The Fuchsia RFC process has evolved from the following RFCs:
This page collates the above RFCs and captures the current process.
After reviewing this process, you can follow this guide to create an RFC.
The Fuchsia RFC process is intended to provide a consistent and transparent path for making project-wide, technical decisions. For example, the RFC process can be used to evolve the project roadmap and the system architecture.
The RFC process establishes a consistent and transparent path for making project-wide technical decisions and ensuring that the appropriate stakeholders are involved in each decision.
This section describes the design of the RFC process.
The RFC process can be used for any change to Fuchsia that would benefit from its structured approach to decision making, escalation help from the Eng Council and/or its durable record of the decision.
The vast majority of changes do not require an RFC. Instead, these changes can be made using the code review process. Contributors should feel free to use the RFC process if they find it useful, and may stop at any point if there's agreement that the process is not required or does not add value in a particular case. However, technical decisions that have broad impact across the project require broader agreement and must be socialized with the project using the RFC process.
The following kinds of changes must use the RFC process:
Adding constraints on future development. Some decisions, once made, constrain the future development of the system. We need to be careful when making such decisions because they can be difficult to revise later.
Making project policy. Project policies have broad impact across the system, often affecting contributors throughout the project. Examples include: changing the set of supported languages (impacts everyone who needs to debug and understand the system), deprecating a widely-used API, and changing testing requirements for a broad class of code changes.
Changing the system architecture. The system architecture describes how the system fits together as a whole. Changing the system architecture, by definition, crosses boundaries between subsystems and requires careful consultation with many stakeholders.
Delegating decision-making authority. There are often classes of decisions that the project needs to make frequently and that benefit from specialized expertise. Rather than making all these decisions through the RFC process, the project can delegate decision-making authority for those classes of decisions to another group or process. For example, we often need to make decisions about platform APIs, which add constraints on future development, but it would not be practical to use the RFC process for every change to the platform API.
Escalations. Finally, contentious changes can benefit from the transparency and clarity of the RFC process. If there is a disagreement about technical direction that cannot be resolved by an individual technical leader, the decision can be escalated to the RFC process either by one of the disagreeing parties or by another contributor.
In addition to the general considerations outlined above, some areas declare additional criteria. Please consult these documents when relevant:
| Area | Criteria RFC |
|---|---|
| Component Framework | RFC-0098 |
| FIDL | RFC-0049 |
| Software Delivery | RFC-0103 |
| Zircon | RFC-0006 |
Other changes that might benefit of the RFC process are ones that require manual or automated large scale changes of the codebase. For example how logs are written or how error paths are handled. Rather than live with islands of consistency, the aspiration is to find the best patterns and uniformly apply them to the entire codebase.
Authors are encouraged to initiate the RFC process with a problem statement as soon as they find it useful. This should be relatively lightweight, and the author may choose to exit the RFC process later if they decide that publishing an RFC is not necessary.
Some ideas may benefit from early discussion with stakeholders to discover requirement while other ideas benefit from a prototype to understand the tradeoffs.
People interact with the RFC process in several roles:
RFC Authors. An RFC Author is a person who writes an RFC. Everyone who contributes to Fuchsia can be an RFC Author. A given RFC can have one or more authors. The authors of a given RFC drive the process for that RFC.
Eng Council. The Eng Council (FEC) facilitate discussion and make the final decision as to whether the project accepts an RFC.
Facilitator. The person appointed by FEC to shepherd this RFC through the RFC process. Today, this person is typically an FEC member. The facilitator advises the author and may also act as a point of escalation to ensure timeline feedback from stakeholders.
Stakeholder. A stakeholder is a person who has a stake in whether the project accepts a given RFC. Stakeholders are typically Fuchsia contributors, but some RFCs might have stakeholders beyond the Fuchsia project. For example, stakeholders might be involved in other projects that use Fuchsia or are otherwise affected by changes to Fuchsia. Stakeholders do not always participate directly in discussions about RFCs. Instead, stakeholders are often represented by someone, often a technical lead or other person responsible for a group of stakeholders.
Reviewer(s). The stakeholders whose +1 or -1 will be considered when the FEC decides to accept or reject the RFC. (While a +2 is the “approve” on code CLs, we tend to look to reviewers to +1 or -1 to indicate their support or lack thereof, and look to the facilitator to +2 upon approval.)
