AEP's 2024 Year in Review
Building Better APIs Together: AEP’s 2024 Year in Review
As we close out 2024, we want to share the significant strides the API Enhancement Proposals (AEP) project has made in creating a more cohesive API ecosystem. What started as a fork of Google’s API Improvement Proposals has evolved into something much more ambitious: an open, community-driven standard for building resource-oriented APIs that work consistently across different protocols and platforms.
A brief summary of the achievements outlined below are:
- The creation of aepc, an AEP “compiler” that takes a succinct resource definition and generates protobuf and OpenAPI schemas.
- The 0.1 release of aepcli, which can consume aep-compliant APIs and generate a resource-oriented command-line-interfaces dynamically.
- A complete linter for protobuf APIs, and starting an OAS variant.
- aep-explorer: a prototype of a WEB UI to explore aep-compliant APIs.
- A redesigned website (aep.dev), where this blog post is published!
The Vision Takes Shape
This year clarified our core belief that API design shouldn’t be a bikeshedding honeypot. By collecting hard-won design patterns from across the industry, we’ve worked to narrow the decisions API producers need to make while improving the experience for API consumers. Our approach focuses on resource-oriented design principles that can be expressed in both Protocol Buffers and OpenAPI, making AEPs protocol-agnostic while maintaining strong opinions about what makes APIs more usable and maintainable.
Major Technical Achievements
aepc: The AEP compiler
We introduced aepc, our service compiler that transforms concise resource definitions into fully-specified APIs. With just a few dozen lines of YAML describing your resources and their relationships, aepc generates complete Protocol Buffer and OpenAPI specifications that adhere to AEP standards. This dramatically reduces the boilerplate needed to create consistent APIs while enforcing best practices through generation rather than just validation.
aepc is just a prototype with no official release at this moment, but it has been very useful, producing AEP-compliant OpenAPI and protobuf specifications that are used as examples in the specification.
aepcli: A Command-Line Interface for Everyone
The launch of version 0.1 of aepcli marked a significant milestone in our tooling journey. Rather than requiring every API provider to build their own CLI, aepcli dynamically generates a powerful command-line interface from any AEP-compliant API’s OpenAPI specification. This client-side approach means new API features are immediately available without requiring CLI updates, solving a common pain point in API tooling.
aep-explorer
To complement our command-line tools, we developed a web-based UI for browsing and interacting with AEP-compliant APIs: aep-explorer . This provides a more visual way to understand and experiment with APIs while maintaining the same consistent interaction patterns that make AEPs valuable.
Enhanced Linting Capabilities
A major focus this year was improving our linting capabilities, particularly for OpenAPI specifications. Mike Kistler led the effort to revitalize our OpenAPI linter, implementing rules for key AEPs including AEP-132 (List methods) and AEP-135. The linter helps teams validate their APIs against AEP guidance, catching common issues early in the development process.
Significantly progress was also made for our protobuf linter, which is now compliant with all of the updated guidance in aep.dev.
The linter’s approach balances pragmatism with standards enforcement - while some rules are mandatory, others can be selectively adopted based on an organization’s needs. This flexibility helps teams gradually adopt AEP practices while maintaining consistent APIs. The project uses Spectral as its foundation, allowing teams to build on an established tooling ecosystem while adding AEP-specific validations.
To help teams get started, we’ve included comprehensive test cases and example APIs that demonstrate proper implementation of AEP patterns. The linter has already helped identify areas where our documentation needed clarification, particularly around operation IDs and resource naming conventions.
Improved Infrastructure
A major focus this year was improving the components used for learning about the AEP standards and enforcing them in our organization.
To help teams get started, we’ve built comprehensive test cases and example APIs that demonstrate proper implementation of AEP patterns. The linters have already helped identify areas where our documentation needed clarification, particularly around operation IDs and resource naming conventions.
Additionally, we’ve built out a new aep.dev website based on a new framework to help highlight our guidance and to help the team release new content over time.
Community Growth
The March Barn Raising
On Pi Day (March 14), we held our first community “barn raising” event, bringing together contributors from across companies and time zones. The event focused on improving documentation, adding OpenAPI examples, and making AEPs more accessible to newcomers. This collaborative effort helped us identify and address gaps in our guidance while strengthening our community bonds.
Expanding Global Reach
Recognizing our growing international community, we established EU-friendly meeting times and welcomed contributors from companies like DoubleVerify, providing valuable feedback on real-world AEP adoption. This led to improvements in our documentation and examples, particularly around pagination and custom methods.
Educational Content
We launched the @aepdev YouTube channel featuring detailed demonstrations of our tooling and explanations of AEP concepts. These videos help newcomers understand both the technical details and the broader vision of what we’re building.
Looking Forward to 2025
As we enter the new year, our focus areas include:
- Expanding our linting tools across both Protocol Buffer and OpenAPI specifications
- Building more client generators, including Terraform providers and Kubernetes operators
- Working with the OpenAPI community on resource-oriented API patterns
- Supporting more companies in adopting AEPs, with clear migration paths and tooling support
Get Involved
We’re building AEPs in the open and welcome contributions of all kinds. You can join us:
- On CNCF Slack in the #aep channel
- At our weekly community meetings (Fridays at 11:30am PT)
- On GitHub at github.com/aep-dev
- Through our documentation at aep.dev
Whether you’re building new APIs or working to improve existing ones, we believe AEPs can help make that process more consistent and maintainable. Join us in building better APIs together!