Solana Improvement Documents (SIMD): Complete Guide

Solana Improvement Documents (SIMD) provide a public format for proposing and discussing changes to the Solana protocol and ecosystem standards. A SIMD can document a technical direction, but publication alone does not guarantee acceptance, implementation, validator adoption, or activation on mainnet.

Last updated: July 2025

Key Takeaways

• A Solana Improvement Document (SIMD) is the formal written proposal mechanism used to change the Solana blockchain protocol
• Every SIMD moves through six defined stages: Draft, Review, Accepted, Activated, Withdrawn, or Rejected
• SIMDs fall into three main categories: Standards Track, Meta, and Informational
• SIMD-0228 reduced SOL's inflation schedule after ratification by a validator supermajority, proving that governance votes carry direct economic consequences
• The process is open to anyone; all proposals are publicly hosted at github.com/solana-foundation/solana-improvement-documents

Solana Improvement Documents (SIMD): Governance Overview

A Solana Improvement Document (SIMD) is a formal written proposal used to suggest and ratify changes to the Solana (SOL) blockchain protocol. It is the official mechanism through which Solana's community governs how the network evolves. In crypto, SIMD stands for Solana Improvement Document, and it serves the same function that Ethereum Improvement Proposals (EIPs) serve for Ethereum or that Bitcoin Improvement Proposals (BIPs) originally established for Bitcoin (the model both later systems derive from).

Sometimes called Solana Improvement Proposals, SIMDs are officially termed Solana Improvement Documents. The distinction matters because the name signals the formal, document-driven nature of the process rather than a looser suggestion forum.

Solana (SOL) is a high-throughput Layer 1 blockchain combining Proof of History (PoH), a cryptographic timekeeping mechanism that sequences events on the network, with Proof of Stake (PoS) for validator selection. It was co-founded by Anatoly Yakovenko and launched in 2020. As the network grew and protocol decisions became more consequential, the community formalized its change process through the SIMD framework.

Two key organizations interact with that framework in distinct ways. Solana Labs, the for-profit core development company, frequently authors and champions SIMDs. Like any other proposer, however, its proposals must go through full community review and validator and ecosystem adoption. The Solana Foundation, a separate nonprofit that hosts the SIMD repository and provides editorial oversight, facilitates the process without holding decisional authority.

SIMDs govern everything from core consensus changes to SOL's inflation schedule and transaction fee mechanics. When a SIMD is ratified, it becomes a binding protocol upgrade. The questions of who can propose a SIMD, how proposals get accepted, and which SIMDs have already changed SOL's economics all carry direct relevance for SOL holders and the developers and validators who build on the network.

Disambiguation: SIMD here stands for Solana Improvement Document, not "Single Instruction, Multiple Data," a CPU architecture term that shares the acronym. The two have no relationship.

How the SIMD Process Works: From Draft to Activated Protocol Upgrade

Solana governance works through a structured, multi-stage proposal process. Anyone can write a SIMD, submit it publicly to a GitHub repository, and guide it through community review before Solana validators and contributors assess it through public review, implementation work, software adoption, and any proposal-specific signaling process. This hybrid model, combining off-chain deliberation with on-chain ratification, distinguishes it from pure on-chain governance (where smart contracts execute votes) and from informal governance (where a core team decides unilaterally).

The Six Stages of a SIMD: Draft to Activation

Every SIMD moves through six defined status stages, as established in SIMD-0001:

1. Draft: The author submits the written proposal as a pull request to the Solana Foundation's public GitHub repository. The proposal is open for community discussion from the moment it appears. Any stakeholder can comment, question, or suggest revisions.

2. Review: SIMD editors assigned by the Solana Foundation evaluate the proposal for completeness and process compliance. The broader community continues deliberating technical merits and economic implications. This stage can last weeks or months depending on complexity.

3. Accepted: The proposal has gathered sufficient community consensus to move toward implementation. This does not mean it is live on the network. It means the community has aligned on the direction and that validator and ecosystem adoption can proceed.

4. Activated: The proposed change is live on the Solana network. Validators implement the protocol upgrade and the change takes effect for all users and applications interacting with Solana. Every network participant, from validators to exchanges, must accommodate the resulting changes.

5. Withdrawn: The proposal's author has pulled it from consideration, typically after determining that the idea needs significant reworking or that community appetite is insufficient. A Withdrawn SIMD can be revised and resubmitted as a new proposal.

6. Rejected: The proposal did not advance after review or failed to gain sufficient support. A Rejected SIMD is formally marked in the GitHub repository and can be revised and resubmitted. Rejection on one attempt does not permanently close the topic.

