# tscircuit
URL: /runtime/reference/tscircuit



`@taucad/tscircuit` evaluates `.tsx` and `.jsx` boards in browser workers and Node hosts, retaining settled circuit JSON for views and exports.

## Authoring contract [#authoring-contract]

Each entry file default-exports one board component. `React` is provided as a global by the worker, so the import is optional. Give each part a unique `name`; footprints are footprinter strings such as `0402`, `0603`, `soic8`, or `dip8`; positions are millimetres.

```tsx
export default () => (
  <board width='20mm' height='20mm'>
    <resistor name='R1' resistance='1k' footprint='0402' pcbX={-4} pcbY={0} />
    <led name='LED1' color='red' footprint='0603' pcbX={4} pcbY={0} />
    <trace from='.R1 > .pin2' to='.LED1 > .anode' />
  </board>
);
```

Traces use tscircuit selectors (`.R1 > .pin1`, `net.GND`). Optional `defaultParameters` exports become editable parameters that Tau passes to the component as props.

## Views and exports [#views-and-exports]

One evaluation retains the settled circuit JSON. It offers these separately declared views from that handle:

| View ID     | Artifact                                               |
| ----------- | ------------------------------------------------------ |
| `board`     | Textured GLB board with feature-edge lines             |
| `schematic` | Schematic SVG, with one instance per authored sheet    |
| `pcb`       | Fitted PCB layout SVG; `pinNumbers` is its view option |

The kernel declares export IDs `board` (GLB), `bom` (CSV), `netlist` (text), and `circuit` (JSON). Each has its own title, MIME type, extension, and optional options schema. A schematic-only result may offer only the schematic view; the ordered offers are returned by `evaluate`.

Each sheet is rendered through its converter ID. A uniquely named authored sheet keeps a stable selection across reorder; unnamed or duplicate-name sheets have evaluation-local IDs and titles marked “current evaluation,” and expire after reevaluation. With no authored sheets, the schematic renders the whole circuit. Parts outside all sheets produce a warning naming those parts. The SVG dimensions are fitted pixels, with no physical-unit claim.

The document client opens synchronously with `client.open({ source })`, selects PCB with `document.view('pcb', { options: { pinNumbers: true } })`, and waits for the result with `await pcb.rendering()`.

## Offline behaviour [#offline-behaviour]

The circuit uses the local autorouter and no parts engine. The kernel blocks `fetch` during evaluation and GLB conversion, so `http(s)://` footprint and `cadModel` URLs are never requested; each attempt becomes a `warning` naming the URL. Library references (`kicad:`, `jlcpcb:`) produce a `warning` and an unplaced part. The render completes with local bodies and bounding boxes.

## Install [#install]

Install `@taucad/tscircuit` with its runtime and Zod peers. The package includes its upstream engine, so consumers need no pnpm hook or bundler alias.

```bash
npm install @taucad/tscircuit @taucad/runtime zod
```

## Related [#related]

* [Choose a Kernel](/runtime/guides/choosing-a-kernel)
* [Kernel Plugins](/runtime/api/kernels)
* [Kernel Selection](/runtime/concepts/kernel-selection)