EventCatalog has been another great month for EventCatalog with almost 2k stars on GitHub, and 1000 Discord members. Our project continues to grow about 10/15% every month in usage.

We are happy to share our first initial release of EventCatalog Cloud.

Our vision here is to offer you a new way to experience EventCatalog, which will include:

• Hosting - Manage hosting for your EventCatalog instance
• Licensing - Manage your plugin licenses and updates
• Ask your Catalog questions - Using AI to answer questions about your Catalog, quickly get answers to your questions
• Collaborate - Design with EventCatalog Studio, and collaborate with your team

Integration licenses on EventCatalog Cloud​

To help keep the project sustainable and open source we have now introduced license keys for our plugins. All our plugins were dual licensed, but did not require any license key to run or use them. This small change allows us to offer a better experience for our users and a sustainable project.

All plugins will now have a 14 day trial period (you can extend contacting us), after which you will need to purchase a license key to continue using the plugin.

To obtain a license key for a plugin or a trial you can login to EventCatalog Cloud and navigate to the integrations page.

What's next?​

We will be adding more features to EventCatalog Cloud in the coming months, including:

• Plugin improvements - We will be adding more plugins (e.g GitHub, GitLab) and improving the existing ones
• Improvements to EventCatalog - New features and customization options for EventCatalog.
• EventCatalog Studio - A new way to design and collaborate on your EventCatalog (Beta launch)
• AI - Ask your Catalog questions, and get answers quickly

Summary​

January was slightly a slow month in terms of maintenance and features as I was focused on EventCatalog Cloud, and talks for NDC and FOSDEM. These events were great and I met a lot of new people, and got to catch up with old friends.

I am looking forward to February, we have a lot of great features and quality of life improvements planned.

If you want to join us on this journey feel free to join our Discord community, and if you want to sponsor the project you can do so here.

Speak soon!

David Boyne

Welcome to the monthly update for EventCatalog, here you can find what’s next, how to get started, and what’s coming next.

EventCatalog community continues to grow ❤️, now we have 937 Discord members, 1.9k Stars on GitHub, we hit over 1000 pull requests into the project, 423 new Catalogs have been created in December and over 5,000 catalogs built into production this month. EventCatalog got a great shoutout at re:Invent 2024, and the project continues with 15-20% growth every month.

EventCatalog sponsors OSO and Gravitee continue their sponsorship for the project (thank you!) 🙏.

Sponsorships help our goal towards open source sustainability. EventCatalog is free to use and open source, if you want to support the project checkout the tiers on GitHub or contact me directly at dave@eventcatalog.dev , I really appreciate any support ❤️

Our integration platform continues to grow, including OpenAPI, AsyncAPI and Amazon EventBridge, Backstage, GitHub and GitLab. Automate your documentation with any of these integrations or contact us to build a custom integration.

In December we introduced the ability to filter resources by custom badges, ability to document Ubiquitous Language, over 200,000 icons support with Mermaid v11, new tab components, 80% increased build times and we launched EventCatalog Federation.

In this blog post we will dive deeper into features that were released in December, why they were built and how they can help you govern your architectures. At the end of the blog post I will share a personal update and what’s planned for January 2025.

Introducing EventCatalog Federation​

In December we launched our first version of EventCatalog Federation. EventCatalog federation let’s you unify your documentation across your organization into one view.

EventCatalog Federation takes many catalogs and merges them into one view for your organization.

This let’s your teams keep their own documentation, schemas and spec files close to their code, and merge this information into one view for the organization.

Federation benefits to organizations include:

• Give your architects and company the ability to get a holistic view of the whole architecture
• See ownership of domains, services and messages and contact them
• Let your teams quickly find events, schemas and specs they want to start consuming
• Let’s your team own their own documentation, focusing on their domain and service

Our vision with EventCatalog is to bring discoverability to architectures for teams saving them time from discovering a message to the implementation phase. We believe EventCatalog Federation can help scale EventCatalog within your teams and business.

To get started you can read the documentation here, or if you would prefer to walk through your problems and how EventCatalog can help you can email hello@eventcatalog.dev for a walkthrough/demo.

Introducing the ubiquitous language dictionary​

Event-driven architecture and domain-driven design work very well together (see visual here). Many teams are embracing domain-driven design practices whilst building their event-driven architecture. Part of this process includes understanding and defining a ubiquitous language.

