macOS periodically deletes files from /tmp that haven't been accessed in ~3 days. The @atproto/dev-env PDS stores actor signing keys as plain files, so after a few days without writes the key disappears and every putRecord fails with InternalServerError. Setting TMPDIR to ~/.local/share/starhaven-dev-pds before starting the PDS process causes os.tmpdir() to resolve there, putting all PDS data in a location macOS will not clean up.