.Dd $Mdocdate$
.Dt SNAC 1
.Os
.Sh NAME
.Nm snac
.Nd A simple, minimalistic ActivityPub instance
.Sh SYNOPSIS
.Nm
.Cm command
.Ar basedir
.Op Ar option ...
.Sh DESCRIPTION
The
.Nm
daemon processes messages from other servers in the Fediverse
using the ActivityPub protocol.
.Pp
This is the user manual and expects an already running
.Nm
installation. For the administration manual, see
.Xr snac 8 .
For file and data formats, see
.Xr snac 5 .
.Ss Web Interface
The web interface provided by
.Nm
is split in two data streams: the public timeline and the
private timeline. There are no other feeds like the server-scoped
or the federated firehoses provided by other similar ActivityPub
implementations like Mastodon or Pleroma.
.Pp
The public timeline, also called the local timeline, is what an
external visitor sees about the activity of a
.Nm
user: that is, only the list of public notes, boosts and likes
the user generates or participates into. This is, obviously,
read-only, and not very remarkable, unless the user publishes
messages of staggering genious. A set of history links, grouped
by month, will also be available at the bottom of the page.
.Pp
The private timeline, or simply the timeline, is the private,
password-protected area of a
.Nm
server where the user really interacts with the rest of the
Fediverse.
.Pp
The top area of the timeline provides a big text area to write
notes for the public (i.e. for the user followers). As this is
the second most important activity on the Fediverse, this is
located in the most prominent area of the user page. You can
enter plain text, @user@host mentions and other things. See the
.Xr snac 5
manual for more information on the allowed markup.
.Pp
Other fields immediately below the big text one allow some control
about the post to be sent:
.Bl -tag -offset indent
.It Sensitive content
If you set this checkbox, your post will be marked with a
content warning. The immediately following, optional text box
allows you to write a description about why your content is
so sensitive.
.It Only for mentioned people
If you set this checkbox, your text will not be public, but only
sent to those people you mention in the post body.
.It Reply to (URL)
If you fill this optional text field with the URL of another one's
post, your text will be considered as a reply to it, not a
standalone one.
.El
.Pp
More options are hidden under a toggle control. They are the
following:
.Bl -tag -offset indent
.It Follow (by URL or user@host)
Fill the input area with a user 'actor' URL or a user@host
Fediverse identifier to follow.
.It Boost (by URL)
Fill the input area with the URL of a Fediverse note to be
boosted.
.It User setup...
This option opens the user setup dialog.
.El
.Pp
The user setup dialog allows some user information to be
changed, specifically:
.Bl -tag -offset indent
.It User name
Your user name, or not really that. People like to include
emojis, flags and strange symbols for some reason.
.It Avatar URL
The URL of a picture to be used as your avatar in timelines
around the world.
.It Bio
Enter here a bunch of self-indulgent blurb about yourself.
The same markup options available for text notes apply here.
.It Always show sensitive content
By default,
.Nm
hides content marked as sensitive by their publishers.
If you check this option, sensitive content is always shown.
.It Email address for notifications
If this field is not empty, an email message will be sent
to this address whenever a post written by you is liked,
boosted or replied to.
.It Telegram notifications
To enable notifications via Telegram, fill the two provided
fields (Bot API key and Chat id). You need to create both
a Telegram channel and a bot for this; the process is rather
cumbersome but it's documented everywhere. The Bot API key
is a long string of alphanumeric characters and the chat id
is a big, negative number.
.It ntfy notifications
To enable notifications via ntfy (both self-hosted or
standard ntfy.sh server), fill the two provided
fields (ntfy server/topic and, if protected, the token).
You need to refer to the https://ntfy.sh web site for
more information on this process.
.It Maximum days to keep posts
This numeric value specifies the number of days to pass before
posts (yours and others') will be purged. This value overrides
what the administrator defined in the global server settings
only if it's lesser (i.e. you cannot keep posts for longer
than what the admin desires). A value of 0 (the default) means
that the global server settings will apply to the posts in your
timeline.
.It Drop direct messages from people you don't follow
Just what it says in the tin. This is to mitigate spammers
coming from Fediverse instances with lax / open registration
processes. Please take note that this also avoids possibly
legitimate people trying to contact you.
.It Password
Write the same string in these two fields to change your
password. Don't write anything if you don't want to do this.
.El
.Pp
The rest of the page contains your timeline in reverse
chronological order (i.e., newest interactions first).
.Nm
shows the conversations as nested trees, unlike other Fediverse
software; everytime you contribute something to a conversation,
the full thread is bumped up, so new interactions are shown
always at the top of the page while the forgotten ones languish
at the bottom.
.Pp
Private notes (a.k.a. direct messages) are also shown in
the timeline as normal messages, but marked with a cute lock
to mark them as non-public. Replies to direct messages are
also private and cannot be liked nor boosted.
.Pp
For each entry in the timeline, a set of reasonable actions
in the form of buttons will be shown. These can be:
.Bl -tag -offset indent
.It Reply
Unveils a text area to write your intelligent and acute comment
to an uninformed fellow. This note is sent to the original
author as well as to your followers. The note can include
mentions in the @user@format; these people will also become
recipients of the message. If you reply to a boost or like,
you are really replying to the note, not to the admirer of it.
.It Like
Click this if you admire this post. The poster and your
followers will be informed.
.It Boost
Click this if you want to propagate this post to all your
followers. The original author will also be informed.
.It Follow
Click here if you want to start receiving all the shenanigans
the original author of the post will write in the future.
.It Unfollow
Click here if you are fed up of this fellow's activities.
.It Delete
Click here to send this post to the bin. If it's an activity
written by you, the appropriate message is sent to the rest
of involved parts telling them that you no longer want your
thing in their servers (not all implementations really obey
this kind of requirements, though).
