How does ConfigCat work?

The ConfigCat SDK polls the CDN for the latest feature flag and setting values repeatedly and caches them. When a feature flag value is requested by our customer's application the SDK evaluates feature flag values locally on the client side and returns them. This way no data leaves the client application even if the feature flag values depend on sensitive user info. In case of no internet connection a customer provided default value will be returned, making sure the application runs smoothly.

Architecture diagram of ConfigCat


Graphical user interface (GUI) even for non-technical people to easily manage Configs, Feature Flags and Settings, invite team mates, add/remove Group Permissions or view the Audit Log. Dashboard

ConfigCat Public Management API

Publicly available API to provide management access to Feature Flags & Settings programmatically. Runs the business logic and keeps CDN Servers consistent with the Database.

CDN Nodes

Serving our customers' JSON configuration files containing Feature Flags, Settings and their values. Designed to scale quickly and to handle a massive number of requests.

Data Center Locations:

  • EU: Frankfurt, Amsterdam
  • America: New York City, Newark, Fremont, San Francisco
  • Asia & Oceania: Singapore, Sydney
ConfigCat Data Center Locations

ConfigCat SDKs

Responsible for downloading and caching the JSON configuration files. Also providing an interface to access Feature Flag and Setting values simply from any Desktop, Mobile, Frontend or Backend application. All the SDKs are open source on GitHub.


A request is counted every time your application downloads a configuration file from the ConfigCat CDN. The frequency of these downloads is totally under your control. Between downloads you can access your feature flags as many times as you like, it still counts as one.
Learn more about requests.

You can monitor the amount of your requests real-time on the ConfigCat Dashboard.

ConfigCat real time request statistics.

Service Status Monitor

Get info about of the current status of our systems on: