pythonnative
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
@@ -35,6 +35,21 @@ jobs:
       - name: Type check (MyPy)
         run: uv run mypy
 
+      # The Inbox and e2e apps each own a top-level ``app`` package, so
+      # they're checked from their own directories rather than whole-tree.
+      - name: Type check the Inbox example (strict)
+        working-directory: examples/inbox
+        env:
+          MYPYPATH: ../inbox-extension/src
+        run: uv run --project ../.. mypy --strict app
+
+      - name: Type check the e2e suite (strict)
+        working-directory: examples/e2e-suite
+        run: uv run --project ../.. mypy --strict app
+
+      - name: Rules of hooks (pn lint)
+        run: uv run pn lint src/pythonnative examples
+
       # Produces the sdist and wheel through the setuptools backend. Note
       # this builds but does not install them, so the previous non-editable
       # install smoke test is not replaced.

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
@@ -68,7 +68,9 @@ Unsolicited pull requests for issues that are already assigned or already have a
   - `journal.py`: the undo journal a failed render pass rolls back through
   - `native_views/`: the thin backend accessor (`get_backend` / `set_backend`) and the bridge backend that serializes commits
   - `native_modules/`: device module facades and their Python fallbacks
-  - `navigation/`: navigators, container, hooks, linking, theme, and the navigation ref
+  - `navigation/`: navigator values, screens, container, hooks, deep-link table, and the navigation ref
+  - `theme.py`, `style.py`, `store.py`: the app `Theme`, `StyleSheet` namespaces and style resolution, and `Store`
+  - `lint.py`: the `pn lint` rules-of-hooks checker
   - `testing/`: the headless testing library and the shipped pytest plugin (`testing/pytest_plugin.py`)
   - `bridge/`: JSON codec and per-platform transports into the native rendering core
   - `cli/`: `pn` command
@@ -201,7 +203,7 @@ Recommended scopes (choose the smallest, most accurate unit; prefer module/direc
   - `bridge`: wire codec, transports, handshake, and native-to-Python callback (`bridge/`)
   - `cli`: CLI tool and `pn` command (`src/pythonnative/cli/`)
   - `component`: the `@component` decorator, `Component`, and `memo` (`component.py`)
-  - `components`: declarative element-creating functions (`components/`)
+  - `components`: declarative element-creating functions and their shared props (`components/`)
   - `element`: Element descriptor class (`element.py`)
   - `events`: tag-based event routing between native views and Python callbacks (`events.py`)
   - `gestures`: gesture descriptors and the pure-Python recognition arbiter (`gestures.py`)
@@ -213,10 +215,11 @@ Recommended scopes (choose the smallest, most accurate unit; prefer module/direc
   - `hot_reload`: module reloader and Fast Refresh (`hot_reload.py`)
   - `journal`: render undo journal (`journal.py`)
   - `layout`: Yoga layout integration and the host binding (`layout.py`, `native/yoga/`)
+  - `lint`: the `pn lint` rules-of-hooks checker (`lint.py`)
   - `mutations`: batched mutation ops between reconciler and native backends (`mutations.py`)
   - `native_modules`: native module registry, Python facades, and Python fallbacks (`native_modules/`)
   - `native_views`: view backend accessor and bridge backend (`native_views/`)
-  - `navigation`: navigation state, container, navigators, hooks, linking, theme, and ref (`navigation/`)
+  - `navigation`: navigation state, container, navigators, screens, hooks, linking, and ref (`navigation/`)
   - `net`: awaitable HTTP client (`net.py`)
   - `package`: `src/pythonnative/__init__.py` exports and package boundary
   - `platform`: `Platform.OS`/`Platform.select` and version detection (`platform.py`)
@@ -227,9 +230,11 @@ Recommended scopes (choose the smallest, most accurate unit; prefer module/direc
   - `runtime`: framework-wide asyncio loop and thread-safe future helpers (`runtime.py`)
   - `sdk`: public extension SDK for custom native components (`sdk/`)
   - `storage`: AsyncStorage key/value persistence and `use_persisted_state` (`storage.py`)
+  - `store`: the `Store` app-state container and `use_store` (`store.py`)
   - `scheduler`: render batching and transition queues (`scheduler.py`)
-  - `style`: StyleSheet and theming (`style.py`)
+  - `style`: the `Style` type, style resolution, and `StyleSheet` (`style.py`)
   - `testing`: public test utilities and the pytest plugin (`testing/`)
+  - `theme`: `Theme`, `ThemeProvider`, `use_theme`, and `use_styles` (`theme.py`)
   - `utils`: shared utilities (`utils.py`)
 