.It MUTE
This is the most important button in
.Nm
and the Fediverse in general. Click it if you don't want
to read crap from this user again in the forseeable future.
.It Hide
If a conversation is getting long and annoying but not enough
to MUTE its author forever, click this button to avoid seeing
the post and its children anymore.
.It Edit
Posts written by you on 
.Nm
version 2.19 and later can be edited and resent to their
recipients.
.El
.Ss Command-line options
The command-line tool provide the following commands:
.Bl -tag -offset indent
.It Cm init Op basedir
Initializes the data storage. This is an interactive command; necessary
information will be prompted for. The
.Ar basedir
directory must not exist.
.It Cm upgrade Ar basedir
Upgrades the data storage after installing a new version.
Only necessary if
.Nm
complains and demands it.
.It Cm httpd Ar basedir
Starts the daemon.
.It Cm purge Ar basedir
Purges old data from the timeline of all users.
.It Cm adduser Ar basedir Op uid
Adds a new user to the server. This is an interactive command;
necessary information will be prompted for.
.It Cm resetpwd Ar basedir Ar uid
Resets a user's password to a new, random one.
.It Cm queue Ar basedir Ar uid
Processes the output queue of the specied user, sending all
enqueued messages and re-enqueing the failing ones. This command
must not be executed if the server is running.
.It Cm follow Ar basedir Ar uid Ar actor
Sends a Follow message for the specified actor URL.
.It Cm request Ar basedir Ar uid Ar url
Requests an object and dumps it to stdout. This is a very low
level command that is not very useful to you.
.It Cm announce Ar basedir Ar uid Ar url
Announces (boosts) a post via its URL.
.It Cm note Ar basedir Ar uid Ar text Op file file ...
Enqueues a Create + Note message to all followers. If the
.Ar text
argument is -e, the external editor defined by the EDITOR
environment variable will be invoked to prepare a message; if
it's - (a lonely hyphen), the post content will be read from stdin.
The rest of command line arguments are treated as media files to be
attached to the post.
.It Cm block Ar basedir Ar instance_url
Blocks a full instance, given its URL or domain name. All subsequent
incoming activities with identifiers from that instance will be immediately
blocked without further inspection.
.It Cm unblock Ar basedir Ar instance_url
Unblocks a previously blocked instance.
.It Cm verify_links Ar basedir Ar uid
Verifies all links stored as metadata for the given user. This verification
is done by downloading the link content and searching for a link back to
the
.Nm
user url that also contains a rel="me" attribute. These links are specially
marked as verified in the user's public timeline and also via the Mastodon API.
.It Cm state Ar basedir
Dumps the current state of the server and its threads. For example:
.Bd -literal -offset indent
server: comam.es (snac/2.45-dev)
uptime: 0:03:09:52
job fifo size (cur): 45
job fifo size (peak): 1532
thread #0 state: input
thread #1 state: input
thread #2 state: waiting
thread #3 state: waiting
thread #4 state: output
thread #5 state: output
thread #6 state: output
thread #7 state: waiting
.Ed
.Pp
The job fifo size values show the current and peak sizes of the
in-memory job queue. The thread state can be: waiting (idle waiting
for a job to be assigned), input or output (processing I/O packets)
or stopped (not running, only to be seen while starting or stopping
the server).
.El
.Ss Migrating an account from Mastodon
See 
.Xr snac 8
for details.
.Ss Using Mastodon-compatible apps
Since version 2.27,
.Nm
includes support for the Mastodon API, so you can use Mastodon-compatible
mobile and desktop applications to access your account. Given a correctly
configured server, the usage of these programs should be straightforward.
Please take note that they will show your timeline in a 'Mastodon fashion'
(i.e., as a plain list of posts), so you will lose the fancy, nested thread
post display with the most active threads at the top that the web interface of
.Nm
provides.
.Ss Implementing post bots
.Nm
makes very easy to post messages in a non-interactive manner. This example
posts a string:
.Bd -literal -offset indent
uptime | snac note $SNAC_BASEDIR $SNAC_USER -
.Ed
.Pp
You can setup a line like this from a
.Xr crontab 5
or similar. Take note that you need a) command-line access to the same machine
that hosts the
.Nm
instance, and b) write permissions to the storage directories and files.
.Pp
You can also post non-interactively using the Mastodon API and a command-line
http tool like
.Xr curl 1
or similar. This has the advantage that you can do it remotely from any host,
anywhere; the only thing you need is an API Token. This is an example:
.Bd -literal -offset indent
curl -X POST https://$SNAC_HOST/api/v1/statuses \\
--header "Authorization: Bearer ${TOKEN}" -d "status=$(uptime)"
.Ed
.Pp
You can obtain an API Token by connecting to the following URL:
.Bd -literal -offset indent
https://$SNAC_HOST/oauth/x-snac-get-token
.Ed
.Pp
.Sh ENVIRONMENT
.Bl -tag -width Ds
.It Ev DEBUG
Overrides the debugging level from the server 'dbglevel' configuration
variable. Set it to an integer value. The higher, the deeper in meaningless
verbiage you'll find yourself into.
.It Ev EDITOR
The user-preferred interactive text editor to prepare messages.
.El
.Sh SEE ALSO
.Xr snac 5 ,
.Xr snac 8
.Sh AUTHORS
.An grunfink Lk https://comam.es/snac/grunfink @grunfink@comam.es
.Sh LICENSE
See the LICENSE file for details.
.Sh CAVEATS
Use the Fediverse sparingly. Don't fear the MUTE button.
.Sh BUGS
Probably plenty. Some issues may be even documented in the TODO.md file.