There is no fixed timeline for moving through these stages. Simple technical improvements with strong community support may progress from Draft to Activated in a matter of weeks. Economically significant proposals, like SIMD-0228 which addressed SOL's inflation schedule, can take months of community debate and validator deliberation before a vote is called.

SIMD-0001: The Rulebook That Governs All SIMDs

SIMD-0001 is the Meta-type Solana Improvement Document that defines the SIMD process itself. It is the document that all subsequent SIMDs are written and evaluated against. SIMD-0001 established what a SIMD is, how to write one, what the six status stages mean, and how review and acceptance criteria work. Every piece of status terminology used in this article (Draft, Review, Accepted, Activated, Withdrawn, Rejected) comes directly from SIMD-0001's definitions. You can read the full framework document at the official Solana Foundation GitHub repository.

How Validators Signal Support for SIMDs

A Solana validator is a node operator who stakes SOL, locking it as collateral, to participate in transaction processing and governance votes on the Solana network. Staking gives validators the right to process transactions, earn rewards, and cast governance votes, with voting power proportional to the amount of SOL staked. This is why the system is described as stake-weighted.

Solana uses Proof of Stake (PoS), meaning validator selection and voting power both derive from staked SOL. Solana's PoS implementation is paired with Proof of History (PoH), which creates a verifiable record of time that allows the network to process transactions at high speed. This technical architecture makes governance decisions particularly consequential, since changes affect a network handling thousands of transactions per second.

When a Standards Track SIMD reaches the ratification stage, validators signal their vote through an on-chain mechanism, meaning the vote is recorded directly on the Solana blockchain. A supermajority of stake-weighted votes is typically required for a Standards Track SIMD to be Accepted. A supermajority means validators controlling a large share of total staked SOL (generally two-thirds or more) must signal approval. The exact threshold is defined in SIMD-0001 and may evolve as the governance process matures. Verify the current threshold directly in SIMD-0001 before citing a specific figure.

For SOL holders: The validator voting process governs any change to SOL's inflation schedule, staking rewards, or transaction fees. This mechanism is the foundation for understanding why SIMDs matter to your holdings.

Types of SIMDs: The Category Framework

SIMDs fall into three main categories (Standards Track, Meta, and Informational), each with a different scope, ratification requirement, and purpose within the governance process.

Standards Track SIMDs propose actual changes to the Solana protocol (affecting consensus, networking, or interfaces) and require validator and ecosystem adoption to become Activated. Meta SIMDs describe the governance process itself rather than proposing a protocol change. SIMD-0001 is the prime example: it defines how all other SIMDs work without itself being a protocol upgrade. Informational SIMDs document guidelines and best practices without requiring ratification.

Most SIMDs that generate public attention, including SIMD-0228 and SIMD-0096, are Standards Track (Core), because they propose changes to economic parameters or consensus behavior that affect every participant on the network.

How to Participate in Solana Governance Through SIMDs

The SIMD process is open to anyone. No special permission is required to read active proposals, comment on governance discussions, submit a new SIMD, or cast a vote as a validator.

For Developers: How to Write and Submit a SIMD

Anyone can submit a SIMD through the Solana Foundation's public GitHub repository. The process is not restricted to Solana Labs or the Foundation.

Here are the steps to submit a SIMD:

1. Read SIMD-0001: Before writing anything, read the SIMD-0001 process document to understand the required template, formatting guidelines, and what makes a proposal complete.

2. Identify a clear protocol problem or improvement: SIMDs should address a specific, well-defined issue with the Solana protocol. Vague or insufficiently scoped proposals are unlikely to advance through the Review stage.

3. Start a community discussion before drafting: Share your idea on Solana's community forums or Discord to gauge interest and identify potential concerns before writing a full draft. Early feedback saves significant revision time later.

4. Fork the Solana Foundation's SIMD GitHub repository: Go to github.com/solana-foundation/solana-improvement-documents and fork the repository to your own GitHub account.

5. Write the SIMD following the standard template: Use the template defined in SIMD-0001. A complete SIMD includes an abstract, motivation, specification, and backwards compatibility analysis alongside the technical rationale.

6. Submit a pull request to the repository: Open a pull request from your fork to the main Solana Foundation repository. This formally enters your proposal into the Draft stage.

7. Engage with SIMD editors and the community through Review: SIMD editors will review your submission for completeness. The broader community will evaluate technical and economic merits. Be prepared to revise based on feedback.

Submitting a SIMD does not guarantee a validator vote. The Review stage is a community filter, and proposals that lack sufficient technical rigor or community support may remain in Review or be Withdrawn before reaching a vote.

Find all SIMDs and the official submission repository at: github.com/solana-foundation/solana-improvement-documents

For Validators: How to Vote on Active SIMDs

Validators vote on SIMD ratification through an on-chain signaling mechanism. Your voting power is proportional to the amount of SOL you have staked, so a validator controlling a large share of staked SOL carries more influence in ratification decisions.