 - Other scopes:

diff --git a/README.md b/README.md
@@ -35,7 +35,8 @@ PythonNative is a cross-platform toolkit for building native Android and iOS app
 - **Native widgets and layout:** Swift and Kotlin component managers own UIKit and Android widgets. The shared Yoga C++ engine computes layout beside the controls, using platform measurements for text and intrinsic sizes.
 - **Standard asyncio:** Components, effects, event handlers, and tasks run on a dedicated Python application thread. Native UI threads handle widgets, scrolling, and animation frames. Component-owned tasks are canceled on unmount.
 - **Incremental reconciliation:** State changes update affected component subtrees. Versioned bridge commits validate operations and acknowledge revisions; events and controlled text inputs carry identities that prevent stale updates.
-- **Native lists and navigation:** UIKit collection views and Android recycler views recycle cells for fixed or variable row sizes, grids, sections, and horizontal lists. Native navigation containers present logical screen roots at every nesting level while providers and component state remain in the shared Python tree; navigators take screen options, groups, themes, tab-bar styles, and a navigation ref usable outside components.
+- **Typed, Pythonic authoring:** Components return `pn.Node` and their signatures are their props, so a strict type checker verifies element trees and conditional children. Screens are components whose parameters are their route params (`nav.push(ItemScreen(id=42))`), navigators are module-level values with deep links derived from each screen's `path`, one `Theme` dataclass styles the app and its navigators, `StyleSheet` namespaces give styles typed names, and `pn.Store` holds app state with selector-based re-renders. `pn lint` checks the rules of hooks.
+- **Native lists and navigation:** UIKit collection views and Android recycler views recycle cells for fixed or variable row sizes, grids, sections, and horizontal lists. Native navigation containers present logical screen roots at every nesting level while providers and component state remain in the shared Python tree; navigators take screen options, groups, tab-bar styles, and a navigation ref usable outside components.
 - **Animation and gestures:** Serialized animation graphs support timing with named or bezier easing, springs, React Native's decay model, arithmetic, interpolation, and native scroll and gesture bindings. Swift and Kotlin recognize mobile gestures with Gesture Handler-style activation offsets and update supported animation bindings without Python work on every frame.
 - **Assets and graphics:** Drop images, fonts, and SVGs under `app/assets/` and reference them by path. Density variants, bundled fonts, a vector `Icon` set, `Svg` drawing, gradients, and blur render natively on both platforms and in the browser preview.
 - **Device APIs:** Python facades expose camera, location, notifications, storage, permissions, keyboard, dimensions and pixel ratio, device info, localization, accessibility settings, and other native services, with a Python fallback for headless tests. Test permissions and platform behavior on your deployment targets.
@@ -62,15 +63,15 @@ import pythonnative as pn
 
 
 @pn.component
-def App():
+def App() -> pn.Node:
     count, set_count = pn.use_state(0)
     return pn.Column(
         pn.Text(f"Count: {count}", style=pn.style(font_size=24, bold=True)),
         pn.Button(
             "Tap me",
             on_press=lambda: set_count(count + 1),
         ),
-        style=pn.style(spacing=12, padding=16),
+        style=pn.style(gap=12, padding=16),
     )
 ```
 

diff --git a/docs/api/appearance.md b/docs/api/appearance.md
@@ -11,12 +11,12 @@ import pythonnative as pn
 
 
 @pn.component
-def SchemeAwareBadge():
+def SchemeAwareBadge() -> pn.Node:
     scheme = pn.use_color_scheme()  # "light" or "dark"
-    theme = pn.use_theme()  # built-in theme for the scheme
+    theme = pn.use_theme()  # the theme for the scheme
     return pn.Text(
         f"Currently {scheme}",
-        style={"color": theme.text_color},
+        style={"color": theme.colors.text},
     )
 ```
 
