[DRAFT] SIMP-1: SIMP Purpose and Guidelines

Table of Contents

What is a SIMP?

SIMP stands for StarkNet IMprovement Proposal. A SIMP is a design document providing information to the StarkNet community, or describing a new feature for StarkNet or its processes or environment. The SIMP should provide a concise technical specification of the feature and a rationale for the feature. The SIMP author is responsible for building consensus within the community and documenting dissenting opinions.

SIMP Rationale

We intend SIMPs to be the primary mechanisms for proposing new features, for collecting community technical input on an issue, and for documenting the design decisions that have gone into StarkNet. Because the SIMPs are maintained as text files in a versioned repository, their revision history is the historical record of the feature proposal.

For StarkNet implementers, SIMPs are a convenient way to track the progress of their implementation. Ideally each implementation maintainer would list the SIMPs that they have implemented. This will give end users a convenient way to know the current status of a given implementation or library.

SIMP Types

There are three types of SIMP:

  • A Standards Track SIMP describes any change that affects most or all StarkNet implementations, such as—a change to the network protocol, a change in block or transaction validity rules, proposed application standards/conventions, or any change or addition that affects the interoperability of applications using StarkNet. Standards Track SIMPs consist of two parts: a design document and an implementation. Furthermore, Standards Track SIMPs can be broken down into the following categories:
    • Core : improvements requiring a rollup contract upgrade or migration.
    • Networking : includes improvements around node communication.
    • Interface : includes improvements around client API/RPC specifications and standards, and also certain Cairo language-level standards like method names and contract ABIs.
    • Application : application-level standards and conventions, including contract standards such as Account or Token standards, URI schemes, library/package formats, and wallet formats.
  • A Meta SIMP describes a process surrounding StarkNet or proposes a change to (or an event in) a process. Process SIMPs are like Standards Track SIMPs but apply to areas other than the StarkNet protocol itself. They may propose an implementation, but not to StarkNet’s codebase; they often require community consensus; unlike Informational SIMPs, they are more than recommendations, and users are typically not free to ignore them. Examples include procedures, guidelines, changes to the decision-making process, and changes to the tools or environment used in StarkNet development. Any meta-SIMP is also considered a Process SIMP.
  • An Informational SIMP describes an StarkNet design issue, or provides general guidelines or information to the StarkNet community, but does not propose a new feature. Informational SIMPs do not necessarily represent StarkNet community consensus or a recommendation, so users and implementers are free to ignore Informational SIMPs or follow their advice.

It is highly recommended that a single SIMP contain a single key proposal or new idea. The more focused the SIMP, the more successful it tends to be. A change to one client doesn’t require a SIMP; a change that affects multiple clients, or defines a standard for multiple apps to use, does.

A SIMP must meet certain minimum criteria. It must be a clear and complete description of the proposed enhancement. The enhancement must represent a net improvement. The proposed implementation, if applicable, must be solid and must not complicate the protocol unduly.

SIMP Work Flow

Shepherding a SIMP

Parties involved in the process are you, the champion or SIMP author and the SIMP editors.

Before you begin writing a formal SIMP, you should vet your idea. Ask the StarkNet community first if an idea is original to avoid wasting time on something that will be rejected based on prior research. It is thus recommended to open a discussion thread on the StarkNet Shamans forum to do this.

Once the idea has been vetted, your next responsibility will be to present (by means of a SIMP) the idea to the reviewers and all interested parties, invite editors, developers, and the community to give feedback on the aforementioned channels. You should try and gauge whether the interest in your SIMP is commensurate with both the work involved in implementing it and how many parties will have to conform to it. For example, the work required for implementing a Core SIMP will be much greater than for an Application SIMP and the SIMP will need sufficient interest from the StarkNet client teams. Negative community feedback will be taken into consideration and may prevent your SIMP from moving past the Draft stage.

SIMP Process

The following is the standardization process for all SIMPs in all tracks:

Idea - An idea that is pre-draft. This is not tracked within the SIMP Repository.

