diff --git a/example/example.dart b/example/example.dart
new file mode 100644
index 0000000..fb4deae
--- /dev/null
+++ b/example/example.dart
@@ -0,0 +1,70 @@
+// ignore_for_file: avoid_print
+import 'package:h3_core/h3_core.dart';
+
+void main() {
+  // Convert a coordinate to an H3 cell index at resolution 9.
+  final sf = LatLng(37.7749295, -122.4194155);
+  final cell = latLngToCell(sf, 9);
+  print('H3 cell: ${cell.toHex()}'); // e.g. 8928308280fffff
+
+  // Get the center of the cell.
+  final center = cellToLatLng(cell);
+  print('Center: ${center.lat}, ${center.lng}');
+
+  // Inspect the cell.
+  print('Resolution: ${getResolution(cell)}');
+  print('Valid: ${isValidCell(cell)}');
+  print('Pentagon: ${isPentagon(cell)}');
+
+  // Get the cell boundary vertices.
+  final boundary = cellToBoundary(cell);
+  print('Boundary vertices: ${boundary.vertices.length}');
+
+  // Find neighbors within 1 grid step.
+  final neighbors = gridDisk(cell, 1);
+  print('Neighbors (k=1): ${neighbors.length}');
+
+  // Grid distance between two cells.
+  final other = neighbors.last;
+  final distance = gridDistance(cell, other);
+  print('Grid distance: $distance');
+
+  // Hierarchy: parent and children.
+  final parent = cellToParent(cell, 8);
+  print('Parent (res 8): ${parent.toHex()}');
+
+  final children = cellToChildren(cell, 10);
+  print('Children (res 10): ${children.length}');
+
+  // Compact and uncompact.
+  final compacted = compactCells(children);
+  print('Compacted: ${compacted.length}');
+
+  // Measurements.
+  final area = cellAreaKm2(cell);
+  print('Cell area: ${area.toStringAsFixed(4)} km²');
+
+  final dist = greatCircleDistanceKm(sf, LatLng(40.7128, -74.0060));
+  print('SF to NYC: ${dist.toStringAsFixed(1)} km');
+
+  // Directed edges.
+  final neighbor = neighbors[1];
+  if (areNeighborCells(cell, neighbor)) {
+    final edge = cellsToDirectedEdge(cell, neighbor);
+    print('Edge: ${edge.toHex()}');
+    print('Edge length: ${edgeLengthKm(edge).toStringAsFixed(3)} km');
+  }
+
+  // Region: fill a polygon with cells.
+  final polygon = GeoPolygon([
+    LatLng(37.78, -122.42),
+    LatLng(37.78, -122.41),
+    LatLng(37.77, -122.41),
+    LatLng(37.77, -122.42),
+  ]);
+  final filled = polygonToCells(polygon, 9);
+  print('Cells in polygon: ${filled.length}');
+
+  // Version info.
+  print('h3_core ${H3Version.package}, H3 native ${H3Version.native}');
+}
diff --git a/lib/src/errors.dart b/lib/src/errors.dart
index d789243..75ee5e4 100644
--- a/lib/src/errors.dart
+++ b/lib/src/errors.dart
@@ -1,10 +1,18 @@
-/// Base exception for all H3 errors.
+/// Exception thrown when an H3 operation fails.
+///
+/// Each error has a numeric [code] corresponding to the H3 C library error
+/// codes and a human-readable [message].
 class H3Exception implements Exception {
+  /// The H3 error code (1–19).
   final int code;
+
+  /// A human-readable description of the error.
   final String message;
 
+  /// Creates an [H3Exception] with the given [code] and [message].
   const H3Exception(this.code, this.message);
 
+  /// Creates an [H3Exception] from an H3 C library error [code].
   factory H3Exception.fromCode(int code) {
     return switch (code) {
       1 => const H3Exception(1, 'Operation failed'),
diff --git a/lib/src/h3_ffi.dart b/lib/src/h3_ffi.dart
index b890c41..1ff0535 100644
--- a/lib/src/h3_ffi.dart
+++ b/lib/src/h3_ffi.dart
@@ -13,6 +13,8 @@ import 'models/lat_lng.dart';
 
 // Indexing
 
+/// Converts a [latLng] coordinate to the H3 cell index at the given
+/// [resolution] (0–15).
 H3Index latLngToCell(LatLng latLng, int resolution) {
   return using((Arena arena) {
     final ll = arena<c.LatLng>();
@@ -25,6 +27,7 @@ H3Index latLngToCell(LatLng latLng, int resolution) {
   });
 }
 
+/// Returns the center coordinate of the given H3 [cell].
 LatLng cellToLatLng(H3Index cell) {
   return using((Arena arena) {
     final ll = arena<c.LatLng>();
@@ -33,6 +36,7 @@ LatLng cellToLatLng(H3Index cell) {
   });
 }
 
+/// Returns the boundary vertices of the given H3 [cell].
 CellBoundary cellToBoundary(H3Index cell) {
   return using((Arena arena) {
     final cb = arena<c.CellBoundary>();
@@ -54,18 +58,25 @@ CellBoundary cellToBoundary(H3Index cell) {
 
 // Inspection
 
+/// Returns the resolution (0–15) of the given H3 index.
 int getResolution(H3Index h) => c.getResolution(h.toInt());
 
+/// Returns the base cell number (0–121) of the given H3 index.
 int getBaseCellNumber(H3Index h) => c.getBaseCellNumber(h.toInt());
 
+/// Returns whether [h] is a valid H3 cell index.
 bool isValidCell(H3Index h) => c.isValidCell(h.toInt()) == 1;
 
+/// Returns whether [h] is any valid H3 index (cell, edge, or vertex).
 bool isValidIndex(H3Index h) => c.isValidIndex(h.toInt()) == 1;
 
+/// Returns whether [h] is a pentagon cell.
 bool isPentagon(H3Index h) => c.isPentagon(h.toInt()) == 1;
 
+/// Returns whether [h] has Class III resolution orientation.
 bool isResClassIII(H3Index h) => c.isResClassIII(h.toInt()) == 1;
 
+/// Returns the icosahedron face(s) that the given cell intersects.
 List<int> getIcosahedronFaces(H3Index h) {
   return using((Arena arena) {
     final maxOut = arena<Int>();
@@ -84,11 +95,14 @@ List<int> getIcosahedronFaces(H3Index h) {
   });
 }
 
+/// Returns whether [edge] is a valid H3 directed edge index.
 bool isValidDirectedEdge(H3Index edge) =>
     c.isValidDirectedEdge(edge.toInt()) == 1;
 
+/// Returns whether [vertex] is a valid H3 vertex index.
 bool isValidVertex(H3Index vertex) => c.isValidVertex(vertex.toInt()) == 1;
 
+/// Returns the direction digit at the given [resolution] for index [h].
 int getIndexDigit(H3Index h, int resolution) {
   return using((Arena arena) {
     final out = arena<Int>();
@@ -97,6 +111,8 @@ int getIndexDigit(H3Index h, int resolution) {
   });
 }
 
