Faebryk Core Module

The Faebryk core here is the TypeGraph + edge types implemented in Zig and exposed to Python via faebryk.core.faebrykpy.

Source-of-truth for API + behavior:

• src/faebryk/core/faebrykpy.py (Python-facing wrapper + type-safe EdgeTrait.traverse)
• src/faebryk/core/zig/gen/faebryk/typegraph.pyi (public stubbed API surface)
• src/faebryk/core/zig/src/faebryk/* (Zig implementation)

Quick Start

import faebryk.core.faebrykpy as fbrk
import faebryk.core.graph as graph

g = graph.GraphView.create()
tg = fbrk.TypeGraph.create(g=g)

Relevant Files

• src/faebryk/core/faebrykpy.py (re-exports + EdgeTraversal + type-safe EdgeTrait.traverse)
• src/faebryk/core/zig/gen/faebryk/typegraph.pyi (TypeGraph stub)
• Key edge types (imported by faebrykpy.py):
  • EdgeComposition (parent/child structure)
  • EdgeTrait / Trait (trait attachment)
  • EdgePointer (references)
  • EdgeInterfaceConnection (interface connections)
  • EdgeOperand (solver operand wiring)
  • EdgeType / EdgeNext (type graph plumbing)
• Linker:
  • Linker (used by compiler/linking stages)

Dependants (Call Sites)

• FabLL: src/faebryk/core/node.py (binds Python classes into the TypeGraph; uses composition/trait edges)
• Compiler: src/atopile/compiler/* (creates and links TypeGraphs)
• Solver: src/faebryk/core/solver/* (operand edges and instance traversal)
• Build/export pipeline: src/atopile/build_steps.py (visits type/instance edges for PCB/layout features)

How to Work With / Develop / Test

Core Concepts

• GraphView + TypeGraph: a TypeGraph is created against a GraphView:

  import faebryk.core.graph as graph
  import faebryk.core.faebrykpy as fbrk
  
  g = graph.GraphView.create()
  tg = fbrk.TypeGraph.create(g=g)

• Type nodes vs instance nodes:
  • TypeGraph stores type definitions (“what exists structurally on a type”)
  • GraphView also holds instances created from those types (“a concrete design graph”)
• EdgeTraversal: TypeGraph.ensure_child_reference(..., path=[...]) uses EdgeTraversal items to walk references through the type graph.

Development Workflow

1. Zig-side changes: edit src/faebryk/core/zig/src/faebryk/* (edges, typegraph internals).
2. Rebuild bindings: ato dev compile (imports faebryk.core.zig).
3. Python ergonomics: add wrappers/helpers in src/faebryk/core/faebrykpy.py (example: type-safe EdgeTrait.traverse).

Testing

• TypeGraph-heavy tests live in compiler/runtime suites:
  • ato dev test --llm test/compiler/test_typegraph.py -q
  • ato dev test --llm test/compiler/test_runtime.py -q
• Zig-backed traversal tests:
  • ato dev test --llm test/core/zig/test_interface_pathfinder.py -q

Best Practices

• Import edges/TypeGraph via faebryk.core.faebrykpy (so callers get Python helpers, not just raw generated types).
• Prefer type-safe trait traversal:
  • EdgeTrait.traverse(trait_type=SomeTrait) over stringly-typed trait_type_name=....
• When building reference paths, be explicit about edge semantics (composition vs pointer vs trait) rather than relying on implicit string behavior.