Consulted. The stakeholders whose feedback on the RFC was sought, but whose +1 or -1 is not considered when the FEC decides to accept or reject the RFC.
This section describes each step involved in the RFC process.
The first step in the RFC process is to identify a problem, and socialize that problem with your project. Are other people aware of this problem? Someone else might already be working on the problem or might have some background or context about the problem that would be useful to you. The earlier you discover this information, the better.
Please note that the problem statement does not need to be polished or formally written up before starting this step. It's best to start socializing as early as possible to receive feedback on whether the idea is feasible and if the direction is correct. This can potentially save the authors time and effort in case the idea does not materialize or if the direction needs to change significantly.
There are no constraints on the method(s) of communication used at this stage of the process. While the formal writeup for an RFC eventually takes shape as a markdown file reviewed using a Gerrit code change, authors should use whatever medium they find useful at this stage.
Exit criteria: The author has a clear understanding of the problem they want to solve OR the author decides this problem does not require the RFC process.
The author should write up a brief statement of the problem to be solved. This can be in any format that's useful for discussion, and should provide enough information so that readers can determine which Fuchsia subsystems may be affected. This problem statement should be specific about any requirements known at this stage, although more may be discovered later. It should also make any “non-goals” clear, to avoid scope-creep.
Exit criteria: The author emails the problem statement to Eng Council (FEC).
Engineering council assigns a facilitator. This facilitator is a resource for the RFC author to help refine the problem statement and identify relevant stakeholders. The facilitator may also advise the author about whether this problem requires or will benefit from a formal RFC writeup. In some cases, a facilitator may advise the author to simply proceed to design and implementation outside the RFC process.
Exit criteria: Facilitator is assigned, author receives email notifying them of their facilitator.
During this phase, the RFC author should identify the stakeholders for this RFC. The author may ask their facilitator to advise in this process. The list of stakeholders should be written down alongside the problem statement. This may take place in a Google Doc, or the author may choose to create an RFC CL with a mostly-empty RFC template and fill out its stakeholder section.
Note: If needed, stakeholders may be added or removed later in the process by the author or the facilitator.
Exit criteria: Author and facilitator agree on a set of stakeholders, and the stakeholders are recorded in a Google Doc or a changelist with the RFC template.
During this phase, identify solutions to your problems and the pros and cons of each solution. Socialize these solutions with your stakeholders, and incorporate their feedback. If you are unsure how to socialize your idea, consider asking your facilitator or a technical leader for advice. They will often have more experience socializing ideas and might be able to point you in a good direction.
Example. This RFC was socialized by having a discussion in the Eng Forum, which is a regular meeting inside Google of various engineering leaders involved in the project. The RFC was also socialized with the creators of the FTP and CTP process, who have good background and context about these processes.
Exit criteria: When the author feels they have enough information to proceed. This is per the author's discretion. If they feel that this is accomplished, then they have several options:
Once the author has gathered all the background and context they can through socialization, they are ready to start the formal part of the RFC process. The next step is to write a draft of the RFC document itself. Early drafts and feedback may happen outside of markdown (e.g. in a Google Doc). However if there is a formal RFC writeup later in the process, it is strongly encouraged to carry over the relevant context from the more dynamic medium over to RFC writeup in markdown. For instance, back-and-forth conversations may lead to additional “alternatives considered” entries to be added.
When the author is ready, they should create a CL that adds a file to the //docs/contribute/governance/rfcs directory, starting with a copy of the RFC template.
Any other files that are part of the RFC, diagrams for example, can be added to the resources directory under a subfolder with the same name as the RFC itself. Example://docs/contribute/governance/rfcs/resources/<RFC_name>/diagram.png.
Do not worry about assigning a number to the RFC at this stage. Instead, use NNNN as a placeholder. For example, the file name should be something like NNNN_my_idea.md. The RFC will get a number shortly before landing.
Tip. Consult the RFC best practices doc for advice about drafting and iterating on the RFC.
Suggestion. Consider marking the CL containing the RFC as a “work-in-progress” until you are ready for feedback.
