diff --git a/src/browser/js/Local.zig b/src/browser/js/Local.zig
index bc4f6d7ca..ad4ab25db 100644
--- a/src/browser/js/Local.zig
+++ b/src/browser/js/Local.zig
@@ -82,6 +82,18 @@ pub fn newObject(self: *const Local) js.Object {
     };
 }
 
+pub fn newDate(self: *const Local, time_ms: f64) !js.Value {
+    const handle = v8.v8__Date__New(self.handle, time_ms) orelse return error.JsException;
+    return .{ .local = self, .handle = handle };
+}
+
+pub fn newNumber(self: *const Local, f: f64) !js.Value {
+    return .{
+        .local = self,
+        .handle = self.isolate.initNumber(f).handle,
+    };
+}
+
 pub fn newArray(self: *const Local, len: u32) js.Array {
     return .{
         .local = self,
diff --git a/src/browser/js/Value.zig b/src/browser/js/Value.zig
index 3669448f6..9a2a5cb73 100644
--- a/src/browser/js/Value.zig
+++ b/src/browser/js/Value.zig
@@ -126,6 +126,10 @@ pub fn isArrayBuffer(self: Value) bool {
     return v8.v8__Value__IsArrayBuffer(self.handle);
 }
 
+pub fn isDate(self: Value) bool {
+    return v8.v8__Value__IsDate(self.handle);
+}
+
 pub fn isUint8Array(self: Value) bool {
     return v8.v8__Value__IsUint8Array(self.handle);
 }
diff --git a/src/browser/tests/indexeddb.html b/src/browser/tests/indexeddb.html
index 1c818a6eb..b8d8d4cae 100644
--- a/src/browser/tests/indexeddb.html
+++ b/src/browser/tests/indexeddb.html
@@ -187,6 +187,89 @@
 }
 </script>
 
+<!-- cmp across the full key-type ordering (number < string < binary < array)
+     plus array element-wise comparison and prefix rules. -->
+<script id="cmp_key_types" type=module>
+{
+    // Cross-type ordering.
+    testing.expectEqual(-1, indexedDB.cmp(42, "42"));             // number < string
+    testing.expectEqual(-1, indexedDB.cmp("z", new Uint8Array([0]))); // string < binary
+    testing.expectEqual(-1, indexedDB.cmp(new Uint8Array([255]), [0])); // binary < array
+
+    // Arrays compare element-wise; a shorter prefix sorts first.
+    testing.expectEqual(-1, indexedDB.cmp([1], [1, 2]));
+    testing.expectEqual(1, indexedDB.cmp([1, 2], [1, 1]));
+    testing.expectEqual(0, indexedDB.cmp([1, "a"], [1, "a"]));
+    testing.expectEqual(-1, indexedDB.cmp([1, [2]], [1, [3]])); // nested
+
+    // Binary keys compare by byte value.
+    testing.expectEqual(-1, indexedDB.cmp(new Uint8Array([1, 2]), new Uint8Array([1, 3])));
+
+    // Invalid keys (boolean, null, NaN) are DataErrors.
