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 (3.11–3.14)¶

Mylonite requires >=3.11,<3.15. The upper bound tracks litellm, which declares <3.15, so on a newer Python the install fails with a resolver error.

If you have more than one Python installed, pick a supported one explicitly with the py launcher:

py -3.14 -m venv .venv
.\.venv\Scripts\Activate.ps1
python --version   # 3.14.x

Any of 3.11–3.14 works: py -3.12 -m venv .venv is fine too.

All commands below assume this 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, provider calls can fail CERTIFICATE_VERIFY_FAILED unless Mylonite reads your OS's own certificate store — see Enterprise networking for why. Nothing extra to install: truststore is a base dependency of mylonite itself (and so already present in the [dev] install above), not a separate add-on step.

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 does run a Windows job (test-windows, plus a Windows leg of the offline demo), so an encoding regression should be caught there too — but if you hit one locally that CI missed, it is worth filing, since Windows-only failures are the easiest class to miss in review.

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.