The author should invite stakeholders to provide feedback on the RFC by adding them to the “Reviewers” (for stakeholders whose +1 is required) or “CC” fields (for “consulted” stakeholders) in the CL, as for a normal code review. In addition, the author may email their CL to eng-council-discuss@fuchsia.dev soliciting additional feedback. The stakeholders should provide feedback by leaving comments on the RFC in the code review tool.
Reviewers are expected to respond to requests for review and to followup comments within five business days. The author and reviewers should use Gerrit's “attention set” feature to keep track of who needs to respond. If responses will take longer than this (e.g. if a protype needs to be built) this should be indicated in CL comments.
If the discussion is too complex for the code review tool or is taking longer than you would like, consider scheduling a meeting with the relevant stakeholders to have a more efficient discussion. After the meeting, you must post a summary of the meeting in a comment on the CL so that people who were not at the meeting can understand what was discussed during the meeting.
If the author runs into any issues or delays during the discussion, the facilitator can help resolve them. Below are some common issues that arise during these discussions:
If the discussion becomes contentious or if you have difficulty getting feedback from a stakeholder, please let your faciliator know. Your faciliator can help move the discussion forward, for example by providing additional structure to the discussion or moving the discussion to another forum, such as a synchronous meeting or an engineering review. Regardless of how the discussion proceeds, the results of any off-CL discussion must be captured in the CL, often by posting a summary of the discussion as a CL comment.
Feedback may include comments from people who are not stakeholders. The author should respond to these comments if relevant, but settling them is not necessarily required to move to the Last Call stage. If the comments point to a disagreement about who is a stakeholder, FEC can help resolve this.
If the problem ceases to be relevant or the author and stakeholders agree that the problem does not warrant an RFC, the author may withdraw the RFC at this point. In this case, the author should mark the CL containing the RFC as abandoned. The author, or someone else, can always resurrect your RFC later if circumstances change. When resurrecting an RFC created by someone else, you should start the RFC process over from the beginning, but you can use the withdrawn RFC as a starting point rather than TEMPLATE.md. Please confer with the original authors to determine whether they wish to continue to have their names associated with the new incarnation of the RFC.
Note to reviewers: The RFC process is meant to encourage a variety of perspectives and vibrant discussions. Often, giving negative feedback in a public forum might be difficult. If needed, reviewers can reach out to their leads, peers or Eng Council for help.
Suggestion. If you are interested in RFCs, consider configuring the Gerrit Code Review tool to send you an email notification when a CL modifies the
//docs/contribute/governance/rfcsdirectory.
Exit criteria: RFC CL is out for review, with feedback solicited and incorporated into the RFC CL OR RFC is withdrawn.
Once the discussion on the RFC is converging, the author must ask their facilitator to move the RFC's status to Last Call. The faciliator will mark the RFC as being in Last Call in the tracker, which generates automatic email to eng-council-discuss@fuchsia.dev, and will comment on the CL to solicit any final feedback before moving to the decision step. The RFC will be open for feedback for the next 7 calendar days.
Typically, reviewers sign off with a +1 and the facilitator will sign off with a +2. Consulted stakeholders may also sign off with a +1 or +2 if they wish to express their enthusiasm for the RFC, although this is not required.
Stakeholders who wish to object to an RFC can set the Code-Review flag to -1 or -2, depending on how strongly they feel that the RFC should not move forward. When setting the Code-Review flag to -1 or -2, a stakeholder must state their reason for objecting, ideally in a way that would let someone understand the objection clearly without having to read the entire discussion that preceded the objection.
A stakeholder setting the Code-Review flag to -1 or -2 does not necessarily prevent the project from accepting the RFC. See the “How decisions are made” section below for more details about how the project decides whether to accept an RFC.
After all the stakeholders have weighed in with their Code-Review flags, send an email to eng-council@fuchsia.dev to prompt the Eng Council to decide whether to accept your RFC.
Exit criteria: Feedback provided by all stakeholders; all feedback addressed.
If the project decides to accept your RFC, a member of the Eng Council will comment on your CL stating that the RFC is accepted and will assign the RFC a number, typically the next available number in the series. If there are any -1 or -2 Code-Review flags, the Eng Council will explicitly clear each flag by summarizing the objection and by describing why the RFC is moving forward despite the objection. Eng Council will indicate if any additional information needs to be documented in your RFC, such as rationale for a different approach or tradeoffs being made.