+/// Constructs an H3 cell index from [res], [baseCellNumber], and direction
+/// [digits].
 H3Index constructCell(int res, int baseCellNumber, List<int> digits) {
   return using((Arena arena) {
     final digitsPtr = arena<Int>(digits.length);
@@ -111,6 +127,8 @@ H3Index constructCell(int res, int baseCellNumber, List<int> digits) {
 
 // String conversion
 
+/// Parses a [hex] string into an [H3Index], throwing [H3Exception] on
+/// invalid input.
 H3Index stringToH3(String hex) {
   return using((Arena arena) {
     final str = hex.toNativeUtf8(allocator: arena);
@@ -120,6 +138,7 @@ H3Index stringToH3(String hex) {
   });
 }
 
+/// Returns the hex string representation of the given H3 index.
 String h3ToString(H3Index h) {
   return using((Arena arena) {
     final buf = arena<Char>(17);
@@ -130,6 +149,7 @@ String h3ToString(H3Index h) {
 
 // Traversal
 
+/// Returns all cells within [k] grid steps of [origin] (filled disk).
 List<H3Index> gridDisk(H3Index origin, int k) {
   return using((Arena arena) {
     final sizeOut = arena<Int64>();
@@ -146,6 +166,7 @@ List<H3Index> gridDisk(H3Index origin, int k) {
   });
 }
 
+/// Returns cells within [k] steps of [origin] mapped to their grid distance.
 Map<H3Index, int> gridDiskDistances(H3Index origin, int k) {
   return using((Arena arena) {
     final sizeOut = arena<Int64>();
@@ -166,6 +187,7 @@ Map<H3Index, int> gridDiskDistances(H3Index origin, int k) {
   });
 }
 
+/// Returns cells exactly [k] grid steps from [origin] (hollow ring).
 List<H3Index> gridRing(H3Index origin, int k) {
   return using((Arena arena) {
     final sizeOut = arena<Int64>();
@@ -182,6 +204,7 @@ List<H3Index> gridRing(H3Index origin, int k) {
   });
 }
 
+/// Returns the minimum grid distance between [origin] and [destination].
 int gridDistance(H3Index origin, H3Index destination) {
   return using((Arena arena) {
     final out = arena<Int64>();
@@ -190,6 +213,7 @@ int gridDistance(H3Index origin, H3Index destination) {
   });
 }
 
+/// Returns the cells along the shortest grid path from [start] to [end].
 List<H3Index> gridPathCells(H3Index start, H3Index end) {
   return using((Arena arena) {
     final sizeOut = arena<Int64>();
@@ -205,6 +229,7 @@ List<H3Index> gridPathCells(H3Index start, H3Index end) {
 
 // Hierarchy
 
+/// Returns the parent cell of [cell] at the coarser [parentRes].
 H3Index cellToParent(H3Index cell, int parentRes) {
   return using((Arena arena) {
     final out = arena<Uint64>();
@@ -213,6 +238,7 @@ H3Index cellToParent(H3Index cell, int parentRes) {
   });
 }
 
+/// Returns the children of [cell] at the finer [childRes].
 List<H3Index> cellToChildren(H3Index cell, int childRes) {
   return using((Arena arena) {
     final sizeOut = arena<Int64>();
@@ -226,6 +252,7 @@ List<H3Index> cellToChildren(H3Index cell, int childRes) {
   });
 }
 
+/// Returns the center child of [cell] at the finer [childRes].
 H3Index cellToCenterChild(H3Index cell, int childRes) {
   return using((Arena arena) {
     final out = arena<Uint64>();
@@ -234,6 +261,7 @@ H3Index cellToCenterChild(H3Index cell, int childRes) {
   });
 }
 
+/// Returns the position of [child] within its parent at [parentRes].
 int cellToChildPos(H3Index child, int parentRes) {
   return using((Arena arena) {
     final out = arena<Int64>();
@@ -242,6 +270,7 @@ int cellToChildPos(H3Index child, int parentRes) {
   });
 }
 
+/// Returns the child cell at [childPos] within [parent] at [childRes].
 H3Index childPosToCell(int childPos, H3Index parent, int childRes) {
   return using((Arena arena) {
     final out = arena<Uint64>();
@@ -250,6 +279,7 @@ H3Index childPosToCell(int childPos, H3Index parent, int childRes) {
   });
 }
 
+/// Compacts a set of [cells] by replacing complete groups with their parent.
 List<H3Index> compactCells(List<H3Index> cells) {
   return using((Arena arena) {
     final h3Set = arena<Uint64>(cells.length);
@@ -267,6 +297,7 @@ List<H3Index> compactCells(List<H3Index> cells) {
   });
 }
 
+/// Expands compacted [cells] to the given [resolution].
 List<H3Index> uncompactCells(List<H3Index> cells, int resolution) {
   return using((Arena arena) {
     final h3Set = arena<Uint64>(cells.length);
@@ -292,6 +323,7 @@ List<H3Index> uncompactCells(List<H3Index> cells, int resolution) {
 
 // Directed edges
 
+/// Returns whether [origin] and [destination] share an edge.
 bool areNeighborCells(H3Index origin, H3Index destination) {
   return using((Arena arena) {
     final out = arena<Int>();
@@ -300,6 +332,7 @@ bool areNeighborCells(H3Index origin, H3Index destination) {
   });
 }
 
+/// Returns the directed edge from [origin] to [destination].
 H3Index cellsToDirectedEdge(H3Index origin, H3Index destination) {
   return using((Arena arena) {
     final out = arena<Uint64>();
@@ -310,6 +343,7 @@ H3Index cellsToDirectedEdge(H3Index origin, H3Index destination) {
   });
 }
 
+/// Returns the origin cell of the directed [edge].
 H3Index getDirectedEdgeOrigin(H3Index edge) {
   return using((Arena arena) {
     final out = arena<Uint64>();
@@ -318,6 +352,7 @@ H3Index getDirectedEdgeOrigin(H3Index edge) {
   });
 }
 
+/// Returns the destination cell of the directed [edge].
 H3Index getDirectedEdgeDestination(H3Index edge) {
   return using((Arena arena) {
     final out = arena<Uint64>();
@@ -326,6 +361,7 @@ H3Index getDirectedEdgeDestination(H3Index edge) {
   });
 }
 
+/// Returns the origin and destination cells of the directed [edge].
 List<H3Index> directedEdgeToCells(H3Index edge) {
   return using((Arena arena) {
     final out = arena<Uint64>(2);
@@ -334,6 +370,7 @@ List<H3Index> directedEdgeToCells(H3Index edge) {
   });
 }
 
+/// Returns all directed edges originating from [origin].
 List<H3Index> originToDirectedEdges(H3Index origin) {
   return using((Arena arena) {
     final out = arena<Uint64>(6);
@@ -345,6 +382,7 @@ List<H3Index> originToDirectedEdges(H3Index origin) {
   });
 }
 
+/// Returns the boundary vertices of the directed [edge].
 CellBoundary directedEdgeToBoundary(H3Index edge) {
   return using((Arena arena) {
     final cb = arena<c.CellBoundary>();
@@ -366,6 +404,7 @@ CellBoundary directedEdgeToBoundary(H3Index edge) {
 
