound      │  │ 🌐 SEPA          │           │
+│ │ 🌉 Bridge        │  │ 🏦 FedNow        │           │
+│ │                  │  │                  │           │
+│ └──────────────────┘  └──────────────────┘           │
+│                                                        │
+│ Selected: ISO-20022 Pay                               │
+│                                                        │
+│ [Add to Palette] [Cancel]                            │
+└────────────────────────────────────────────────────────┘
+```
+
+### Features
+- **Category Filtering**: Separate DeFi and Fiat/DTL adapters
+- **Whitelist Toggle**: Show only approved/whitelisted adapters
+- **Adapter Status**: Visual indicators (✓ Approved, ⚠ Deprecated, 🔒 Restricted)
+- **Search**: Quick search for specific adapters
+- **Version Info**: Shows adapter version and last updated date
+
+---
+
+## 6. User Flows
+
+### Flow 1: Building a Simple Combo (DeFi Only)
+1. User opens Builder page
+2. User drags "Borrow" from DeFi palette → Canvas
+3. Configures borrow step (asset, amount, collateral)
+4. Drags "Swap" from palette → Canvas (after borrow step)
+5. Configures swap step (from/to tokens, amount)
+6. Summary panel updates automatically
+7. User clicks "Review & Sign" (compliance auto-checked)
+8. Redirected to preview/sign page
+
+### Flow 2: Building Hybrid Combo (DeFi + Fiat)
+1. User opens Builder page
+2. Compliance badge shows: ✓ LEI, ✓ KYC, ✓ AML
+3. User drags "Borrow" (DeFi) → Canvas
+4. User drags "Swap" (DeFi) → Canvas
+5. User drags "Pay" (Fiat/DTL) → Canvas
+6. Configures pay step (IBAN, amount, beneficiary)
+7. Compliance overlay appears: "Fiat step requires LEI"
+8. LEI auto-populated from user session
+9. User optionally enables simulation toggle
+10. Clicks "Simulate" → sees results
+11. Clicks "Review & Sign" → proceeds
+
+### Flow 3: Advanced User with Simulation
+1. User enables "Simulation" toggle in summary panel
+2. Builds workflow as normal
+3. Before signing, clicks "Simulate" button
+4. Simulation results panel shows:
+   - Gas estimate
+   - Slippage analysis
+   - Liquidity checks
+   - Failure predictions
+5. User reviews results, adjusts workflow if needed
+6. Clicks "Proceed to Sign" after simulation passes
+
+### Flow 4: Compliance Validation Failure
+1. User builds workflow with fiat step requiring LEI
+2. User has not provided LEI in settings
+3. Compliance badge shows: ⚠ LEI Missing
+4. User attempts to sign
+5. Error modal: "LEI required for this workflow. Please update your identity in Settings."
+6. User redirected to Settings page to add LEI
+7. Returns to Builder, workflow auto-validated
+
+---
+
+## 7. Responsive Design
+
+### Desktop (≥1024px)
+- Full layout with sidebar palette, canvas, and summary panel
+- All features visible simultaneously
+
+### Tablet (768px - 1023px)
+- Collapsible sidebar palette
+- Canvas takes full width when palette collapsed
+- Summary panel remains at bottom
+
+### Mobile (<768px)
+- Palette accessible via bottom sheet/modal
+- Canvas scrollable vertically
+- Step cards stack vertically
+- Summary panel sticky at bottom
+
+---
+
+## 8. Accessibility Requirements
+
+- **Keyboard Navigation**: Full keyboard support for drag-and-drop (arrow keys, space/enter)
+- **Screen Reader Support**: ARIA labels for all interactive elements
+- **Color Contrast**: WCAG AA compliance for all text and UI elements
+- **Focus Indicators**: Clear focus states for all interactive elements
+- **Error Messages**: Clear, actionable error messages for all validation failures