@@ -38,5 +38,5 @@ pn.appearance.set_color_scheme(None)  # follow the system again
 ## Next steps
 
 - Theming with [`use_theme`][pythonnative.use_theme] and
-  [`ThemeContext`][pythonnative.ThemeContext]: see
-  [Style](style.md) and the [Styling guide](../guides/styling.md).
+  [`ThemeProvider`][pythonnative.ThemeProvider]: see
+  [Theme](theme.md) and the [Styling guide](../guides/styling.md#themes).
diff --git a/docs/api/cli.md b/docs/api/cli.md
@@ -27,10 +27,11 @@ the documented behavior never drifts from the code.
   satisfied. See [PyPI packages](../guides/pypi-packages.md).
 - `pn start [entry]`: run the dev server. It watches `app/`, syncs
   every save to each connected debug build with Fast Refresh, relays
-  their logs, and serves the browser preview page. Flags: `--port`
-  (default 8765), `--host` (default `0.0.0.0`), `--open` to also open
-  the browser preview. See the
-  [Development workflow](../guides/dev-workflow.md).
+  their logs, and serves the browser preview page. Every client needs
+  your dev token from `~/.pythonnative/dev-token`, which the printed URLs
+  carry. Flags: `--port` (default 8765), `--host` (default `0.0.0.0`),
+  `--open` to also open the browser preview. See the
+  [Development workflow](../guides/dev-workflow.md#the-dev-token).
 - `pn preview [entry]`: `pn start` plus opening the browser preview in
   your default browser. Flags: `--port`, `--host`, `--no-open`. See the
   [Browser preview guide](../guides/browser-preview.md).
@@ -45,7 +46,7 @@ the documented behavior never drifts from the code.
   reinstalled. Flags: `--device` (target a specific device by
   identifier or name), `--prepare-only`, `--no-logs`, `--rebuild`
   (force the toolchain), `--dev-server URL` (override the server URL
-  baked into the app), `--port` (where `pn start` listens),
+  passed to the app; include the `?token=` from `pn start`), `--port` (where `pn start` listens),
   `--dev-client` (build a shell app with a connect screen that loads
   any project from a dev server).
 - `pn logs android|ios`: stream logs from the running app without
@@ -62,6 +63,13 @@ the documented behavior never drifts from the code.
   scripting; the config
   error goes to stderr instead, and a missing config still exits 1.
 - `pn clean`: remove the local `build/` directory.
+- `pn lint [paths...]`: check the rules of hooks without running the
+  code. With no paths it lints `app/`, or the current directory if
+  there's no `app/`. Each finding prints as `path:line:col: CODE
+  message`. Flag: `--json` to print a JSON array of findings to stdout
+  for scripting; the summary line goes to stderr instead. Exits 1 when
+  there are findings and 2 when a path doesn't exist. See the
+  [Linting guide](../guides/linting.md).
 - `pn --version` (`-V`): print the installed PythonNative version.
 
 ::: pythonnative.cli.pn

diff --git a/docs/api/component-properties.md b/docs/api/component-properties.md
@@ -39,9 +39,8 @@ All components accept these layout properties in their `style` dict:
 - `margin`: outer spacing. Accepts a number (all sides), or a dict with any
   of `horizontal`, `vertical`, `left`, `top`, `right`, `bottom`.
 - `padding`: inner spacing on container elements. Same shape as `margin`.
-- `spacing`: gap between children of a flex container (applied along the
-  main axis).
-- `gap`: alias for `spacing`.
+- `gap`: space between children of a flex container. `row_gap` and
+  `column_gap` set one axis.
 
 ### Position
 
@@ -92,7 +91,7 @@ pn.View(*children, style={
     "justify_content": "center",
     "align_items": "center",
     "overflow": "hidden",
-    "spacing": 8,
+    "gap": 8,
     "padding": 16,
     "background_color": "#F5F5F5",
 })
@@ -106,7 +105,7 @@ Flex container properties (inside `style`):
 - `justify_content`: `"flex_start"`, `"center"`, `"flex_end"`, `"space_between"`, `"space_around"`, `"space_evenly"`
 - `align_items`: `"stretch"`, `"flex_start"`, `"center"`, `"flex_end"`
 - `overflow`: `"visible"` (default), `"hidden"`
-- `spacing`, `padding`, `background_color`
+- `gap`, `padding`, `background_color`
 
