SNAC(1)

NAME
snac - A simple, minimalistic ActivityPub instance

SYNOPSIS
snac command basedir [option ...]

DESCRIPTION
The snac daemon processes messages from other servers in the Fediverse using the ActivityPub protocol.

This is the user manual and expects an already running snac installation. For the administration manual, see snac(8). For file and data formats, see snac(5).

  Web Interface
The web interface provided by snac 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.

The public timeline, also called the local timeline, is what an external visitor sees about the activity of a snac 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.

The private timeline, or simply the timeline, is the private, password-protected area of a snac server where the user really interacts with the rest of the Fediverse.

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 snac(5) manual for more information on the allowed markup.

Other fields immediately below the big text one allow some control about the post to be sent:

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.

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.

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.

More options are hidden under a toggle control. They are the following:

Follow (by URL or user@host)
    Fill the input area with a user 'actor' URL or a user@host Fediverse identifier to follow.

Boost (by URL)
    Fill the input area with the URL of a Fediverse note to be boosted.

User setup...
    This option opens the user setup dialog.

The user setup dialog allows some user information to be changed, specifically:

User name
    Your user name, or not really that. People like to include emojis, flags and strange symbols for some reason.

Avatar URL
    The URL of a picture to be used as your avatar in timelines around the world.

Bio Enter here a bunch of self-indulgent blurb about yourself. The same markup options available for text notes apply here.

Always show sensitive content
    By default, snac hides content marked as sensitive by their publishers. If you check this option, sensitive content is always shown.

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.

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.

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.

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.

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.

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.

The rest of the page contains your timeline in reverse chronological order (i.e., newest interactions first). snac shows the conversations as nested trees, unlike other Fediverse software; every time 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.

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.

For each entry in the timeline, a set of reasonable actions in the form of buttons will be shown. These can be:

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.

Like
    Click this if you admire this post. The poster and your followers will be informed.

Boost
    Click this if you want to propagate this post to all your followers. The original author will also be informed.

Follow
    Click here if you want to start receiving all the shenanigans the original author of the post will write in the future.

Unfollow
    Click here if you are fed up of this fellow's activities.

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).

MUTE
    This is the most important button in snac and the Fediverse in general. Click it if you don't want to read crap from this user again in the foreseeable future.

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.

Edit
    Posts written by you on snac version 2.19 and later can be edited and resent to their recipients.

  Command-line options
The command-line tool provide the following commands:

init [basedir]
    Initializes the data storage. This is an interactive command; necessary information will be prompted for. The basedir directory must not exist.

upgrade basedir
    Upgrades the data storage after installing a new version. Only necessary if snac complains and demands it.

httpd basedir
    Starts the daemon.

purge basedir
    Purges old data from the timeline of all users.

adduser basedir [uid]
    Adds a new user to the server. This is an interactive command; necessary information will be prompted for.

resetpwd basedir uid
    Resets a user's password to a new, random one.

queue basedir uid
    Processes the output queue of the specified user, sending all enqueued messages and re-enqueing the failing ones. This command must not be executed if the server is running.

follow basedir uid actor
    Sends a Follow message for the specified actor URL.

request basedir uid url
    Requests an object and dumps it to stdout. This is a very low level command that is not very useful to you.

announce basedir uid url
    Announces (boosts) a post via its URL.

note basedir uid text [file file ...]
    Enqueues a Create + Note message to all followers. If the 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.

block basedir 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.

unblock basedir instance_url
    Unblocks a previously blocked instance.

verify_links basedir 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 snac 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.

state basedir
    Dumps the current state of the server and its threads. For example:

        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

    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).

  Migrating an account from Mastodon
See snac(8) for details.

  Using Mastodon-compatible apps
Since version 2.27, snac 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 snac provides.

  Implementing post bots
snac makes very easy to post messages in a non-interactive manner. This example posts a string:

    uptime | snac note $SNAC_BASEDIR $SNAC_USER -

You can setup a line like this from a crontab(5) or similar. Take note that you need a) command-line access to the same machine that hosts the snac instance, and b) write permissions to the storage directories and files.

You can also post non-interactively using the Mastodon API and a command-line http tool like 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:

    curl -X POST https://$SNAC_HOST/api/v1/statuses \
    --header "Authorization: Bearer ${TOKEN}" -d "status=$(uptime)"

You can obtain an API Token by connecting to the following URL:

    https://$SNAC_HOST/oauth/x-snac-get-token

ENVIRONMENT

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.

EDITOR
    The user-preferred interactive text editor to prepare messages.

SEE ALSO
snac(5), snac(8)

AUTHORS
grunfink @grunfink@comam.es: https://comam.es/snac/grunfink

LICENSE
See the LICENSE file for details.

CAVEATS
Use the Fediverse sparingly. Don't fear the MUTE button.

BUGS
Probably plenty. Some issues may be even documented in the TODO.md file.