Installing on Windows¶

Mylonite runs on Windows, but a few platform defaults bite. This page collects the friction points so a Windows install takes minutes, not half an hour.

1. Pick a supported Python (3.11–3.13, not 3.14)¶

Mylonite requires >=3.11,<3.14. The upper bound tracks litellm, which has no installable wheel on Python 3.14 yet — so if your system default is 3.14 the install fails with a confusing resolver error.

Install Python 3.12 (or 3.11/3.13) and invoke it explicitly via the py launcher:

py -3.12 -m venv .venv
.\.venv\Scripts\Activate.ps1
python --version   # 3.12.x

All commands below assume this 3.12 venv is active.

2. Clone with the schannel TLS backend (corporate proxy)¶

Behind a TLS-inspecting proxy, git's bundled OpenSSL backend can't find the org CA and fails with unable to get local issuer certificate. Use Windows' native certificate store:

git -c http.sslBackend=schannel clone https://github.com/Abidemialade/mylonite

3. Install Mylonite (+ the reference target for the test suite)¶

pip install -e ".[dev]"
# The full test suite imports the deliberately-vulnerable reference target,
# which is a SEPARATE editable package:
pip install -e ./reference_targets/mcp_kitchen_sink

For live scans behind a corporate proxy, also install the OS-trust-store helper so provider calls don't fail CERTIFICATE_VERIFY_FAILED — see Enterprise networking. It now also ships in [dev], so a dev install already has it:

pip install -e ".[enterprise]"   # end users / non-dev installs

4. UTF-8 output — handled automatically, with a fallback¶

The Windows console defaults to the legacy cp1252 code page, which used to crash on the non-ASCII glyphs Mylonite prints (✓, │, …). The mylonite CLI now forces UTF-8 on its own stdout/stderr before any output (errors="replace", so it degrades rather than crashes even if a stream still can't encode something) — verified locally against a chcp 1252 console with PYTHONUTF8 unset: mylonite scan reference:vulnerable renders cleanly. You should not need to set anything for mylonite commands themselves.

pytest run directly (not through the mylonite CLI) does not get this automatic reconfiguration, since it never goes through cli.py's startup path. If you see mangled output or a UnicodeEncodeError from a plain pytest run, force UTF-8 for the session as a fallback:

$env:PYTHONUTF8 = "1"

Add it to your profile (or set it as a user environment variable) to make it permanent. CI runs on Linux and never catches encoding issues like this, so they only show up locally.

5. Verify¶

mylonite version
pytest -q

A green suite (run from the project root) confirms the install. If a live scan/gate/ validate run can't reach the configured provider, it classifies the failure as auth/TLS/network/rate-limit with a concrete remedy rather than a raw traceback.