# The canvas

> The Flow canvas: a visual workspace for designing, connecting, and debugging processes with Build mode and Debug mode.

## What it is

The canvas is the main workspace where you build processes in Studio Web. It opens when you create or open a `.flow` file. The canvas has two modes: **Build mode** for designing and configuring your process, and **Debug mode** for running and inspecting it.

## How it works

![Flow canvas overview with four labeled areas: the canvas in the center, the bottom toolbar, the properties panel on the right, and the node palette.](https://dev-assets.cms.uipath.com/assets/images/maestro/flow-canvas-replace-node-eafb719e.webp)

The canvas has four main areas:

| Area | Location | What it's for |
|---|---|---|
| **Canvas** | Center | Place, connect, and arrange nodes |
| **Toolbar** | Bottom center | Add nodes, undo/redo, debug controls |
| **Properties panel** | Right | Configure the selected node; manage variables |
| **Execution panel** | Bottom (during debug) | View execution trace, errors, and variable values |

## Debugging

Selecting **Debug** in the toolbar runs your process. The execution panel appears at the bottom showing the execution trace. The debug session ends when you select **Stop**, or automatically when you make a change to the process.

![Canvas during a debug session showing nodes with green success indicators and the execution panel open at the bottom.](https://dev-assets.cms.uipath.com/assets/images/maestro/flow-execution-panel-60f39272.webp)

## Adding nodes

The **+** button in the **bottom toolbar** opens the node palette.

![Flow canvas with the node palette open, showing the search bar and node categories. The + button in the bottom toolbar is highlighted.](https://dev-assets.cms.uipath.com/assets/images/maestro/flow-add-node-fd9cf17c.webp)

The node palette supports:

- **Search** by name or keyword
- **Browse** by category: Control flow, Data operations, Connector, Agent, Human task, RPA workflow, API workflow, Trigger

The **+** on a node's outgoing handle adds a new node and connects it in one step.

:::note
Triggers can only be added from the bottom toolbar, not from node handles.
:::

## Connecting nodes

Nodes connect via output handles (right side) to input handles (left side). The canvas validates connections in real time — green indicates a valid connection, red indicates an invalid one. Connections respect node constraints (for example, a trigger cannot connect to another trigger).

## The properties panel

The properties panel opens on the right when a node is selected.

The properties panel has two tabs:

- **Properties** — the node's configuration form (inputs, parameters, settings)
- **Variables** — manage variables for the process, and view node-produced variables (read-only)

A node's full-screen expanded view of its properties is available from its hover toolbar.

![Properties panel open with the Properties tab active, showing a node's configuration form fields.](https://dev-assets.cms.uipath.com/assets/images/maestro/flow-properties-tab-7c3e2ede.webp)

## The execution panel

When you debug a process, the execution panel appears at the bottom of the screen.

| Tab | What it shows |
|---|---|
| **Spans** | Execution trace — each node, its timing, and success/failure status |
| **Incidents** | Errors and failures that occurred during execution |
| **Variables** | Runtime variable values at each step |

Selecting a span highlights the corresponding node on the canvas.

## Debug controls

In Debug mode, the bottom toolbar shows debug controls:

- **Debug** — start execution
- **Stop** — end the current session
- **Step Over** — execute the next node and pause
- **Continue** — resume execution until the next breakpoint or end
- **Restart** — re-run the process from the beginning

### Breakpoints

Breakpoints are markers set from a node's hover toolbar. Execution pauses when it reaches a breakpoint. **Step Over** and **Continue** control how execution resumes.

Breakpoints can be set in both Build mode and Debug mode.

## Right-click menu

Right-clicking the canvas background shows layout options:

- **Tidy all** — auto-arrange all nodes
- **Tidy selected** — auto-arrange selected nodes (2+ selected)
- **Align** — left, center, right, top, middle, bottom (2+ selected)
- **Distribute** — horizontal, vertical (3+ selected)
- **Copy / Paste / Delete**

## Keyboard shortcuts

See the [Keyboard shortcuts reference](keyboard-shortcuts-for-maestro.md) for the full list.

Key canvas shortcuts:

- `Cmd+Z` / `Ctrl+Z` — Undo
- `Cmd+Shift+Z` / `Ctrl+Shift+Z` — Redo
- `Cmd+Shift+L` / `Ctrl+Shift+L` — Auto-layout all nodes
- `Delete` / `Backspace` — Delete selected nodes

## Related pages

- **[Your first Flow](quickstart.md)** — step-by-step quickstart
- **[Keyboard shortcuts](keyboard-shortcuts-for-maestro.md)** — full shortcut reference
- **[Debugging effectively](debugging-effectively.md)** — tips for Debug mode