Developer overview

You can make two kinds of content for Swofty Launcher. A mod is content players drop on the launcher's Mods page: a .serps package, .erp files or a community track zip. An addon is a folder or .swoftyaddon file with a swofty.json, installed on the Addons page. Find what you want to make below, then start on its first page.

What do you want to make?

You want to	Build	Start at
Share database, text or texture changes you made in Simplified Studio	A .serps mod	Mods
Share a community track	A track package (a mod)	Track packages
Change database values, in-game text, textures or models with exact edits, optionally behind a setting	A data addon	Data addons
Move, add or restyle elements on a menu screen	A menu edit, shipped in a data addon	Menus and UI
Add a screen or a home tile in game	An addon with screens and an engine plugin	In-game UI
Run your own code in the game: hook engine functions, read telemetry, draw an overlay	An engine plugin	Engine plugins
Add a launcher page, an importer, a swofty command or a build step	A launcher plugin	Launcher plugins

Every addon follows the same five steps, whatever it holds. They're on Addons.

The three building blocks

An addon is made from up to three blocks. Its swofty.json lists each one it uses, and one addon can use all three.

Operations. Data changes listed under operations in swofty.json: set a database field, replace a texture, add a line of text, copy a file, register a screen. The launcher applies them when it builds a profile, to copies of the game's files or in memory while the game boots. An addon with only operations is a data addon; it needs no compiler. See Operations for every kind.

Engine plugin. A Windows x86-64 DLL named in operations.native. The in-game loader loads it into F1 25 and hands it the SwoftyApi, which hooks engine functions through the mixin system and gives access to the standard library: events, overlay, telemetry, database reads, storage, settings and logging. See Engine plugins.

Launcher plugin. A program named in the launcher block. The launcher runs it as a subprocess that speaks newline-delimited JSON, and it adds sidebar pages, an importer for dropped files, ops at build time, swofty subcommands and a line on the profile card. See Launcher plugins.

Settings work with all three: a db setting fills values in operations, and a native setting reaches the engine plugin while the game runs.

Tools

Tool	What it does	Page
Swofty UI	Browses, renders and edits the game's menu scenes (.idf), and exports checked scenes for an addon. Releases ship it as bin/swofty-ui	Swofty UI
swofty	The command line: install and enable addons, import mods, build a profile, run the game and follow its logs, restore the game folder	Command line
tools/gamedb.py	Dumps the game database and gets or sets one value by path	Game database tools
tools/map_check.py	Checks a profile built with tracks against the game it was built from, using the build's plan.json	Game database tools
tools/idf.py	Prints a menu scene's elements and edits them from the command line	UI scenes

The Python tools are in the repository's tools/ folder. Releases don't ship them, except Swofty UI.

Reference

• Addon manifest: every swofty.json field.
• Database operations, ERP operations, File operations, UI patches and Asset op files: every operation.
• Game database, ERP archives and !pkg resources: the game's file formats.
• Engine API: the engine functions and structs an engine plugin can call and hook.
• Development: build the launcher from source.