OpenEthan/SMSBoom ? reverse-engineered prompt

Build me a small Python tool for testing SMS style API requests in a safe way, using only dummy numbers and mock endpoints.

I want a command line app that can load API definitions from a JSON file, replace simple placeholders like a phone number and timestamp, and send requests in parallel or one at a time for load testing. It should support setting how many times to run, delays between runs, and optional proxy settings if I want to test through one. Please also add a simple web or desktop style interface for editing and testing the API list, plus a way to update the API config from a remote source.

Make it easy to run locally, and if possible include a Docker setup. If you need current docs for any libraries, look them up online first.