Getting started

You’ll add Funes to a Rails application and generate a migration that creates the table where Funes stores events. There are two short steps.

Install the gem

Add Funes to your Gemfile:

gem "funes-rails"

Then install the gem:

$ bundle install

Add the events table

Funes stores all events in a single table called event_entries. Generate the migration that creates this table:

$ bin/rails generate funes:install

This command creates a migration file under db/migrate/. Open the file and you’ll see that it sets up the event_entries table with the columns Funes needs:

• the event class
• a stream identifier
• the event attributes, as JSON
• a version number, for concurrency control
• two timestamps: created_at for when Funes recorded the event, and occurred_at for when the event actually happened

On Postgres, the migration uses jsonb instead of json for the attributes and metainformation columns. The data is the same, but the database can index and query it.

Now run the migration:

$ bin/rails db:migrate

Your events table is ready. Funes will append rows to event_entries as soon as you define your first event stream.

Next steps

• The Concepts section explains events, event streams, and projections — the three ideas that form the core of Funes.
• The Recipes section shows how to apply these ideas: append events from controllers, interpret them with a historic perspective, ship projections to S3, and more.