Ubiquitous language is the language (terms) you use within a particular domain. For example a Policy in a Underwriter Domain might be completely different to a Policy in a User Domain.

This language often get’s translated into code/models within your architecture, but the meaning of these terms/words can often get lost or confused.

The EventCatalog ubiquitous language dictionary gives you the ability to document your domains language with a simple markdown file. These definitions will get rendered into EventCatalog and can help your teams understand terms used within your architectures domain, helping with any confusion that may occur.

The ubiquitous language dictionary is powered by markdown files, this let’s you document short or large descriptions of your language and users can quickly filter and search for terms in your domain.

To get started you need to create a ubiquitous-language.md in your domain folder, and then EventCatalog will render this for your users. To understand more and get started you can read the documentation here.

Introducing custom filters in EventCatalog​

EventCatalog has a discover feature (see demo) that allows you to quickly search and filter domains, services and messages.

We have now added the ability to search and filter by badges. Badges are custom tags you can add to your resources in EventCatalog, this let’s you add any metadata you like to your domains, services, flows and messages.

If you want to enable quick filtering/search based on custom information you can use badge filters to do this.

To get started, you need to add badges to your resources and EventCatalog will render the filters for you.

Mermaid v11 and 200,000 icons have beed added​

EventCatalog let’s you use mermaid code blocks in all resources, this is handy if you want to provide extra visualisations or information about your domains, services or messages.

In December we updated Mermaid to V11. This gives you the ability to render Architecture Diagrams and now supports over 200,000 icons for your diagrams.

You can also render Block Diagrams, C4 Diagrams, Mind maps and much more (see examples).

Mermaid can be a great way to provide additional information for your developers and teams in EventCatalog. To get started you can read our documentation on how to use mermaid in EventCatalog.

Other improvements made in December​

• EventCatalog builds are now 80% faster!
• EventCatalog now renders Avro Schemas in the UI (with AsyncAPI files)
• EventCatalog got updated to Astro v5
• You can now use Tab components in EventCatalog
• You can now add Microsoft teams (contact information) to your users and teams in EventCatalog

EventCatalog Studio​

In November we started working on EventCatalog Studio. This visual editor for EventCatalog, letting you quickly explore, experiment and design your architecture with a drag and drop interface. The vision is to go from design to implementation faster than ever.

We continue to work on this in Q1 2025, if you would like to sign up to the beta you can sign up here. Or if you want to understand how it can help your teams feel free to reach out to us at hello@eventcatalog.dev .

Whats next in 2025​

Our vision is to help companies bring discoverability to their event-driven architecture through open source community and software. The project usage is growing 15-20% a month and we aim to at least double this in 2025.

Community​

Our aim is to work backwards from the community and EventCatalog users to define a public roadmap and continue to grow our community. The community and open source is the core of the project and we want to do everything we can to help maintain this and grow.

We will focus on making a welcoming community, have community meetings and create a place where people can learn, explore and help each other.

Working with companies​

We have started to work with companies to help them govern their event-driven architectures and make best use of EventCatalog. If you want to work with us reach out at hello@eventcatalog.dev , we would love to help you understand how EventCatalog can help your organization, provide value and solve problems you may be facing.

Sponsors​

We will continue to explore project sponsors. This helps keep the core of the project free and open source. If you or your company would like to sponsor our project we would love to connect. You can reach out at hello@eventcatalog.dev and we can share details with you on what you can get from sponsoring the project. We currently have 2 sponsors, our 2025 goal is to double this.

Integration platform​

We will continue to grow our integration platform. This includes working with cloud providers, broker providers and companies to integrate EventCatalog into their eco-system. If you would to see an integration or get help building a custom integration we can help.

EventCatalog ecosystem​

We will continue to explore the EventCatalog eco system. Looking at tools like EventCatalog Studio and other tools that users may find useful. We believe that EventCatalog can had a huge amounts of value to businesses and teams, and we are just starting.

With the EventCatalog ecosystem we believe we can save teams time and money and get them building and documenting event-driven architectures faster than ever.

Summary​

We are excited for what 2025 has in store for EventCatalog, we have a lot of ideas and plans to help grow the project and community. We are looking forward to working with you and your teams to help you document and govern your event-driven architectures.