+    for (const bad of [true, null, NaN, {}]) {
+        let threw = null;
+        try { indexedDB.cmp(1, bad); } catch (e) { threw = e; }
+        testing.expectEqual("DataError", threw && threw.name);
+    }
+}
+</script>
+
+<!-- Array and binary values can be used as object-store keys and round-trip
+     through get(). -->
+<script id="array_binary_keys" type=module>
+{
+    const state = await testing.async();
+    const open = indexedDB.open("akeys-db", 1);
+    open.onupgradeneeded = (e) => e.target.result.createObjectStore("s");
+    open.onsuccess = (e) => {
+        const tx = e.target.result.transaction("s", "readwrite");
+        const store = tx.objectStore("s");
+        store.add("composite", ["a", 1]);
+        store.add("blob", new Uint8Array([1, 2, 3]));
+
+        const g1 = store.get(["a", 1]);
+        const g2 = store.get(new Uint8Array([1, 2, 3]));
+        g2.onsuccess = () => state.resolve({ composite: g1.result, blob: g2.result });
+    };
+    await state.done((got) => {
+        testing.expectEqual("composite", got.composite);
+        testing.expectEqual("blob", got.blob);
+    });
+}
+</script>
+
+<!-- Date values are keys (number < date < string), round-trip through get(),
+     and getKey/cursor decode them back to Date objects. An invalid Date is a
+     DataError. -->
+<script id="date_keys" type=module>
+{
+    testing.expectEqual(-1, indexedDB.cmp(42, new Date(0)));      // number < date
+    testing.expectEqual(-1, indexedDB.cmp(new Date(1), "a"));     // date < string
+    testing.expectEqual(-1, indexedDB.cmp(new Date(1), new Date(2)));
+
+    let threw = null;
+    try { indexedDB.cmp(1, new Date(NaN)); } catch (e) { threw = e; }
+    testing.expectEqual("DataError", threw && threw.name);
+
+    const state = await testing.async();
+    const open = indexedDB.open("date-db", 1);
+    open.onupgradeneeded = (e) => e.target.result.createObjectStore("s");
+    open.onsuccess = (e) => {
+        const store = e.target.result.transaction("s", "readwrite").objectStore("s");
+        const when = new Date(1700000000000);
+        store.add("event", when);
+        const g = store.get(when);
+        const k = store.getKey(when);
+        k.onsuccess = () => state.resolve({ value: g.result, key: k.result });
+    };
+    await state.done((got) => {
+        testing.expectEqual("event", got.value);
+        testing.expectEqual(true, got.key instanceof Date);
+        testing.expectEqual(1700000000000, got.key.getTime());
+    });
+}
+</script>
+
 <!-- During upgradeneeded, request.transaction is the versionchange transaction;
      a store created in the upgrade belongs to it and seeded data persists. -->
 <script id="request_transaction" type=module>
@@ -307,6 +390,248 @@
 }
 </script>
 
+<!-- In-line keys: a store with a keyPath extracts the key from the value, and
+     an explicit key argument is a DataError. -->
+<script id="inline_keys" type=module>
+{
+    const state = await testing.async();
+    const open = indexedDB.open("inline-db", 1);
+    open.onupgradeneeded = (e) => e.target.result.createObjectStore("books", { keyPath: "isbn" });
+    open.onsuccess = (e) => {
+        const tx = e.target.result.transaction("books", "readwrite");
+        const store = tx.objectStore("books");
+        testing.expectEqual("isbn", store.keyPath);
+        testing.expectEqual(false, store.autoIncrement);
+
+        store.add({ isbn: "111", title: "A" });
+
+        // Supplying an explicit key to an in-line store throws DataError.
+        let threw = null;
+        try { store.add({ isbn: "222" }, "extra"); } catch (err) { threw = err; }
+
+        const g = store.get("111");
+        g.onsuccess = () => state.resolve({ title: g.result.title, threw: threw && threw.name });
+    };
+    await state.done((got) => {
+        testing.expectEqual("A", got.title);
+        testing.expectEqual("DataError", got.threw);
+    });
+}
+</script>
+
+<!-- Nested key path "a.b" extracts a key from a nested property. -->
+<script id="nested_keypath" type=module>
+{
+    const state = await testing.async();
+    const open = indexedDB.open("nested-db", 1);
+    open.onupgradeneeded = (e) => e.target.result.createObjectStore("s", { keyPath: "id.value" });
+    open.onsuccess = (e) => {
+        const store = e.target.result.transaction("s", "readwrite").objectStore("s");
+        store.add({ id: { value: 7 }, name: "deep" });
+        const g = store.get(7);
+        g.onsuccess = () => state.resolve(g.result && g.result.name);
+    };
+    await state.done((name) => testing.expectEqual("deep", name));
+}
+</script>
+
+<!-- autoIncrement generates keys for out-of-line stores, returns the key from
+     add(), and the generator advances past an explicitly supplied higher key. -->
+<script id="auto_increment" type=module>
+{
+    const state = await testing.async();
+    const open = indexedDB.open("autoinc-db", 1);
+    open.onupgradeneeded = (e) => e.target.result.createObjectStore("s", { autoIncrement: true });
+    open.onsuccess = (e) => {
+        const store = e.target.result.transaction("s", "readwrite").objectStore("s");
+        const a = store.add("first");   // key 1
