Basic Concepts

API Simulatorâ„¢ is a versatile tool for easily creating and running API simulations.

API simulations are stand-ins, substitutes that imitate the behavior and data of real APIs or APIs that are yet to be developed. One can think of API simulations as more powerful and smarter remote stubs and mocks.

An API simulation consists of a set of simlets. For synchronous request/response type of APIs, like those exposed over HTTP, each simlet simulates the output (the HTTP response) for a given input (the HTTP request).

API Simulator inspects the input by applying matching rules. Those matching rules usually look for key values in the input but can also try to match the complete input verbatim.

A matched input is then mapped to the simlet that will produce the simulated output for that input.

There are two options for when no simlet from the simulation matches an input: to use a default fallback simlet, or to forward unrecognized requests to their actual destination and pass back the live responses.

The output produced by a simlet is rendered from a template. The template is comprised of fragments. Special kinds of fragments – placeholders – make it possible to provide dynamic output.