 // Vertices
 
+/// Returns the vertex at index [vertexNum] (0–5) of the [cell].
 H3Index cellToVertex(H3Index cell, int vertexNum) {
   return using((Arena arena) {
     final out = arena<Uint64>();
@@ -374,6 +413,7 @@ H3Index cellToVertex(H3Index cell, int vertexNum) {
   });
 }
 
+/// Returns all vertices of the given [cell].
 List<H3Index> cellToVertexes(H3Index cell) {
   return using((Arena arena) {
     final out = arena<Uint64>(6);
@@ -385,6 +425,7 @@ List<H3Index> cellToVertexes(H3Index cell) {
   });
 }
 
+/// Returns the coordinates of the given [vertex].
 LatLng vertexToLatLng(H3Index vertex) {
   return using((Arena arena) {
     final ll = arena<c.LatLng>();
@@ -395,6 +436,7 @@ LatLng vertexToLatLng(H3Index vertex) {
 
 // Measurements
 
+/// Returns the great-circle distance between [a] and [b] in kilometers.
 double greatCircleDistanceKm(LatLng a, LatLng b) {
   return using((Arena arena) {
     final aPtr = arena<c.LatLng>();
@@ -407,6 +449,7 @@ double greatCircleDistanceKm(LatLng a, LatLng b) {
   });
 }
 
+/// Returns the great-circle distance between [a] and [b] in meters.
 double greatCircleDistanceM(LatLng a, LatLng b) {
   return using((Arena arena) {
     final aPtr = arena<c.LatLng>();
@@ -419,6 +462,7 @@ double greatCircleDistanceM(LatLng a, LatLng b) {
   });
 }
 
+/// Returns the exact area of the [cell] in km².
 double cellAreaKm2(H3Index cell) {
   return using((Arena arena) {
     final out = arena<Double>();
@@ -427,6 +471,7 @@ double cellAreaKm2(H3Index cell) {
   });
 }
 
+/// Returns the exact area of the [cell] in m².
 double cellAreaM2(H3Index cell) {
   return using((Arena arena) {
     final out = arena<Double>();
@@ -435,6 +480,7 @@ double cellAreaM2(H3Index cell) {
   });
 }
 
+/// Returns the exact length of the directed [edge] in kilometers.
 double edgeLengthKm(H3Index edge) {
   return using((Arena arena) {
     final out = arena<Double>();
@@ -443,6 +489,7 @@ double edgeLengthKm(H3Index edge) {
   });
 }
 
+/// Returns the exact length of the directed [edge] in meters.
 double edgeLengthM(H3Index edge) {
   return using((Arena arena) {
     final out = arena<Double>();
@@ -451,6 +498,7 @@ double edgeLengthM(H3Index edge) {
   });
 }
 
+/// Returns the average hexagon area in km² at the given [resolution].
 double getHexagonAreaAvgKm2(int resolution) {
   return using((Arena arena) {
     final out = arena<Double>();
@@ -459,6 +507,7 @@ double getHexagonAreaAvgKm2(int resolution) {
   });
 }
 
+/// Returns the average hexagon area in m² at the given [resolution].
 double getHexagonAreaAvgM2(int resolution) {
   return using((Arena arena) {
     final out = arena<Double>();
@@ -467,6 +516,7 @@ double getHexagonAreaAvgM2(int resolution) {
   });
 }
 
+/// Returns the average hexagon edge length in km at the given [resolution].
 double getHexagonEdgeLengthAvgKm(int resolution) {
   return using((Arena arena) {
     final out = arena<Double>();
@@ -475,6 +525,8 @@ double getHexagonEdgeLengthAvgKm(int resolution) {
   });
 }
 
+/// Returns the average hexagon edge length in meters at the given
+/// [resolution].
 double getHexagonEdgeLengthAvgM(int resolution) {
   return using((Arena arena) {
     final out = arena<Double>();
@@ -483,6 +535,7 @@ double getHexagonEdgeLengthAvgM(int resolution) {
   });
 }
 
+/// Returns the total number of cells at the given [resolution].
 int getNumCells(int resolution) {
   return using((Arena arena) {
     final out = arena<Int64>();
@@ -493,6 +546,7 @@ int getNumCells(int resolution) {
 
 // Coordinate systems
 
+/// Converts [cell] to local IJ coordinates relative to [origin].
 CoordIJ cellToLocalIj(H3Index origin, H3Index cell) {
   return using((Arena arena) {
     final ij = arena<c.CoordIJ>();
@@ -501,6 +555,7 @@ CoordIJ cellToLocalIj(H3Index origin, H3Index cell) {
   });
 }
 
+/// Converts local [ij] coordinates relative to [origin] back to an H3 cell.
 H3Index localIjToCell(H3Index origin, CoordIJ ij) {
   return using((Arena arena) {
     final ijPtr = arena<c.CoordIJ>();
@@ -514,6 +569,7 @@ H3Index localIjToCell(H3Index origin, CoordIJ ij) {
 
 // Regions
 
+/// Returns all cells whose centers are within the [polygon] at [resolution].
 List<H3Index> polygonToCells(GeoPolygon polygon, int resolution) {
   return using((Arena arena) {
     final gp = arena<c.GeoPolygon>();
@@ -558,6 +614,7 @@ List<H3Index> polygonToCells(GeoPolygon polygon, int resolution) {
   });
 }
 
+/// Returns cells within the [polygon] using the specified containment [mode].
 List<H3Index> polygonToCellsExperimental(
   GeoPolygon polygon,
   int resolution, {
@@ -611,6 +668,8 @@ List<H3Index> polygonToCellsExperimental(
   });
 }
 
+/// Returns the outlines of a set of [cells] as a GeoJSON-style
+/// multi-polygon.
 List<List<List<LatLng>>> cellsToMultiPolygon(List<H3Index> cells) {
   return using((Arena arena) {
     final h3Set = arena<Uint64>(cells.length);
@@ -664,8 +723,10 @@ List<List<List<LatLng>>> _extractMultiPolygon(
 
 // Utilities
 
+/// Returns the number of resolution-0 cells (always 122).
 int res0CellCount() => c.res0CellCount();
 
+/// Returns all 122 resolution-0 cells.
 List<H3Index> getRes0Cells() {
   return using((Arena arena) {
     final out = arena<Uint64>(122);
@@ -674,8 +735,10 @@ List<H3Index> getRes0Cells() {
   });
 }
 
+/// Returns the number of pentagons per resolution (always 12).
 int pentagonCount() => c.pentagonCount();
 
+/// Returns all 12 pentagon cells at the given [resolution].
 List<H3Index> getPentagons(int resolution) {
   return using((Arena arena) {
     final out = arena<Uint64>(12);
@@ -684,16 +747,28 @@ List<H3Index> getPentagons(int resolution) {
   });
 }
 
+/// Version constants for the h3_core package and the underlying H3 C library.
 abstract final class H3Version {
+  /// The h3_core Dart package version.
   static const String package = '1.0.1';
+
+  /// The H3 C library version string.
   static const String native = '4.4.1';
+
+  /// The H3 C library major version.
   static const int major = 4;
+
+  /// The H3 C library minor version.
   static const int minor = 4;
+
+  /// The H3 C library patch version.
   static const int patch = 1;
 }
 
 // Async — runs on isolate to keep the UI thread free.
 
