`cd ~/path/to/your-project && curl -fsSL https://paxel.ycombinator.com/upload.sh | bash` is the command from Paxel's website. So you're literally just piping whatever the hell they want into bash. It's long, lots of comments, and honestly would be time consuming to audit properly.

Supposedly this is what it does from the opening comment

  # Paxel upload script
  # ===================
  #
  # What this does (up to 17 steps):
  #   On your machine
  #     1. Check Docker is installed and running
  #     2. Sign you in (browser-based device auth)
  #     3. Pull or build the Paxel Docker image
  #
  #   Inside the container — file bodies stay local; only aggregate metrics +
  #   metadata (paths, commit numstat, session events) are uploaded
  #     4. Discover projects and sessions (Claude Code, Codex CLI, Cursor)
  #     5. Read your git history
  #     6. Parse transcripts
  #     7. Summarize each session (cloud Haiku via YC proxy)
  #     8. Group git commits by session
  #     9. Group sessions into multi-day work streams
  #    10. Extract steering traces
  #    11. Extract decision exchanges (cloud Haiku)
  #    12. Redact code before upload (regex pattern redaction)
  #    13. Link decisions to outcomes
  #    14. Analyze code quality (L1 deterministic)
  #    15. Score episodes across 5 axes (cloud Haiku)
  #    16. Assemble your report
  #    17. Upload redacted summaries + scores to the server
  #
  #   Then: opens your results in the browser

No.

It uploads only the AI coding agent transcripts in the directories you explicitly run the upload script in.