+        const b = store.add("second");  // key 2
+        store.add("tenth", 10);         // explicit key bumps the generator
+        const c = store.add("eleventh"); // key 11
+        c.onsuccess = () => state.resolve({ a: a.result, b: b.result, c: c.result });
+    };
+    await state.done((got) => {
+        testing.expectEqual(1, got.a);
+        testing.expectEqual(2, got.b);
+        testing.expectEqual(11, got.c);
+    });
+}
+</script>
+
+<!-- autoIncrement with a key path injects the generated key back into the
+     stored value. -->
+<script id="auto_increment_inline" type=module>
+{
+    const state = await testing.async();
+    const open = indexedDB.open("autoinc-inline-db", 1);
+    open.onupgradeneeded = (e) => e.target.result.createObjectStore("s", { keyPath: "id", autoIncrement: true });
+    open.onsuccess = (e) => {
+        const store = e.target.result.transaction("s", "readwrite").objectStore("s");
+        const r = store.add({ name: "auto" });
+        r.onsuccess = () => {
+            const g = store.get(r.result);
+            g.onsuccess = () => state.resolve({ key: r.result, stored: g.result });
+        };
+    };
+    await state.done((got) => {
+        testing.expectEqual(1, got.key);
+        testing.expectEqual(1, got.stored.id); // injected
+        testing.expectEqual("auto", got.stored.name);
+    });
+}
+</script>
+
+<!-- autoIncrement with a nested keyPath: a missing intermediate is created and
+     the key injected; a non-object intermediate is a DataError (and must not
+     consume a generated key). -->
+<script id="auto_increment_nested" type=module>
+{
+    const state = await testing.async();
+    const open = indexedDB.open("autoinc-nested-db", 1);
+    open.onupgradeneeded = (e) => e.target.result.createObjectStore("s", { keyPath: "a.b", autoIncrement: true });
+    open.onsuccess = (e) => {
+        const store = e.target.result.transaction("s", "readwrite").objectStore("s");
+
+        const r1 = store.add({ name: "x" });          // a.b missing -> create + inject key 1
+
+        // a is a primitive: the key cannot be injected -> DataError, no key consumed.
+        let threw = null;
+        try { store.add({ a: 5 }); } catch (err) { threw = err; }
+
+        const r2 = store.add({ name: "y" });          // still key 2, generator not bumped
+        r2.onsuccess = () => {
+            const g = store.get(r1.result);
+            g.onsuccess = () => state.resolve({
+                k1: r1.result, k2: r2.result, threw: threw && threw.name, stored: g.result,
+            });
+        };
+    };
+    await state.done((got) => {
+        testing.expectEqual(1, got.k1);
+        testing.expectEqual("DataError", got.threw);
+        testing.expectEqual(2, got.k2); // failed add did not consume key 2
+        testing.expectEqual(1, got.stored.a.b); // injected into a created nested object
+    });
+}
+</script>
+
+<!-- getKey returns the primary key (or undefined); getAllKeys returns every
+     key in order. -->
+<script id="get_key_all_keys" type=module>
+{
+    const state = await testing.async();
+    const open = indexedDB.open("getkey-db", 1);
+    open.onupgradeneeded = (e) => {
+        const s = e.target.result.createObjectStore("s");
+        s.add("a", 3);
+        s.add("b", 1);
+        s.add("c", 2);
+    };
+    open.onsuccess = (e) => {
+        const store = e.target.result.transaction("s", "readonly").objectStore("s");
+        const present = store.getKey(2);
+        const absent = store.getKey(99);
+        const all = store.getAllKeys();
+        all.onsuccess = () => state.resolve({ present: present.result, absent: absent.result, all: all.result });
+    };
+    await state.done((got) => {
+        testing.expectEqual(2, got.present);
+        testing.expectEqual(undefined, got.absent);
+        testing.expectEqual(3, got.all.length);
+        testing.expectEqual(1, got.all[0]); // sorted key order
+        testing.expectEqual(3, got.all[2]);
+    });
+}
+</script>
+
+<!-- IDBKeyRange factory methods, properties, and includes(). -->
+<script id="key_range" type=module>
+{
+    const r = IDBKeyRange.bound(1, 10, false, true);
+    testing.expectEqual(1, r.lower);
+    testing.expectEqual(10, r.upper);
+    testing.expectEqual(false, r.lowerOpen);
+    testing.expectEqual(true, r.upperOpen);
+    testing.expectEqual(true, r.includes(1));
+    testing.expectEqual(true, r.includes(9));
+    testing.expectEqual(false, r.includes(10)); // upper is open
+    testing.expectEqual(false, r.includes(0));
+
+    const only = IDBKeyRange.only("k");
+    testing.expectEqual("k", only.lower);
+    testing.expectEqual("k", only.upper);
+    testing.expectEqual(true, only.includes("k"));
+    testing.expectEqual(false, only.includes("j"));
+
+    const lb = IDBKeyRange.lowerBound(5, true);
+    testing.expectEqual(5, lb.lower);
+    testing.expectEqual(undefined, lb.upper);
+    testing.expectEqual(false, lb.includes(5)); // open
+    testing.expectEqual(true, lb.includes(6));
+
+    const ub = IDBKeyRange.upperBound(5);
+    testing.expectEqual(undefined, ub.lower);
+    testing.expectEqual(true, ub.includes(5));
+
+    // bound() with lower > upper is a DataError.