+/// Async version of [polygonToCells]; runs on an isolate to avoid blocking
+/// the UI thread.
 Future<List<H3Index>> polygonToCellsAsync(
   GeoPolygon polygon,
   int resolution,
@@ -701,14 +776,20 @@ Future<List<H3Index>> polygonToCellsAsync(
   return Isolate.run(() => polygonToCells(polygon, resolution));
 }
 
+/// Async version of [gridDisk]; runs on an isolate to avoid blocking the
+/// UI thread.
 Future<List<H3Index>> gridDiskAsync(H3Index origin, int k) async {
   return Isolate.run(() => gridDisk(origin, k));
 }
 
+/// Async version of [compactCells]; runs on an isolate to avoid blocking
+/// the UI thread.
 Future<List<H3Index>> compactCellsAsync(List<H3Index> cells) async {
   return Isolate.run(() => compactCells(cells));
 }
 
+/// Async version of [uncompactCells]; runs on an isolate to avoid blocking
+/// the UI thread.
 Future<List<H3Index>> uncompactCellsAsync(
   List<H3Index> cells,
   int resolution,
diff --git a/lib/src/h3_stub.dart b/lib/src/h3_stub.dart
index 08a50bb..499525b 100644
--- a/lib/src/h3_stub.dart
+++ b/lib/src/h3_stub.dart
@@ -13,122 +13,248 @@ Never _unsupported() =>
 
 // Indexing
 
+/// Converts a [latLng] coordinate to the H3 cell index at the given
+/// [resolution] (0–15).
 H3Index latLngToCell(LatLng latLng, int resolution) => _unsupported();
+
+/// Returns the center coordinate of the given H3 [cell].
 LatLng cellToLatLng(H3Index cell) => _unsupported();
+
+/// Returns the boundary vertices of the given H3 [cell].
 CellBoundary cellToBoundary(H3Index cell) => _unsupported();
 
 // Inspection
 
+/// Returns the resolution (0–15) of the given H3 index.
 int getResolution(H3Index h) => _unsupported();
+
+/// Returns the base cell number (0–121) of the given H3 index.
 int getBaseCellNumber(H3Index h) => _unsupported();
+
+/// Returns whether [h] is a valid H3 cell index.
 bool isValidCell(H3Index h) => _unsupported();
+
+/// Returns whether [h] is any valid H3 index (cell, edge, or vertex).
 bool isValidIndex(H3Index h) => _unsupported();
+
+/// Returns whether [h] is a pentagon cell.
 bool isPentagon(H3Index h) => _unsupported();
+
+/// Returns whether [h] has Class III resolution orientation.
 bool isResClassIII(H3Index h) => _unsupported();
+
+/// Returns the icosahedron face(s) that the given cell intersects.
 List<int> getIcosahedronFaces(H3Index h) => _unsupported();
+
+/// Returns whether [edge] is a valid H3 directed edge index.
 bool isValidDirectedEdge(H3Index edge) => _unsupported();
+
+/// Returns whether [vertex] is a valid H3 vertex index.
 bool isValidVertex(H3Index vertex) => _unsupported();
+
+/// Returns the direction digit at the given [resolution] for index [h].
 int getIndexDigit(H3Index h, int resolution) => _unsupported();
+
+/// Constructs an H3 cell index from [res], [baseCellNumber], and direction
+/// [digits].
 H3Index constructCell(int res, int baseCellNumber, List<int> digits) =>
     _unsupported();
 
 // String conversion
 
+/// Parses a [hex] string into an [H3Index], throwing [H3Exception] on
+/// invalid input.
 H3Index stringToH3(String hex) => _unsupported();
+
+/// Returns the hex string representation of the given H3 index.
 String h3ToString(H3Index h) => _unsupported();
 
 // Traversal
 
+/// Returns all cells within [k] grid steps of [origin] (filled disk).
 List<H3Index> gridDisk(H3Index origin, int k) => _unsupported();
+
+/// Returns cells within [k] steps of [origin] mapped to their grid distance.
 Map<H3Index, int> gridDiskDistances(H3Index origin, int k) => _unsupported();
+
+/// Returns cells exactly [k] grid steps from [origin] (hollow ring).
 List<H3Index> gridRing(H3Index origin, int k) => _unsupported();
+
+/// Returns the minimum grid distance between [origin] and [destination].
 int gridDistance(H3Index origin, H3Index destination) => _unsupported();
+
+/// Returns the cells along the shortest grid path from [start] to [end].
 List<H3Index> gridPathCells(H3Index start, H3Index end) => _unsupported();
 
 // Hierarchy
 
+/// Returns the parent cell of [cell] at the coarser [parentRes].
 H3Index cellToParent(H3Index cell, int parentRes) => _unsupported();
+
+/// Returns the children of [cell] at the finer [childRes].
 List<H3Index> cellToChildren(H3Index cell, int childRes) => _unsupported();
+
+/// Returns the center child of [cell] at the finer [childRes].
 H3Index cellToCenterChild(H3Index cell, int childRes) => _unsupported();
+
+/// Returns the position of [child] within its parent at [parentRes].
 int cellToChildPos(H3Index child, int parentRes) => _unsupported();
+
+/// Returns the child cell at [childPos] within [parent] at [childRes].
 H3Index childPosToCell(int childPos, H3Index parent, int childRes) =>
     _unsupported();
+
+/// Compacts a set of [cells] by replacing complete groups with their parent.
 List<H3Index> compactCells(List<H3Index> cells) => _unsupported();
+
+/// Expands compacted [cells] to the given [resolution].
 List<H3Index> uncompactCells(List<H3Index> cells, int resolution) =>
     _unsupported();
 
 // Directed edges
 
+/// Returns whether [origin] and [destination] share an edge.
 bool areNeighborCells(H3Index origin, H3Index destination) => _unsupported();
+
+/// Returns the directed edge from [origin] to [destination].
 H3Index cellsToDirectedEdge(H3Index origin, H3Index destination) =>
     _unsupported();
+
+/// Returns the origin cell of the directed [edge].
 H3Index getDirectedEdgeOrigin(H3Index edge) => _unsupported();
+
+/// Returns the destination cell of the directed [edge].
 H3Index getDirectedEdgeDestination(H3Index edge) => _unsupported();
+
+/// Returns the origin and destination cells of the directed [edge].
 List<H3Index> directedEdgeToCells(H3Index edge) => _unsupported();
+
+/// Returns all directed edges originating from [origin].
 List<H3Index> originToDirectedEdges(H3Index origin) => _unsupported();
+
+/// Returns the boundary vertices of the directed [edge].
 CellBoundary directedEdgeToBoundary(H3Index edge) => _unsupported();
 
 // Vertices
 
+/// Returns the vertex at index [vertexNum] (0–5) of the [cell].
 H3Index cellToVertex(H3Index cell, int vertexNum) => _unsupported();
+
+/// Returns all vertices of the given [cell].
 List<H3Index> cellToVertexes(H3Index cell) => _unsupported();
+
+/// Returns the coordinates of the given [vertex].
 LatLng vertexToLatLng(H3Index vertex) => _unsupported();
 
 // Measurements
 
+/// Returns the great-circle distance between [a] and [b] in kilometers.
 double greatCircleDistanceKm(LatLng a, LatLng b) => _unsupported();
+
+/// Returns the great-circle distance between [a] and [b] in meters.
 double greatCircleDistanceM(LatLng a, LatLng b) => _unsupported();
+
+/// Returns the exact area of the [cell] in km².
 double cellAreaKm2(H3Index cell) => _unsupported();
+
+/// Returns the exact area of the [cell] in m².
 double cellAreaM2(H3Index cell) => _unsupported();
+
+/// Returns the exact length of the directed [edge] in kilometers.
 double edgeLengthKm(H3Index edge) => _unsupported();
+
+/// Returns the exact length of the directed [edge] in meters.
 double edgeLengthM(H3Index edge) => _unsupported();
+
+/// Returns the average hexagon area in km² at the given [resolution].
 double getHexagonAreaAvgKm2(int resolution) => _unsupported();
+
+/// Returns the average hexagon area in m² at the given [resolution].
 double getHexagonAreaAvgM2(int resolution) => _unsupported();
+
+/// Returns the average hexagon edge length in km at the given [resolution].
 double getHexagonEdgeLengthAvgKm(int resolution) => _unsupported();
+
+/// Returns the average hexagon edge length in meters at the given
+/// [resolution].
 double getHexagonEdgeLengthAvgM(int resolution) => _unsupported();
+
+/// Returns the total number of cells at the given [resolution].
 int getNumCells(int resolution) => _unsupported();
 
 // Coordinate systems
 
+/// Converts [cell] to local IJ coordinates relative to [origin].
 CoordIJ cellToLocalIj(H3Index origin, H3Index cell) => _unsupported();
+
+/// Converts local [ij] coordinates relative to [origin] back to an H3 cell.
 H3Index localIjToCell(H3Index origin, CoordIJ ij) => _unsupported();
 
 // Regions
 
+/// Returns all cells whose centers are within the [polygon] at [resolution].
 List<H3Index> polygonToCells(GeoPolygon polygon, int resolution) =>
     _unsupported();
+
+/// Returns cells within the [polygon] using the specified containment [mode].
 List<H3Index> polygonToCellsExperimental(
   GeoPolygon polygon,
   int resolution, {
   ContainmentMode mode = ContainmentMode.center,
 }) => _unsupported();
+
+/// Returns the outlines of a set of [cells] as a GeoJSON-style
+/// multi-polygon.
 List<List<List<LatLng>>> cellsToMultiPolygon(List<H3Index> cells) =>
     _unsupported();
 
 // Utilities
 
+/// Returns the number of resolution-0 cells (always 122).
 int res0CellCount() => _unsupported();
+
+/// Returns all 122 resolution-0 cells.
 List<H3Index> getRes0Cells() => _unsupported();
+
+/// Returns the number of pentagons per resolution (always 12).
 int pentagonCount() => _unsupported();
+
+/// Returns all 12 pentagon cells at the given [resolution].
 List<H3Index> getPentagons(int resolution) => _unsupported();
 
 // Version
 
+/// Version constants for the h3_core package and the underlying H3 C library.
 abstract final class H3Version {
+  /// The h3_core Dart package version.
   static const String package = '1.0.1';
+
+  /// The H3 C library version string.
   static const String native = '4.4.1';
+
+  /// The H3 C library major version.
   static const int major = 4;
+
+  /// The H3 C library minor version.
   static const int minor = 4;
+
+  /// The H3 C library patch version.
   static const int patch = 1;
 }
 
 // Async wrappers
 
+/// Async version of [polygonToCells]; runs on an isolate on native platforms.
 Future<List<H3Index>> polygonToCellsAsync(GeoPolygon polygon, int resolution) =>
     _unsupported();
 
+/// Async version of [gridDisk]; runs on an isolate on native platforms.
 Future<List<H3Index>> gridDiskAsync(H3Index origin, int k) => _unsupported();
+
+/// Async version of [compactCells]; runs on an isolate on native platforms.
 Future<List<H3Index>> compactCellsAsync(List<H3Index> cells) => _unsupported();
+
+/// Async version of [uncompactCells]; runs on an isolate on native platforms.
 Future<List<H3Index>> uncompactCellsAsync(
   List<H3Index> cells,
   int resolution,
diff --git a/lib/src/h3_web.dart b/lib/src/h3_web.dart
index 166318b..240375d 100644
--- a/lib/src/h3_web.dart
+++ b/lib/src/h3_web.dart
@@ -54,6 +54,8 @@ T _catchJsError<T>(T Function() fn) {
 
 // Indexing
 
+/// Converts a [latLng] coordinate to the H3 cell index at the given
+/// [resolution] (0–15).
 H3Index latLngToCell(LatLng latLng, int resolution) {
   return _catchJsError(() {
     final hex = js.h3.latLngToCell(
@@ -65,6 +67,7 @@ H3Index latLngToCell(LatLng latLng, int resolution) {
   });
 }
 
+/// Returns the center coordinate of the given H3 [cell].
 LatLng cellToLatLng(H3Index cell) {
   return _catchJsError(() {
     final arr = js.h3.cellToLatLng(_toJs(cell));
@@ -72,6 +75,7 @@ LatLng cellToLatLng(H3Index cell) {
   });
 }
 
+/// Returns the boundary vertices of the given H3 [cell].
 CellBoundary cellToBoundary(H3Index cell) {
   return _catchJsError(() {
     final arr = js.h3.cellToBoundary(_toJs(cell));
@@ -85,18 +89,23 @@ CellBoundary cellToBoundary(H3Index cell) {
 
 // Inspection
 
+/// Returns the resolution (0–15) of the given H3 index.
 int getResolution(H3Index h) {
   return _catchJsError(() => js.h3.getResolution(_toJs(h)).toDartInt);
 }
 
+/// Returns the base cell number (0–121) of the given H3 index.
 int getBaseCellNumber(H3Index h) {
   return _catchJsError(() => js.h3.getBaseCellNumber(_toJs(h)).toDartInt);
 }
 
+/// Returns whether [h] is a valid H3 cell index.
 bool isValidCell(H3Index h) {
   return _catchJsError(() => js.h3.isValidCell(_toJs(h)).toDart);
 }
 
+/// Returns whether [h] is any valid H3 index (cell, edge, or vertex).
+///
 /// Checks cell, edge, and vertex validity (h3-js has no single isValidIndex).
 bool isValidIndex(H3Index h) {
   final hex = _toJs(h);
@@ -105,14 +114,17 @@ bool isValidIndex(H3Index h) {
       js.h3.isValidVertex(hex).toDart;
 }
 
+/// Returns whether [h] is a pentagon cell.
 bool isPentagon(H3Index h) {
   return _catchJsError(() => js.h3.isPentagon(_toJs(h)).toDart);
 }
 
