OpenNMT provides simple translation servers to easily showcase your results remotely.


You can use an easy REST syntax to simply send plain text. Sentences will be tokenized, translated and then detokenized using OpenNMT tools.

The server uses the restserver-xavante dependency, you need to install it by running:

luarocks install restserver-xavante

The translation server can be run using any of the arguments from tokenize.lua or translate.lua.

th tools/rest_translation_server.lua -model ../Recipes/baseline-1M-enfr/exp/model-baseline-1M-enfr_epoch13_3.44.t7 -gpuid 1 -host ... -port -case_feature -bpe_model ...


The default host is set to and default port to 7784.

You can test it with a curl command locally or from any other client:

curl -v -H "Content-Type: application/json" -X POST -d '[{ "src" : "Hello World" }]' http://IP_address:7784/translator/translate

Answer will be embedded in a JSON format, translated sentence in the tgt section. Additionally you can get the attention matrix with the -withAttn option in the server command line.


The server uses the 0MQ for RPC. You can install 0MQ and the Lua bindings on Ubuntu by running:

sudo apt-get install libzmq-dev
luarocks install dkjson
luarocks install lua-zmq ZEROMQ_LIBDIR=/usr/lib/x86_64-linux-gnu/ ZEROMQ_INCDIR=/usr/include

The translation server can be run using any of the arguments from translate.lua.

th tools/translation_server.lua -host ... -port ... -model ...


The default host is set to which only allows local access. If you want to support remote access, use instead.

It runs as a message queue that takes in a JSON batch of src sentences. For example the following 5 lines of Python code can be used to send a single sentence for translation.

import zmq, sys, json
sock = zmq.Context().socket(zmq.REQ)
sock.send(json.dumps([{"src": " ".join(sys.argv[1:])}]))
print sock.recv()

For a longer example, see our Python/Flask server in development.