Solana programs are the foundation of decentralized applications (dApps) on the Solana blockchain. Functionally equivalent to smart contracts on other blockchains like Ethereum, Solana programs are on-chain executable code that enable users to perform complex operations in a trustless, decentralized environment.
These programs power everything from decentralized finance (DeFi) protocols to non-fungible token (NFT) marketplaces and gaming platforms. Understanding how they work is essential for developers building on Solana.
What Are Solana Programs?
On Solana, programs are accounts that store executable code. They are invoked through transactions containing instructions—specific functions the program should execute. Unlike traditional smart contracts, Solana programs are stateless, meaning they do not store data internally. Instead, they interact with other accounts to read from or write to persistent storage.
Key characteristics of Solana programs include:
- Executable accounts: Programs are deployed to special accounts that hold compiled binary code.
- Instruction-based execution: Users send transactions with instructions telling the program what action to perform.
- Stateless design: Programs process logic but rely on external accounts for data storage.
- Upgradeable by default: Most programs can be updated by an assigned upgrade authority unless explicitly locked.
- Verifiable builds: Developers and users can verify that deployed code matches public source code, enhancing security and transparency.
👉 Discover how to deploy your first on-chain program with confidence and ease.
Writing Solana Programs: Rust and Anchor
The vast majority of Solana programs are written in Rust, a systems programming language known for performance and memory safety. There are two primary approaches:
1. Anchor Framework
Anchor is the most popular framework for Solana development. It simplifies coding by providing:
- Macros to reduce boilerplate
- Built-in security checks
- Seamless testing tools
- Support for verifiable builds
For beginners, Anchor is the recommended starting point due to its developer-friendly abstractions and strong community support.
2. Native Rust
Writing programs in native Rust without frameworks offers greater control and flexibility but requires deeper knowledge of Solana’s runtime and account model. This approach is typically used by advanced teams optimizing for performance or custom behavior.
Deploying and Upgrading Programs
Programs are deployed on-chain using loader programs—special system-level programs responsible for managing executable code.
Upgrade Authority
When a program is deployed, an upgrade authority is assigned—usually the deployer’s wallet. This authority has the power to:
- Update program code
- Transfer ownership
- Permanently lock the program by revoking itself
Once the upgrade authority is set to None, the program becomes immutable and cannot be changed.
Verifiable Builds
To ensure trust and transparency, verifiable builds allow anyone to confirm that:
- The on-chain bytecode matches the published source code
- No malicious modifications were introduced during deployment
Tools like the Solana Verifiable Build CLI from Ellipsis Labs enable independent verification. Anchor also includes built-in support for generating verifiable builds.
You can check if a program is verified using Solana Explorer—simply search for the program address and look for verification status.
👉 Learn how secure, auditable programs enhance user trust and adoption.
How Programs Are Compiled and Executed
Solana uses the LLVM compiler infrastructure to compile Rust code into ELF (Executable and Linkable Format) binaries. These contain sBPF (Solana Bytecode Format), a customized version of eBPF optimized for high-performance execution.
During deployment:
- Source code is compiled into an ELF file
- The binary is uploaded to a program account
- The loader marks the account as executable
- Users interact via transactions containing instructions
This compilation pipeline ensures efficient, deterministic execution across all nodes in the network.
Loader Programs: Managing Executable Code
Every Solana program is owned by a loader program, which controls its lifecycle. There are five loader types:
- Native Loader: Owns all other loaders
- BPF Loader v1/v2: Legacy loaders; management functions disabled but still support execution
- BPF Loader v3: Upgradeable but being phased out
- Loader v4: The future standard, designed for secure, upgradeable programs
Loaders enable key operations:
- Deploying new programs
- Upgrading existing ones
- Transferring upgrade authority
- Finalizing immutable programs
Loader v4 is expected to become the default due to improved security and usability features.
Precompiled Programs: High-Performance Cryptographic Operations
Solana includes several precompiled programs that execute cryptographic functions more efficiently than general-purpose programs.
Ed25519 Program
Verifies Ed25519 digital signatures—a common algorithm used in wallets and authentication systems. It processes multiple signatures in a single instruction, returning an error if any fail.
Secp256k1 Program
Supports Ethereum-style public key recovery (ecrecover), enabling cross-chain compatibility with Ethereum-signed messages.
Secp256r1 Program
Verifies up to eight secp256r1 signatures per instruction—a standard used in TLS and WebAuthn systems. Enforces low-S values to prevent signature malleability.
These precompiled programs reduce computational overhead and improve transaction throughput for signature-heavy applications.
Core System Programs
Solana includes several core programs essential to network functionality:
| Program | Function |
|---|---|
| System Program | Manages account creation, lamport transfers, and fee payments |
| Vote Program | Handles validator voting and consensus participation |
| Stake Program | Manages staking delegations and reward distribution |
| Compute Budget Program | Allows setting compute limits and prioritization fees |
| Address Lookup Table Program | Enables larger transactions by expanding account references |
| ZK ElGamal Proof Program | Validates zero-knowledge proofs for encrypted data |
These programs are foundational to Solana’s operation and are used implicitly in most transactions.
Core Keywords
solana programs, rust blockchain development, anchor framework, verifiable builds, upgrade authority, sBPF bytecode, loader programs, precompiled programs
Frequently Asked Questions
What is the difference between a smart contract and a Solana program?
Solana programs are functionally equivalent to smart contracts but differ in design. They are stateless, rely on separate accounts for data storage, and use a unique execution model based on instructions and loaders.
Can all Solana programs be upgraded?
No—only those with an active upgrade authority. Once the authority is revoked, the program becomes immutable and cannot be modified.
How do I verify a program’s source code matches its on-chain version?
Use tools like the Solana Verifiable Build CLI or check verification status on Solana Explorer. Anchor-built programs often include built-in verification artifacts.
Why is Rust the preferred language for Solana development?
Rust offers memory safety, high performance, and fine-grained control over system resources—critical for secure, efficient blockchain execution.
What role does the loader play in program deployment?
The loader owns the program account and provides instructions for deploying, upgrading, and finalizing programs. It acts as a runtime manager for executable code.
Are precompiled programs customizable?
No—they are fixed-function system programs optimized for specific cryptographic operations. Developers cannot modify them but can invoke their functionality in transactions.