+/// Returns whether [h] has Class III resolution orientation.
 bool isResClassIII(H3Index h) {
   return _catchJsError(() => js.h3.isResClassIII(_toJs(h)).toDart);
 }
 
+/// Returns the icosahedron face(s) that the given cell intersects.
 List<int> getIcosahedronFaces(H3Index h) {
   return _catchJsError(() {
     final faces = js.h3.getIcosahedronFaces(_toJs(h));
@@ -120,15 +132,18 @@ List<int> getIcosahedronFaces(H3Index h) {
   });
 }
 
+/// Returns whether [edge] is a valid H3 directed edge index.
 bool isValidDirectedEdge(H3Index edge) {
   return _catchJsError(() => js.h3.isValidDirectedEdge(_toJs(edge)).toDart);
 }
 
+/// Returns whether [vertex] is a valid H3 vertex index.
 bool isValidVertex(H3Index vertex) {
   return _catchJsError(() => js.h3.isValidVertex(_toJs(vertex)).toDart);
 }
 
-/// Extracts the direction digit at [resolution] from [h].
+/// Returns the direction digit at the given [resolution] for index [h].
+///
 /// Uses BigInt since h3-js doesn't expose this and JS can't do 64-bit bit ops.
 int getIndexDigit(H3Index h, int resolution) {
   final bigInt = BigInt.parse(h.toHex(), radix: 16);
@@ -136,7 +151,9 @@ int getIndexDigit(H3Index h, int resolution) {
   return ((bigInt >> shift) & BigInt.from(0x7)).toInt();
 }
 
-/// Builds an H3 cell from resolution, base cell, and direction digits.
+/// Constructs an H3 cell index from [res], [baseCellNumber], and direction
+/// [digits].
+///
 /// Uses BigInt for the same reason as [getIndexDigit].
 H3Index constructCell(int res, int baseCellNumber, List<int> digits) {
   var value = BigInt.zero;
@@ -157,6 +174,8 @@ H3Index constructCell(int res, int baseCellNumber, List<int> digits) {
 
 // String conversion
 
+/// Parses a [hex] string into an [H3Index], throwing [H3Exception] on
+/// invalid input.
 H3Index stringToH3(String hex) {
   final h = H3Index.parse(hex);
   if (!isValidIndex(h)) {
@@ -165,10 +184,12 @@ H3Index stringToH3(String hex) {
   return h;
 }
 
+/// Returns the hex string representation of the given H3 index.
 String h3ToString(H3Index h) => h.toHex();
 
 // Traversal
 
+/// Returns all cells within [k] grid steps of [origin] (filled disk).
 List<H3Index> gridDisk(H3Index origin, int k) {
   return _catchJsError(() {
     final cells = js.h3.gridDisk(_toJs(origin), k.toJS);
@@ -176,6 +197,7 @@ List<H3Index> gridDisk(H3Index origin, int k) {
   });
 }
 
+/// Returns cells within [k] steps of [origin] mapped to their grid distance.
 Map<H3Index, int> gridDiskDistances(H3Index origin, int k) {
   return _catchJsError(() {
     final rings = js.h3.gridDiskDistances(_toJs(origin), k.toJS);
@@ -190,6 +212,7 @@ Map<H3Index, int> gridDiskDistances(H3Index origin, int k) {
   });
 }
 
+/// Returns cells exactly [k] grid steps from [origin] (hollow ring).
 List<H3Index> gridRing(H3Index origin, int k) {
   return _catchJsError(() {
     final cells = js.h3.gridRingUnsafe(_toJs(origin), k.toJS);
@@ -197,12 +220,14 @@ List<H3Index> gridRing(H3Index origin, int k) {
   });
 }
 
+/// Returns the minimum grid distance between [origin] and [destination].
 int gridDistance(H3Index origin, H3Index destination) {
   return _catchJsError(() {
     return js.h3.gridDistance(_toJs(origin), _toJs(destination)).toDartInt;
   });
 }
 
+/// Returns the cells along the shortest grid path from [start] to [end].
 List<H3Index> gridPathCells(H3Index start, H3Index end) {
   return _catchJsError(() {
     final cells = js.h3.gridPathCells(_toJs(start), _toJs(end));
@@ -212,12 +237,14 @@ List<H3Index> gridPathCells(H3Index start, H3Index end) {
 
 // Hierarchy
 
+/// Returns the parent cell of [cell] at the coarser [parentRes].
 H3Index cellToParent(H3Index cell, int parentRes) {
   return _catchJsError(() {
     return _fromJs(js.h3.cellToParent(_toJs(cell), parentRes.toJS));
   });
 }
 
+/// Returns the children of [cell] at the finer [childRes].
 List<H3Index> cellToChildren(H3Index cell, int childRes) {
   return _catchJsError(() {
     final children = js.h3.cellToChildren(_toJs(cell), childRes.toJS);
@@ -225,18 +252,21 @@ List<H3Index> cellToChildren(H3Index cell, int childRes) {
   });
 }
 
+/// Returns the center child of [cell] at the finer [childRes].
 H3Index cellToCenterChild(H3Index cell, int childRes) {
   return _catchJsError(() {
     return _fromJs(js.h3.cellToCenterChild(_toJs(cell), childRes.toJS));
   });
 }
 
+/// Returns the position of [child] within its parent at [parentRes].
 int cellToChildPos(H3Index child, int parentRes) {
   return _catchJsError(() {
     return js.h3.cellToChildPos(_toJs(child), parentRes.toJS).toDartInt;
   });
 }
 
+/// Returns the child cell at [childPos] within [parent] at [childRes].
 H3Index childPosToCell(int childPos, H3Index parent, int childRes) {
   return _catchJsError(() {
     return _fromJs(
@@ -245,6 +275,7 @@ H3Index childPosToCell(int childPos, H3Index parent, int childRes) {
   });
 }
 
+/// Compacts a set of [cells] by replacing complete groups with their parent.
 List<H3Index> compactCells(List<H3Index> cells) {
   return _catchJsError(() {
     final jsArr = <JSString>[for (final c in cells) _toJs(c)].toJS;
@@ -253,6 +284,7 @@ List<H3Index> compactCells(List<H3Index> cells) {
   });
 }
 
+/// Expands compacted [cells] to the given [resolution].
 List<H3Index> uncompactCells(List<H3Index> cells, int resolution) {
   return _catchJsError(() {
     final jsArr = <JSString>[for (final c in cells) _toJs(c)].toJS;
@@ -263,12 +295,14 @@ List<H3Index> uncompactCells(List<H3Index> cells, int resolution) {
 
 // Directed edges
 
+/// Returns whether [origin] and [destination] share an edge.
 bool areNeighborCells(H3Index origin, H3Index destination) {
   return _catchJsError(() {
     return js.h3.areNeighborCells(_toJs(origin), _toJs(destination)).toDart;
   });
 }
 
+/// Returns the directed edge from [origin] to [destination].
 H3Index cellsToDirectedEdge(H3Index origin, H3Index destination) {
   return _catchJsError(() {
     return _fromJs(
@@ -277,18 +311,21 @@ H3Index cellsToDirectedEdge(H3Index origin, H3Index destination) {
   });
 }
 
