Studio reference

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Everything about Studio and its canvases in one place.

Configuration

studio

Option	Type	Default	Description
studio.enabled	boolean	false	Turns Studio on in production. Studio is on in eventcatalog dev unless this is false. false turns it off everywhere.

storage

Option	Type	Default	Description
storage.type	'memory' | 'sqlite'	'memory'	'memory' keeps canvases while the server runs. 'sqlite' keeps them in a database file.
storage.path	string	'.eventcatalog/eventcatalog.db'	The SQLite database file, relative to your catalog.

SQLite storage needs Node.js 22.13 or later.

Related options

Option	Why it matters for Studio
output	Must be 'server' for Studio in production, and for agents to connect through the MCP server.
auth.enabled	With authentication on, only signed-in people can open canvases.
mcp.enabled	Agents connect through the MCP server. Setting it to false stops agents connecting.
security.allowedDomains	Needed when a proxy serves your catalog over HTTPS.

When Studio is on

Command	studio.enabled not set	true	false
eventcatalog dev	On	On	Off
eventcatalog start (output: 'server')	Off	On	Off
Static build (output: 'static')	Off	Off	Off

Example

eventcatalog.config.js

export default {
  output: 'server',
  studio: {
    enabled: true,
  },
  storage: {
    type: 'sqlite',
    path: '/data/eventcatalog.db',
  },
};

See the full configuration reference for every EventCatalog option.

Canvas

Toolbar

Button	Shortcut	What it does
Lock		Locks the canvas, so it can be looked at but not changed
Select	V	Select and move nodes
Hand	H	Drag to move around
L1 / L2 / L3	1 2 3	Change the level
Sticky note	N	Click where the note goes
Text	T	Click anywhere and type
Comment	C	Click a node, or a spot, to comment
Hotspot	A	Click a node, or a spot, to flag a risk

The controls at the bottom left zoom, undo and redo, fit the view (⇧ 1), reorder the diagram, and list comments and hotspots.

Levels

Level	Shows
L1	Domains, systems and their relationships
L2	Services and data stores
L3	Everything, including messages and channels

L1 is unavailable until the canvas has a domain or system.

Canvas menu

The three dots next to the canvas title.

Item	Shortcut
Open…	⌘ O
Save to file…	⌘ S
Export image…	⌘ ⇧ E
Live collaboration…
Connect your AI agent…
Help	?
Rename canvas
Copy link
New canvas
Delete canvas

The bottom of the menu shows the connection status, for example Connected.

Right-click menus

Items are grouped, with their shortcuts on the right. On a locked canvas, only the items that don't change it are shown.

On	Items
A node	Edit details · Cut, Copy, Paste, Duplicate · Add comment, Add hotspot, Add note · Delete
A sticky note or text	Edit text · Cut, Copy, Paste, Duplicate · Colour (sticky notes) · Add comment · Delete
The canvas	Paste here · Add sticky note, Add comment, Add hotspot · Reorder diagram

Cut is offered at L3, where nodes can be copied.

Statuses

Status	Meaning
Draft	Being worked on. Every canvas starts as a draft.
Proposed	Ready for review
Accepted	The agreed design
Rejected	Decided against, kept for the record

• Each status change can have a note. The status menu shows the history, with who changed it, when and the note.
• Changing the nodes or connections on an accepted or rejected canvas makes it a draft again.

Hotspots

Field	Values
Severity	Critical (red), Warning (amber) or Info (blue)
Title	Up to 120 characters, for example "Single point of failure"
Description	Optional. Why it matters, and what to do about it

• A hotspot is on a node, and moves with it, or on a spot on the canvas. Deleting a node deletes its hotspots, and undo brings them back.
• A marker shows the severity's icon, with a count when there's more than one hotspot on it. Click it to open the hotspot beside it.
• An open hotspot shows its title, description, and who flagged it and when. Edit or remove it from its header, or press Delete to remove it.
• The Hotspots list at the bottom left has one row per hotspot, most severe first, with the node it's on. Click a row, or rest the pointer on it, to go to that hotspot and open it.
• At L1 and L2, hotspots inside a domain or system are shown on that domain or system.

Studio page

The Studio page lists canvases with their status, contents, open comments, who created them, and when they were last updated. Filter by name or status. Each canvas's menu has Make a copy and Delete.

Limits

Limit	Value
Canvas title	200 characters
Your name	60 characters
.eventcatalog file	2 MB

Components and connections

Components

New components start at version 0.0.1.

Group	Component	Description
Boundaries	Domain	A business area, e.g. Sales
	System	Services doing one job
Services	Service	An API, worker or function
	View	A screen or app people use
	External System	A third party you use
	Agent	An AI agent at work
Messages	Event	Something that happened
	Command	A request to do something
	Query	A request for data
	Channel	A topic, queue or bus
Data	Database	Tables, e.g. PostgreSQL
	Cache	Fast data, e.g. Redis
	Search index	Search, e.g. Elasticsearch
	Object store	Files and blobs, e.g. S3
	Entity	Part of the domain model
People	Actor	Someone who uses it
	Team	Who owns what

Sticky notes and text are added from the toolbar. Agents and the assistant can add them too, and they're always placed clear of other nodes.

