Warforged

The Warforged were built to fight the wars of the dying, to preserve knowledge of bodies past their time, and in some cases as servants. While the first Warforged were mindless automatons, an unexpected breakthrough produced sapient soldiers, giving rise to what some have only grudgingly accepted as a new species. Warforged are made from magically resonant stone, metal, or other materials, but they can feel pain and emotion. Much like any sentient being, a warforged can be a steadfast ally, a cold-hearted killer, or a visionary in search of meaning.

Living Steel and Stone

Warforged, is less of a single species, and more of a category of sentient beings. To be considered a Warforged, it need to fulfill two main criteria: Have conscious thought of its own, and be a creation of non-flesh materials. So in theory a Warforged can take a number of forms; but they are particularly rare because the skills and knowledge of how to impart a sentience into the inanimate is rare and esoteric indeed. Out in the world, Warforged are most commonly mistaken for Golems, a misconception that few Warforged care to correct.
Both the Elves and Dwarves have their own secret process for creating a warforged, and is the marrying of the soul of a venerated elder or warrior to a arcane body of shaped stone. The creation of Warforged for these two races is a desperate act, one one done in a desperate bid to slow the decay of knowledge or bolster their fighting forces with the ranks of the animated dead. To bind the soul in this way to bind it forever until the destruction of the body, keeping the soul from reaching the afterlife with their deity, and in favor of potentially an eternity of service. To many, this is seen as aborrant as necromancy.
Elsewhere, in the arcane Gnomish workshops of the Grand Duchies of Aranoc, one may run into an altogether different type of warforged. Here, some of the more maverick inventors and tinkerers of groups like the New Dawn Consortiumhave managed to marry a soul, or other sentience to the body of a metal clockwork humanoid. Beings created in this way are also exceedingly rare because of the knowledge needed to do so, the resources, and cost. The majority started as one-off projects of the master to build a shop assistant.

Sleeping Warriors

The vast majority of Elven or Dwarven created warforged do not remain awake at all times, but rather are seconded away in private sanctums and vaults to awoken by their masters when a grave threat has been determined, and the need is dire. The bodies of warforged vary in size from that of a human, to that of a giant. The more powerful the soul, the larger the body it can power on its own.
Warforged are rarely seen outside of the major holds and cities of the dwarves and elves, or the Arcano-cities of Aranoc. The knowledge for how to make a warforged is also rare, and very few still know how to achieve it. The few warforged seen out and about normally fall into one of three categories:
• Escorting someone or something of great value
• Were found in a lost tomb, city, dungeon, etc. and was able to be awoken
• Has been sent on a very specific task
Due to the strange effects a soul has on the materials it is implanted, Resting, healing magic, and the Medicine skill all benefit the warforged in a similar fashion that they do to other humanoids. The Mend spell may also be used to repair stone.
https://www.dndbeyond.com/races/warforged - for stats and rules