Sister Haggra of the Drakon Empire provided Sonic the Hedgehog with one when Mobius was under threat of destruction by the Chaos Siphon, a Syndicate construction. The Drakons were initially reluctant to provide Sonic with a Chaos Tap until the hedgehog reminded them that destruction of Mobius would also mean destruction of the Chaos Emeralds. The Chaos Tap was then given, but Master Scholar knew full well that he could disconnect the Chaos Tap at any time, leaving Mobius at the mercy of the Drakons.Sonic planted the Chaos Tap in a green area away from towns and villages, hoping for nobody to ever find out that he had consorted with the Drakon Empire. The Tap did its job and prevented the Chaos Siphon from firing. Better still, the Chaos energy fed back through the Death Carrier and tore it apart, ending The Syndicate's plans. The excess Chaos energy caused the Chaos Tap to grow several times the size of a regular Mobian. Later, the Drakons put their plan into action and put an insane Doctor Robotnik in charge of taking over Mobius. The Egg Bastion was built around the Chaos Tap and was only located when Sonic followed a trail of Badniks to the Tap's new home.
Following some distractions with the New Robotnik Empire, Sonic knew he had to deactivate the Chaos Tap to remove the Drakon Empire's leverage over his planet. He returned to the Bastion, banking on Omni-Viewer to turn up and drain the excess Chaos energy. Instead, Knuckles the Echidna arrived with the Grey Emerald, absorbing the Chaos Tap's reserves and enlarging the Emerald to several times its own size. Robotnik was infuriated upon learning of the Tap's destruction, but Sonic and Knuckles were already half way across the planet.
A new Chaos Tap
The Free Mobius coalition were beginning to get ever-closer to storming the Egg Bastion and knew that he needed to do something. The Drakon's monitoring software had been deleted by Shadow II, meaning Robotnik was free to leave his chair and take the fight to the heroes. As they prepared to advance on the Bastion, Robotnik set about repairing the Chaos Tap, now with the feature to absorb the energy of the planet (much like in Game Over) and harness it in The Battle of Emerald Hill. To ensure his victory, Robotnik installed it in his new Nega-Wisp Armour.
Since Haggra was the one who provided the Chaos Tap, it would suggest that the Chaos Tap is a mix of magic and technology. The Tap acts similar to the Chaos Emeralds, storing Chaos energy and having the ability to absorb. However, the Chaos Emeralds were originally just Emeralds from the Kohenyu Graveyard area, with no magical properties known (apart from the ability to exist as thirteen separate Emeralds).