syncspirit

Sites: github, notabug gitflic

syncspirit is a continuous file synchronization program, which synchronizes files between devices. It is built using the C++ rotor actor framework. It implements the BEP-protocol for files synchronization, or, simplistically speaking, it is a syncthing-compatible synchronization program at protocol level, which uses the syncthing infrastructure (for global discovery and relaying).

Despite being functional, syncspirit is less feature-rich than syncthing and is still in heavy development

front-ends (aka UIs)

• fltk-based gui app

• headless daemon

All front-ends share the same configuration and database when running on same host.

status

• full-powered files synchronization (aka send and receive)

• global peer discovery

• local (LAN) peer discovery

• upnp & nat passthough

• certificates generation

• relay transport

• conflict resolution

• incoming and outcoming messages (de)compression using lz4

• introducer support

• send only/receive only dirs

missing features

This list is probably incomplete. Here are the most important changes:

• inotify support (aka realtime files watching)

• ignoring pattern files

• QUIC transport

• untrusted devices encryption

run

(headless ui-daemon only, atm)

syncspirit-daemon --log_level debug \
    --config_dir=/tmp/my_dir \
    --command add_peer:peer_label:KUEQE66-JJ7P6AD-BEHD4ZW-GPBNW6Q-Y4C3K4Y-X44WJWZ-DVPIDXS-UDRJMA7 \
    --command add_folder:label=my_label:id=nagkw-srrjz:path=/tmp/my_dir/data \
    --command share:folder=my_label:device=KUEQE66 \
    --command inactivate:120

the output should be like

i.e. it records some peer, adds a folder, then shares the folder with the peer device, connects to the peer and downloads all files into /tmp/my_dir/data . The peer device currently can only be syncthing. Then syncspirit either exits after 2 minutes of inactivity or when you press ctrl+c. The output is successful, because I previously authorized this device with the syncthing web interface, and shared the folder with this device (syncspirit).

I also assume some familiarity with syncthing, so you should understand what's going on here.

For more details see ui-daemon docs and configuration docs.

design and ideas

syncthing is implemented using go programming language, which is a good fit for services. As a result, syncthing itself is written as a web-service, which exposes a REST-API for clients. So, yes, the end-user software should also have a front-end, which is usually web-browser (or embeds web-browser), which is written in different programming language (e.g. javascript or java).

I feel myself a bit uneasy with that design; maybe it's my personal nostalgia, but I like the good old programs, where everything is "in memory" of one program. They are fast, ecological, secure, manageable, have lower CPU and memory pressures.

The actor model, blurs the boundaries between classical desktop and client-server application models. I think, rotor makes it possible to have (and embed) some "core" into multiple different user interfaces (GUIs).

Currently, syncspirit has only a "daemon-ui", i.e. a simple non-interactive application, which shows a synchronization log, and the only possibility is just to stop it. However, as soon as the "core" is complete, there are plans to develop multiple syncspirit UIs: wx-widgets, qt, gtk, maybe native, maybe even native mobile UIs...

Another major idea is scripting support: it should be possible to expose the "core" to lua scripts, and have some user-defined actions like synchronizing files with external folders including flash-sticks, user-defined files ordering and filtering for synchronization, maybe even selective sync, like in resilio. This, however, still needs to be researched, after the core completion.

platforms

• linux
• windows
• mac os x

changes

0.4.1 (05-Aug-2025)

• [core, fltk] support merged cluster folder model
• [core] possibility to import directories outside of syncthing, including partial import, see faq
• [core] performance improvents, upto 5 times on a smaller files
• [core] fix compatibility with global discovery v3 protocol
• [core] support folder_type folder setting (send only, receive only, send & receive)
• [core] support pull_older folder setting (alphabetic, by size, by modification date)
• [core, bep] support disable_temp_indixes (hardcoded to 1 for atm)
• [core, bep] support ignore_permissions folder flag, permissions and no_permissions file flag
• [core, bep] support ignore_deletes folder flag
• [core, bep] support device auto-accept folder flag
• [core, bep] support device introducer and skip_introduction_removals markers
• [core, bep] support outgoing messages to be compressed using lz4
• [core] syncrhonize threads/app startup
• [impl] degoogle: use protopuf instead of protobuf

0.4.0 (22-Feb-2025)

• [feature] new fltk-fronted
• major app refactoring

0.3.3 (12-May-2024)

• [bugfix, win32] governor actor, fix parsing folder path

0.3.2 (11-May-2024)

• [bugfix] folder scan isn't triggered on startup

0.3.1 (23-Apr-2024)

• [feature] added syncspirit binary fow windows xp
• [build, docs] improved build documentation

0.3.0 (14-Apr-2024)

• [feature] implemented complete files synchronization
• [feature] added local files watcher and updates streamer
• [build] switched from git submodules to conan2
• [win32] better platform support

0.2.0 (22-May-2022)

• [feature] implement relay transport, the relay is randomly chosen from the public relays pool
• [feature] output binary is compressed via upx
• [feature] small optimization, use thread less in overall program
• [bugfix] sometimes fs::scan_actor request timeout occurs, which is fatal
• [bugfix] global discovery sometimes skipped announcements

0.1.0 (18-Arp-2022)

• initial release

building from source

see

license

This software is licensed under the GPLv3 license.

Copyright (C) 2019-2022 Ivan Baidakou (aka basiliscos)

This file is part of syncspirit.

syncspirit is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

syncspirit is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with syncspirit.  If not, see <http://www.gnu.org/licenses/>.