If you have any questions or feedback please reach out to us at hello@eventcatalog.dev and we can help you get started.

Happy New Year!

David Boyne

We are happy to share the first initial release of EventCatalog Federation.

EventCatalog Federation is a new plugin that allows you to merge multiple EventCatalog instances into one for a single source of truth.

In this blog post we will cover why federation might be useful for you and your teams, how it works, and how you can get started.

Why EventCatalog Federation?​

In 2024 we have seen a lot of companies and teams adopting EventCatalog. We have seen teams use EventCatalog to document their event-driven architectures and microservices.

Many teams are using EventCatalog as a single source of truth for their domains, services and messages . This gives organizations a single source of truth for their documentation.

EventCatalog is helping developers, architects and business stakeholders understand their architectures and quickly find the information they need.

Whilst speaking to our community we have learned that many teams want the ability to keep their documentation close to their code and still continue to have the single source of truth for their organization.

EventCatalog Federation allows your teams to have their own EventCatalog, stub out dependencies and provide an ability to merge multiple catalogs into one main catalog.

This allows your teams to keep their documentation close to their code, store their documentation in git whilst continuing to provide value to the organization.

How does EventCatalog Federation work?​

Teams owning their own documentation​

Your teams create their own EventCatalog instance, they can use the eventcatalog CLI to create a new catalog.

Your teams own their own documentation, domains, services and messages (all optional). This allows your teams to focus, document what they are doing and what they are consuming.

If your team consumes a dependency from another team, you can use the new EventCatalog stubs to mock them out in your own catalog.

Once teams commit their documentation to their repository, they can run the federation generator to merge their documentation into a main catalog. This main catalog provides the organization with a single source of truth for the entire architecture.

To dive deeper and get started with EventCatalog Federation, read our EventCatalog Federation Setup Team Catalog guide.

Organization EventCatalog​

You will create a main EventCatalog instance that uses the federation generator to merge all the EventCatalog instances from your teams.

Using the federation generator you can specify the source repository to pull from, the branch to pull from, the files to copy from the source repository to your main catalog and if you want to override any conflicts (last-write-wins).

Merging many catalogs into one provides your developers, architects and business stakeholders with a single source of truth for your organization.

The single source of truth lets you see the entire architecture of your organization, and provides a way to understand the dependencies between your teams.

Developers can quickly understand and search for the information they need, and business stakeholders can understand the entire architecture of the organization and start to define business processes (flows) for EventCatalog.

Getting started​

To get started you can read the following guides:

• EventCatalog Federation Setup Team Catalog
• EventCatalog Federation Configuration
• EventCatalog Federation Introduction

Summary​

EventCatalog Federation is a new plugin that allows you to merge multiple EventCatalog instances into one for a single source of truth.

This allows your teams to keep their documentation close to their code, store their documentation in git whilst continuing to provide value to the organization.

We are excited to see what you build with EventCatalog Federation and we are looking forward to seeing the EventCatalog community grow in 2025.

If you have any questions or feedback, please let us know in the EventCatalog Discord.

In this blog post we will dive deeper into features that were released in November, why they were built and how they can help you govern your architectures. At the end of the blog post I will share a personal update and what’s planned for December.

Community, sponsors, and project growth​

EventCatalog community continues to grow ❤️, now we have 890 Discord members, 409 new Catalogs have been created in November and over 4,000 catalogs built into production this month.

EventCatalog is on track to hit 1.9k stars in November, and a shout out to Carlos Rodrigues and Omid Eidivandi for their support with the project and helping with issues, and community feedback ❤️.

EventCatalog got a new gold sponsor from OSO and Gravitee continue their sponsorship (thank you!) 🙏. This sponsorship helps my goal towards open source sustainability.

EventCatalog is free to use and open source, if you want to support the project checkout the tiers on GitHub or contact me directly at dave@eventcatalog.dev , we appreciate any support to help project sustainability ❤️

Introducing EventCatalog Studio​

EventCatalog is proving to be a great tool to help companies govern and document their event-driven architecture. It’s great to see the project, usage and the community grow. Although this is great for folks that have event-driven architectures to document, we still feel there is a pain point when designing your event-driven architecture.

We feel there is a gap between design to implementation with event-driven architectures.