Standards Track SIMDs typically require a supermajority of stake-weighted votes to be Accepted. Verify the current threshold directly in SIMD-0001, as ratification requirements may evolve as the governance process matures. Validators can monitor active governance votes through Solana network dashboards and governance tooling maintained by the community.

Before voting on economically significant proposals, model the impact on your own operations. SIMD-0096 demonstrated that governance votes on commission mechanics have direct consequences for validator revenue and staking economics.

For Everyone: Following and Engaging in SIMD Governance

Participation in Solana governance does not require a GitHub account, validator infrastructure, or technical development experience.

Community members and SOL holders can engage with the SIMD process in several ways:

• Read and comment on active SIMDs. All proposals are publicly visible in the GitHub repository, and anyone can leave comments on pull requests.
• Engage in governance discussions. The Solana Discord and community forums host ongoing discussions about active proposals, often more accessible than the technical GitHub threads.
• Stay informed through governance tracking. Several community resources track SIMD status changes, notable votes, and governance outcomes.
• Participate indirectly by delegating stake to validators whose governance voting positions reflect your views. Token holders influence ratification outcomes through their choice of validator, even without submitting or voting on SIMDs directly.

Unlike DAO governance, which uses dedicated governance tokens to confer voting rights, Solana's SIMD process does not require a separate token. Validator stake-weighting and community deliberation are the mechanisms. Like open-source governance models such as Python's PEP process or the IETF's RFC system, SIMDs provide a transparent, community-accessible framework for deliberating protocol changes.

Track all active and historical SIMDs at: github.com/solana-foundation/solana-improvement-documents

Solana SIMD vs. Ethereum EIP vs. Bitcoin BIP: How Blockchain Governance Compares

Solana governance operates as a hybrid model. SIMD proposals are submitted and deliberated publicly off-chain, while final ratification is recorded through stake-weighted validator votes on-chain. This structure distinguishes it from both Ethereum's rough-consensus approach and DAO-style token voting.

Both SIMD and EIP are open GitHub-based processes that allow anyone to propose protocol changes through a formal written document. The key structural difference is ratification. Solana's SIMD process uses explicit stake-weighted validator voting to formally record ratification on-chain. Ethereum's EIP process relies on rough consensus among client development teams followed by client implementation, a model that is more deliberation-based and does not involve a formal on-chain vote. Bitcoin's BIP process, which established the improvement proposal concept that both EIP and SIMD derive from, uses varying activation mechanisms depending on the proposal type.

No single entity controls Solana governance. Solana Labs authors many SIMDs and is among the most active proposers, but its proposals go through the same community review and validator and ecosystem adoption process as any other submitter. The Solana Foundation hosts the repository and provides SIMD editors who review proposals for completeness and process compliance. The Foundation holds no special voting power; its role is procedural, not decisional. Final ratification authority rests with validators through stake-weighted voting.

SIMD proposals are submitted and discussed publicly via GitHub and community forums (the off-chain layer). The ratification signal is recorded on the Solana blockchain through validator stake-weighted votes (the on-chain layer). Critics note that stake-weighted voting concentrates governance influence among large validators. Supporters argue that open proposal access combined with on-chain ratification provides meaningful accountability. Both observations accurately describe the same design.

What SIMD Governance Means for SOL Holders

Governance decisions made through the SIMD process can directly alter the economic parameters governing SOL's supply, staking yields, and transaction fee structure, making SIMD literacy a practical concern for every SOL holder, not just protocol engineers.

SOL's tokenomics (the economic parameters governing its supply schedule, inflation rate, staking rewards, and fee distribution) are all subject to the SIMD governance process. SIMD-0228 demonstrated that a validator supermajority can change SOL's inflation schedule, meaning fewer new tokens enter circulation over time. Reduced issuance is generally understood to decrease dilution pressure on existing holders. SIMD-0096 and SIMD-0083 showed that SIMDs can also modify how staking rewards are structured and distributed, which affects the economics of holding versus actively staking SOL.

This article is for informational purposes only and does not constitute investment advice. Governance outcomes affect protocol economics but do not guarantee specific price movements for SOL or any other cryptocurrency.

Monitoring the SIMD process is one practical way to stay informed about protocol changes that may affect Solana's economic trajectory. The GitHub repository provides real-time visibility into proposals at every stage, from early Draft discussions through final Activated changes.

Related Solana Architecture Resources

Readers tracking proposal categories and individual documents can use the complete SIMD reference guide; protocol context appears in the overview of Solana's network architecture. The SOL price page provides market context. Users considering staking-related products can review SOL Earn and its current terms separately.