+    let threw = null;
+    try { IDBKeyRange.bound(10, 1); } catch (e) { threw = e; }
+    testing.expectEqual("DataError", threw && threw.name);
+
+    // IDBKeyRange is not constructable.
+    let ctorThrew = false;
+    try { new IDBKeyRange(); } catch (e) { ctorThrew = true; }
+    testing.expectEqual(true, ctorThrew);
+}
+</script>
+
+<!-- Ranged get/getAll/count/delete using a key range and a bare key. -->
+<script id="ranged_queries" type=module>
+{
+    const state = await testing.async();
+    const open = indexedDB.open("range-db", 1);
+    open.onupgradeneeded = (e) => {
+        const s = e.target.result.createObjectStore("s");
+        for (let i = 1; i <= 5; i++) s.add("v" + i, i);
+    };
+    open.onsuccess = (e) => {
+        const db = e.target.result;
+        const store = db.transaction("s", "readwrite").objectStore("s");
+
+        const range = IDBKeyRange.bound(2, 4);
+        const first = store.get(range);          // first value in [2,4]
+        const all = store.getAll(range);         // values for keys 2,3,4
+        const keys = store.getAllKeys(IDBKeyRange.lowerBound(3)); // keys 3,4,5
+        const cnt = store.count(range);          // 3
+        const limited = store.getAll(null, 2);   // first two of everything
+
+        store.delete(IDBKeyRange.bound(4, 5));   // remove keys 4,5
+        const afterDelete = store.count();
+
+        afterDelete.onsuccess = () => state.resolve({
+            first: first.result,
+            all: all.result,
+            keys: keys.result,
+            cnt: cnt.result,
+            limited: limited.result,
+            remaining: afterDelete.result,
+        });
+    };
+    await state.done((got) => {
+        testing.expectEqual("v2", got.first);
+        testing.expectEqual(3, got.all.length);
+        testing.expectEqual("v2", got.all[0]);
+        testing.expectEqual("v4", got.all[2]);
+        testing.expectEqual(3, got.keys.length);
+        testing.expectEqual(3, got.keys[0]);
+        testing.expectEqual(5, got.keys[2]);
+        testing.expectEqual(3, got.cnt);
+        testing.expectEqual(2, got.limited.length);
+        testing.expectEqual(3, got.remaining); // keys 1,2,3 remain
+    });
+}
+</script>
+
 <!-- clear() empties the store; commit() settles the transaction explicitly. -->
 <script id="clear_and_commit" type=module>
 {
diff --git a/src/browser/webapi/storage/idb/Engine.zig b/src/browser/webapi/storage/idb/Engine.zig
index ddd688e9d..0e4d93755 100644
--- a/src/browser/webapi/storage/idb/Engine.zig
+++ b/src/browser/webapi/storage/idb/Engine.zig
@@ -46,6 +46,7 @@ pub fn open(path: [:0]const u8) !Engine {
         \\   name text not null,
         \\   key_path text,
         \\   auto_increment integer not null default 0,
+        \\   key_generator integer not null default 1,
         \\   unique(database_id, name)
         \\ );
         \\ create table if not exists idb_records (
@@ -114,6 +115,53 @@ pub fn objectStoreId(self: *const Engine, database_id: i64, name: []const u8) !?
