Core Actions

settings — App → stdui

Configure the window and application on startup. Send this as the very first message after spawning the process; stdui blocks on startup until it is received.

{
  "action": "settings",
  "data": {
    "title": "My App",
    "windowWidth": 1280,
    "windowHeight": 720,
    "baseFontSize": 14,
    "audioVolume": 0.5,
    "resizable": true
  }
}

All fields in data are optional. Only provided fields are applied; omitted fields keep their defaults.

Field	Type	Default	Description
title	string	"StdUI"	Window title bar text
resizable	boolean	true	Enable or disable window resizing
windowWidth	number	800	Window width in pixels
windowHeight	number	600	Window height in pixels
windowMinWidth	number	400	Minimum allowed window width in pixels
windowMinHeight	number	300	Minimum allowed window height in pixels
windowMaxWidth	number	3840	Maximum allowed window width in pixels
windowMaxHeight	number	2160	Maximum allowed window height in pixels
baseFontSize	number	16.0	Base UI font size in pixels
audioVolume	number	1.0	Audio volume level (0.0 to 1.0)
fontRegular	string	""	Filename of the regular font file (empty = ImGui default)
fontBold	string	""	Filename of the bold font file
fontItalic	string	""	Filename of the italic font file
fontBoldItalic	string	""	Filename of the bold italic font file
colorScheme	object	—	Color palette for the ImGui layer. See Color Scheme
targetFps	number	60	Target frame rate in frames per second

Color Scheme

The colorScheme object controls colors used by the ImGui layer (window backgrounds, buttons, borders, text, etc.). HTML content styled via CSS in your update-content strings is unaffected.

All values are hex strings in #RRGGBB or #RRGGBBAA format (e.g. #0969da33 for 20% opacity). Omitted fields fall back to the built-in light theme defaults. text and textMuted are auto-derived from windowBg when omitted.

Field	Default	Description
windowBg	#ffffff	Background of all pane windows
text	#1f2328	Primary foreground text (auto-derived from windowBg if omitted)
textMuted	#656d76	Secondary / muted text (auto-derived from text if omitted)
elementBg	#f6f8fa	Default background of interactive elements
elementHovered	#eaeef2	Background of interactive elements on hover
elementActive	#d0d7de	Background of interactive elements while pressed
titleBg	#f6f8fa	Background of ImGui window title bars
border	#d0d7de	Element and window border color
primary	#0969da	Accent color used for buttons and focus rings
primaryTranslucent	#0969da 80% alpha	Semi-transparent variant of primary
primarySubtle	#0969da 10% alpha	Very lightly tinted background derived from primary
textSelectionBg	#0969da 20% alpha	Selected-text highlight color
warn	#9a6700	Warning indicators
danger	#d1242f	Destructive actions and error indicators
modalDim	#000000 30% alpha	Overlay color drawn behind modal dialogs

Example — dark theme:

{
  "action": "settings",
  "data": {
    "colorScheme": {
      "windowBg": "#0d1117",
      "text": "#e6edf3",
      "textMuted": "#7d8590",
      "elementBg": "#161b22",
      "elementHovered": "#1f2937",
      "elementActive": "#2d333b",
      "titleBg": "#161b22",
      "border": "#30363d",
      "primary": "#2f81f7",
      "warn": "#d29922",
      "danger": "#f85149"
    }
  }
}

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update-content — App → stdui

Sets the HTML content rendered in a pane. There is no incremental patching — each call replaces the entire content of the target pane.

Plain string (targets the default "main" pane):

{ "action": "update-content", "data": "<h1>Hello</h1>" }

Object form (targets a named pane):

{ "action": "update-content", "data": { "pane": "sidebar", "content": "<h1>Hello</h1>" } }

Field	Description
pane	ID of the target pane, as declared in set-pane-layout
content	HTML string to render

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ready — stdui → App

Emitted once the window and all subsystems are fully initialized. Do not send update-content until this is received.

{ "action": "ready" }

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close — App → stdui

Instructs stdui to close the window and exit cleanly. stdui emits window-closed in response.

{ "action": "close" }

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window-closed — stdui → App

Emitted when the user closes the window (or after a close action). The controlling app should use this as its shutdown signal.

{ "action": "window-closed" }

---

log — stdui → App

Emitted for all internal log messages, including output from raylib.

{ "action": "log", "data": { "namespace": "Main", "message": "Raylib initialized" } }

Field	Description
namespace	Category or subsystem that produced the message (e.g. "Main", "Font")
message	The log message text