CI Go Reference Go Report Card License: Apache 2.0

gopy is a from-scratch Go reimplementation of the CPython interpreter core. The goal is 100% behavioural compatibility with upstream CPython 3.14: same data structures, same models, same wire formats, same error messages. The only thing that changes is the surface API style, which adopts Go idioms modelled on the Go standard library.

Status: very early. v0.0.x is project scaffolding. The interpreter does not run Python code yet. The roadmap is tracked in the project notes and surfaced through the changelog.

• No alternative semantics. If gopy diverges from CPython, the bug is in gopy.
• No CPython C extension ABI. .so and .pyd modules are out of scope. Native modules are reimplemented in Go on demand.
• No Python 2.

Requires Go 1.26 or newer.

go install github.com/tamnd/gopy/cmd/gopy@latest

Or grab a prebuilt binary from the releases page.

$ gopy --version
gopy 0.1.0 (3.14.0+) [go1.26 darwin/arm64]
$ gopy --copyright
Copyright (c) 2026 The gopy Authors. All Rights Reserved.
...

git clone https://github.com/tamnd/gopy
cd gopy
make build
./bin/gopy --version

Common developer tasks live in the Makefile:

gopy/
 build/ version, platform, compiler, copyright strings
 cmd/gopy/ interpreter entry point (mirrors CPython python.c)
 changelog/ per-release changelog fragments
 .github/ workflows, dependabot, code owners, templates

The runtime packages live at the module root (no internal/) so that embedders and companion modules can import them directly.

Patches are welcome. Please read CONTRIBUTING.md and the Code of Conduct before opening a pull request.

Security issues should follow the disclosure procedure in SECURITY.md.

gopy is distributed under the Apache License, Version 2.0. See LICENSE for the full text.

Portions of the design and observable behavior are derived from CPython, which is distributed under the Python Software Foundation License.