Exotic Cipher

"Present this to Xûr or the Monument to Lost Lights to receive a reward. You can only hold one of this item at a time."

- In-game description

Exotic Ciphers are Consumable items in Destiny 2, and may be traded to Xûr, Agent of the Nine or the Monument To Lost Lights in order to receive Exotic items.

Only a single Cipher may be held in the inventory at any time.

Acquisition

 * Certain Triumphs may award one or more Ciphers over the course of their completion. These Ciphers remain until claimed from the Triumphs menu.
 * The free track of any given Season rewards a single Cipher upon completion of Rank 55. These Ciphers may be lost if unclaimed by the end of the season.

Expenditure
Normally, Xûr allows only one Fated (Isochronal) Engram purchase per week. Ciphers may be spent on additional Fated Engrams past this weekly limit.

Alternately, Exotics from past content may be purchased at the Monument To Lost Lights; in addition to the Cipher, this also requires Glimmer and one or more Ascendant Shards, plus either Planetary Materials (for non-Raid exotics) or Spoils of Conquest (for Raid exotics).