borge is a deduplicating backup program with compression and authenticated encryption, written in Go.
borge started as a port of BorgBackup ("borg") from Python/Cython to Go. The great majority of this codebase is a translation of borg's source, and it reads and writes borg's on-disk repository format. Where code from restic is used, the file header says so.
borg is copyright (C) 2015-2026 The Borg Collective and (C) 2010-2014 Jonas Borgström,
licensed under the BSD 3-Clause License. restic is copyright (c) 2014 Alexander Neumann,
licensed under the BSD 2-Clause License. Both license texts are reproduced verbatim
under licenses/ and their conditions continue to apply to the portions
of borge derived from them.
borge is not produced, sponsored or endorsed by the Borg Collective or by the restic project. Please report borge bugs to the borge issue tracker, not to theirs.
borge as a whole is licensed under the Apache License 2.0 — see LICENSE
and NOTICE. The analysis of why Apache-2.0 is compatible with the upstream
BSD licenses is in docs/LICENSING.md.
Pre-release, and interoperable. v0.8.0 (2026-08-22) implements 33 of borg's 36
commands and every repository backend borg has: local paths, sftp:, s3:/b2:,
rclone:, and rest:// served by borge serve --rest. The three commands that are
missing — mount, umount, webdav — are deliberate non-goals, not gaps.
The port targets the borg 2.x repository format (repository version 4), pinned to
the upstream commit recorded in plans/PORTING_PLAN.md. Correctness is defined as
bidirectional interoperability with that borg: an archive written by borg must restore
identically with borge, and vice versa. That is a test suite rather than an intention —
both tools write into one repository, over each backend, and each reads what the other
wrote.
What "pre-release" means here. No interface stability is promised before v1.0.0,
performance work has not been done (stage 9), and borg 1.x repositories are not read at
all. Differences from borg that are deliberate — and the ones that were bugs until they
were found — are written down one by one in docs/DIVERGENCES.md.
Every stage gate has an evidence bundle: the commit, the full test log, the coverage
gates, the pinned borg version and a sha256 manifest, named in the stage's row in
plans/PORTING_PLAN.md and in the release tag.
Three things motivated the port, in priority order:
- Single static binary, no Python runtime. Borg's installation story and its Cython build are a recurring source of friction.
- Restore performance on directories with very many files. borg and restic both degrade badly here; the reference workload for this project is a directory with 118,866 files in it.
- Maintainability. borg's
archive.py(12 classes) andrepository.pyare god modules; the port takes the opportunity to split them (borg issues #10016, #10017).
plans/PORTING_PLAN.md— the staged porting plan and its gatesROADMAP.md— the work that is not a porting stage: format and indexing changes, evidence preservation, the documentation system, and the future GUIAGENTS.md— how the repository is built, tested, planned and trackeddocs/EVIDENCE.md— evidence catalog, ISO workflow, and limitationsdocs/LICENSING.md— license compatibility analysis