# Overview

The Challenge APIs are an HTTP-based API that you can use to programmatically query data about watchtowers/provers, submit and manage challenges. Since the API is HTTP-based it works with any language or software that supports HTTP, including cURL and almost all modern web browsers.

## Basic Concepts <a href="#basics" id="basics"></a>

### Provers

The device connected to Internet whose claimed location or bandwidth needs to be validated

### Watchtowers (aka Challengers)

A pool of decentralized, trustfree servers that validate the location / bandwidth claim of the prover

### Challenge

A series of UDP ping pongs/pings between the prover and watchtowers to validate the claim (Location or Bandwidth)

### Broker

A server which provides APIs for provers/challengers/payers. These APIs are used to login/request-for-challenges/participate-in-challenges/submit-results-of-challenges.

### Challenge Coordinator (CC)

A server which randomly selects eligible challengers for a given challenge.

It ensures that available and compatible challengers are chosen for a given challenge.

CC only responds to events from Broker and does not interact with any other system.