Compile Go to readable Python, call Python from Go.

hebi is a Go toolchain with two directions. hebi build compiles a Go package into readable Python that runs on CPython, with a native fast path behind an identical import. The Python-from-Go direction embeds CPython and generates typed Go bindings, so a Go program can drive a Python library without hand-written glue.

The snake moves both ways.

Pre-alpha, under heavy construction. The current build carries the start of the M0 skeleton and cannot compile a real program yet. Follow the milestones in notes/Spec/2076b/milestones for what lands next.

hebi loads a Go package with go/packages, type-checks it with go/types, and lowers the typed program onto a Python object model that mirrors Go's semantics: fixed-width integers that wrap, value-copied structs, slices over a shared backing, and Go's panic and error surface. The emitter leans on Python idioms wherever they are faithful and reaches for a small runtime shim only where a bare idiom would diverge, so the output reads like Python a person would write. Go is the semantic oracle: where behavior is observable, hebi matches go run, and every deliberate divergence is written down.

The compiled tier emits pure Python plus a small runtime shim and ships as a py3-none-any wheel that also runs on PyPy. The native tier compiles the same source to Go behind a thin abi3 extension for the hot path, chosen automatically and invisible to the caller. Direction B embeds CPython in a Go process and funnels every call through one serializer goroutine that owns the GIL.

Every change lands as one pull request from a feature branch. The build is Go 1.26.5, pinned in go.mod and recorded in versions.env alongside the CPython and PyPy pins. The three-way differential harness compares go run, the compiled tier, and the native tier on a growing fixture corpus, and a change only merges when they agree.