+
+---
+
+## 9. Performance Requirements
+
+- **Initial Load**: < 2 seconds for Builder page
+- **Step Addition**: < 500ms for drag-and-drop response
+- **Summary Calculation**: Real-time updates < 200ms
+- **Simulation**: < 5 seconds for full workflow simulation
+- **Compliance Check**: < 1 second for status validation
+
+---
+
+## 10. Integration Points
+
+### Frontend → Backend API
+- `POST /api/plans` - Create execution plan
+- `GET /api/plans/:id/simulate` - Run simulation (optional)
+- `GET /api/compliance/status` - Fetch compliance status
+- `GET /api/adapters` - List available adapters (filtered by type/whitelist)
+
+### Frontend → Smart Contracts
+- Wallet connection via Wagmi
+- Plan signing via wallet signature
+- Transaction submission via handler contract
+
+---
+
+## 11. Visual Design System
+
+### Color Palette
+- **Primary**: Black (#000000) for actions
+- **Secondary**: Blue (#3B82F6) for compliance/info
+- **Success**: Green (#10B981) for valid states
+- **Warning**: Yellow (#F59E0B) for warnings
+- **Error**: Red (#EF4444) for errors
+- **Background**: White (#FFFFFF) for cards, Gray-50 (#F9FAFB) for canvas
+
+### Typography
+- **Headings**: Inter, 24px/32px (h1), 18px/24px (h2)
+- **Body**: Inter, 14px/20px
+- **Code/Monospace**: Fira Code, 12px/16px for addresses/IDs
+
+### Icons
+- Emoji icons for step types (💰, 🔄, 💳, 📤)
+- Lucide React icons for UI elements (Edit, Remove, Drag, etc.)
+
+---
+
+## 12. Error States & Edge Cases
+
+### Insufficient Balance
+- Red warning badge on step card
+- Error message: "Insufficient balance. You need 100,000 CBDC_USD but have 50,000."
+
+### Invalid Workflow
+- Step dependency error: "Step 2 requires output from Step 1. Please reorder steps."
+- Visual connection lines between dependent steps
+
+### Compliance Failure
+- Modal overlay: "This workflow requires LEI verification. Please update your identity in Settings."
+- Link to Settings page
+
+### Simulation Failure
+- Results panel shows: "⚠ Simulation Failed"
+- Detailed error: "Step 2 (Swap) would fail due to insufficient liquidity."
+
+### Network/Chain Mismatch
+- Warning: "Selected adapter (Uniswap) is on Ethereum, but you're connected to Polygon."
+- Option to switch network or select different adapter
+
+---
+
+## 13. Future Enhancements (Out of Scope for v2)
+
+- **Workflow Templates**: Pre-built combo templates for common strategies
+- **Workflow Sharing**: Share workflows with other users (with compliance validation)
+- **Multi-user Workflows**: Collaborative workflow building
+- **Advanced Analytics**: Historical performance tracking for workflows
+- **Mobile App**: Native mobile app for workflow building
+
+---
+
+## Acceptance Criteria
+
+1. ✅ User can drag adapters from palette to canvas
+2. ✅ User can reorder steps by dragging
+3. ✅ User can configure each step via drawer
+4. ✅ Compliance status is always visible and validated
+5. ✅ Optional simulation works for advanced users
+6. ✅ Summary panel updates in real-time
+7. ✅ Hybrid adapters (DeFi + Fiat) are selectable
+8. ✅ Error states are clearly communicated
+9. ✅ Responsive design works on mobile/tablet/desktop
+10. ✅ Accessibility requirements are met
+
+---
+
+**Document Version**: 1.0  
+**Last Updated**: 2025-01-15  
+**Author**: Engineering Team
+

docs/Wireframes_Mockups.md

@@ -0,0 +1,421 @@
+# Wireframes & Mockups: ISO-20022 Combo Builder
+
+## Overview
+This document provides detailed wireframe sketches and mockup specifications for the five key screens of the Combo Builder v2.
