A simple, minimalistic ActivityPub instance written in portable C
  • C 99.6%
  • Makefile 0.3%
2026-03-23 07:35:42 +01:00
artwork add susie-q (qr) to artwork 2026-01-23 18:03:32 +01:00
doc OpenBSD: Document login class w/ extended openfiles 2026-02-17 23:03:23 +01:00
examples Call ulimit -n to increase file descriptors in examples/snac_netbsd. 2026-03-14 14:21:07 +01:00
po Update po/cs.po 2026-03-02 09:34:30 +01:00
tests enforce tls when supported && add tests 2025-01-24 22:24:05 +01:00
.gitignore enforce tls when supported && add tests 2025-01-24 22:24:05 +01:00
activitypub.c Commented out aliases in webfinger, as they are generating following problems. 2026-03-22 09:06:21 +01:00
CONTRIBUTING.md Minor tweak to CONTRIBUTING.md. 2026-03-09 08:38:02 +01:00
data.c Also purge the 'pending/' subdirectory. 2026-03-22 16:45:00 +01:00
docker-compose.yaml Add docker-compose support, so a working development server with HTTPS can be started with: 2022-12-12 10:26:38 +00:00
Dockerfile Add tzdata to container image 2025-09-04 15:25:24 -03:00
FEDERATION.md Updated documentation. 2025-12-19 10:30:33 +01:00
format.c Added emoji categories. 2026-01-12 06:03:04 +01:00
html.c If latitude or longitude are not numbers, use them as string. 2026-03-18 15:52:37 +01:00
http.c Tweaked check_signature() for GET variables. 2026-02-03 07:15:22 +01:00
httpd.c Implemented tootfinder.ch compatibility mimic Mastodon Behaviour 2026-03-19 11:50:03 +01:00
landloc.h update landloc.h 2024-12-30 11:31:11 +01:00
LICENSE Bumped copyright year. 2026-01-01 17:01:03 +01:00
main.c New command-line option 'refresh'. 2026-01-19 15:53:19 +01:00
Makefile Added translatable month names. 2026-02-02 17:51:40 +01:00
Makefile.NetBSD New command-line option top_ten. 2026-01-10 21:29:32 +01:00
mastoapi.c fix: another small leak in mastoapi 2026-03-19 23:04:50 +01:00
README.md CONTRIBUTING.md new file. 2026-03-09 08:28:02 +01:00
RELEASE_NOTES.md Updated RELEASE_NOTES. 2026-03-22 10:07:20 +01:00
rss.c Add attachments to RSS. 2026-03-19 19:15:22 +01:00
sandbox.c strip_exif support for the OpenBSD sandbox 2026-02-05 21:17:44 +01:00
SECURITY.md Reworded SECURITY.md. 2025-09-09 09:14:35 +02:00
snac.c strip_exif support for the OpenBSD sandbox 2026-02-05 21:17:44 +01:00
snac.h Implemented tootfinder.ch compatibility mimic Mastodon Behaviour 2026-03-19 11:50:03 +01:00
TODO.md Updated TODO. 2026-03-19 19:17:13 +01:00
upgrade.c Bumped copyright year. 2026-01-01 17:01:03 +01:00
utils.c Use the metadata pronouns. 2026-01-12 05:09:21 +01:00
webfinger.c More webfinger fixes. 2026-03-22 09:34:58 +01:00
xs.h Bumped copyright year. 2026-01-01 17:01:03 +01:00
xs_curl.h Bumped copyright year. 2026-01-01 17:01:03 +01:00
xs_fcgi.h Bumped copyright year. 2026-01-01 17:01:03 +01:00
xs_glob.h Bumped copyright year. 2026-01-01 17:01:03 +01:00
xs_hex.h Bumped copyright year. 2026-01-01 17:01:03 +01:00
xs_html.h Bumped copyright year. 2026-01-01 17:01:03 +01:00
xs_http.h Bumped copyright year. 2026-01-01 17:01:03 +01:00
xs_http_codes.h xs_http.h: new file. 2025-10-13 13:07:06 +02:00
xs_httpd.h Bumped copyright year. 2026-01-01 17:01:03 +01:00
xs_io.h Break on read errors in xs_read(). 2026-03-23 07:35:42 +01:00
xs_json.h Fixed another new error in the JSON parser. 2026-02-24 18:02:20 +01:00
xs_list_tools.h New file xs_list_tools.h. 2026-01-10 20:40:13 +01:00
xs_match.h Bumped copyright year. 2026-01-01 17:01:03 +01:00
xs_mime.h Bumped copyright year. 2026-01-01 17:01:03 +01:00
xs_openssl.h Deleted unused goto label. 2026-03-17 20:37:38 +01:00
xs_po.h Bumped copyright year. 2026-01-01 17:01:03 +01:00
xs_random.h Bumped copyright year. 2026-01-01 17:01:03 +01:00
xs_regex.h Fixed possible crash in xs_regex_split_n(). 2026-02-23 07:15:28 +01:00
xs_set.h Bumped copyright year. 2026-01-01 17:01:03 +01:00
xs_socket.h Bumped copyright year. 2026-01-01 17:01:03 +01:00
xs_time.h Fixed timezones. 2026-02-23 05:31:02 +01:00
xs_unicode.h fixing out of bounds 2026-01-24 22:05:16 +01:00
xs_unicode_tbl.h New function xs_unicode_right_to_left(). 2024-11-20 18:10:02 +01:00
xs_unix_socket.h Bumped copyright year. 2026-01-01 17:01:03 +01:00
xs_url.h Fixed latest breakage in xs_multipart_form_data(). 2026-02-23 13:52:35 +01:00
xs_version.h New file xs_list_tools.h. 2026-01-10 20:40:13 +01:00
xs_webmention.h Bumped copyright year. 2026-01-01 17:01:03 +01:00

