Web Builder

Node type: web_builder · Version: 1 · Category: System Combine HTML, JavaScript, and CSS into a localhost site. This node can change external state or produce an external side effect.

Configuration

Field	Type	Default	What it controls
`html`	string	`""`	HTML source, normally mapped from the `code` output of an HTML Code node.
`javascript`	string	`""`	Browser-side JavaScript source, normally mapped from the `code` output of a JavaScript Code node.
`css`	string	`""`	CSS source, normally mapped from the `code` output of a CSS Code node.
`port`	number	`0`	Loopback port from 0 to 65535. Use 0 to choose an available port automatically.
`openBrowser`	boolean	`true`	Open the generated localhost URL in the default browser after the server starts.

The node card exposes separate HTML, JS, and CSS connectors. Connecting a matching Code node creates both the dependency edge and its code output binding.

The server binds only to 127.0.0.1. Port 0 selects an available port, /health reports server status, and rerunning this node replaces its previous server for the same workflow.

The combined source is limited to 4 MB. The local site remains available while the desktop app is running.

Workflow JSON

The editor stores this node with the following implemented default configuration:

Default node configuration

{
  "type": "web_builder",
  "version": 1,
  "configuration": {
    "html": "",
    "javascript": "",
    "css": "",
    "port": 0,
    "openBrowser": true
  }
}

Values may be entered literally or mapped from an earlier compatible output when the inspector exposes a mapping control. See Variables and data mapping.

Inputs

Port	Type	Required	Description
`html`	`string`	Yes	HTML
`javascript`	`string`	Yes	JavaScript
`css`	`string`	Yes	CSS

Outputs

Port	Type	Required	Description
`url`	`string`	No	Localhost URL
`port`	`number`	No	Port
`status`	`string`	No	Server status

Where it can run

Desktop local runner

Test and inspect

Use Test node in the editor to preview this step with the current configuration. A full run records resolved inputs, outputs, logs, duration, and any artifacts in the execution inspector. Side-effecting or destructive nodes can require an additional confirmation or approved workflow permission.

Node reference

Triggers

Logic

Data

Network

Browser

Communication

System

Configuration

Workflow JSON

Inputs

Outputs

Where it can run

Test and inspect

​Configuration

​Workflow JSON

​Inputs

​Outputs

​Where it can run

​Test and inspect

Configuration

Workflow JSON

Inputs

Outputs

Where it can run

Test and inspect