 Containers also fully support absolute positioning for their children:
 
@@ -165,8 +164,8 @@ pn.Button(title, on_press=handler, style={"color": "#FFF", "background_color": "
 ## Column / Row
 
 ```python
-pn.Column(*children, style={"spacing": 12, "padding": 16, "align_items": "center"})
-pn.Row(*children, style={"spacing": 8, "justify_content": "space_between"})
+pn.Column(*children, style={"gap": 12, "padding": 16, "align_items": "center"})
+pn.Row(*children, style={"gap": 8, "justify_content": "space_between"})
 ```
 
 Convenience wrappers for `View` with fixed `flex_direction`:
@@ -176,7 +175,7 @@ Convenience wrappers for `View` with fixed `flex_direction`:
 
 - `*children`: child elements (positional)
 - Style properties:
-  - `spacing`: gap between children (dp / pt)
+  - `gap`: space between children (dp / pt)
   - `padding`: inner padding (int for all sides, or dict with `horizontal`, `vertical`, `left`, `top`, `right`, `bottom`)
   - `align_items`: cross-axis alignment: `"stretch"`, `"flex_start"`, `"center"`, `"flex_end"`, `"leading"`, `"trailing"`
   - `justify_content`: main-axis distribution: `"flex_start"`, `"center"`, `"flex_end"`, `"space_between"`, `"space_around"`, `"space_evenly"`
@@ -303,7 +302,7 @@ pn.Image(source="https://example.com/photo.jpg",
          on_load_start=lambda: ..., on_load=lambda e: ..., on_load_end=lambda: ...,
          on_error=lambda message: ...,
          fade_duration=200, headers={"Authorization": f"Bearer {token}"},
-         style={"width": 200, "height": 150, "scale_type": "cover"})
+         scale_type="cover", style={"width": 200, "height": 150})
 ```
 
 - `source`: a bundled [`Asset`][pythonnative.Asset], an image URL
@@ -586,7 +585,8 @@ pn.Element("TabBar", {
 })
 ```
 
-Native tab bar, typically created automatically by `Tab.Navigator`.
+Native tab bar, typically created automatically by a
+[`TabNavigator`][pythonnative.TabNavigator].
 
