ThatLanguage::Service

A thin Sinatra wrapper that exposes the ThatLanguage language-detection library over HTTP as eight JSON endpoints.

This is a library gem, not an application: it ships a config.ru but declares no web server, so the deployment picks its own.

Installation

Add it to your Gemfile:

gem "that_language-service"

Note. The published that_language 0.1.2 on rubygems.org predates the Ruby 3+ fixes and will not run on a modern Ruby. Until that_language 0.1.3 is released, point at the source directly:

gem "that_language", git: "https://github.com/Deradon/that_language.git"

Running it

$ bundle install
$ bundle exec puma config.ru -p 9292

Then:

$ curl --get --data-urlencode 'text=Hallo Welt' http://localhost:9292/detect
{"language":"German","language_code":"de","confidence":0.5}

Endpoints

Every endpoint answers both GET and POST, takes the input in a text parameter, and responds with Content-Type: application/json.

Endpoint	Returns
/language	{"language": "German"}
/language_code	{"language_code": "de"}
/detect	{"language": …, "language_code": …, "confidence": …}
/details	the full ranked result set, best match first
/available	{"available": {"de": "German", …}}
/available_languages	list of language names
/available_language_codes	list of language codes
/version	the core library version, not the service version

/details returns every candidate language with its scoring breakdown:

{"results":[{"language":"German","language_code":"de","confidence":0.5,
             "value":1.0,"hit_ratio":0.5,"hit_count":1,"words_count":2}]}

Configuration

The wordlist tier is a property of the core library, not of this service. Configure it before the application is mounted:

ThatLanguage.configure do |config|
  config.wordlist_path = File.join("wordlists", "100k")
end

Warm the cache at boot. The wordlists are loaded lazily on the first request, which costs about a second and a few hundred megabytes. Without a warm-up the first user pays for it:

ThatLanguage.language_code("Hello world!")  # in config.ru, before `run`

Cross-origin requests

Rack::Protection::JsonCsrf is deliberately disabled — it answers 403 to any request carrying a cross-origin Referer, which would block the intended browser use case while guarding data that is already public. CORS headers are not set here; the deployment adds them.

Development

$ bundle install
$ bundle exec rspec
$ bundle exec rubocop

Requires Ruby >= 3.1; developed and pinned against 4.0.6 (see .tool-versions).

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/Deradon/that_language-service. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

License

Available as open source under the terms of the MIT License.