Env Python Entrypoint

• the repo may or may not have a local virtualenv
• the repo may override the default resolution order in runtime-bootstrap.md

Steps

1. Read the repo or workspace codex-template.json.
2. Read runtime-bootstrap.md if present.
3. Resolve Python in this order:
   • .venv/bin/python
   • .venv/bin/python3
   • venv/bin/python
   • venv/bin/python3
   • python3
   • python
4. Prefer the repo-local executable when available.
5. If the repo documents a different Python entrypoint explicitly, honor the repo documentation.

Outputs

Return:

• chosen executable
• why it was chosen
• any mismatch between documented and discovered runtime conventions

Failure Modes

• no usable Python executable is available
• repo documentation conflicts with the discovered executable layout

Validation

• Contract: confirm the skill contract matches runtime-bootstrap.md and the shared runtime rules.
• Probe: verify the first matching executable in the documented order is the one reported.