If I have access to the logs, python env and git commits, is there an API to log those to the experiments too?

Sure:
task.update_task see here:
https://clear.ml/docs/latest/docs/references/sdk/task#update_task
example:
task.update_task(task_data={'script': {'branch': 'new_branch', 'repository': 'new_repo'}})The easiest way to get all the different sections (they should be relatively self explanatory) is calling task.export_task() which returns a dict with all the fields you can manually configure.
https://clear.ml/docs/latest/docs/references/sdk/task#export_task