Catalog resources

You can add these resources from your catalog: domains, systems, services, events, commands, queries, channels and data stores. They are added at their latest version, with their name, version and summary from your catalog.

Connection labels

When you connect two nodes, Studio labels the connection with EventCatalog's wording:

From	To	Label
Service, agent, actor, external system or view	Event	publishes event
Service, agent, actor, external system or view	Command	invokes
Service, agent, actor, external system or view	Query	requests
Event	Anything but a message or channel	subscribed by
Command or query	Anything but a message or channel	accepts
Message	Message	triggers
Message	Channel	sent to
Channel	Anything	routes to
Anything else	Channel	publishes to
Anything	Data store	writes to
Data store	Anything	read by
Actor	Anything	uses
Anything	View	serves
Anything	External system	calls
Anything	Actor	notifies
Team	Anything	owns
Entity	Entity	references
Message	Entity	carries
Anything else	Entity	manages

Agents can set their own labels through the MCP tools.

MCP tools

When Studio is on, the EventCatalog MCP server has these tools for canvases. Unlike the other MCP tools, they change your canvases.

Tool	What it does
openCanvas	Shows a canvas in the chat, in clients that support MCP Apps
listCanvases	Lists canvases and who is on each one
createCanvas	Creates a canvas and returns its link
getCanvas	Reads a canvas: its nodes, connections, hotspots, comments and who is on it
addToCanvas	Adds catalog resources, new components, sticky notes and text, and connects them
updateCanvasNode	Renames, describes, versions or moves a node
connectCanvasNodes	Connects nodes
removeFromCanvas	Removes nodes or connections
layoutCanvas	Lays out the whole canvas
setCanvasStatus	Sets the status to draft, proposed, accepted or rejected, with a note
commentOnCanvas	Starts a comment thread on a node or a spot
replyToCanvasComment	Replies to a thread
resolveCanvasComment	Resolves or reopens a thread

Every tool takes an optional agentName, the name people on the canvas see. It defaults to the name of the client, for example Claude, Claude Code, ChatGPT or Cursor.

addToCanvas can bring more than one resource at a time:

• contents: true on a catalog domain or system adds it with everything in it: its systems, services, messages and data stores, connected and laid out.
• connections on a catalog service or message adds what it connects to. For a service: sends, receives and dataStores. For a message: senders and receivers.
• A node with type note is a sticky note, and type text is text on the canvas, with an optional fontSize.

How agents appear

• An agent has its own pointer and name on the canvas.
• Its changes appear one step at a time, with what it is doing, for example "Connecting InstalmentPlanApproved to Notification Service".
• A banner shows when an agent is working. Choose Follow to move your view with it.

Browser tools (WebMCP)

When WebMCP is turned on in the Connect your AI agent dialog, the open canvas offers agents in the browser these tools: get_canvas, search_catalog, add_to_canvas, update_node, connect_nodes, remove_from_canvas, layout_canvas, set_canvas_status, add_comment, reply_to_comment, resolve_comment and show_nodes.

Assistant tools

When you draw with AI, the EventCatalog Assistant works on the canvas it was opened on with these tools, using the model in eventcatalog.chat.js. They're only offered when Studio is on.

Tool	What it does
getCanvas	Reads the canvas: its nodes, connections, hotspots and comments
addToCanvas	Adds catalog resources, new components, sticky notes and text, like the MCP tool
updateCanvasNode	Renames, describes, versions, moves or resizes the text of a node
connectCanvasNodes	Connects nodes
removeFromCanvas	Removes nodes or connections
layoutCanvas	Lays out the whole canvas, when you ask it to
addHotspot	Flags a node or a spot with a critical, warning or info hotspot
showOnCanvas	Takes your view to nodes and highlights them
walkThrough	Shows a step-by-step walkthrough in the chat, with each step's nodes

• The assistant appears on the canvas as EventCatalog AI, with its own pointer, like other agents. It works about three times as fast as an MCP agent, because you're waiting on it in the chat.
• After a turn where it added nodes or connections, the canvas is laid out again, with sticky notes and text kept beside what they're about.

Keyboard shortcuts

Press ? on a canvas to see these shortcuts. On Windows and Linux, use Ctrl instead of ⌘.

Tools

Action	Shortcut
Select	V
Hand (move around)	H
Sticky note	N
Text	T
Comment	C
Hotspot	A
Level 1 / 2 / 3	1 2 3
Back to selecting	Esc

Canvas

Action	Shortcut
Select everything	⌘ A
Select several	⇧ + click
Delete what's selected	Delete
Remove the open hotspot	Delete
Duplicate	⌘ D
Copy / paste	⌘ C / ⌘ V
Undo / redo	⌘ Z / ⌘ ⇧ Z
Move around	Scroll
Zoom	⌘ + scroll
Fit view	⇧ 1

Notes and text

Action	Shortcut
Write on one	Double-click
Finish writing	Esc

Files

Action	Shortcut
Open a file	⌘ O
Save to file	⌘ S
Export image	⌘ ⇧ E
Help	?