     );
 }
 
+pub const StoreInfo = struct {
+    id: i64,
+    key_path: ?[]const u8,
+    auto_increment: bool,
+};
+
+pub fn objectStoreInfo(self: *const Engine, arena: Allocator, database_id: i64, name: []const u8) !?StoreInfo {
+    var row = (try self.conn.row(
+        "select id, key_path, auto_increment from idb_object_stores where database_id = ?1 and name = ?2",
+        .{ database_id, name },
+    )) orelse return null;
+    defer row.deinit();
+
+    const key_path = row.get(?[]const u8, 1);
+    return .{
+        .id = row.get(i64, 0),
+        .key_path = if (key_path) |kp| try arena.dupe(u8, kp) else null,
+        .auto_increment = row.get(bool, 2),
+    };
+}
+
+// key_generator starts at 1, we increment it, but want to return the
+// previous value, hence the - 1.
+pub fn nextGeneratedKey(self: *Engine, store_id: i64) !i64 {
+    return (try self.conn.scalar(
+        i64,
+        "update idb_object_stores set key_generator = key_generator + 1 where id = ?1 returning key_generator - 1",
+        .{store_id},
+    )) orelse error.NotFound;
+}
+
+// If an explicit key was given, we need to bump the generator so that a future
+// generated key doesn't collide
+pub fn maybeBumpGenerator(self: *Engine, store_id: i64, key: f64) !void {
+    if (key < 1) {
+        return;
+    }
+
+    // Cap at 2^53, the largest integer the generator tracks per spec.
+    const capped = @min(@floor(key), 9007199254740992);
+    const want: i64 = @intFromFloat(capped + 1);
+    try self.conn.exec(
+        "update idb_object_stores set key_generator = ?2 where id = ?1 and key_generator < ?2",
+        .{ store_id, want },
+    );
+}
+
 pub fn createObjectStore(
     self: *Engine,
     database_id: i64,
@@ -158,30 +206,98 @@ pub fn get(self: *const Engine, allocator: Allocator, object_store_id: i64, key:
     return try allocator.dupe(u8, row.get([]const u8, 0));
 }
 
-pub fn delete(self: *Engine, object_store_id: i64, key: []const u8) !void {
-    return self.conn.exec(
-        "delete from idb_records where object_store_id = ?1 and key = ?2",
-        .{ object_store_id, key },
-    );
-}
-
 pub fn clear(self: *Engine, object_store_id: i64) !void {
     return self.conn.exec("delete from idb_records where object_store_id = ?1", .{object_store_id});
 }
 
-pub fn count(self: *const Engine, object_store_id: i64) !i64 {
-    return (try self.conn.scalar(
-        i64,
-        "select count(*) from idb_records where object_store_id = ?1",
-        .{object_store_id},
-    )) orelse 0;
+pub const Bounds = struct {
+    lower: []const u8,
+    upper: []const u8,
+
+    // These are built-time string literal operators, e.g. ">= ". Not worried
+    // about some SQL injection.
+    lower_op: []const u8,
+    upper_op: []const u8,
+
+    // optimization flag for point queries.
+    is_point: bool,
+
+    // Every encoded key begins with a type tag from 10 to 50]...
+    // 0 sorts below, and...
+    pub const min_sentinel: []const u8 = &.{0x00};
+    // 255 sorts above
+    pub const max_sentinel: []const u8 = &.{0xFF};
+
+    pub fn unbounded() Bounds {
+        return .{ .lower = min_sentinel, .upper = max_sentinel, .lower_op = ">= ", .upper_op = "<= ", .is_point = false };
+    }
+
+    pub fn point(encoded: []const u8) Bounds {
+        return .{ .lower = encoded, .upper = encoded, .lower_op = "", .upper_op = "", .is_point = true };
+    }
+};
+
+pub fn getRange(self: *const Engine, allocator: Allocator, object_store_id: i64, b: Bounds) !?[]u8 {
+    var buf: [256]u8 = undefined;
+    const sql = try rangeSql(&buf, "select value", b, " order by key limit 1");
+    var row = (try self.conn.row(sql, .{ object_store_id, b.lower, b.upper })) orelse return null;
+    defer row.deinit();
+    return try allocator.dupe(u8, row.get([]const u8, 0));
 }
 
-pub fn getAll(self: *const Engine, arena: Allocator, object_store_id: i64) ![]const []u8 {
-    var rows = try self.conn.rows(
-        "select value from idb_records where object_store_id = ?1 order by key",
-        .{object_store_id},
+pub fn getKeyRange(self: *const Engine, allocator: Allocator, object_store_id: i64, b: Bounds) !?[]u8 {
+    var buf: [256]u8 = undefined;
+    const sql = try rangeSql(&buf, "select key", b, " order by key limit 1");
+    var row = (try self.conn.row(sql, .{ object_store_id, b.lower, b.upper })) orelse return null;
+    defer row.deinit();
+    return try allocator.dupe(u8, row.get([]const u8, 0));
+}
+
+pub fn countRange(self: *const Engine, object_store_id: i64, b: Bounds) !i64 {
+    var buf: [256]u8 = undefined;
+    const sql = try rangeSql(&buf, "select count(*)", b, "");
+    return (try self.conn.scalar(i64, sql, .{ object_store_id, b.lower, b.upper })) orelse 0;
+}
+
+pub fn deleteRange(self: *Engine, object_store_id: i64, b: Bounds) !void {
+    var buf: [256]u8 = undefined;
+    const sql = try rangeSql(&buf, "delete", b, "");
+    return self.conn.exec(sql, .{ object_store_id, b.lower, b.upper });
+}
+
+// Every injected string is a compile-time known/safe value.