+
+---
+
+## 1. Main Builder Canvas
+
+### Desktop Layout (1024px+)
+```
+┌────────────────────────────────────────────────────────────────────────────────────────────┐
+│ 🏠 CurrenciCombo    [User: john@example.com] [LEI: ✓] [Wallet: 0x1234...5678] [⚙️]      │
+├──────────────┬──────────────────────────────────────────────────────────────────────────────┤
+│              │                                                                              │
+│ ADAPTER      │                          CANVAS (Drop Zone)                                 │
+│ PALETTE      │                                                                              │
+│              │  ┌────────────────────────────────────────────────────────────────────┐  │
+│ [Filter: All]│  │  Step 1: Borrow                                   [Edit] [Remove]    │  │
+│              │  │  💰 CBDC_USD: 100,000 | Collateral: TokenX:123    [⋮⋮]               │  │
+│ DeFi:        │  │  ✓ LEI | ✓ KYC | ✓ AML                                              │  │
+│ ┌──────────┐ │  └────────────────────────────────────────────────────────────────────┘  │
+│ │ 🔄 Swap  │ │                                                                              │
+│ │ 💰 Borrow│ │  ┌────────────────────────────────────────────────────────────────────┐  │
+│ │ 📊 Deposit│ │  │  Step 2: Swap                                    [Edit] [Remove]    │  │
+│ │ 🌉 Bridge │ │  │  🔄 CBDC_USD → CBDC_EUR: 100,000 → 90,000      [⋮⋮]               │  │
+│ └──────────┘ │  │  ✓ LEI | ✓ KYC | Slippage: 0.5%                                    │  │
+│              │  └────────────────────────────────────────────────────────────────────┘  │
+│ Fiat/DTL:    │                                                                              │
+│ ┌──────────┐ │  ┌────────────────────────────────────────────────────────────────────┐  │
+│ │ 📤 Pay   │ │  │  Step 3: Pay                                      [Edit] [Remove]    │  │
+│ │ 💳 Repay │ │  │  📤 EUR: 78,000 to IBAN: DE89...3000            [⋮⋮]               │  │
+│ │ 🌐 Transfer│  │  │  ✓ LEI | ✓ KYC | ✓ AML | Beneficiary: Verified                │  │
+│ └──────────┘ │  └────────────────────────────────────────────────────────────────────┘  │
+│              │                                                                              │
+│ Compliance:  │  ┌────────────────────────────────────────────────────────────────────┐  │
+│ ✓ LEI        │  │  Drop zone: Drag adapters here to add steps                        │  │
+│ ✓ KYC        │  │  or click [+] to add from list                                      │  │
+│ ✓ AML        │  └────────────────────────────────────────────────────────────────────┘  │
+│ ✓ DID        │                                                                              │
+└──────────────┴──────────────────────────────────────────────────────────────────────────────┘
+┌────────────────────────────────────────────────────────────────────────────────────────────┐
+│ SUMMARY PANEL                                                                              │
+│ ┌──────────────────────┬──────────────────────┬──────────────────────┬─────────────────┐│
+│ │ Initial Funds         │ You will receive     │ Fees                 │ Actions          ││
+│ │ 100,000 CBDC_USD     │ ~78,000 EUR          │ 0.2% (200 USD)       │ [Simulate] [✓] ││
+│ │ (from wallet)         │ (estimated)         │ Included             │ [Review & Sign] ││
+│ └──────────────────────┴──────────────────────┴──────────────────────┴─────────────────┘│
+│ Compliance: ✓ LEI ✓ KYC ✓ AML ✓ DID | Simulation: [Toggle: OFF]                          │
+└────────────────────────────────────────────────────────────────────────────────────────────┘
+```
+
+### Key Elements
+- **Left Sidebar (240px)**: Adapter palette with DeFi and Fiat/DTL sections
+- **Center Canvas (flexible)**: Drop zone and step cards
+- **Bottom Panel (60px)**: Summary with initial funds, output, fees, actions
+- **Header**: User identity, compliance badges, wallet connection
+
+---
+
+## 2. Step Configuration Drawer
+
+### Layout
+```
+┌─────────────────────────────────────────────────────────────────────────────┐
+│ Configure Step: Swap                                        [✕ Close]       │
+├─────────────────────────────────────────────────────────────────────────────┤
+│                                                                              │
+│ Step Type: Swap [🔄]                                                        │
+│                                                                              │
+│ ┌───────────────────────────────────────────────────────────────────────┐ │
+│ │ From Token                                                              │ │
