Runtime variable is defined in Script, usually it's used to generate hash value dynamically for url or save a request's response and use it in another request.

Runtime variable can be defined in Global Function, Common Pre Request Script, Pre Request Script and Test.

Use this API as below:

hitchhiker.setEnvVariable('rt_var', 'test');  // define a variable with key: `rt_var`, value: `test`
const value = hitchhiker.getEnvVariable('rt_var'); // get variable's value (`test`)

A typical scenario:

We have 4 APIs: create, select, update, delete. create API create a item and return id. we need this id to test the 3 other APIs, so we can set id to a Runtime variable in Test script of create and use it in select, update, delete.