Draft - The first formally tracked stage of a SIMP in development. a SIMP is merged by a SIMP Editor into the SIMP repository when properly formatted.

Review - a SIMP Author marks a SIMP as ready for and requesting Peer Review.

Last Call - This is the final review window for a SIMP before moving to Final . a SIMP editor will assign Last Call status and set a review end date ( last-call-deadline ), typically 14 days later.

If this period results in necessary normative changes it will revert the SIMP to Review .

Final - This SIMP represents the final standard. A Final SIMP exists in a state of finality and should only be updated to correct errata and add non-normative clarifications.

Stagnant - Any SIMP in Draft or Review or Last Call if inactive for a period of 6 months or greater is moved to Stagnant . a SIMP may be resurrected from this state by Authors or SIMP Editors through moving it back to Draft or it’s earlier status. If not resurrected, a proposal may stay forever in this status.

SIMP Authors are notified of any algorithmic change to the status of their SIMP

Withdrawn - The SIMP Author(s) have withdrawn the proposed SIMP. This state has finality and can no longer be resurrected using this SIMP number. If the idea is pursued at later date it is considered a new proposal.

Living - A special status for SIMPs that are designed to be continually updated and not reach a state of finality. This includes most notably SIMP-1.

What belongs in a successful SIMP?

Each SIMP should have the following parts:

  • Preamble - RFC 822 style headers containing metadata about the SIMP, including the SIMP number, a short descriptive title (limited to a maximum of 44 characters), a description (limited to a maximum of 140 characters), and the author details. Irrespective of the category, the title and description should not include SIMP number.
  • Abstract - Abstract is a multi-sentence (short paragraph) technical summary. This should be a very terse and human-readable version of the specification section. Someone should be able to read only the abstract to get the gist of what this specification does.
  • Motivation (*optional) - A motivation section is critical for SIMPs that want to change the StarkNet protocol. It should clearly explain why the existing protocol specification is inadequate to address the problem that the SIMP solves. SIMP submissions without sufficient motivation may be rejected outright.
  • Specification - The technical specification should describe the syntax and semantics of any new feature. The specification should be detailed enough to allow competing, interoperable implementations for any of the current StarkNet platforms and clients (starknet.py, starknet.js, nile, starknet-devnet, pathfinder, etc).
  • Rationale - The rationale fleshes out the specification by describing what motivated the design and why particular design decisions were made. It should describe alternate designs that were considered and related work, e.g. how the feature is supported in other languages. The rationale should discuss important objections or concerns raised during discussion around the SIMP.
  • Backwards Compatibility - All SIMPs that introduce backwards incompatibilities must include a section describing these incompatibilities and their severity. The SIMP must explain how the author proposes to deal with these incompatibilities. SIMP submissions without a sufficient backwards compatibility treatise may be rejected outright.
  • Test Cases - Test cases for an implementation are mandatory for SIMPs that are affecting rollup contract upgrades. Tests should either be inlined in the SIMP as data (such as input/expected output pairs, or included in ../assets/SIMP-###/<filename> .
  • Reference Implementation - An optional section that contains a reference/example implementation that people can use to assist in understanding or implementing this specification.
  • Security Considerations - All SIMPs must contain a section that discusses the security implications/considerations relevant to the proposed change. Include information that might be important for security discussions, surfaces risks and can be used throughout the life-cycle of the proposal. E.g. include security-relevant design decisions, concerns, important discussions, implementation-specific guidance and pitfalls, an outline of threats and risks and how they are being addressed. SIMP submissions missing the “Security Considerations” section will be rejected. a SIMP cannot proceed to status “Final” without a Security Considerations discussion deemed sufficient by the reviewers.
  • Copyright Waiver - All SIMPs must be in the public domain. See the bottom of this SIMP for an example copyright waiver.

SIMP Formats and Templates

SIMPs should be written in markdown format.