+│ │ [CBDC_USD ▼]                    Balance: 150,000                      │ │
+│ └───────────────────────────────────────────────────────────────────────┘ │
+│                                                                              │
+│ ┌───────────────────────────────────────────────────────────────────────┐ │
+│ │ Amount                                                                │ │
+│ │ [100,000] USD                                                          │ │
+│ │ [Use Max] [Use 50%] [Use 25%]                                         │ │
+│ └───────────────────────────────────────────────────────────────────────┘ │
+│                                                                              │
+│ ┌───────────────────────────────────────────────────────────────────────┐ │
+│ │ To Token                                                              │ │
+│ │ [CBDC_EUR ▼]                    Balance: 0                            │ │
+│ └───────────────────────────────────────────────────────────────────────┘ │
+│                                                                              │
+│ ┌───────────────────────────────────────────────────────────────────────┐ │
+│ │ Minimum Receive (Auto-calculated)                                     │ │
+│ │ [90,000] EUR                              Expected: ~90,000 EUR       │ │
+│ │ Based on current liquidity (0.5% slippage)                           │ │
+│ └───────────────────────────────────────────────────────────────────────┘ │
+│                                                                              │
+│ ┌───────────────────────────────────────────────────────────────────────┐ │
+│ │ Slippage Tolerance                                                    │ │
+│ │ ○ 0.1%  ○ 0.5%  ○ 1.0%  ● Custom: [0.5] %                            │ │
+│ └───────────────────────────────────────────────────────────────────────┘ │
+│                                                                              │
+│ ────────────────────────────────────────────────────────────────────────── │
+│                                                                              │
+│ Compliance Requirements                                                      │
+│ ┌───────────────────────────────────────────────────────────────────────┐ │
+│ │ ☑ LEI Required                                                        │ │
+│ │    [5493000IBP32UQZ0KL24]                          ✓ Verified          │ │
+│ └───────────────────────────────────────────────────────────────────────┘ │
+│ ┌───────────────────────────────────────────────────────────────────────┐ │
+│ │ ☑ KYC Status                                                          │ │
+│ │    Level 2 Verified (Expires: 2026-12-31)            ✓ Valid            │ │
+│ └───────────────────────────────────────────────────────────────────────┘ │
+│ ┌───────────────────────────────────────────────────────────────────────┐ │
+│ │ ☑ AML Check                                                            │ │
+│ │    Last check: 2025-01-15                              ✓ Passed        │ │
+│ └───────────────────────────────────────────────────────────────────────┘ │
+│                                                                              │
+│ Step Dependencies                                                           │
+│ ┌───────────────────────────────────────────────────────────────────────┐ │
+│ │ This step receives output from: Step 1 (Borrow)                      │ │
+│ │ Input: 100,000 CBDC_USD                                               │ │
+│ └───────────────────────────────────────────────────────────────────────┘ │
+│                                                                              │
+│ ┌──────────────┐  ┌──────────────┐                                          │
+│ │ [Save]       │  │ [Cancel]     │                                          │
+│ └──────────────┘  └──────────────┘                                          │
+└─────────────────────────────────────────────────────────────────────────────┘
+```
+
+### Key Features
+- **Slide-up drawer**: From bottom (mobile) or side (desktop)
+- **Auto-population**: Compliance fields from user session
+- **Real-time validation**: Balance checks, slippage calculations
+- **Dependency visualization**: Shows which previous steps feed this step
+- **Token selector**: Dropdown with balances and search
+
+---
+
+## 3. Simulation Results Panel (Optional)
+
+### Layout
+```
+┌─────────────────────────────────────────────────────────────────────────────┐
+│ Simulation Results                                       [✕ Close]          │
+├─────────────────────────────────────────────────────────────────────────────┤
+│                                                                              │
