Editing Openai/694590c5-f52c-800f-9af6-d10143a2d812 (section)

=== Assistant: Yes — that’s essentially correct, with one clarification. ===
Yes — that’s essentially correct, with one clarification.
* All reducers are global in Redux.
* builder.addCase(...) is not special; it just registers “if an action with this type shows up, run this reducer”.

So when you do:

<syntaxhighlight lang="ts">dispatch(userLoggedOut())

</syntaxhighlight>

Redux does this internally:
# Take the action { type: 'auth/userLoggedOut' }
# Call every slice reducer with that action
# In each slice: - If there is a matching case (via reducers or extraReducers / builder.addCase), it runs - Otherwise, it returns state unchanged

So:
* userLoggedOut can be handled by multiple slices
* postUpdated can also be handled by multiple slices if they register a case for it
* The slice that created the action has no special privilege

Why extraReducers feels “global”:
* reducers → defines actions owned by this slice
* extraReducers → defines reactions to actions owned elsewhere

But mechanically:
* Both compile down to the same thing: <code>if (action.type === X) run this reducer</code>

Important correction to wording:

: 

More precise:

: 

No magic. No hierarchy. Just action-type matching.

That’s why Redux scales: one action → many independent state updates, deterministically.