packages/docs/docs/state-management.md

@@ -228,11 +228,7 @@ interface UserProfile {
 
 class ProfileState extends Context.Service<
   ProfileState,
-  {
-    readonly profile: Lens.Lens<UserProfile>
-    readonly name: Lens.Lens<string>
-    readonly role: Lens.Lens<string>
-  }
+  { readonly profile: Lens.Lens<UserProfile> }
 >()("ProfileState") {
   static readonly layer = Layer.effect(
     ProfileState,
@@ -249,18 +245,28 @@ class ProfileState extends Context.Service<
           },
         }),
       )
-      const name = Lens.focusObjectOn(profile, "name")
-      const role = Lens.focusObjectOn(profile, "role")
 
-      return { profile, name, role } as const
+      return { profile } as const
     }),
   )
 }
 
 const ProfileNameView = Component.make("ProfileName")(function*() {
   const state = yield* ProfileState
-  const [name, setName] = yield* Lens.useState(state.name)
-  const [role] = yield* View.useAll([state.role])
+  const [nameLens, roleLens, cityLens] = yield* Component.useOnMount(() =>
+    Effect.succeed([
+      Lens.focusObjectOn(state.profile, "name"),
+      Lens.focusObjectOn(state.profile, "role"),
+      state.profile.pipe(
+        Lens.focusObjectOn("contact"),
+        Lens.focusObjectOn("address"),
+        Lens.focusObjectOn("city"),
+      ),
+    ] as const),
+  )
+
+  const [name, setName] = yield* Lens.useState(nameLens)
+  const [role, city] = yield* View.useAll([roleLens, cityLens])
 
   return (
     <label>
@@ -270,27 +276,21 @@ const ProfileNameView = Component.make("ProfileName")(function*() {
         onChange={(event) => setName(event.currentTarget.value)}
       />
       <span>Role: {role}</span>
+      <span>City: {city}</span>
     </label>
   )
 })
 ```
 
-Updating the focused `name` Lens through `Lens.useState` updates the parent
-`profile` Lens. The focused `role` Lens is only read, so it stays on the simpler
-`View.useAll` path.
+The service owns only the root `profile` Lens. The component chooses the fields
+it needs, creates those focused Lenses once in `Component.useOnMount`, and
+subscribes only to them. Updating `nameLens` through `Lens.useState` still
+updates the parent `profile` Lens.
 
 Lens focus helpers have a dual API. They can be called in data-first form, such
 as `Lens.focusObjectOn(profile, "name")`, or in curried form with only the key
-or index. The curried form composes naturally with `pipe` for deeper paths:
-
-```tsx
-// profileLens is a Lens.Lens<UserProfile>
-const cityLens = profileLens.pipe(
-  Lens.focusObjectOn("contact"),
-  Lens.focusObjectOn("address"),
-  Lens.focusObjectOn("city"),
-)
-```
+or index. The `cityLens` above uses the curried form with `pipe` to focus through
+a deeper path without storing intermediate Lenses.
 
 For focusing into nested state, deriving lenses, custom write behavior, and the
 complete API, refer to the