Many teams use whiteboards to design and explore their event-driven architecture (in person or virtual). During this process many discussions and ideas are captured but lost. Also there is an increasing effort to go from initial design to implementation. We believe there must be better way.

This is why we are building EventCatalog Studio.

EventCatalog Studio is a visual designer for event-driven architectures. EventCatalog Studio can sync with your local EventCatalog, and provide you with an editing experience, ability to collaborate with your teams, experiment ,and create draft designs to get feedback.

With EventCatalog Studio you can design new architectures, draft new ideas, design and explore your schemas, ask questions about your architecture, and much more. Everything is mapped to your EventCatalog.

EventCatalog Studio let’s you walk away from your white board sessions with something tangible, schemas to get your started and code models to help.

We are aiming to get our MVP out in December 2024, and if this is something you could find useful you can sign up to beta access here.

EventCatalog now supports channels​

EventCatalog let’s you document your domains, services and messages (commands, queries and events). One core part missing was the ability to document a channel.

In EventCatalog a channel represents the organization and transmission of messages.

Channels in EventCatalog describe how a messages transport between producers and consumers.

Documenting channels in EventCatalog gives your team deeper understand of how your messages are transmitted between producers and consumers, what broker they use and any other information you may find useful.

As EventCatalog is technology agnostic this means you can document any channel and protocol you like including http, amqp, eventbridge, googlepubsub, kafka, mercure, nats, pulsar, redis, sns, solace, sqs and ws (websockets).

Adding channels to EventCatalog​

Channels are resources in EventCatalog that you can define in your /channels directory.

Any message (event, command or query) can be associated to one or many channels.

When you assign a channel to a message, EventCatalog will render these channels between your messages and services (see demo)

Our plugins for AsyncAPI and Amazon EventBridge have been updated, allowing you to document your channels from your specification files.

If you want to learn more, and get started you can read our getting started with channels guide.

Simulating message flow in the visualizer​

You can now simulate messages in the EventCatalog visualizer. This new feature let’s you quickly see what type of events are flowing between your services.

To turn on the feature, use the Visualizer Settings and click Simulate Messages.

This is the first version of message simulation, ideas we have is the ability to define frequency flow in your documentation to help your teams understand how busy messages are, and even connecting this to live systems. If you have any ideas or requests please join Discord and let us know.

Services can now send/receive the same message​

Sometimes your service will send and receive the same message, previously in EventCatalog this was not possible, but we are happy to share that EventCatalog now supports this.

In EventCatalog you can document what messages your service sends and receives.

When the service sends and receives the same message, EventCatalog visualiser will now represent this.

---
id: OrderService
... # other service frontmatter
receives:
    # id of the message this service receives
    - id: PaymentProcessed
sends:
    # id of the message this service sends
    - id: PaymentProcessed
---

<!-- Markdown contents... -->

To learn how do document your services and messages with EventCatalog, you can read our service guide.

OpenAPI Generator 3.0 is now out​

You can automate EventCatalog using your OpenAPI files. This plugin let’s you document services and messages (commands, queries and events) through your OpenAPI files. EventCatalog will keep track of changes, versions and let you add documentation to these messages.

The 3.0 plugin now includes:

• Ability to document events, queries and commands (using the x-eventcatalog-message-type extension)
• Ability to define custom names and ids for your messages (using x-eventcatalog-message-id and x-eventcatalog-message-name)
• By default all messages are now documented as queries (previously commands)

If you and your teams have OpenAPI files, you can use EventCatalog to get discoverability for them. To get started you can read the OpenAPI integration guide.

New support levels added​

In November we have been working with companies to help them understand the importance of governance with event-driven architecture and getting them started.

We offer a range of support including internal talks, internal workshops, and hands on catalog builds.

If you are interested in working with us you can reach out on LinkedIn or email at hello@eventcatalog.dev

Want to learn more about event-driven architectures?

We have created free resources for you to dive deeper into event-driven architectures called EDA Visuals. EDA visuals are designs I have made with extra resources. You can view them and download the book for free!

What’s next in December​

In December we will be continuing the work for EventCatalog Studio and getting an initial beta version out. If you want to keep up to date and get access you can sign up here.

We will continue to review feature requests and work backwards from the community. If you have any feature requests, ideas or bugs please let us know on Discord.

Towards the end of the month we will be taking time off to recharge and focus on what’s next for 2025. I feel EventCatalog has a huge roadmap and vision ahead and we are only just getting started ❤️.

