Source: Eberron - Rising from the Last War

Wondrous item, rare (requires attunement by a warforged)

A docent is a small metal sphere, about 2 inches across, studded with dragonshards. To attune to a docent , you must embed the item somewhere on your body, such as your chest or your eye socket.

Sentience. A docent is a sentient item of any alignment with an Intelligence of 16, a Wisdom of 14, and a Charisma of 14. It perceives the world through your senses. It communicates telepathically with you and can speak, read, and understand any language it knows (see "Random Properties" below).

Life Support. Whenever you end your turn with 0 hit points, the docent can make a Wisdom (Medicine) check with a +6 bonus. If this check succeeds, the docent stabilizes you.

Random Properties. A docent has the following properties:

• Languages. The docent knows Common, Giant, and 1d4 additional languages chosen by the DM. If a docent knows fewer than six languages, it can learn a new language after it hears or reads the language through your senses.
• Skills. The docent has a +7 bonus to one of the following skills (roll a d4): (1) Arcana, (2) History, (3) Investigation, or (4) Nature.
• Spells. The docent knows one of the following spells and can cast it at will, requiring no components (roll a d6): (1-2) Detect Evil and Good or (3-6) Detect Magic . The docent decides when to cast the spell.

Personality. A docent is designed to advise and assist the warforged it's attached to. One of the simple functions of a docent is to serve as a translator. The docent's properties are under its control, and if you have a bad relationship with your docent , it might refuse to assist you.