+/// Returns the origin cell of the directed [edge].
 H3Index getDirectedEdgeOrigin(H3Index edge) {
   return _catchJsError(() {
     return _fromJs(js.h3.getDirectedEdgeOrigin(_toJs(edge)));
   });
 }
 
+/// Returns the destination cell of the directed [edge].
 H3Index getDirectedEdgeDestination(H3Index edge) {
   return _catchJsError(() {
     return _fromJs(js.h3.getDirectedEdgeDestination(_toJs(edge)));
   });
 }
 
+/// Returns the origin and destination cells of the directed [edge].
 List<H3Index> directedEdgeToCells(H3Index edge) {
   return _catchJsError(() {
     final cells = js.h3.directedEdgeToCells(_toJs(edge));
@@ -296,6 +333,7 @@ List<H3Index> directedEdgeToCells(H3Index edge) {
   });
 }
 
+/// Returns all directed edges originating from [origin].
 List<H3Index> originToDirectedEdges(H3Index origin) {
   return _catchJsError(() {
     final edges = js.h3.originToDirectedEdges(_toJs(origin));
@@ -303,6 +341,7 @@ List<H3Index> originToDirectedEdges(H3Index origin) {
   });
 }
 
+/// Returns the boundary vertices of the directed [edge].
 CellBoundary directedEdgeToBoundary(H3Index edge) {
   return _catchJsError(() {
     final arr = js.h3.directedEdgeToBoundary(_toJs(edge));
@@ -316,12 +355,14 @@ CellBoundary directedEdgeToBoundary(H3Index edge) {
 
 // Vertices
 
+/// Returns the vertex at index [vertexNum] (0–5) of the [cell].
 H3Index cellToVertex(H3Index cell, int vertexNum) {
   return _catchJsError(() {
     return _fromJs(js.h3.cellToVertex(_toJs(cell), vertexNum.toJS));
   });
 }
 
+/// Returns all vertices of the given [cell].
 List<H3Index> cellToVertexes(H3Index cell) {
   return _catchJsError(() {
     final verts = js.h3.cellToVertexes(_toJs(cell));
@@ -329,6 +370,7 @@ List<H3Index> cellToVertexes(H3Index cell) {
   });
 }
 
+/// Returns the coordinates of the given [vertex].
 LatLng vertexToLatLng(H3Index vertex) {
   return _catchJsError(() {
     final arr = js.h3.vertexToLatLng(_toJs(vertex));
@@ -338,6 +380,7 @@ LatLng vertexToLatLng(H3Index vertex) {
 
 // Measurements
 
+/// Returns the great-circle distance between [a] and [b] in kilometers.
 double greatCircleDistanceKm(LatLng a, LatLng b) {
   return _catchJsError(() {
     return js.h3
@@ -350,6 +393,7 @@ double greatCircleDistanceKm(LatLng a, LatLng b) {
   });
 }
 
+/// Returns the great-circle distance between [a] and [b] in meters.
 double greatCircleDistanceM(LatLng a, LatLng b) {
   return _catchJsError(() {
     return js.h3
@@ -358,42 +402,49 @@ double greatCircleDistanceM(LatLng a, LatLng b) {
   });
 }
 
+/// Returns the exact area of the [cell] in km².
 double cellAreaKm2(H3Index cell) {
   return _catchJsError(() {
     return js.h3.cellArea(_toJs(cell), 'km2'.toJS).toDartDouble;
   });
 }
 
+/// Returns the exact area of the [cell] in m².
 double cellAreaM2(H3Index cell) {
   return _catchJsError(() {
     return js.h3.cellArea(_toJs(cell), 'm2'.toJS).toDartDouble;
   });
 }
 
+/// Returns the exact length of the directed [edge] in kilometers.
 double edgeLengthKm(H3Index edge) {
   return _catchJsError(() {
     return js.h3.edgeLength(_toJs(edge), 'km'.toJS).toDartDouble;
   });
 }
 
+/// Returns the exact length of the directed [edge] in meters.
 double edgeLengthM(H3Index edge) {
   return _catchJsError(() {
     return js.h3.edgeLength(_toJs(edge), 'm'.toJS).toDartDouble;
   });
 }
 
+/// Returns the average hexagon area in km² at the given [resolution].
 double getHexagonAreaAvgKm2(int resolution) {
   return _catchJsError(() {
     return js.h3.getHexagonAreaAvg(resolution.toJS, 'km2'.toJS).toDartDouble;
   });
 }
 
+/// Returns the average hexagon area in m² at the given [resolution].
 double getHexagonAreaAvgM2(int resolution) {
   return _catchJsError(() {
     return js.h3.getHexagonAreaAvg(resolution.toJS, 'm2'.toJS).toDartDouble;
   });
 }
 
+/// Returns the average hexagon edge length in km at the given [resolution].
 double getHexagonEdgeLengthAvgKm(int resolution) {
   return _catchJsError(() {
     return js.h3
@@ -402,6 +453,8 @@ double getHexagonEdgeLengthAvgKm(int resolution) {
   });
 }
 
+/// Returns the average hexagon edge length in meters at the given
+/// [resolution].
 double getHexagonEdgeLengthAvgM(int resolution) {
   return _catchJsError(() {
     return js.h3
@@ -410,6 +463,7 @@ double getHexagonEdgeLengthAvgM(int resolution) {
   });
 }
 
+/// Returns the total number of cells at the given [resolution].
 int getNumCells(int resolution) {
   return _catchJsError(() {
     return js.h3.getNumCells(resolution.toJS).toDartInt;
@@ -418,6 +472,7 @@ int getNumCells(int resolution) {
 
 // Coordinate systems
 
+/// Converts [cell] to local IJ coordinates relative to [origin].
 CoordIJ cellToLocalIj(H3Index origin, H3Index cell) {
   return _catchJsError(() {
     final ij = js.h3.cellToLocalIj(_toJs(origin), _toJs(cell));
@@ -425,6 +480,7 @@ CoordIJ cellToLocalIj(H3Index origin, H3Index cell) {
   });
 }
 
+/// Converts local [ij] coordinates relative to [origin] back to an H3 cell.
 H3Index localIjToCell(H3Index origin, CoordIJ ij) {
   return _catchJsError(() {
     final jsIj = js.CoordIJJsLiteral(i: ij.i, j: ij.j);
@@ -434,6 +490,7 @@ H3Index localIjToCell(H3Index origin, CoordIJ ij) {
 
 // Regions
 
+/// Returns all cells whose centers are within the [polygon] at [resolution].
 List<H3Index> polygonToCells(GeoPolygon polygon, int resolution) {
   return _catchJsError(() {
     final coords = _geoPolygonToJsCoords(polygon);
@@ -442,6 +499,8 @@ List<H3Index> polygonToCells(GeoPolygon polygon, int resolution) {
   });
 }
 
+/// Returns cells within the [polygon] using the specified containment [mode].
+///
 /// Only [ContainmentMode.center] is supported on web (h3-js v4 limitation).
 List<H3Index> polygonToCellsExperimental(
   GeoPolygon polygon,
@@ -457,6 +516,8 @@ List<H3Index> polygonToCellsExperimental(
   );
 }
 