I'm happy to share that EventCatalog 2.13.0 is now out.

This release includes the following highlights:

• ⭐️ Document your message channels, supporting any protocol in the world.
• ⭐️ Simulate your messages in the visualizer
• ⭐️ Visualizer improvements

In this blog post we will go over the new features, help you understand them and how you can get started.

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Amazon EventBridge is an AWS service that helps developers build event-driven applications at scale. Amazon EventBridge offers multiple services including Event Bus, Amazon EventBridge Pipes and Amazon EventBridge Scheduler.

October has been a busy month for EventCatalog. The community has grown from 800 Discord members to 856, with 360 new Catalogs created and over 120 organizations actively using EventCatalog.

EventCatalog got a new gold sponsor Gravitee and Hookdeck continues their sponsorship 🙏, this is a great step towards open source sustainability. If you would like to sponsor the project you can check out the tiers on GitHub or contact me directly at dave@eventcatalog.dev.

;

In many distributed architectures, domains and services communicate through different types of messages, typically categorized as events, commands, and queries.

EventCatalog now includes support for documenting queries, allowing you to clearly outline which queries a service accepts and which it invokes. Queries are often seen in protocols such as HTTP and gRPC.

September 2024 has been a great month for EventCatalog. In this blog post I want to highlight some growth and new features you can start using with EventCatalog.

📈 Growth​

• 1,258 new catalogs were created, bringing the total to 16,974.
• Our Discord community now has over 800 members.
• 1,703 total GitHub stars

⭐️ Features and improvements​

• OpenAPI and AsyncAPI integrations
• New landing page for all catalogs
• UX improvements to visualizer
• New components to use in your Catalog (Tiles and Steps)
• Build your own generators with the new plugin generator

Last week we launched the new AsyncAPI Plugin and today I'm happy to share we have now launched our next integration: OpenAPI Plugin.

The EventCatalog OpenAPI plugin connects your OpenAPI files to EventCatalog and automates the hydration of your catalog, versioning and schema management.

I'm happy to share the first integration plugin for EventCatalog has been released.

The EventCatalog AsyncAPI plugin connects your AsyncAPI files to EventCatalog and automates the hydration of your catalog, versioning and schema management.

It’s been a couple of months since I left my full time job at AWS to pursue my passion for event-driven architecture (EventCatalog) and cloud computing (Wing). I wanted to share an update on the exciting changes we rolled out for EventCatalog in August, it's been a busy month.

EventCatalog 2.5.0 is out now! This release includes the new resource flows, visualizer improvements, and various bug fixes.
This release includes the following highlights:

• ⭐️ Document business features and workflows with the new content type "Flows"
• ⭐️ Simplified visualizer and visual changes
• ⭐️ Fixing domains visualizer
• ⭐️ Astro updates

I'm excited to share that EventCatalog 2.3.1 is now available, featuring support for custom components.

You can now add custom components to your domains, services and messages.

Custom components allows you to create dynamic templates, reuse markdown across pages, client-side JavaScript and more.

I'm excited to share that EventCatalog 2.2.0 is now available, featuring support for changelogs.

You can now add changelogs to your domains, services and messages (events/commands).

I'm excited to announce the release of the new JavaScript/TypeScript EventCatalog SDK. This SDK is designed to help users programmatically interact with their EventCatalogs, streamlining the process of managing event-driven architectures.

Event-driven architectures share a common challenge: their complexity can quickly escalate as more domains, services, and messages are added.

As business requirements evolve and teams adapt, governing and understanding this distributed architecture becomes increasingly difficult. What begins as a straightforward system often transforms into a complex structure with minimal documentation and discoverability, leaving most people struggling to comprehend it (I share my thoughts on EDA complexity in this GOTO EDA Day 2024 keynote).

In January 2022 EventCatalog v1 was launched to help bring discoverability and documentation to event-driven architectures. Since its inception, EventCatalog has seen over 13,000 catalogs created, attracted 45 contributors, grown a community of more than 600 members on Discord and was added to Thoughtworks Technology Radar.

The growing popularity of EventCatalog in recent years highlights the challenges of complexity in building event-driven architectures. It also highlights the importance of discoverability and documentation. That's why I'm excited to announce the release of EventCatalog v2.