If the project decides to reject your RFC, a member of the Eng Council will comment on your CL stating that the RFC is rejected, provide a rationale for the rejection and will assign the RFC a number. Rejected RFCs are valuable engineering artifacts. The Eng Council will work with the RFC Authors to land a version of the RFC that is marked as rejected and incorporates the rationale.
Rarely, if the Eng Council identifies one or many unresolved open items, the RFC may be moved back to the draft stage. The Eng Council will ask of the author(s) to resolve the open items identified with the relevant stakeholders before another request to review the RFC will be granted.
You should upload a new patchset of your RFC with the assigned number, both in the title of the RFC and in the filename. If your RFC is approved and requires implementation, please make sure you have an issue filed in the issue tracker and put a link to the issue in the header of your RFC.
The Eng Council will then mark your CL Code-Review +2 and you can land your RFC!
Congratulations! You have contributed a valuable engineering artifact to the project!
Exit criteria: RFC number assigned; any applicable rationale, tradeoffs and Eng Council feedback incorporated; RFC merged.
If you area not currently interested in moving your RFC forward, for example because your priorities have shifted or because the problem the RFC was aiming to solve is no longer as salient, you can move your RFC to the On Hold state. When an RFC is On Hold, stakeholders are not expected to provide feedback and the FEC will not actively facilitate progress.
If there is no visible progress on the CL for your RFC in a month, the RFC bot will send an email to you and your facilitator to prompt a discussion about whether to move your RFC to the On Hold state or how to move your RFC forward. Ideally, if you are encountering difficulities or delays, you would have escalated this situation to your faciliator before this point, but this conversation is also a good time to surface those issues.
You can move your RFC out of the On Hold state at any time by contacting your faciliator and letting them know that you plan to resume work on your RFC. If you would like a new faciliator, contact any member of the FEC and they can assign you a new facilaitor. At this point, your RFC will move back to the draft stage.
Exit criteria: RFC Author states their intention to resume active work on their RFC; Faciliator comments on the CL for the RFC indicating that the RFC is no longer on hold.
The decision whether to accept an RFC is made by the Eng Council, acting in rough consensus with each other. If the decision involves an RFC that has Eng Council members as authors, those members must recuse themselves from the decision.
If the Eng Council cannot reach rough consensus, the RFC is not accepted. In deciding whether to accept an RFC, the Eng Council will consider the following factors:
Decisions made by the Eng Council can be escalated to the governing authority for the project.
An existing RFC can be amended if the following criteria are met:
For changes in design, please capture what the original design goals were, and why and how they changed.
For any significant changes in design, please submit a new RFC.
If the RFC process is being updated, please also update the RFC process page.
This RFC serves as documentation for the RFC process.
The primary cost of implementing this proposal is that introducing a formal decision-making process might slow down the pace of decision-making. The process might be heavier than necessary for some kinds of decisions.
Recording decisions in the source repository has the effect of making those decisions more difficult to change. That effect might be positive in some scenarios, but the effect might also be negative in other scenarios.
The criteria in the “when to use the process” section attempts to mitigate this drawback by scoping the process to consequential situations but such scoping is bound to have false positives and false negatives.
There are a large number of possible alternative strategies for solving the underlying problem. For example, we could use a decision-making process that centers around a synchronous meeting, but such a process will have difficulty scaling to a global open-source project. We could also have selected a different decision-making mechanism that balanced more towards consensus or more towards authority.
There is a good deal of prior art about decision-making processes for open-source projects. This proposal is strongly influenced by the following existing processes:
IETF RFC process. The IETF has run a successful, large-scale decision-making process for a long period of time. The process described in this document draws a number of ideas from the IETF process, including some of the terminology.
Rust RFC process. The Rust community runs an RFC process, which has been effective at making decisions for somewhat similar software engineering project. The process described in this document is fairly directly modelled after the Rust RFC process.
Blink Intent-to-implement process. The Chromium project runs a decision-making process for behaviors that affect web pages. The process described in this document is informed by my (abarth) experience helping to design and run that process for a period of time.
FIDL Tuning Proposal. The Fuchsia project has had direct experience using a similar process to make decisions about the FIDL language. This proposal exists because of the success of that decision-making process.
