Free course · State

State layer: terminology for the AI era

Where a value lives, how a change is described, applied and observed, and how async work stays honest — the Redux-family vocabulary every store in the templates shares.

3 modules · 7 lessons · about 21 min of reading · no signup

Before you start: Comfortable with JavaScript objects and arrays. Redux, NgRx and Pinia examples are explained as they appear.

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What you will be able to do

• Decide whether a value is local, global, server or URL state before an agent puts it in the store.
• Read an action, a reducer and a middleware as one write path and spot the impure step.
• Specify selectors and async operations so the UI never computes, races or lies about loading.

Course contents

Module 1 Where state lives

Classify a value first; the store is one answer, not the default.

1. Mark “State: decide where a value lives first” complete 01 State: decide where a value lives first State Basics · 3 min
2. Mark “Store: one source of truth, one way in” complete 02 Store: one source of truth, one way in Store · 3 min

Module 2 The write path

An event is described, applied purely, and intercepted on the way.

1. Mark “Actions: describe what happened, not what to set” complete 03 Actions: describe what happened, not what to set Actions · 3 min
2. Mark “Reducer: the only place state changes” complete 04 Reducer: the only place state changes Reducer · 3 min
3. Mark “Middleware: the pipeline between dispatch and reducer” complete 05 Middleware: the pipeline between dispatch and reducer Middleware · 3 min

Module 3 The read path and async

Derive instead of storing, and model every request as a lifecycle.

1. Mark “Selectors: derive, don't store” complete 06 Selectors: derive, don't store Selectors · 3 min
2. Mark “Operations: every request is a lifecycle” complete 07 Operations: every request is a lifecycle Operations · 3 min