FAQ: Solana Improvement Documents (SIMD)

What is a SIMD in cryptocurrency?

A Solana Improvement Document (SIMD) is the formal governance mechanism used to propose and ratify changes to the Solana blockchain protocol. SIMDs govern protocol changes ranging from network performance improvements to SOL's inflation schedule and validator economics, serving the same function that Ethereum Improvement Proposals serve for Ethereum.

How does Solana governance work?

Solana governance works through a structured proposal process called the SIMD framework. Any community member can submit a written SIMD to the Solana Foundation's public GitHub repository. The proposal moves through community review stages before Solana validators cast stake-weighted on-chain votes to ratify or reject it. Discussion happens off-chain; ratification is recorded on-chain.

Who can submit a SIMD?

Anyone can submit a SIMD. The process is open to developers, validators, and community members through the Solana Foundation's public GitHub repository. Submitters must follow the formatting template defined in SIMD-0001, engage in community discussion, and work with SIMD editors through the Review stage. No special affiliation with Solana Labs or the Foundation is required.

What are the different types of SIMDs?

SIMDs are organized into three main categories. Standards Track SIMDs (with Core, Networking, and Interface subcategories) propose actual protocol changes and require validator and ecosystem adoption. Meta SIMDs describe the governance process itself rather than proposing a change; SIMD-0001 is the prime example. Informational SIMDs document non-binding guidelines and best practices.

How long does a SIMD take to be approved?

There is no fixed timeline for SIMD approval. Simple technical improvements with strong community support may move from Draft to Activated in a matter of weeks. Economically significant or contentious proposals, like SIMD-0228 which involved months of community debate before a validator vote was called, can take considerably longer. Timeline depends on technical complexity, community consensus, and implementation readiness.

What was the most controversial SIMD?

SIMD-0228 and SIMD-0096 generated the most significant community debate in Solana's governance history. SIMD-0228 proposed reducing SOL's inflation schedule, dividing validators over the economic implications. SIMD-0096 proposed changes to validator commission and reward sharing, directly affecting validator economics and generating extended deliberation before ratification.

Does Solana have decentralized governance?

Solana uses a hybrid governance model. The SIMD submission process is open to anyone (any developer, validator, or community member can write and submit a proposal). Ratification requires a supermajority of stake-weighted validator votes, with the final signal recorded on-chain. The Solana Foundation facilitates the process procedurally but holds no special voting power. Critics note that stake-weighted voting concentrates influence among large validators; the open proposal process and on-chain ratification are the primary decentralization mechanisms.

How is Solana SIMD different from Ethereum EIP?

Both SIMD and EIP are open proposal processes hosted on GitHub that allow anyone to propose blockchain protocol changes through formal written documents. The key difference is ratification. Solana's SIMD process requires explicit stake-weighted validator voting recorded on-chain. Ethereum's EIP process relies on rough consensus among client development teams followed by client implementation, a more deliberation-based approach without a formal on-chain ratification vote.

What happens when a SIMD is rejected?

A rejected SIMD is formally marked with Rejected or Withdrawn status in the Solana Foundation's GitHub repository. The proposal's author can revise it based on community feedback and resubmit as a new SIMD. Rejection on one attempt does not permanently close discussion on the topic. The same protocol question can be addressed by a future SIMD with improved specification or changed circumstances.

Can a SIMD change SOL's inflation rate?

Yes. SIMD-0228 demonstrated that the SIMD process can directly change SOL's inflation schedule. The proposal was ratified by a validator supermajority, resulting in a reduction of Solana's native inflation rate, meaning fewer new SOL tokens enter circulation over time. This confirms that SOL's economic parameters, including its inflation schedule, are subject to the SIMD governance process.

Conclusion: SIMDs Are the Engine Room of Solana's Evolution

SIMDs are the engine room of Solana's evolution, the formal mechanism through which the community shapes the protocol's direction. From defining the governance framework itself (SIMD-0001) to changing SOL's inflation schedule (SIMD-0228) and reshaping validator economics (SIMD-0096), Solana Improvement Documents have already shaped the network in ways that matter to everyone who holds, builds on, or operates infrastructure for Solana.

The process is more accessible than its technical surface suggests. Proposals live in a public repository. Discussion is open. Validator voting is on-chain and auditable. The participation pathway (whether you want to submit a SIMD, vote as a validator, or simply follow governance discussions as an informed holder) is available to anyone willing to engage.

As Solana matures and the SIMD process evolves, governance literacy will become increasingly valuable across all participant roles.

To follow active SIMD discussions, track proposals in real time, and read the full SIMD-0001 framework document, visit the official Solana Foundation SIMD repository:

github.com/solana-foundation/solana-improvement-documents