snac

A simple, minimalistic ActivityPub instance

Features

  • Lightweight, minimal dependencies
  • Extensive support of ActivityPub operations, e.g. write public notes, follow users, be followed, reply to the notes of others, admire wonderful content (like or boost), write private messages...
  • Multiuser
  • Mastodon API support, so Mastodon-compatible apps can be used
  • Simple but effective web interface
  • Easily-accessed MUTE button to silence morons
  • Tested interoperability with related software
  • No database needed
  • Totally JavaScript-free
  • No cookies either
  • Not much bullshit

About

This program runs as a daemon (proxied by a TLS-enabled real httpd server) and provides the basic services for a Fediverse / ActivityPub instance (sharing messages and stuff from/to other systems like Mastodon, Pleroma, Friendica, etc.).

This is not the manual; man pages snac(1) (user manual), snac(5) (formats) and snac(8) (administrator manual) are what you are looking for.

snac stands for Social Networks Are Crap.

Building and installation

This program is written in highly portable C. It uses the __attribute__((__cleanup__)) GNU extension, that is supported at least by the gcc, clang and tcc C compilers. The only external dependencies are openssl and curl.

On Debian/Ubuntu, you can satisfy these requirements by running

apt install libssl-dev libcurl4-openssl-dev 

On OpenBSD you just need to install curl:

pkg_add curl 

On FreeBSD, to install curl just type:

pkg install curl 

On NetBSD, to install curl just type:

pkgin install curl 

The source code is available here.

Run make and then make install as root.

If you're compiling on NetBSD, you should use the specific provided Makefile and run make -f Makefile.NetBSD and then make -f Makefile.NetBSD install as root.

From version 2.27, snac includes support for the Mastodon API; if you are not interested on it, you can compile it out by running

make CFLAGS=-DNO_MASTODON_API 

If your compilation process complains about undefined references to shm_open() and shm_unlink() (it happens, for example, on Ubuntu 20.04.6 LTS), run it as:

make LDFLAGS=-lrt 

If it still gives compilation errors (because your system does not implement the shared memory functions), you can fix it with

make CFLAGS=-DWITHOUT_SHM 

From version 2.68, Linux Landlock sandboxing is included (not supported on Linux kernels older than 5.13.0). It's still a bit experimental, so you must compile it in explicitly with

make CFLAGS=-DWITH_LINUX_SANDBOX 

From version 2.73, the language of the web UI can be configured; the po/ source subdirectory includes a set of translation files, one per language. After initializing your instance, copy whatever language file you want to use to the lang/ subdirectory of the base directory.

See the administrator manual on how to proceed from here.

Testing via Docker

A docker-compose file is provided for development and testing. To start snac with an nginx HTTPS frontend, run:

docker-compose build && docker-compose up 

This will:

  • Start snac, storing data in data/
  • Configure snac to listen on port 8001 with a server name of localhost (see examples/docker-entrypoint.sh)
  • Create a new user testuser and print the user's generated password on the console (see examples/docker-entrypoint.sh)
  • Start nginx to handle HTTPS, using the certificate pair from nginx-alpine-ssl/nginx-selfsigned.* (see examples/nginx-alpine-ssl/entrypoint.sh)

Incredibly awesome CSS themes for snac

License

See the LICENSE file for details.

Contributing

See the CONTRIBUTING.md file for details.

Author

grunfink @grunfink@comam.es with the help of others.

Buy grunfink a coffee: https://ko-fi.com/grunfink/

Contribute via LiberaPay: https://liberapay.com/grunfink/