API Simulator 1.3 Release

May 6, 2019


API Simulator version 1.3 is GA! As usual – with more goodies added to the toolbox.

Here are the new features and major changes:

  • Delay for latency simulation is now non-blocking – elevating to new levels performance testing of APIs with simulated latency! No more naive blocking of the execution thread.
  • Added normal and lognormal distributions of delay values for more real lifelike latency simulations.
  • Added Access Logging. When enabled, it captures timestamp, remote and local addresses, the request method and URI, simlet name, delay applied, and internal elapsed time from the time of receiving the first byte to the complete streaming of the response.
  • Some aspects of logging can now be controlled via individual startup arguments and without having to make changes to the logging configuration file. That includes easily changing the logging destination to the console for when running in a container.
  • Changed the format of the log entries timestamp – it now also has the time zone offset. That helps with consolidating logs from different data centers or cloud regions or when distributed team members collaborate.
  • Added support for HTTP/S proxy when forwarding unmatched requests.
  • It is now possible to accept both HTTP and HTTPS requests on the same port number and for the same simulation.
  • API Recorder changes to support HTTP/S proxy.
  • API Recorder changes to support HTTP and HTTPS calls on the same port number.
  • Fix for the rare cases when API Recorder may have recorded two requests and their two responses in the same output files.
  • API Simulator and its tools now work with JDK/JRE 11 (in which some classes, like javax.xml.bind, have been removed)
  • The Docker image built and published on Docker Hub is now based on JDK 11.
  • Fix in the processing of the YAML DSL for matchers to detect improper syntax and error out with a better exception description.


We invite you to learn more about API Simulator, download and install it, and run the examples included in the download. Why not even create API simulations to help your own testing and development?

Let us know what you think at [feedback at APISimulator.com]. Many thanks for your interest and support!


Happy API Simulating!