SIMP Header Preamble

Each SIMP must begin with an RFC 822 style header preamble, preceded and followed by three hyphens ( --- ). This header is also termed “front matter” by Jekyll. The headers must appear in the following order.

simp : SIMP number (this is determined by the SIMP editor)

title : The SIMP title is a few words, not a complete sentence

description : Description is one full (short) sentence

author : The list of the author’s or authors’ name(s) and/or username(s), or name(s) and email(s). Details are below.

discussions-to : The url pointing to the official discussion thread

status : Draft, Review, Last Call, Final, Stagnant, Withdrawn, Living

last-call-deadline : The date last call period ends on (Optional field, only needed when status is Last Call )

type : One of Standards Track , Meta , or Informational

category : One of Core , Networking , Interface , or Application (Optional field, only needed for Standards Track SIMPs)

created : Date the SIMP was created on

requires : SIMP number(s) (Optional field)

withdrawal-reason : A sentence explaining why the SIMP was withdrawn. (Optional field, only needed when status is Withdrawn )

Headers that permit lists must separate elements with commas.

Headers requiring dates will always do so in the format of ISO 8601 (yyyy-mm-dd).

author header

The author header lists the names, email addresses or usernames of the authors/owners of the SIMP. Those who prefer anonymity may use a username only, or a first name and a username. The format of the author header value must be:

Random J. User address@dom.ain


Random J. User (@username)

if the email address or GitHub username is included, and

Random J. User

if the email address is not given.

It is not possible to use both an email and a GitHub username at the same time. If important to include both, one could include their name twice, once with the GitHub username, and once with the email.

At least one author must use a GitHub username, in order to get notified on change requests and have the capability to approve or reject them.

discussions-to header

While a SIMP is a draft, a discussions-to header will indicate the URL where the SIMP is being discussed.

The preferred discussion URL is a topic on StarkNet Shamans. The URL cannot point to Github pull requests, any URL which is ephemeral, and any URL which can get locked over time (i.e. Reddit topics).

type header

The type header specifies the type of SIMP: Standards Track, Meta, or Informational. If the track is Standards please include the subcategory (core, networking, interface, or application ).

category header

The category header specifies the SIMP’s category. This is required for standards-track SIMPs only.

created header

The created header records the date that the SIMP was assigned a number. Both headers should be in yyyy-mm-dd format, e.g. 2001-08-14.

requires header

SIMPs may have a requires header, indicating the SIMP numbers that this SIMP depends on.

Linking to External Resources

Links to external resources SHOULD NOT be included. External resources may disappear, move, or change unexpectedly.

Linking to other SIMPs

References to other SIMPs should follow the format SIMP-N where N is the SIMP number you are referring to. Each SIMP that is referenced in a SIMP MUST be accompanied by a relative markdown link the first time it is referenced, and MAY be accompanied by a link on subsequent references. The link MUST always be done via relative paths so that the links work in this GitHub repository, forks of this repository, the main SIMPs site, mirrors of the main SIMP site, etc. For example, you would link to this SIMP with [SIMP-1](/SIMPs/SIMP-1) .

Auxiliary Files

Images, diagrams and auxiliary files should be included in a subdirectory of the assets folder for that SIMP as follows: assets/SIMP-N (where N is to be replaced with the SIMP number). When linking to an image in the SIMP, use relative links such as ../assets/SIMP-1/image.png .

Transferring SIMP Ownership

It occasionally becomes necessary to transfer ownership of SIMPs to a new champion. In general, we’d like to retain the original author as a co-author of the transferred SIMP, but that’s really up to the original author. A good reason to transfer ownership is because the original author no longer has the time or interest in updating it or following through with the SIMP process, or has fallen off the face of the ‘net (i.e. is unreachable or isn’t responding to email). A bad reason to transfer ownership is because you don’t agree with the direction of the SIMP. We try to build consensus around a SIMP, but if that’s not possible, you can always submit a competing SIMP.

If you are interested in assuming ownership of a SIMP, send a message asking to take over, addressed to both the original author and the SIMP editor. If the original author doesn’t respond to the email in a timely manner, the SIMP editor will make a unilateral decision (it’s not like such decisions can’t be reversed :)).

