# Transceiver

A mutable object that reports its updates to atom.io.

Source: docs/source/concepts/transceiver.md
Packages: atom.io, atom.io/foundations/json
Related: mutable-atom, timeline, transaction

A transceiver is a mutable value that can describe its own updates.

Built-in transceivers include `UList`, which behaves like a set, and `OList`,
which behaves like an array. They let atom.io observe collection updates without
requiring a whole collection replacement every time.

Use transceivers when mutating a collection is the natural operation and atom.io
still needs to track the change reactively.