[svachalek]

Well, rather than getting into a debate on what constitutes "nothing special" or "side effect", I'll let the docs explain the details.

http://redux.js.org/docs/advanced/AsyncActions.html

Note however that it does say "This function doesn’t need to be pure; it is thus allowed to have side effects, including executing asynchronous API calls."

[amackera]

Out of curiosity, would it be possible to be able to do async actions without side effects?

[adyus]

setTimeout() ?

[danmaz74]

Creating a timeout modifies the global state and is therefore a side effect.