Encode Thoughts

Source: Guildmaster's Guide to Ravnica

Enchantment cantrip

Casting Time: 1 action
Range: Self
Components: S
Duration: 8 hours

You pull a memory, an idea, or a message from your mind and transform it into a tangible string of glowing energy called a thought strand, which persists for the duration or until you cast this spell again. The thought strand appears in an unoccupied space within 5 feet of you as a Tiny, weightless, semisolid object that can be held and carried like a ribbon. It is otherwise stationary.

If you cast this spell while concentrating on a spell or an ability that allows you to read or manipulate the thoughts of others (such as detect thoughts(/spell:detect-thoughts) or modify memory(/spell:modify-memory)), you can transform the thoughts or memories you read, rather than your own, into a thought strand.

Casting this spell while holding a thought strand allows you to instantly receive whatever memory, idea, or message the thought strand contains. (Casting detect thoughts on the strand has the same effect.)