+│ Status: ✓ Simulation Successful                                              │
+│                                                                              │
+│ ┌───────────────────────────────────────────────────────────────────────┐ │
+│ │ Execution Summary                                                      │ │
+│ │                                                                         │ │
+│ │ Step 1: Borrow                                                         │ │
+│ │   ✓ 100,000 CBDC_USD borrowed                                          │ │
+│ │   ✓ Collateral locked: TokenX:123                                     │ │
+│ │   ✓ LTV: 45% (within limit)                                           │ │
+│ │                                                                         │ │
+│ │ Step 2: Swap                                                           │ │
+│ │   ✓ 100,000 CBDC_USD → 90,000 CBDC_EUR                                 │ │
+│ │   ✓ Slippage: 0.3% (within tolerance)                                  │ │
+│ │   ✓ Liquidity: Sufficient (Pool: 500,000 EUR)                          │ │
+│ │                                                                         │ │
+│ │ Step 3: Pay                                                            │ │
+│ │   ✓ 78,000 EUR sent to IBAN: DE89...3000                               │ │
+│ │   ✓ ISO-20022 pacs.008 generated                                      │ │
+│ │   ✓ Bank confirmation: Pending                                         │ │
+│ └───────────────────────────────────────────────────────────────────────┘ │
+│                                                                              │
+│ ┌───────────────────────────────────────────────────────────────────────┐ │
+│ │ Cost Estimates                                                        │ │
+│ │                                                                         │ │
+│ │ Gas Estimate: 450,000 gas                                             │ │
+│ │ Estimated Cost: $25.50 (at 50 gwei)                                  │ │
+│ │ Network: Ethereum Mainnet                                             │ │
+│ │                                                                         │ │
+│ │ Platform Fee: 0.2% (200 USD)                                          │ │
+│ │ Total Cost: $225.50                                                    │ │
+│ └───────────────────────────────────────────────────────────────────────┘ │
+│                                                                              │
+│ ┌───────────────────────────────────────────────────────────────────────┐ │
+│ │ Risk Analysis                                                          │ │
+│ │                                                                         │ │
+│ │ Slippage Risk: Low (0.3% expected)                                    │ │
+│ │ Liquidity Risk: Low (Pool depth: 500k EUR)                            │ │
+│ │ Compliance Risk: None (All checks passed)                              │ │
+│ │ Network Risk: Low (Gas price stable)                                  │ │
+│ └───────────────────────────────────────────────────────────────────────┘ │
+│                                                                              │
+│ ┌──────────────┐  ┌──────────────┐  ┌──────────────┐                      │
+│ │ [Run Again]  │  │ [Export]     │  │ [Proceed]    │                      │
+│ └──────────────┘  └──────────────┘  └──────────────┘                      │
+└─────────────────────────────────────────────────────────────────────────────┘
+```
+
+### Key Features
+- **Modal overlay**: Centered on desktop, full-screen on mobile
+- **Step-by-step results**: Visual checkmarks for each step
+- **Cost breakdown**: Gas, fees, total cost
+- **Risk analysis**: Slippage, liquidity, compliance, network risks
+- **Action buttons**: Run again, export results, proceed to sign
+
+---
+
+## 4. Compliance Status Dashboard Overlay
+
+### Layout
+```
+┌─────────────────────────────────────────────────────────────────────────────┐
+│ Compliance Status                                        [✕ Dismiss]         │
+├─────────────────────────────────────────────────────────────────────────────┤
+│                                                                              │
+│ ┌───────────────────────────────────────────────────────────────────────┐ │
+│ │ Identity Verification                                                 │ │
+│ │                                                                         │ │
+│ │ ✓ LEI: 5493000IBP32UQZ0KL24                                           │ │
+│ │   Legal Entity: Example Corp Ltd.                                       │ │
+│ │   Status: Active                                                       │ │
