Wallet Balance Query - SOL balance retrieval implementation

[Haydart]

---

name: Wallet Balance Query - SOL balance retrieval implementation
status: open
created: 2025-09-19T16:02:24Z
updated: 2025-09-19T16:42:04Z
github: #125
depends_on: [127, 129, 124]
parallel: false
conflicts_with: []

Task: Wallet Balance Query - SOL balance retrieval implementation

Description

Implement the get_wallet_balance() method in the SolanaBlockchainService class to retrieve SOL balance for a given wallet address. This method provides the foundation for wallet balance queries and serves as the simplest blockchain data retrieval operation in the service.

Acceptance Criteria

• get_wallet_balance(address: str) -> Optional[float] method implemented
• Proper SOL balance conversion from lamports to SOL (division by 1e9)
• Address validation before making RPC calls
• Error handling for invalid addresses and network failures
• Retry logic implementation with exponential backoff
• Return None for addresses with zero balance or non-existent accounts
• Unit tests will be handled in Unit Testing - Comprehensive test suite with mocked responses #128

Technical Details

Implementation Approach

• Use solana.rpc.api.Client.get_balance() method for balance retrieval
• Convert lamports to SOL using standard Solana conversion (1 SOL = 1e9 lamports)
• Implement address validation using Solana address format checks
• Apply retry logic with exponential backoff for network failures
• Handle RPC errors gracefully with meaningful error messages

Key Considerations

• Precision: Use float for SOL amounts with proper lamport conversion
• Error Recovery: Distinguish between permanent errors (invalid address) and temporary errors (network issues)
• Edge Cases: Handle zero balances, non-existent accounts, and malformed addresses

Code Locations/Files Affected

• src/services/solana_blockchain_service.py (get_wallet_balance method)

Dependencies

• Core Service Implementation - SolanaBlockchainService class with RPC client setup #127: Core Service Implementation (SolanaBlockchainService class)
• Data Models - Dataclass definitions for all return types #129: Data Models (basic dataclass structures)
• Error Handling - Custom exception classes and retry logic #124: Error Handling (custom exception classes)

Effort Estimate

• Size: S
• Hours: 3-4 hours
• Parallel: false (requires core service foundation)

Definition of Done

• get_wallet_balance method implemented and functional
• Proper lamport to SOL conversion verified
• Address validation working for valid/invalid Solana addresses
• Error handling tested for network failures and invalid inputs
• Retry logic functioning with exponential backoff
• Unit tests will be handled in Unit Testing - Comprehensive test suite with mocked responses #128
• Method returns correct Optional[float] type as per interface

[Haydart]

Closing as part of epic completion - SimpleSolanaService implementation is complete