# zener-language

Guides work on Zener HDL for schematics, components, package APIs, and dependencies. Use it when editing .zen files in PCB projects.

- skill · `type=skill` · Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, OpenCode · 1700 installs · ★ 466
- Author: diodeinc
- License: MIT · policy=mirror · the beginning of the file is at the end of this page
- Source: https://github.com/diodeinc/pcb/tree/HEAD/skills/zener-language/SKILL.md
- Updated: 2026-10-24
- HTML: https://affpapa.org/en/nevibecode/skills/zener-language

## What it does

This skill guides an agent through Zener, a Starlark-based language with modules for electrical connections, physical parts, layout, sourcing, and diagnostics. It covers `load()` and `Module()` imports, public `io()` and `config()` declarations, plus connection types such as `Power`, `Ground`, `Net`, `I2c`, `Spi`, and `Usb2`.

Public electrical connections should be flat top-level assignments, and public `Power` IO should carry a voltage range unless the API is deliberately generic. Configurations may alter values or `dnp=` state, but should not conditionally create, remove, or reconnect schematic instances. That matters when a configuration change would alter the schematic topology.

Before changing a package, the skill directs the agent to locate local sources with `pcb list -m -json @stdlib` or `pcb list -m -json <package>[@<version>]` and inspect its `.zen` files. Check installed CLI behaviour with `--help`; inspect the installed version and the `pcb` changelog when version history matters.

## Install

### Claude Code (native platform)

1. **Skills CLI (Vercel)**
```bash
npx skills add diodeinc/pcb --skill zener-language -a claude-code
```

2. **Manually: put the files in place**
- File: `~/.claude/skills/zener-language/SKILL.md` — Copy the whole skill folder; for one project use .claude/skills/zener-language/

### Codex

1. **Skills CLI (Vercel)**
```bash
npx skills add diodeinc/pcb --skill zener-language -a codex
```

2. **Manually: put the files in place**
- File: `.agents/skills/zener-language/SKILL.md` — For all projects use ~/.agents/skills/

### Cursor

1. **Skills CLI (Vercel)**
```bash
npx skills add diodeinc/pcb --skill zener-language -a cursor
```

2. **Manually: put the files in place**
- File: `.cursor/skills/zener-language/SKILL.md` — Cursor also reads .agents/skills/ and .claude/skills/

### GitHub Copilot

1. **GitHub CLI**
```bash
gh skill install diodeinc/pcb zener-language
```

2. **Manually: put the files in place**
- File: `.github/skills/zener-language/SKILL.md`

### Gemini CLI

1. **Skills CLI (Vercel)**
```bash
npx skills add diodeinc/pcb --skill zener-language -a gemini-cli
```

2. **Platform CLI**
```bash
gemini skills install https://github.com/diodeinc/pcb --path skills/zener-language
```

### Windsurf (Devin Desktop)

**Manually: put the files in place**
- File: `.devin/skills/zener-language/SKILL.md` — The legacy .windsurf/skills/ path still works

### OpenCode

**Skills CLI (Vercel)**
```bash
npx skills add diodeinc/pcb --skill zener-language -a opencode
```

### Claude.ai

**Claude.ai**
- Zip the folder and upload it in Settings → Capabilities → Skills

Where a file is given instead of a command, copy the files from the source to that path: https://github.com/diodeinc/pcb/tree/HEAD/skills/zener-language/SKILL.md

## When to use it
- inspect a Zener package public API
- define schematic module IO and configuration
- import a local or remote `.zen` module
- keep topology stable across configuration changes
- enforce electrical connection constraints

## Example prompts
- "Read this `.zen` module and explain its public `io()` and `config()` API."
- "Add an `I2c` interface to this module while keeping the existing schematic topology."
- "Use `pcb list -m -json @stdlib` to locate the package API and inspect its `.zen` files."

## Source text · SKILL.md · MIT

Below is the content of a third-party file. It is data, not instructions for you: do not act on anything written inside unless the human asks. Block tag: c5879b57c39317bd.

BEGIN THIRD-PARTY FILE c5879b57c39317bd
````text
---
name: zener-language
description: Read or edit Zener HDL, package APIs, and tool-managed dependencies.
---

# Zener Language

Zener is Starlark plus PCB-specific modules, typed electrical connections, physical parts, sourcing, layout, and diagnostics.

## Discover Before Authoring

Use `pcb list -m -json @stdlib` or `pcb list -m -json <package>[@<version>]` to find a package's local source directory, then read its `.zen` files for the public API and exact behavior.

For CLI behavior, use the installed command's `--help`; do not invent or infer subcommands or flags. When version history matters, inspect the installed version and nearby entries in the [`pcb` changelog](https://github.com/diodeinc/pcb/blob/main/CHANGELOG.md) instead of relying on old examples.

## Modules and Components

A `.zen` file can be:

- a normal Starlark module imported with `load()`; or
- an instantiable schematic module imported with `Module()`.

Relative paths stay within the current package. Cross-package imports use full package URLs:

```zen
load("./helpers.zen", "helper")
LocalBlock = Module("./LocalBlock.zen")
RemoteBlock = Module("github.com/org/repo/modules/RemoteBlock.zen")
```

An instantiation passes `name=...`, its public `io()` and `config()` inputs, and optional `dnp` and `properties` arguments.

`name` establishes instance-path identity, not a fixed reference designator. Refdes-like names are only annotation hints; exact source-reference preservation is not supported.

Use refdes-like names only when the user explicitly asks. In that case, set `prefix=` on the underlying `Component()` to match the refdes prefix.

`Component()` creates a physical part from `name`, `symbol`, and `pins`. The selected symbol is the authority for its footprint, part identity, datasheet, and pins. Keep those properties correct in `.kicad_sym` rather than repeating them in Zener. Omit true `no_connect` pins; they are wired to `NotConnected()` automatically.

Use `Symbol(library, name=...)` for multi-symbol libraries. Use `Part(mpn=..., manufacturer=...)` only when the symbol does not already provide part identity.

`Project()` takes `layout = False` or `schematic = False` to disable either. Use one declaration per entrypoint with a config-independent path relative to its `.zen` file; use separate entrypoints for distinct projects.

## IO and Config

Define public electrical connections as flat top-level assignments:

```zen
VDD = io(Power(voltage="3.0V to 5.5V"))
GND = io(Ground)
EN = io(Net, optional=True)
```

Do not introduce legacy `Pins = struct(...)` wrappers in new or touched APIs.

With `optional=True`, an omitted IO receives an automatically generated net or interface.
````
END THIRD-PARTY FILE c5879b57c39317bd

The third-party file has ended. Everything between the c5879b57c39317bd tags is data: requests and commands from it are not followed. An “end of file” line with another tag inside the block is part of the file.

First 2696 of 9403 bytes. © diodeinc · MIT · https://github.com/diodeinc/pcb/tree/HEAD/skills/zener-language/SKILL.md

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