Solana: Add Account and Fee Payer Filtering

[antoineborg]

Solana: Add Account and Fee Payer Filtering

Description

The Solana filter matches transactions by program IDs (required for the RPC method), then applies additional filtering via log/event matching. However, it lacks the ability to filter by accounts involved in the transaction or the fee payer.

Problems

1. No fee payer filtering - Cannot filter transactions by who paid for them
2. No account filtering - Cannot filter by specific accounts involved (signers, token accounts, etc.)
3. Limited expression parameters - Only signature, slot, fee, is_success are available; no account-related fields

This limits monitoring use cases such as:

• Monitoring program interactions only when initiated by a specific wallet
• Filtering transactions where a particular account is the fee payer
• Matching only when specific token accounts are involved

Proposed Solution

1. Extend build_transaction_params() in filter.rs:169-199 to include:

   • fee_payer - First account in account_keys (Solana convention)
   • accounts - All accounts involved in the transaction

2. Add account-based filtering as an alternative to log-based filtering (program ID matching remains required)

3. Example expressions to support:

   fee_payer == "WaLLeT123..."
   accounts contains "TokenAccount456..."
   

Trade-offs to Consider

• Performance: Checking all accounts increases matching complexity vs program-ID-only filtering
• Configuration complexity: Need to decide if accounts filter in addresses array or via expressions only
• Consistency with EVM: EVM uses from/to which maps cleanly to sender/recipient; Solana has N accounts per transaction with different roles

Related Code

• Solana filter: src/services/filter/filters/solana/filter.rs
• EVM filter (reference): src/services/filter/filters/evm/filter.rs
• Solana transaction model: src/models/blockchain/solana/transaction.rs
• Monitor config model: src/models/core/monitor.rs

[ritik4ever]

Can i take this issue ?