Flask REST API for Open Targets Platform
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Open Targets REST API

Circle CI build: CircleCI

(maintained, but not used in dev/prod:) Docker Repository on Quay

How to deploy

Documentation on how we deploy the public version lives at https://github.com/opentargets/rest_api/tree/master/.circleci


Testing locally

  • clone repository
  • cd flask-rest-api
  • pip install -r requirements.txt (possiby in a virtualenv)
  • python manage.py runserver runs the dev server. Do not use in production.
  • python manage.py runserver -p 8123 runs the dev server on port 8123
  • python manage.py test runs the test suites.

By default the rest api is available at http://localhost:5000

Swagger YAML documentation is exposed at http://localhost:5000/api/docs/swagger.yaml

Elasticsearch backend

It expects to have an Elasticsearch instance on http://localhost:9200. Alternative configurations are available using the OPENTARGETS_API_CONFIG environment variable Valid OPENTARGETS_API_CONFIG options:

  • development: default option
  • staging: to be used in staging area
  • production: to be used in production area
  • testing: to be used for tests

see the config.py file for details


We never run flask directly. Even in the manage.py script we spawn off a WSGIServer(). Hence Flask debug mode does not work out of the box.

To debug while running flask locally (ie. using python manage.py runserver) one can pass API_DEBUG=True instead than the traditional FLASK_DEBUG=True environment variable to turn on the Flask debugger and increase the level of logging. This works by wrapping the app in werkzeug middleware. More details on http://stackoverflow.com/questions/10364854/flask-debug-true-does-not-work-when-going-through-uwsgi

However this will not work when the app is run by uwsgi, as it is in the docker container and in production. This is intentional since DEBUG mode there would allow code injection.

Custom data sources

Custom data sources can be specified via and environment variable, assuming that the relevant indices exist in the Elasticsearch instance to which the API is pointing. The environment variable must be named CUSTOM_DATASOURCE, and expressed in the form new_data_source_name:data_type, e.g. export CUSTOM_DATASOURCE=genomics_england_tiering:genetic_association Multiple custom data sources of the same type can be passed as a comma-separated list.

Docker Container


You can build the container from source:

docker build -t rest_api:local .

or use our docker containers on quay.io (Docker Repository on Quay)


Notice you can specify the elasticsearch server using the ELASTICSEARCH_URL environment variable and the data version you have loaded in elasticsearch with the OPENTARGETS_DATA_VERSION environment variable (⚠️ example below assumes localhost:9200 and data version 17.12 - adjust to your own situation):

docker run -d -p 8080:80 \
-e "ELASTICSEARCH_URL=http://localhost:9200" \
--privileged quay.io/opentargets/rest_api

For more options available when using docker run you can take a look at the ansible role that we use to spin a single instance of our frontend stack.

Check that is running Supposing the container runs in localhost and expose port 8080, Swagger UI is available at: http://localhost:8080/v3/platform/docs

You can ping the API with curl localhost:8080/v3/platform/public/utils/ping

You can check that is talking to your instance of Elasticsearch by using the /platform/latest/public/utils/stats method.

Why privileged mode?

The rest api container runs 3 services talking and launching each other: nginx, uwsgi and the actual flask app. nginx and uwsgi talks trough a binary protocol in a unix socket. it is very efficient, but by default sockets have a small queue, so if nginx is under heavy load and sends too many requests to uwsgi they get rejected by the socket and raise an error. to increase the size of the queue unfortunately you need root privileges. at the moment we think that the performance gain is worth the privileged mode. but it strongly depends on the environment you deploy the container into


Copyright 2014-2018 Biogen, Celgene Corporation, EMBL - European Bioinformatics Institute, GlaxoSmithKline, Takeda Pharmaceutical Company and Wellcome Sanger Institute

This software was developed as part of the Open Targets project. For more information please see: http://www.opentargets.org

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at


Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.