# Loadable

A reactive value that may still be waiting on asynchronous work.

Source: docs/source/concepts/loadable.md
Packages: atom.io, atom.io/react
Related: selector, catch, effect

A loadable value represents state that may currently be a pending `Promise`, a
resolved value, or a handled error stored through `catch`.

Async selectors can produce loadable behavior when they return promises. React
code can use `useLoadable` to observe the loaded value, a `loading` flag while a
newer promise is pending, and typed error information when a caught load fails.

Use loadable state when data comes from an asynchronous source but still needs
to participate in atom.io's reactive graph.

For query data, fetched data, RPC (remote procedure call) contracts, loading
flows, and suspense-like async state, see the
[remote data guide](/docs/remote-data).