Docs

#Dash designer

Design dashes for the FX Pro screen (USB mode, usb-mode.md), import SimHub dashes and fine-tune them, and see changes on the wheel as you make them. Three ways in, all backed by the same code (Usb/DashTools.cs), so they agree with each other and with the wheel:

The dash format: dash-format.md. Designing with an AI agent: the /create-dash skill in .claude/skills/ (and the "For agents" section below).

#Web designer (Dash Studio)

SimHub → FXPro Unlocked → Unlocked → Dashes → Designer (or http://127.0.0.1:8899/ while SimHub runs; port in settings, DesignerPort). Offline: fxdash serve (no wheel, SimHub formulas not evaluated). Same look as the plugin.

• Top bar: the dash's name (edit in place; amber dot = unsaved), undo/redo, Edit / Exact / Demo lap (Exact and Demo are the plugin's own rendering, exactly what the wheel draws), On wheel (the wheel follows every change), the checks pill (click for the list), Save and a menu (save as, download/open JSON, new, import, delete).
• Left: Add (element tiles: click, or drag onto the screen where you want it), Layers (top = in front; drag to reorder; eye = shown/hidden in previews for conditional elements; ⚠ = a check issue; hover highlights on the screen), Dashes (the library with rendered thumbnails, New, From SimHub).
• Screen: in a bezel, with the wheel's visible area dashed (the padding). Click to select, drag to move, 8 handles to resize; smart snapping (screen edges/centre, the visible area, other elements) with red guides; Alt = no snap, Shift = straight moves / keep proportions. Right-click menu, double-click to edit the text or data, zoom (+/-/0, Ctrl+wheel). A click only selects (no undo step).
• Inspector: position & size (drag the X/Y/W/H letters to scrub), align in the visible area; text with a font picker that measures the element's widest text in every screen font ("use the biggest that fits"); colour swatches (palette, hex, opacity); data picker (searchable, grouped, plain-English, or any SimHub property / formula); format chips; widest-text chips; colour from data; Show when conditions as chips; raw JSON.
• Keys: arrows (Shift = 10 px), Del, Ctrl+D, Ctrl+C/V, Ctrl+Z/Y, [ ], Esc, Ctrl+S, 1/2/3 views, ? for the list.
• Development: FXDASH_DESIGNER_DIR=<repo>\Usb\Designer fxdash serve --port 8898 serves the page's files from disk (edit and reload, no rebuild).

#SimHub import

Import SimHub dash… (or fxdash import, POST /api/import) converts any installed SimHub dash (SimHub\DashTemplates), or a .djson path:

• Scaled to fit the screen minus the wheel's padding; the main in-game screen (a screen named Main/Race/Dash, else the in-game screen with the most on it), or the one you pick; background/foreground layer screens included; overlay screens not.
• Layers and widgets flattened (widget screens switched by a formula become groups shown while the formula gives their index), in SimHub's drawing order.
• Shapes, rounded borders, gradients, images (from the dash's .ressources zip or SimHub's ImageLibrary; stored in the dash at their drawn size, reduced to a few colours; if drawing would take longer than the budget, colours are cut, then the largest images dropped), text (the tallest screen font that fits; SimHub's fonts can't be used), linear gauges as bars, text borders as boxes, colour gradients as ColorStops.
• Every binding is kept as a SimHub formula (ncalc:/js:) and evaluated live by SimHub's own engine, so values, visibility and colours behave as in SimHub; the dash's JavascriptExtensions folder is used for its JS helpers. SimHub's built-in text items (gear, speed, lap times, fuel...) become data keys.
• Pop-ups and warnings (a condition shared by a filled shape and its text, or big/flashing overlays) start hidden in previews; live, SimHub's conditions decide.
• Not converted (listed in the report): dial/circular gauges, charts, maps, leaderboards, web pages, buttons, shift light images, shade/progress items.
• Old dash files (Newtonsoft $id/$values) are read too. All 85 dashes in a stock SimHub install import (2026-09-27).

Expect to fine-tune: labels too wide for their box in the screen's fonts, overlapping texts, the main screen choice. The report lists them and the checks point at each.

#HTTP API

http://127.0.0.1:8899 (plugin) or http://127.0.0.1:<port> (fxdash serve); local only. JSON in and out; CORS open. GET /api lists everything.

#fxdash

tools/fxdash (dotnet build -c Release, then bin\Release\net48\fxdash.exe). JSON on stdout; exit 1 when check finds errors, 2 on failure. --simhub DIR if SimHub isn't in C:\Program Files (x86)\SimHub.

fxdash schema | bindings | fonts [--sample TEXT] | suggest-font W H TEXT
fxdash check DASH.json [--pad 10,20]
fxdash render DASH.json OUT.png [--mode preview|demo] [--seconds N] [--pad L,T]
fxdash fit-bands DASH.json [OUT.json]    # values whose text crosses a border line: nudged or a smaller font (no flashing)
fxdash verify DASH.json [--seconds N]    # demo lap on a simulated wheel: traffic, flashes, drawing errors (exit 1 if not ok)
fxdash builtin [ID] [OUT.json]           # e.g. fxdash builtin lmgt3-mustang mustang.json
fxdash simhub | simhub-screens NAME
fxdash import NAME|PATH OUT.json [--screen S] [--fit 790,460] [--colors N] [--no-images] [--png OUT.png]
fxdash serve [--port 8899]

#For agents

The loop that works: read the format (fxdash schema), write the dash JSON, fxdash check it, fxdash render it and look at the PNG, fix, repeat; then save it into the dashes folder (or PUT /api/dashes/{id}), and with SimHub running POST /api/wheel/show to see it on the wheel. The skill .claude/skills/create-dash/SKILL.md (/create-dash) spells this out with the screen's constraints. In the browser, window.fxdash exposes the designer's dash (fxdash.dash, fxdash.load(d)).