zener-language

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 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:

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.