Set Up Soroban Smart Contract Client Service

[Mathews-25]

Context:
StellarSwipe uses Soroban smart contracts for automated trade execution with risk gates. The backend needs to interact with deployed contracts.

Problem:
Create a service that connects to Soroban RPC, invokes contract methods, and handles transaction submission.

What Done Looks Like:

• Soroban client service
• Contract method invocation helpers
• Transaction simulation before submission
• Error handling for contract failures
• Network fee estimation

Folder Structure:

src/
├── soroban/
│   ├── soroban.service.ts
│   ├── soroban.module.ts
│   ├── contracts/
│   │   ├── trade-executor.contract.ts
│   │   └── stake-manager.contract.ts
│   ├── dto/
│   │   └── invoke-contract.dto.ts
│   └── interfaces/
│       └── contract-result.interface.ts

Implementation Guidelines:

• Use @stellar/stellar-sdk SorobanRpc namespace
• Configure RPC URL from environment
• Implement contract invocation wrapper
• Simulate transactions before submission
• Parse contract events from results
• Handle network congestion (Protocol 23 parallel execution)

Key Methods:

• invokeContract(contractId, method, params)
• simulateTransaction(tx)
• getContractEvents(txHash)
• estimateFees(operation)

Edge Cases:

• Contract execution failure
• Insufficient balance for fees
• Network timeout
• Invalid contract parameters

Validation:

• Successfully invoke test contract
• Simulation detects errors
• Events parsed correctly
• Fee estimation accurate

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