How to Activate the Mastodon v4 DeepL API Text Translation Service

DeepL is a machine translation service with a REST API supported by the Mastodon social networking software. As of the Mastodon v4 release, instance administrators can configure support for user post translations between the following languages:

[Source: DeepL Translation Languages]

How to Configure DeepL Translations on Your Mastodon Instance

Sign Up for the DeepL REST API Service

At the time of this writing, DeepL includes a free plan that supports translations of up to 500,000 characters per month. Paid plans are available for instances that require translation volumes over this limit.

Sign up for a DeepL API account at this sign-up page, then copy your account API KEY from the https://www.deepl.com/account/summary page.

Configure Mastodon to Use the DeepL REST API

Navigate to the Mastodon directory on your server and open your instance .env.production file in a text editor. Add the following environment variables to the file, replacing [API KEY] with the API KEY that you copied from the DeepL account summary page in the step above:

DEEPL_API_KEY=[API KEY]
DEEPL_PLAN=free

Restart Your Mastodon Services

Restart your Mastodon services by executing the following commands on your server:

$ systemctl restart mastodon-sidekiq
$ systemctl reload mastodon-web

Confirm Activation of the DeepL Translation Service

The Mastodon v2 JSON API returns a translation JSON field at the following public API endpoint:

https://[your instance domain]/api/v2/instance 

You should receive "translation":{"enabled":true}} in the response configuration field if your instance is correctly configured to translate Mastodon posts.

Instance users will see a “Translate” UI text link in their posts if the posting user properly configures the post language:

An image of a Mastodon post with a Translate user interface link that can be clicked to translate the post text

The text is replaced with translated text inline when the user clicks the 'Translate' link.

#admin #mastodon