SIMP Editors

The current SIMP editors are

  • ?

SIMP Editor Responsibilities

For each new SIMP that comes in, an editor does the following:

  • Read the SIMP to check if it is ready: sound and complete. The ideas must make technical sense, even if they don’t seem likely to get to final status.
  • The title should accurately describe the content.
  • Check the SIMP for language (spelling, grammar, sentence structure, etc.), markup (GitHub flavored Markdown), code style

If the SIMP isn’t ready, the editor will send it back to the author for revision, with specific instructions.

Once the SIMP is ready for the repository, the SIMP editor will:

  • Assign a SIMP number (generally the PR number, but the decision is with the editors)
  • Close the corresponding Discourse topic
  • Send a message back to the SIMP author with the next step.

The SIMP editors monitor SIMP changes, and correct any structure, grammar, spelling, or markup mistakes we see.

The editors don’t pass judgment on SIMPs. We merely do the administrative & editorial part.

Style Guide


The title field in the preamble:

  • Should not include the word “standard” or any variation thereof; and
  • Should not include the SIMP’s number.


The description field in the preamble:

  • Should not include the word “standard” or any variation thereof; and
  • Should not include the SIMP’s number.

SIMP numbers

When referring to a SIMP by number, it should be written in the hyphenated form SIMP-X where X is the SIMP’s assigned number.

RFC 2119

SIMPs are encouraged to follow RFC 2119 for terminology and to insert the following at the beginning of the Specification section:

The key words “MUST”, “MUST NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”, “SHOULD NOT”, “RECOMMENDED”, “MAY”, and “OPTIONAL” in this document are to be interpreted as described in RFC 2119.


This document was derived heavily from Ethereum’s EIP-1 written by Martin Becze, Hudson Jameson, et al. which in turn was derived from Bitcoin’s BIP-0001 written by Amir Taaki which in turn was derived from Python’s PEP-0001. In many places text was simply copied and modified. Although the PEP-0001 text was written by Barry Warsaw, Jeremy Hylton, and David Goodger, they are not responsible for its use in the StarkNet Improvement Process, and should not be bothered with technical questions specific to StarkNet or the SIMP. Please direct all comments to the SIMP editors.


Copyright and related rights waived via CC0.


Please cite this document as:

Martín Triay, “SIMP-1: SIMP Purpose and Guidelines,” StarkNet Improvement Proposals , no. 1, May 2022. [Online serial]. Available: [DRAFT] SIMP-1: SIMP Purpose and Guidelines.


awesome, i think its a good time to start setting some of these processes as the language matures and the number of dev increase. i realize it may be a little too specific but i feel like the no external links and reference implementation optional section contradict each other.


External links would be external from this forum (relative) or to an eventual github repo if this were to move there.


right but wouldn’t reference implementations live in external github repos?


We can just mimic EIP repos, and have implementations be part of pull requests.


As discussed with Louis, we initiated the SIMPs repository.
Thanks @martriay for raising this discussion.
Please find the link of the repo: GitHub - CairOpen/SIMPs: StarkNet Improvement Proposal repository

Still a lot to be done, it is just the initialization.
We need to think about the CI, the website generation, the list of SIMPs editor,…
Many topic to discuss but at least we can move forward in terms of standardization.


This is to be avoided, as SIMP should be immutable once finalised. Content on external GitHub repo can change unexpectedly, which IMO would break the immutability assumption

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“Simp” as a word has some negative connotations (Simp Meaning & Origin | Slang by Dictionary.com). Social media posts including SIMP could potentially be labelled as offensive and therefore impact discussions there. For instance twitch banned this word.
I am probably late with my suggestion, but maybe we could call it SIP instead of SIMP?


This has been discussed several times, just yesterday I raised it again with @bbrandtom. It seems to be the case that the community has already adopted/embraced SIMP and it’s been hard to flip. I like SNIP or SIP better.

(BTW I consulted before naming this proposal, I wrote SIMP above just in response to the community’s decision, not the other way around)