Add pump fun buy example with optimized CUs

[smypmsa]

Added example of CU consumed by a transaction using setLoadedAccountsDataSizeLimit.

https://www.anza.xyz/blog/cu-optimization-with-setloadedaccountsdatasizelimit

Summary by CodeRabbit

• New Features
  • Added a new learning example demonstrating token purchase workflows on Solana with compute unit optimization and transaction simulation capabilities. The module enables monitoring token creation events, simulating buy transactions to estimate costs, and executing optimized token purchases with explicit compute unit accounting.

[coderabbitai]

Caution

Review failed

The pull request is closed.

Walkthrough

A new Solana token-purchase module added with compute unit optimization and simulation. Includes price calculation via bonding curves, transaction building, WebSocket monitoring for token creation, buy simulation without on-chain execution, and optimized token acquisition with CU accounting.

Changes

Cohort / File(s)

Summary

New Solana Token Purchase Workflow learning-examples/manual_buy_cu_optimized.py

Introduces end-to-end tooling for monitoring Solana token creation events, calculating bonding curve prices, simulating token purchases to estimate compute unit consumption, executing optimized buys with optional CU preflight limits, and analyzing transaction metrics. Includes BondingCurveState class, async RPC helpers, transaction builders, WebSocket listeners, PDA derivation utilities, and main orchestration logic.

Sequence Diagram(s)

sequenceDiagram
    participant Main
    participant WebSocket
    participant RPC
    participant Program as On-Chain Program

    Main->>WebSocket: listen_for_create_transaction()
    WebSocket->>WebSocket: Subscribe to block notifications
    activate WebSocket
    Note over WebSocket: Wait for pump program transaction
    WebSocket-->>Main: Decoded token creation data
    deactivate WebSocket

    Main->>RPC: get_pump_curve_state(curve_address)
    RPC->>Program: Fetch account data
    Program-->>RPC: Curve state (reserves, decimals)
    RPC-->>Main: BondingCurveState

    Main->>Main: calculate_pump_curve_price(curve_state)
    Note over Main: Price = virtual_token_reserves /<br/>virtual_sol_reserves

    Main->>Main: simulate_buy(token_amount)
    activate Main
    Note over Main: Build tx with compute budget<br/>Simulate without sending
    Main->>RPC: simulateTransaction()
    RPC->>Program: Execute in simulation
    Program-->>RPC: Result with CU consumed
    RPC-->>Main: Estimated CUs
    deactivate Main

    Main->>Main: buy_token (with CU optimization)
    activate Main
    Note over Main: Insert preflight CU limit<br/>Build buy instruction
    Main->>RPC: sendTransaction()
    RPC->>Program: Execute buy on-chain
    Program-->>RPC: Transaction signature
    RPC-->>Main: CU consumed from details
    deactivate Main

    Main->>Main: Report CU consumption & savings

Loading

Estimated code review effort

🎯 4 (Complex) | ⏱️ ~45 minutes

• Bonding curve price calculation: Verify reserve arithmetic and token decimal handling for correctness
• Compute unit budget instruction: Validate correct program ID and instruction encoding for CU limits
• Transaction simulation logic: Ensure simulation message construction matches actual transaction flow
• PDA derivation functions: Confirm seeds and program IDs match Pump program specifications
• WebSocket event parsing: Check discriminator validation and instruction decoding against IDL
• Slippage and token amount computation: Verify decimal scaling and max amount calculations in token purchases

Poem

🐰 A hop through Solana's curves so sweet,
Where compute units and tokens meet!
Simulate, optimize, buy with flair—
CU savings floating through the air! ✨

✨ Finishing touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch feat/cu-opt-example

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📜 Recent review details

Configuration used: CodeRabbit UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 68cac87 and bfcac6c.

📒 Files selected for processing (1)

• learning-examples/manual_buy_cu_optimized.py (1 hunks)

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[smypmsa]

Unfortunately, this method didn't show significant improvements in the CU consumed. The screenshot above is misleading since it shows a decrease due to already existing ATA ... Didn't notice that. I will update this example.

[smypmsa]

Except for spamming multiple transactions and checking the results, it seems there is no way of proving the actual impact. But theoretically, it should improve transaction priority. Clarifying comments to the example will be provided in the next few commits.