Build on Candeo

Four ways in

Effects can also follow the music: what Candeo hears, and how a setting follows it.

Your files, in your folder

What you write lives in your Documents, where you can back it up, version it or share it:

• Documents\candeo\effects — one .ts file per effect;
• Documents\candeo\devices — one .json file per device definition.

The ones Candeo ships are listed beside yours and open read only. Duplicate an effect, or Copy to yours a device definition, to start from one that works. A file dropped in the folder shows up after Refresh.

The editor

Candeo opens both kinds of file in its own editor — the one behind Visual Studio Code — and checks them as you type: an effect against the effects API, with completion and the types of everything it receives; a device definition against its schema, with the documentation of each field on hover.

• Ctrl+S puts the text in shape and saves it;
• F1, or the ⌨ button, lists the other shortcuts;
• an effect plays in the simulator as soon as it is saved; a device definition takes effect on the device at once, when it is the one the device uses.

Prefer your own editor? Edit the files there, then Refresh.

References

• The effects API — every type and helper an effect can use, as the editor knows them.
• The device definition schema — every field of a definition, and what it accepts. Name it in $schema and any editor that reads JSON schemas checks your file.
• The signals API — the one local endpoint, its token and what it accepts.
• The MCP server — the tools and resources an assistant reads, and what it is never given.
• The shipped effects and the built-in device definitions — written against the same API and schema as yours.

How Candeo is built

• The protocols are documented, with how each fact was established and the firmware version behind it — docs/protocol.
• Decisions are written before the code, and kept when they turn out wrong — docs/design.
• A device is data, read by one interpreter, and every built-in definition replays reference frames captured on the device: the tests check the bytes without the hardware.
• One engine runs the effects, in Rust, in a thread that outlives the window: closing it changes nothing on the keyboard.

The protocols were established by observing the hardware: USB captures, then writes and reads checked one by one. Facts about a protocol are not subject to copyright, and surveying them for interoperability is provided for by Article L.122-6-1 IV of the French Intellectual Property Code, transposing Directive 2009/24/EC, Article 6.

Contribute

Candeo is a Tauri application — Rust underneath, Vue and TypeScript for the window — under the GPL, version 3 only. To run it from source, with stable Rust 1.97 or later, Node 22 or later and pnpm 10 or later:

AGENTS.md holds the rules for changing the repository and the checks CI runs. A device of yours can become a built-in one: see making it built in.

What comes next

• The computer as a source — CPU, memory and network for effects and settings, then temperatures and the GPU (#242).
• More devices, contributed — what a protocol contribution carries to be reviewable by someone without the hardware.
• Linux with a real device, then the nobody at the computer trigger there (#183).
• winget — installing and updating in one command.