What is snac?

snac (Social Networks Are Crap) is a Fediverse server: one small daemon speaking ActivityPub so an individual or a small group can run their own instance and exchange posts with Mastodon, Pleroma, Friendica and other systems. The code is plain C with only OpenSSL and curl needed at build time, everything is kept as files in a base directory rather than in a database, and the browser side is free of JavaScript and cookies while offering public, private and instance timelines that render conversations as nested trees. Writing supports a Markdown-like subset, media attachments, polls, drafts, scheduled publishing, content warnings and public / unlisted / followers-only / direct scopes; users can follow, mute, hide, limit or block accounts, admins can block whole instances, hashtags can be followed or blocked, and incoming post content can be filtered with regular expressions. From version 2.27 an optional Mastodon API lets third-party mobile and desktop clients connect with an API token, and bookmarks, lists and follows can be exported or imported as Mastodon-compatible CSV, including migrating an account away to Mastodon. Installation is make plus make install, then snac init <basedir>, snac adduser and snac httpd <basedir>, with nginx, Apache2 or OpenBSD httpd in front for TLS; tuning happens in server.json, and notifications can go out by email, webhook, Telegram or ntfy. The bundled docker-compose setup is only meant for development and testing, and the storage layout relies on a filesystem with hard-link support.

Should you self-host snac?

snac scores 61/100 on selfhost.directory (how scoring works) and ranks #18 of 69 in Social Networks & Forums.

There was no stable release in the past 12 months, so check the repository's recent activity before you rely on it.

Setup is advanced: plan for several services and some ongoing maintenance. It is MIT-licensed.

Its closest alternative on selfhost.directory is Discourse (83/100, 48 024 stars). It scores higher overall, so compare the two before you pick. See snac vs Discourse side by side.

Features

ActivityPub Federation
Content warnings
Hashtag following and blocking
Mastodon API supportOptional at build time via -DNO_MASTODON_API
Mastodon-compatible import/export
Media attachments
Multi-user support
Nested conversation threads
No Database Required
Notifications
Polls
Post visibility levels
Scheduled posts
Web Interface

How to install snac

Install snac with Build from Source

curl

Environment variables

DEBUG, SNAC_BASEDIR, EDITOR, LANG

Requirements:

apt install libssl-dev libcurl4-openssl-dev # as root

Build and install:

make
make install # as root

Then `snac init <basedir>`, `snac adduser` and `snac httpd <basedir>` behind a TLS reverse proxy.

