Mastodon-Twitter Crossposter

This is an app for crossposting between Mastodon and Twitter. The app is made so that multiple users can connect to it using the OAuth interface from both Twitter and Mastodon and choose options on how the crosspost should work.

If you just want to use it, there's one running at https://crossposter.masto.donte.com.br, which you can use from whatever Mastodon server you are in

Features

• Post from Twitter to Mastodon

  • You can choose between posting only your tweets, or also posting retweets and quotes.
  • You can choose between posting retweets and quotes as links or as the old-style RTs, starting by RT @username@twitter.com.
  • Quotes bigger than 500 characters are automatically split in two toots, one replying to the other.
  • Your own threads can also be crossposted!
  • No other replies will be posted. There's no risk of filling your Mastodon timeline with replies to people that are not there.
  • Possibility to add a content warning to all tweets being posted to Mastodon
  • Infer content warnings: if your tweet begins with a line containing "content warning" it will be posted behind a content warning on Mastodon. More information about which formats are supported can be seen below at Experimental Content Warning recognition

• Post from Mastodon to Twitter

  • Any toot bigger than 280 characters will be posted with a link to the original toot. (Be careful, if you post your private toots, your followers might not be able to see the original post!)
  • Mind your privacy: you can choose which privacy levels you want to crosspost. Only posting public toots, for instance.
  • You can choose between posting boosts or not.
  • Automatically fix mentions to twitter users! If you post @user@twitter.com they will be mentioned on twitter when the toot gets crossposted.
  • Your own threads can also be crossposted, respecting to the choices you made regarding your privacy.
  • No other replies will be posted. There's no risk of filling your twitter timeline with replies to people that are not there.

The crossposter will never follow anyone or post anything but the content you selected to be crossposted.

If you decide to crosspost from Twitter to Mastodon, remember to turn on notifications about when people mention you to avoid not seeing interactions!

Ruby on Rails

Ruby 2.5.1

Rails 5.1

Requirements

Without extra configuration, a local postgres instance is needed. Node 6.11 is needed for statsd, can be installed using nvm.

The poster uses the ruby-filemagic gem for detecting the types of the files posted. Follow the instructions described in the README to install the needed library and headers.

Setup

You need to install Yarn and Ruby 2.4.4. Yarn has installation instructions for several OSs here: https://yarnpkg.com/lang/en/docs/install/ and Ruby can be installed either using RVM (https://rvm.io/rvm/install) or rbenv (https://github.com/rbenv/rbenv#installation). After you have ruby and yarn setup, you'll need to do:

# Install bundler
gem install bundler
# Use bundler to install Ruby dependencies
bundle install --deployment --without development test
# Use yarn to install node.js dependencies
yarn install --pure-lockfile

A separate user is recommended.

By default, the crossposter will use a statsd instance to send error and stats data to Librato. If you don't want that or want to setup something else, you need to change statsd-config.js

To start the web app, the worker which will fetch tweets and toots in background and the statsd instance, you need to do: bundle exec foreman start -e .env.production"

If you are using systemd, you can create a service with something like:

[Unit]
Description=crossposter-service
After=network.target

[Service]
Type=simple
User=crossposter
WorkingDirectory=/home/crossposter/live
ExecStart=/bin/bash -lc "bundle exec foreman start -e .env.production"
TimeoutSec=15
Restart=always

[Install]
WantedBy=multi-user.target

And put it on /etc/systemd/system/crossposter.service

And a second one like this:

[Unit]
Description=crossposter-sidekiq-service
After=network.target

[Service]
Type=simple
User=crossposter
WorkingDirectory=/home/crossposter/live
Environment="RAILS_ENV=production"
Environment="RAILS_MAX_THREADS=5"
ExecStart=/bin/bash -lc "bundle exec sidekiq -c 5 -q default"
TimeoutSec=15
Restart=always

[Install]
WantedBy=multi-user.target

And put it on /etc/systemd/system/crossposter-sidekiq.service (note that RAILS_MAX_THREADS and the number of sidekiq threads should be the same)

These example files are provided in the config/systemd-services directory. You may copy these files (with necessary modifications, if applicable) to /etc/systemd/system/ to run the system in the background.

Tests

Run RAILS_ENV=test bundle exec rake db:setup to create the test database (a postgres running locally is needed), and after that run the tests with bundle exec rake test (or COVERAGE=1 bundle exec rake test if coverage information is desired)

Starting

To start the project locally, you can do foreman start which will start both the webserver and the daemons. Or you can take a look at the procfile to start each of them separately (if you don't want the web interface to be accessible, for instance).

Experimental Content Warning recognition

When posting from Twitter to Mastodon the Crossposter tries to detect content warnings in the tweets and post them over to Mastodon. The detected CW takes precedence over the default twitter one if exists. Some formats are supported and more can be added in the future, but currently, this are the ones that will be recognized:

CW: content warning
my tweet

TW: content warning
my tweet

CW/TW: content warning
my tweet

TW, CW, content warning
my tweet

Spoiler: content warning
my tweet

CN: content warning
my tweet

All of these posts will be posted in Mastodon with the same content: my tweet and will have a content warning of content warning. The crossposter attempts to remove any extra spaces between the CW: (or equivalent) tag.

This also works for quote-retweets. That is, if you are retweeting and you want to add a content warning to the tweet, you can just quote-retweet writing CW: content warning.

This does not work for several tweets in a thread. Each tweet needs to have it's own CW.

Even though this is an experimental feature, it cannot be disabled. The reason is that content warnings are important for people in Mastodon and the crossposter should still try to keep it in a good environment, even if bringing content from Twitter.