Using bert-as-service to serve HTTP requests in JSON

Besides calling bert-as-service from Python, one can also call it via HTTP request in JSON. It is quite useful especially when low transport layer is prohibited. Behind the scene, bert-as-service spawns a Flask server in a separate process and then reuse a BertClient instance as a proxy to communicate with the ventilator.

To enable this feature, we need to first install some Python dependencies:

pip install -U bert-serving-client flask flask-compress flask-cors flask-json

Then simply start the server with:

bert-serving-start -model_dir=/YOUR_MODEL -http_port 8125

Your server is now listening HTTP and TCP requests at port 8125 simultaneously!

To send a HTTP request, first package payload in JSON as following:

    "id": 123,
    "texts": ["hello world", "good day!"],
    "is_tokenized": false

, where id is a unique identifier helping you to synchronize the results; is_tokenized follows the meaning in `BertClient API`_ and false by default.

Then simply call the server via HTTP POST request. You can use javascript or whatever, here is an example using curl:

curl -X POST http://xx.xx.xx.xx:8125/encode \
  -H 'content-type: application/json' \
  -d '{"id": 123,"texts": ["hello world"], "is_tokenized": false}'

, which returns a JSON:

    "id": 123,
    "results": [[768 float-list], [768 float-list]],
    "status": 200

To get the server’s status and client’s status, you can send GET requests at /status/server and /status/client, respectively.

Finally, one may also config CORS to restrict the public access of the server by specifying -cors when starting bert-serving-start. By default -cors=*, meaning the server is public accessible.