Rust for Solana Best Practices

Habits that keep Solana programs safe, cheap to run, and easy to audit. Walk this list before mainnet deploy and during code review.

How to Use This List

• Use as a PR checklist for any instruction or account layout change.
• Pair with LiteSVM 0.6.x tests - rules here should have a test or lint where possible.
• Revisit after Agave or toolchain upgrades; CU costs and limits can shift.

A - Safety & Validation

• Validate every account's owner, signer, and writable flags before use. Prevents privilege escalation and account substitution.
• Use checked arithmetic for all token and lamport math. Eliminates wrap-based drain attacks.
• Reject duplicate account keys in financial instructions. Stops double-spend style confusions.
• Store canonical PDA bumps and verify seeds on-chain. Blocks bump hunting and PDA forgery.
• Return ProgramError instead of panicking. Fails cleanly with decodable codes.

B - Data & Layout

• Prefix accounts with a unique discriminator or version byte. Prevents type confusion attacks.
• Precompute LEN constants and assert data_len() at runtime. Avoids partial writes and parse panics.
• Prefer fixed-size layouts for hot paths; use Borsh for variable tails. Balances CU and flexibility.
• Document and test schema migrations before upgrading programs. Protects live user funds.
• Zero account data on close and send rent to a defined recipient. Stops revival attacks.

C - Performance

• Cap loop bounds from user input length. Prevents CU exhaustion.
• Minimize msg! and string formatting in production paths. Logs are expensive.
• Audit cargo tree for non-no_std dependencies. Keeps binaries building and small.
• Measure CU with simulation in CI for critical instructions. Catches regressions early.
• Batch CPIs when semantics allow. Reduces per-invocation overhead.

FAQs

Related

• Rust for Solana Basics - Section intro
• Native Programs Best Practices - Native-specific rules
• Program Security Auditing - Pre-audit prep

Stack versions: This page was written for Agave 4.1.1, Solana CLI 3.0.10, Anchor 0.32.1, anchor-lang 0.32.1, Rust 1.91.1, @solana/kit 7.0.0, Surfpool 0.12.0, and LiteSVM 0.6.x.