How to configure snac

addresslocalhostListen network address; a leading / means a UNIX socket instead.
Listen network address; a leading / means a UNIX socket instead.
admin_accountUser name of the instance administrator (optional).
User name of the instance administrator (optional).
admin_emailEmail address of the instance administrator (optional).
Email address of the instance administrator (optional).
badlogin_expire300Seconds a blocked IP address stays ignored in login attempts.
Seconds a blocked IP address stays ignored in login attempts.
badlogin_retries5Failed logins from one IP before further attempts are rejected.
Failed logins from one IP before further attempts are rejected.
cssurlsList of site-wide CSS file URLs loaded before each user's own CSS.
List of site-wide CSS file URLs loaded before each user's own CSS.
dbglevel0Debug verbosity as an integer.
Debug verbosity as an integer.
values: 0-3
DEBUGOverrides the dbglevel configuration value; higher means more verbose output.
Overrides the dbglevel configuration value; higher means more verbose output.
values: 0-3
def_timeline_entriesDefault number of timeline entries shown in the web interface.
Default number of timeline entries shown in the web interface.
disable_block_notificationsNever send notifications about Block activities.
Never send notifications about Block activities.
values: true/false
disable_cacheTurn off timeline caching; for debugging only, makes everything slower.
Turn off timeline caching; for debugging only, makes everything slower.
values: true/false
disable_email_notificationsSend no email notification for any user.
Send no email notification for any user.
values: true/false
disable_emojireactDisable all EmojiReact support, input and output.
Disable all EmojiReact support, input and output.
values: true/false
disable_historyDo not serve monthly history snapshots or their links.
Do not serve monthly history snapshots or their links.
values: true/false
disable_inbox_collectionSkip inbox collection, which helps discovery but adds traffic.
Skip inbox collection, which helps discovery but adds traffic.
values: true/false
disable_notify_webhookForbid users from setting a notification webhook URL.
Forbid users from setting a notification webhook URL.
values: true/false
disable_openbsd_securityDisable use of unveil(2) and pledge(2) under OpenBSD.
Disable use of unveil(2) and pledge(2) under OpenBSD.
values: true/false
disable_sandboxDisable Linux Landlock sandboxing (needs it compiled in and kernel 5.13.0+).
Disable Linux Landlock sandboxing (needs it compiled in and kernel 5.13.0+).
values: true/false
EDITORInteractive text editor used when posting notes with the -e argument.
Interactive text editor used when posting notes with the -e argument.
enable_svgShow SVG image attachments, which are hidden by default since 2.73.
Show SVG image attachments, which are hidden by default since 2.73.
values: true/false
fastcgiTalk to the front-end http server over FastCGI instead of HTTP proxying.
Talk to the front-end http server over FastCGI instead of HTTP proxying.
values: true/false
favicon_urlURL of a favicon, replacing the default one.
URL of a favicon, replacing the default one.
ffmpeg_pathffmpegOverride the default ffmpeg command name or path.
Override the default ffmpeg command name or path.
force_ipv6_requestsMake outgoing HTTP requests use only IPv6.
Make outgoing HTTP requests use only IPv6.
values: true/false
hide_delete_post_buttonDo not show the button that deletes a post.
Do not show the button that deletes a post.
values: true/false
hostHost name of the instance.
Host name of the instance.
http_headersExtra HTTP response header/value pairs to add.
Extra HTTP response header/value pairs to add.
keep_replied_meAdd a remote reply to one of your posts to the local public timeline.
Add a remote reply to one of your posts to the local public timeline.
values: true/false
keep_replied_postsAdd the remote parent post to the local public timeline when you reply to it.
Add the remote parent post to the local public timeline when you reply to it.
values: true/false
LANGLanguage of posts sent from the command line.
Language of posts sent from the command line.
layoutDisk storage layout version; should never be edited by hand.
Disk storage layout version; should never be edited by hand.
local_purge_daysSame as timeline_purge_days but for user-written local timeline entries.
Same as timeline_purge_days but for user-written local timeline entries.
max_attachments4Maximum attachments per post.
Maximum attachments per post.
max_failing_days15Days of continuous failed outgoing messages before an instance is considered down.
Days of continuous failed outgoing messages before an instance is considered down.
max_poll_option_length60Maximum length of a single poll option.
Maximum length of a single poll option.
max_poll_options8Maximum number of options in a poll.
Maximum number of options in a poll.
max_public_entries20Maximum posts returned in user RSS feeds and outboxes.
Maximum posts returned in user RSS feeds and outboxes.
max_timeline_entriesMaximum timeline entries shown in the web interface.
Maximum timeline entries shown in the web interface.
min_account_ageReject activity from accounts created more recently than this many seconds (anti-spam).
Reject activity from accounts created more recently than this many seconds (anti-spam).
mogrify_pathmogrifyOverride the default mogrify command name or path.
Override the default mogrify command name or path.
num_threadsExact number of threads used when processing connections; values below 4 are ignored.
Exact number of threads used when processing connections; values below 4 are ignored.
port8001Listen network port (ignored when address is a UNIX socket).
Listen network port (ignored when address is a UNIX socket).
prefixURL path prefix the instance is mounted under.
URL path prefix the instance is mounted under.
propagate_local_purgeSend a Delete activity everywhere for every purged local post.
Send a Delete activity everywhere for every purged local post.
values: true/false
protocolhttpsURL schema used; set to http only when running inside hidden networks such as Tor or I2P.
URL schema used; set to http only when running inside hidden networks such as Tor or I2P.
values: https|http
proxy_mediaProxy remote image, audio and video links through snac to hide user IPs.
Proxy remote image, audio and video links through snac to hide user IPs.
values: true/false
purge_staticDelete files in user static directories that are not attached, used as avatar/header/favicon or served as emoji.
Delete files in user static directories that are not attached, used as avatar/header/favicon or served as emoji.
values: true/false
queue_retry_maxMaximum retries for outgoing messages that failed to post.
Maximum retries for outgoing messages that failed to post.
queue_retry_minutesMinutes to wait before retrying a failed message, multiplied by retries already done.
Minutes to wait before retrying a failed message, multiplied by retries already done.
queue_timeoutMaximum seconds to wait while sending a queued message.
Maximum seconds to wait while sending a queued message.
queue_timeout_2Timeout for servers that already timed out on the previous retry.
Timeout for servers that already timed out on the previous retry.
rss_hashtag_poll_hours4How often hashtag RSS feeds are polled, in hours (minimum 1).
How often hashtag RSS feeds are polled, in hours (minimum 1).
shared_inboxesAnnounce shared inboxes or not; optimizes incoming traffic on bigger instances.
Announce shared inboxes or not; optimizes incoming traffic on bigger instances.
values: true/false
short_descriptionTextual short description about the instance (optional).
Textual short description about the instance (optional).
short_description_rawWhether the short description is kept raw or converted to HTML.
Whether the short description is kept raw or converted to HTML.
values: true/false
show_instance_timelineServe a latest-user-posts timeline at the instance base URL instead of the static greeting page.
Serve a latest-user-posts timeline at the instance base URL instead of the static greeting page.
values: true/false
smtp_passwordPassword for the SMTP server, if it needs credentials.
Password for the SMTP server, if it needs credentials.
smtp_urlSMTP URL used for email notifications instead of piping to sendmail.
SMTP URL used for email notifications instead of piping to sendmail.
smtp_userCredentials for the SMTP server, if it needs them.
Credentials for the SMTP server, if it needs them.
SNAC_BASEDIROptional base directory so it need not be passed to command-line operations.
Optional base directory so it need not be passed to command-line operations.
strict_public_timelinesShow only posts and boosts originating from an account in public timelines (no conversation trees).
Show only posts and boosts originating from an account in public timelines (no conversation trees).
values: true/false
strip_exifStrip EXIF and other metadata from uploaded images and videos; needs mogrify and ffmpeg installed.
Strip EXIF and other metadata from uploaded images and videos; needs mogrify and ffmpeg installed.
values: true/false
timeline_purge_daysAge in days after which timeline entries are purged; 0 disables purging.
Age in days after which timeline entries are purged; 0 disables purging.
titleName of the instance (optional).
Name of the instance (optional).
TZTime zone used by the docker entrypoint example when initializing the container.
Time zone used by the docker entrypoint example when initializing the container.
vkeyPublic VAPID key used for notifications on some client.
Public VAPID key used for notifications on some client.