kfnetlist

kfnetlist is a standalone, Rust-backed netlist schema for kfactory and netlist tooling.

It provides a fast, type-safe data model for circuit connectivity — instances, nets, ports, and arrays — with full JSON/dict serialization and Pydantic v2 integration. The core is implemented in Rust via PyO3 and has zero runtime Python dependencies.

Key Features

• Rust core — Netlist, Net, and port types implemented in Rust for speed and memory safety
• Zero runtime dependencies — the base package has no Python dependencies
• Full serialization — to_json() / from_json() and to_dict() / from_dict() on every type
• Pydantic v2 support — all types implement __get_pydantic_core_schema__
• Equivalent ports — fold electrically-equivalent ports into canonical names for netlist comparison
• Instance flattening — merge sub-cell instances into the parent, reconnecting touching nets
• Port checking — PortCheck bitmask and check_connection() for geometric port-pair comparison
• Netlist extraction — extract hierarchical netlists from kfactory/klayout cells
• L2N parsing — convert klayout LayoutToNetlist results to JSON-serializable dicts
• Short detection — find geometric polygon overlaps between distinct nets
• Open detection — find unconnected ports, singleton nets, and missing nets vs. a reference
• Connectivity verification — complete LVS workflow combining open detection, net comparison, and short detection

Relationship to kfactory

kfnetlist is the netlist data model that kfactory uses internally. It is published as a separate package so that:

• Tools that only need netlist manipulation do not have to depend on kfactory or klayout
• The netlist schema can evolve on its own release cadence
• Downstream projects can consume netlists without pulling in a full layout framework

For end-to-end examples of netlist extraction using kfactory, see the kfactory schematics documentation.