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CFN Language Discussion

What is it?

This repo is a place to propose and discuss new language features for the CloudFormation template language. It is also a great place to request CloudFormation template language features, report CloudFormation template language bugs or any general discussion related to the CloudFormation template language.

Go to: What is an RFC | RFC Process

# Title Owner Status
43,73,79 Fn::FindInMap enhancements (default value and intrinsic fns) @mingxingong ✅ done (docs)
80 Add RFC for Fn::NumberComparison @mingxingong ✍️ review
9 Adding looping functionality in CFN Template @arthurboghossian ✅ done (docs)
14 Convert Template Block to JSON String @mluk-aws ✅ done (docs)
11 Allow Intrinsic Functions and Pseudo-Parameter References in DeletionPolicy and UpdateReplacePolicy @MalikAtalla-AWS ✅ done (docs)
70 Adding Fn::Length support in CFN Template @juegong2 ✅ done (docs)

What is an RFC?

An RFC (request for comment) is a text document proposing a change to the CloudFormation template language. RFCs will only contain customer-facing syntax and behavior, not implementation details, and while we welcome all customer feedback on the proposal, the CloudFormation team will have final authority on decisions around the proposal.

Who should submit an RFC?

In general, anyone can submit RFCs, but it can be a time-consuming process, so we recommend that the community submit feature requests to discuss the proposal at a high level. The CloudFormation team can then gather all the community feedback in feature requests to formulate the RFCs.

RFC Process

1. Tracking issue

Each RFC starts with a tracking issue. This issue is the hub for conversation, community signal (+1s) and a unique identifier for the RFC. CloudFormation team members will comment on the issue to help clarify problems, stabilize syntax and make sure no breaking changes are introduced. The goal of this discussion is to make sure there is no major disagreement on the high-level proposal.

Before creating any issue, please make sure there are no similar issues in the issue list or RFCs in the RFC table.

The tracking issue includes a checklist which helps the RFC owner drive the RFC throughout the process.

2. RFC Document

Now you can start drafting the RFC document itself.

Create a file under RFCs/NNNN-my-feature based on the template under, where NNNN is your tracking issue number and my-feature is descriptive. Follow the template which includes guidance on completing the RFC.

3. Feedback

Once you have the initial draft of your RFC ready, please submit it as a pull request and start collecting feedback. The CloudFormation team will assign two reviewers within 5 business days.

4. Sign-off

Before you can merge your RFC, you will need both reviewers to sign off on the RFC.

Once signed off, reviewers will add the status/approved label to the RFC pull request.

5. Final Comments Period

At this stage, you have reached consensus about the majority concerns/questions brought up during the review period. This is a period for the broader community to get a chance to look into this RFC, which usually takes about a week. If no major concerns are raised, your pull request is ready to be merged.

6. Implementation

Once the CloudFormation Language team picks up the RFC and starts implementation, we will update the tracking issue accordingly

  • Started implementation (label: status/implementing)

7. Complete

Once Implementation is complete, the CloudFormation Language team will change the status label to status/done and close the tracking issue.

Report bugs or suggest features in the CloudFormation Template Language

We welcome you to use the GitHub issue tracker to report bugs or suggest features.

When filing an issue, please check existing open or recently closed issues to make sure somebody else hasn't already reported the issue.

Please use the bug report template for reporting bugs and the feature request template for requesting new features.


If you discover a potential security issue in this project we ask that you notify AWS Security via our vulnerability reporting page. Please do not create a public github issue.


This project is licensed under the Apache-2.0 License.


AWS CloudFormation Language Improvement RFC process owes its inspiration to AWS CDK's RFC Process