+/// Returns the outlines of a set of [cells] as a GeoJSON-style
+/// multi-polygon.
 List<List<List<LatLng>>> cellsToMultiPolygon(List<H3Index> cells) {
   return _catchJsError(() {
     final jsArr = <JSString>[for (final c in cells) _toJs(c)].toJS;
@@ -496,8 +557,10 @@ JSAny _geoPolygonToJsCoords(GeoPolygon polygon) {
 
 // Utilities
 
+/// Returns the number of resolution-0 cells (always 122).
 int res0CellCount() => 122;
 
+/// Returns all 122 resolution-0 cells.
 List<H3Index> getRes0Cells() {
   return _catchJsError(() {
     final cells = js.h3.getRes0Cells();
@@ -505,8 +568,10 @@ List<H3Index> getRes0Cells() {
   });
 }
 
+/// Returns the number of pentagons per resolution (always 12).
 int pentagonCount() => 12;
 
+/// Returns all 12 pentagon cells at the given [resolution].
 List<H3Index> getPentagons(int resolution) {
   return _catchJsError(() {
     final cells = js.h3.getPentagons(resolution.toJS);
@@ -514,16 +579,27 @@ List<H3Index> getPentagons(int resolution) {
   });
 }
 
+/// Version constants for the h3_core package and the underlying H3 C library.
 abstract final class H3Version {
+  /// The h3_core Dart package version.
   static const String package = '1.0.1';
+
+  /// The H3 C library version string.
   static const String native = '4.4.1';
+
+  /// The H3 C library major version.
   static const int major = 4;
+
+  /// The H3 C library minor version.
   static const int minor = 4;
+
+  /// The H3 C library patch version.
   static const int patch = 1;
 }
 
 // Async — on web h3-js is sync, so these just wrap in a future.
 
+/// Async version of [polygonToCells]; wraps in a future on web.
 Future<List<H3Index>> polygonToCellsAsync(
   GeoPolygon polygon,
   int resolution,
@@ -531,14 +607,17 @@ Future<List<H3Index>> polygonToCellsAsync(
   return polygonToCells(polygon, resolution);
 }
 
+/// Async version of [gridDisk]; wraps in a future on web.
 Future<List<H3Index>> gridDiskAsync(H3Index origin, int k) async {
   return gridDisk(origin, k);
 }
 
+/// Async version of [compactCells]; wraps in a future on web.
 Future<List<H3Index>> compactCellsAsync(List<H3Index> cells) async {
   return compactCells(cells);
 }
 
+/// Async version of [uncompactCells]; wraps in a future on web.
 Future<List<H3Index>> uncompactCellsAsync(
   List<H3Index> cells,
   int resolution,
diff --git a/lib/src/models/cell_boundary.dart b/lib/src/models/cell_boundary.dart
index d6d2d49..6bffb90 100644
--- a/lib/src/models/cell_boundary.dart
+++ b/lib/src/models/cell_boundary.dart
@@ -1,9 +1,11 @@
 import 'lat_lng.dart';
 
-/// Cell boundary as a list of vertices in degrees.
+/// Cell boundary as an ordered list of vertices in degrees.
 class CellBoundary {
+  /// The boundary vertices in order. Typically 6 for hexagons, 5 for pentagons.
   final List<LatLng> vertices;
 
+  /// Creates a [CellBoundary] from an ordered list of [vertices].
   const CellBoundary(this.vertices);
 
   @override
diff --git a/lib/src/models/coord_ij.dart b/lib/src/models/coord_ij.dart
index 639f344..de5f973 100644
--- a/lib/src/models/coord_ij.dart
+++ b/lib/src/models/coord_ij.dart
@@ -1,8 +1,15 @@
-/// IJ coordinates for local coordinate operations.
+/// Local IJ coordinate pair for grid-local coordinate operations.
+///
+/// IJ coordinates are a 2D coordinate system anchored at a given origin cell,
+/// useful for local grid traversal and distance calculations.
 class CoordIJ {
+  /// The I (column) coordinate.
   final int i;
+
+  /// The J (row) coordinate.
   final int j;
 
+  /// Creates a [CoordIJ] with the given [i] and [j] coordinates.
   const CoordIJ(this.i, this.j);
 
   @override
diff --git a/lib/src/models/geo_polygon.dart b/lib/src/models/geo_polygon.dart
index 05f4883..7d71fa1 100644
--- a/lib/src/models/geo_polygon.dart
+++ b/lib/src/models/geo_polygon.dart
@@ -15,10 +15,15 @@ enum ContainmentMode {
   overlappingBbox,
 }
 
-/// Polygon for region operations.
+/// Polygon defined by an exterior ring and optional holes, for region
+/// operations such as [polygonToCells].
 class GeoPolygon {
+  /// The exterior ring of the polygon as a list of coordinates.
   final List<LatLng> exterior;
+
+  /// Optional interior rings (holes) to exclude from the polygon.
   final List<List<LatLng>> holes;
 
+  /// Creates a [GeoPolygon] with an [exterior] ring and optional [holes].
   const GeoPolygon(this.exterior, [this.holes = const []]);
 }
diff --git a/lib/src/models/h3_index.dart b/lib/src/models/h3_index.dart
index 75e20cc..349d793 100644
--- a/lib/src/models/h3_index.dart
+++ b/lib/src/models/h3_index.dart
@@ -1,11 +1,18 @@
-/// H3 cell/edge/vertex index stored as a hex string.
+/// H3 cell, directed edge, or vertex index stored as a hex string.
 ///
-/// String-backed to avoid JS number precision loss (H3 indexes are 64-bit,
-/// JS doubles only hold 53 bits exactly).
+/// Backed by a [String] rather than [int] to avoid precision loss on the
+/// web platform — H3 indexes are 64-bit integers, but JavaScript doubles
+/// only hold 53 bits of integer precision.
 extension type const H3Index(String _hex) {
+  /// Creates an [H3Index] from a 64-bit integer value.
   factory H3Index.fromInt(int value) => H3Index(value.toRadixString(16));
+
+  /// Parses a hex string into an [H3Index], normalising to lower case.
   factory H3Index.parse(String hex) => H3Index(hex.toLowerCase());
 
+  /// Returns the 64-bit integer value of this index.
   int toInt() => int.parse(_hex, radix: 16);
+
+  /// Returns the lowercase hex string representation of this index.
   String toHex() => _hex;
 }
diff --git a/lib/src/models/lat_lng.dart b/lib/src/models/lat_lng.dart
index a0bcadc..a715e95 100644
--- a/lib/src/models/lat_lng.dart
+++ b/lib/src/models/lat_lng.dart
@@ -1,8 +1,12 @@
-/// Latitude/longitude in degrees.
+/// Latitude/longitude coordinate pair in degrees.
 class LatLng {
+  /// Latitude in degrees, from -90 to 90.
   final double lat;
+
+  /// Longitude in degrees, from -180 to 180.
   final double lng;
 
+  /// Creates a coordinate from [lat] and [lng] in degrees.
   const LatLng(this.lat, this.lng);
 
   @override