A simple library, and command-line tool, to export your team's entire history using Slack's API. All you need is a token.
slack-auto-export
performs the function as Slack's web export service; only better because this is programmatic and can be automated for a rolling history archive.
git clone git@github.com:hfaran/slack-auto-export.git
cd slack-auto-export
pip install -r requirements.txt
./slack_auto_export.py --help
./slack_auto_export.py -t your-api-token -o /path/to/output/dir