event-catalog/eventcatalog

What is EventCatalog?

EventCatalog is an open‑source documentation platform built specifically for software architecture. It lets teams record and explore the moving parts of a system – domains, services, messages, schemas, and business flows – in a single, searchable UI.

Core capabilities (as described in the README)

Feature	What it does	Why it matters
Architecture documentation	Create pages for domains, services, events, commands, and messages.	Keeps a living map of how the system is structured, which is easier to maintain than scattered markdown files.
AI‑powered discovery	Built‑in chat interface that answers natural‑language questions about the catalog.	Lets engineers and non‑technical stakeholders quickly locate information without memorising exact names.
Schema explorer	Indexes OpenAPI, AsyncAPI, Protobuf, JSON Schema, Avro, etc., and makes them searchable.	One place to find any contract definition, reducing friction when integrating services.
Schema‑field search	Search for a specific field name across all schemas and see where it is used.	Helps assess impact of changes and detect breaking changes early.
Bring‑your‑own docs	Attach ADRs, runbooks, or any markdown/MDX docs to any catalog entity.	Keeps operational documentation versioned alongside the architecture it describes.
Business flow visualisation	Draw end‑to‑end workflow diagrams that reference existing services and messages.	Provides a higher‑level view for product owners and new team members.
Versioning & governance	Semantic versioning for events, commands, services, plus breaking‑change detection.	Supports safe evolution of contracts in large, distributed teams.
Generators	15+ auto‑generators for AsyncAPI, OpenAPI, Kafka, Confluent, AWS EventBridge, etc.	Quickly bootstrap a catalog from existing infrastructure definitions.
Customisation & enterprise features	Themes, MDX components, OAuth2, RBAC, schema governance.	Fits into existing security and branding requirements.

How you get started

# One‑line scaffolding – creates a ready‑to‑run catalog in a new folder
npx @eventcatalog/create-eventcatalog@latest my-catalog

Then open http://localhost:3000 and start adding domains, services, and messages through the UI or the provided SDK.

Project structure (high‑level)

Package	Role
@eventcatalog/core	The main Astro + React application that renders the catalog UI.
@eventcatalog/sdk	Node.js library for programmatic creation, update, and deletion of catalog entities.
@eventcatalog/create-eventcatalog	CLI tool that scaffolds a new catalog repository.
@eventcatalog/visualiser	Stand‑alone React component that can be embedded elsewhere to visualise a catalog.

Who might use it?

• Engineering teams that need a single source of truth for event‑driven or micro‑service architectures.
• Product & ops folks who want to browse business flows and runbooks without digging through code repos.
• Enterprises looking for a self‑hosted, customizable solution with RBAC and version‑controlled contracts.

Community & support

• Live demo sites showcase real‑world e‑commerce, finance, healthcare, and SaaS catalogs.
• Documentation site: https://www.eventcatalog.dev/docs
• Discord community for help and feature discussion.
• MIT + Commercial license, with a badge indicating active CI (verify-build.yml).

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TL;DR: EventCatalog is a purpose‑built, open‑source tool for documenting and exploring software architectures, especially event‑driven systems. It combines searchable schema indexing, AI‑assisted Q&A, visual flow diagrams, and enterprise‑grade features, all delivered via a modern web UI and a set of npm packages.