Anchor Framework Guide
Build Solana programs with the Anchor framework — from setup to deployment.
Anchor is the most popular framework for Solana program development, providing a structured approach to building programs with automatic account validation, IDL generation, and client SDK generation.
Program Structure
An Anchor program consists of a lib.rs file with the program module, account structs decorated with #[account], instruction handlers decorated with #[program], and error enums. The #[derive(Accounts)] macro generates account validation code from your struct definitions.
Account Validation
Anchor's account constraints (#[account(...)]) handle common validation patterns automatically: checking account ownership, verifying PDA seeds, ensuring accounts are mutable, and validating account discriminators. This prevents many common security vulnerabilities.
IDL Generation
Anchor automatically generates an IDL (Interface Definition Language) file from your program code. The IDL describes all instructions, accounts, and types, enabling automatic client SDK generation and human-readable transaction display in block explorers.
Testing
Anchor provides a testing framework using Mocha/Chai with a local validator. Write tests in TypeScript using the Anchor workspace object. Use bankrun for faster unit tests that don't require a full validator.
Deployment
Deploy with anchor deploy or anchor build && solana program deploy. For upgradeable programs, use the BPF Loader Upgradeable program. Always test on devnet before deploying to mainnet.