+│ │                                                                         │ │
+│ │ ✓ DID: did:web:example.com:user:123                                    │ │
+│ │   Issuer: Entra Verified ID                                            │ │
+│ │   Status: Verified                                                     │ │
+│ │                                                                         │ │
+│ │ ✓ KYC: Level 2 Verified                                                │ │
+│ │   Provider: Onfido                                                     │ │
+│ │   Expires: 2026-12-31                                                  │ │
+│ │   Status: Valid                                                        │ │
+│ │                                                                         │ │
+│ │ ✓ AML: Passed                                                          │ │
+│ │   Last Check: 2025-01-15                                               │ │
+│ │   Provider: Chainalysis                                                │ │
+│ │   Status: Clean                                                        │ │
+│ └───────────────────────────────────────────────────────────────────────┘ │
+│                                                                              │
+│ ┌───────────────────────────────────────────────────────────────────────┐ │
+│ │ Current Workflow Compliance                                            │ │
+│ │                                                                         │ │
+│ │ Requirements:                                                          │ │
+│ │ • LEI: Required for all steps              ✓ Provided                  │ │
+│ │ • KYC: Level 2 required for fiat steps     ✓ Met                      │ │
+│ │ • AML: Required for payments > 10k EUR     ✓ Passed                   │ │
+│ │ • DID: Required for notarization           ✓ Verified                 │ │
+│ │                                                                         │ │
+│ │ Missing Requirements: None                                             │ │
+│ └───────────────────────────────────────────────────────────────────────┘ │
+│                                                                              │
+│ ┌──────────────┐  ┌──────────────┐                                          │
+│ │ [Update]     │  │ [Details]    │                                          │
+│ └──────────────┘  └──────────────┘                                          │
+└─────────────────────────────────────────────────────────────────────────────┘
+```
+
+### Key Features
+- **Expandable overlay**: Triggered from compliance badge in header
+- **Identity details**: Full LEI, DID, KYC, AML information
+- **Workflow validation**: Checks compliance for current workflow
+- **Expiration warnings**: Alerts if credentials expiring soon
+- **Quick actions**: Update identity, view detailed compliance report
+
+---
+
+## 5. Adapter Selection Modal
+
+### Layout
+```
+┌─────────────────────────────────────────────────────────────────────────────┐
+│ Select Adapter Type                                      [✕ Close]          │
+├─────────────────────────────────────────────────────────────────────────────┤
+│                                                                              │
+│ Filter: [● All] [○ DeFi] [○ Fiat/DTL] [○ Whitelisted Only]                │
+│ Search: [Search adapters...]                                                │
+│                                                                              │
+│ ┌──────────────────────────────────┬──────────────────────────────────────┐ │
+│ │ DeFi Protocols                   │ │ Fiat/DTL Rails                      │ │
+│ ├──────────────────────────────────┤ ├──────────────────────────────────────┤ │
+│ │                                  │ │                                      │ │
+│ │ ┌──────────────────────────────┐ │ │ ┌──────────────────────────────┐   │ │
+│ │ │ 🔄 Uniswap V3                │ │ │ │ 📤 ISO-20022 Pay              │   │ │
+│ │ │ Swap on Uniswap V3           │ │ │ │ Send payment via ISO-20022   │   │ │
+│ │ │ ✓ Approved | v3.0.1          │ │ │ │ ✓ Approved | v1.2.0           │   │ │
+│ │ └──────────────────────────────┘ │ │ └──────────────────────────────┘   │ │
+│ │                                  │ │                                      │ │
+│ │ ┌──────────────────────────────┐ │ │ ┌──────────────────────────────┐   │ │
+│ │ │ 💰 Aave                       │ │ │ │ 💳 SWIFT MT                   │   │ │
+│ │ │ Lend/borrow on Aave           │ │ │ │ SWIFT message transfer        │   │ │
+│ │ │ ✓ Approved | v3.0.5          │ │ │ │ ✓ Approved | v2.1.0          │   │ │
+│ │ └────────────────────────────┘ │ │ └──────────────────────────────┘   │ │