 | Platform | Native view              |
 |----------|--------------------------|
@@ -642,7 +642,7 @@ pn.FlatList(data=items, render_item=render_fn, key_extractor=key_fn,
 ```python
 pn.SectionList(sections=[pn.Section(key="a", title="A", data=["Apple"])],
                render_item=lambda item, i, s: pn.Text(item),
-               render_section_header=lambda section, s: pn.Text(section["title"]),
+               render_section_header=lambda section, s: pn.Text(section.title),
                sticky_section_headers=True, inverted=False,
                item_separator=lambda: pn.View(style={"height": 1, "background_color": "#EEE"}),
                on_viewable_items_changed=handler)

diff --git a/docs/api/component.md b/docs/api/component.md
@@ -4,11 +4,15 @@ The [`@component`][pythonnative.component.component] decorator turns a plain
 function into a [`Component`][pythonnative.Component]: calling it
 returns an [`Element`][pythonnative.Element] instead of running the
 body, and the reconciler runs the body (with hooks) when the element
-mounts or its props change. Positional arguments are children; keyword
-arguments are props. [`memo`][pythonnative.memo] skips re-rendering
-when props are unchanged.
-
-[](){ #pythonnative.Component.keyed }
+mounts or its props change. The component's signature is its prop
+list, so type checkers verify every call. Positional `*children`
+receive child nodes; keyword arguments are props. Key a component's
+element with [`Element.with_key`][pythonnative.element.Element.with_key]
+(`Row(item).with_key(item.id)`), since `key=` isn't a prop.
+[`memo`][pythonnative.memo] skips re-rendering when props are
+unchanged. In development builds, props are also checked against the
+function's annotations; see
+[`prop_checks`](#development-prop-checks).
 
 ::: pythonnative.component
     options:
@@ -17,6 +21,14 @@ when props are unchanged.
       members_order: source
       filters: ["!^_"]
 
+## Development prop checks
+
+::: pythonnative.prop_checks
+    options:
+      show_root_heading: false
+      show_root_toc_entry: false
+      members: false
+
 ## Next steps
 
 - Learn the model in [Components](../concepts/components.md).

diff --git a/docs/api/components.md b/docs/api/components.md
@@ -5,9 +5,11 @@ return immutable [`Element`][pythonnative.Element] descriptors; nothing
 is mounted to a native view tree until the
 [`Reconciler`][pythonnative.reconciler.Reconciler] processes them.
 
-Every argument is a keyword argument on the factory, which makes it
-part of the generated native contract for iOS, Android, and the browser
-preview. Platform notes (an Android-only ripple, an iOS-only keyboard
+Containers take their children positionally as `*children: pn.Node`,
+and every other argument is a keyword argument on the factory, which
+makes it part of the generated native contract for iOS, Android, and
+the browser preview. Keywords shared by many components are declared
+once as [shared props](#shared-props) instead of in every factory. Platform notes (an Android-only ripple, an iOS-only keyboard
 appearance) are recorded on the argument itself. Event callbacks
 receive the [typed payloads](#typed-event-payloads) below rather than
 dicts, and a `ref=` argument receives a typed
@@ -26,6 +28,23 @@ For the visual and layout properties accepted by each component's
         - "!^_"
         - "!^(ContentSizeEvent|ImageLoadEvent|KeyPressEvent|LayoutEvent|ScrollEvent|SelectionEvent|WebNavigationEvent)$"
 
+## Shared props
+
+Every built-in view accepts the
+[`AccessibilityProps`][pythonnative.AccessibilityProps] keywords, and
+`View`, `Column`, `Row`, and `Pressable` also accept the
+[`ViewProps`][pythonnative.ViewProps] layout and gesture keywords.
+Factories declare them as `**props: Unpack[...]`, so a type checker
+validates each keyword as if it were spelled out in the signature.
+Built-in props are validated at run time only in development builds.
+
+::: pythonnative.components.props
+    options:
+      show_root_heading: false
+      show_root_toc_entry: false
+      members_order: source
+      filters: ["!^_"]
+
 ## List data and records
 
 `ListData` publishes explicit keyed edits to `FlatList`. `Section` gives each
@@ -60,5 +79,5 @@ callbacks. Field names match the wire payload, which is what lets
 
 - Wire interactions with [Hooks](hooks.md).
 - Drive a mounted view through its [handle](handles.md).
-- Compose styles with [`StyleSheet`][pythonnative.StyleSheet].
+- Group named styles with [`StyleSheet`][pythonnative.StyleSheet].
 - Build navigation with [`NavigationContainer`][pythonnative.NavigationContainer].
diff --git a/docs/api/devserver.md b/docs/api/devserver.md
@@ -23,6 +23,15 @@ guide for how they fit together; this page documents the modules.
       members_order: source
       filters: ["!^_"]
 
+### Authentication
+
+::: pythonnative.devserver.auth
+    options:
+      show_root_heading: false
+      show_root_toc_entry: false
+      members_order: source
+      filters: ["!^_"]
+
 ### File watcher and source snapshots
 
 ::: pythonnative.devserver.watcher

diff --git a/docs/api/diagnostics.md b/docs/api/diagnostics.md
@@ -23,6 +23,8 @@ Most apps never call this module directly; it exists so framework
 code (and custom component libraries) can report problems in a way
 that reaches the developer instead of disappearing into a log.
 
+[](){ #pythonnative.diagnostics }
+
 ::: pythonnative.diagnostics
     options:
       show_root_heading: false

diff --git a/docs/api/element.md b/docs/api/element.md
@@ -8,6 +8,13 @@ tree. `Element` instances are produced by the
 You almost never construct an `Element` by hand; the factory functions
 exist precisely so app code stays in plain Python.
 
+[`Node`][pythonnative.element.Node] is the type of anything that can
+appear in a tree: an element, `None` or a `bool` for "nothing", or a
+(possibly nested) iterable of nodes. Built-in containers take
+`*children: pn.Node`, and components return `pn.Node`.
+[`Element.with_key`][pythonnative.element.Element.with_key] returns a keyed
+copy, the typed way to key a user component.
+
 ::: pythonnative.element
     options:
       show_root_heading: false