+│ │                                  │ │                                      │ │
+│ │ ┌──────────────────────────────┐ │ │ ┌──────────────────────────────┐   │ │
+│ │ │ 📊 Compound                   │ │ │ │ 🌐 SEPA                      │   │ │
+│ │ │ Lend/borrow on Compound       │ │ │ │ SEPA credit transfer         │   │ │
+│ │ │ ✓ Approved | v2.8.0          │ │ │ │ ✓ Approved | v1.0.3          │   │ │
+│ │ └──────────────────────────────┘ │ │ └──────────────────────────────┘   │ │
+│ │                                  │ │                                      │ │
+│ │ ┌──────────────────────────────┐ │ │ ┌──────────────────────────────┐   │ │
+│ │ │ 🌉 Bridge                      │ │ │ │ 🏦 FedNow                   │   │ │
+│ │ │ Cross-chain bridge            │ │ │ │ FedNow instant payment      │   │ │
+│ │ │ ⚠ Deprecated | v1.5.0        │ │ │ │ ✓ Approved | v1.0.0          │   │ │
+│ │ └──────────────────────────────┘ │ │ └──────────────────────────────┘   │ │
+│ │                                  │ │                                      │ │
+│ └──────────────────────────────────┴──────────────────────────────────────┘ │
+│                                                                              │
+│ Selected: ISO-20022 Pay                                                      │
+│                                                                              │
+│ ┌──────────────┐  ┌──────────────┐                                          │
+│ │ [Add]        │  │ [Cancel]     │                                          │
+│ └──────────────┘  └──────────────┘                                          │
+└─────────────────────────────────────────────────────────────────────────────┘
+```
+
+### Key Features
+- **Two-column layout**: DeFi protocols on left, Fiat/DTL rails on right
+- **Filter tabs**: All, DeFi, Fiat/DTL, Whitelisted Only
+- **Search bar**: Quick search for specific adapters
+- **Adapter cards**: Show name, description, approval status, version
+- **Status indicators**: ✓ Approved, ⚠ Deprecated, 🔒 Restricted
+
+---
+
+## 6. Mobile Responsive Layouts
+
+### Mobile Builder Canvas (<768px)
+```
+┌─────────────────────────┐
+│ [☰] CurrenciCombo [⚙️]  │
+├─────────────────────────┤
+│ [User] [Wallet] [LEI ✓] │
+├─────────────────────────┤
+│                         │
+│  Step 1: Borrow         │
+│  💰 CBDC_USD: 100k      │
+│  [Edit] [Remove]        │
+│                         │
+│  Step 2: Swap           │
+│  🔄 USD → EUR           │
+│  [Edit] [Remove]        │
+│                         │
+│  Step 3: Pay            │
+│  📤 EUR to IBAN         │
+│  [Edit] [Remove]        │
+│                         │
+│  [+ Add Step]           │
+│                         │
+├─────────────────────────┤
+│ Initial: 100k USD       │
+│ Receive: ~78k EUR       │
+│ Fees: 0.2%              │
+│ [Simulate] [Review]    │
+└─────────────────────────┘
+```
+
+### Mobile Adapter Palette (Bottom Sheet)
+```
+┌─────────────────────────┐
+│ Adapters        [✕]     │
+├─────────────────────────┤
+│ [All] [DeFi] [Fiat]     │
+├─────────────────────────┤
+│ 🔄 Swap                 │
+│ 💰 Borrow               │
+│ 📊 Deposit              │
+│ 🌉 Bridge               │
+│ ─────────────────────── │
+│ 📤 ISO-20022 Pay        │
+│ 💳 SWIFT MT             │
+│ 🌐 SEPA                 │
+│ 🏦 FedNow               │
+└─────────────────────────┘
+```
+
+---
+
+## 7. Visual Design Tokens
+
+### Colors
+- **Primary**: #000000 (Black)
+- **Secondary**: #3B82F6 (Blue)
+- **Success**: #10B981 (Green)
+- **Warning**: #F59E0B (Yellow)
+- **Error**: #EF4444 (Red)
+- **Background**: #FFFFFF (White), #F9FAFB (Gray-50)
+- **Border**: #E5E7EB (Gray-200)
+
+### Typography
+- **Font Family**: Inter (UI), Fira Code (Monospace)
+- **H1**: 24px/32px, Bold
+- **H2**: 18px/24px, Semibold
+- **Body**: 14px/20px, Regular
+- **Small**: 12px/16px, Regular
+
+### Spacing
+- **Unit**: 4px base
+- **Card Padding**: 16px
+- **Section Gap**: 24px
+- **Element Gap**: 8px
+
+### Icons
+- **Step Icons**: Emoji (💰, 🔄, 💳, 📤)
+- **UI Icons**: Lucide React (24px, stroke-width: 2)
+
+---
+
+## 8. Interaction States
+
+### Drag & Drop States
+- **Dragging**: Opacity 50%, cursor: grabbing
+- **Over Drop Zone**: Blue outline, background: blue-50
+- **Invalid Drop**: Red outline, error message
+
+### Button States
+- **Default**: Black background, white text
+- **Hover**: Gray-800 background
+- **Active**: Gray-700 background
+- **Disabled**: Gray-300 background, cursor: not-allowed
+
+### Step Card States
+- **Default**: White background, border
+- **Hover**: Shadow-md
+- **Selected**: Blue border, blue-50 background
+- **Error**: Red border, red-50 background
+
+---
+
+**Document Version**: 1.0  
+**Last Updated**: 2025-01-15  
+**Author**: Design Team
+