+fn rangeSql(buf: []u8, head: []const u8, b: Bounds, tail: []const u8) ![:0]u8 {
+    if (b.is_point) {
+        // optimized query for [common] point query. (key = ?2 or key = ?3)
+        // to keep the param list the side for the caller.
+        return std.fmt.bufPrintZ(
+            buf,
+            "{s} from idb_records where object_store_id = ?1 and (key = ?2 or key = ?3) {s}",
+            .{ head, tail },
+        );
+    }
+
+    return std.fmt.bufPrintZ(
+        buf,
+        "{s} from idb_records where object_store_id = ?1 and key {s} ?2 and key {s} ?3{s}",
+        .{ head, b.lower_op, b.upper_op, tail },
     );
+}
+
+// What a ranged getAll/getAllKeys returns: the value or key column.
+pub const Column = enum {
+    value,
+    key,
+};
+
+pub fn getAllRange(self: *const Engine, arena: Allocator, object_store_id: i64, b: Bounds, column: Column, limit_: ?u32) ![]const []u8 {
+    var buf: [256]u8 = undefined;
+    const head = if (column == .value) "select value" else "select key";
+    const sql = try rangeSql(&buf, head, b, " order by key limit ?4");
+    // SQLite treats a negative LIMIT as "no limit".
+    const limit: i64 = if (limit_) |c| @intCast(c) else -1;
+
+    var rows = try self.conn.rows(sql, .{ object_store_id, b.lower, b.upper, limit });
     defer rows.deinit();
 
     var list: std.ArrayList([]u8) = .empty;
@@ -192,6 +308,86 @@ pub fn getAll(self: *const Engine, arena: Allocator, object_store_id: i64) ![]co
 }
 
 const testing = @import("../../../../testing.zig");
+test "IDB - Engine: ranged getAll/count honour open and closed bounds" {
+    var arena_state = std.heap.ArenaAllocator.init(testing.allocator);
+    defer arena_state.deinit();
+    const arena = arena_state.allocator();
+
+    var engine = try Engine.open(":memory:");
+    defer engine.close();
+    const db_id = try engine.upsertDatabase("app", 1);
+    const store_id = try engine.createObjectStore(db_id, "s", null, false);
+    try seedNumbers(&engine, store_id, arena, &.{ 3, 1, 5, 2, 4 });
+
+    const k2 = try numKey(arena, 2);
+    const k4 = try numKey(arena, 4);
+
+    // Closed [2,4]: keys 2,3,4 in sorted order.
+    {
+        const b = boundsFor(k2, false, k4, false);
+        const vals = try engine.getAllRange(arena, store_id, b, .value, null);
+        try testing.expectEqual(3, vals.len);
+        try testing.expectEqualSlices(u8, "v2", vals[0]);
+        try testing.expectEqualSlices(u8, "v4", vals[2]);
+        try testing.expectEqual(3, try engine.countRange(store_id, b));
+    }
+
+    // Open lower (2,4]: keys 3,4.
+    {
+        const b = boundsFor(k2, true, k4, false);
+        try testing.expectEqual(2, try engine.countRange(store_id, b));
+        const vals = try engine.getAllRange(arena, store_id, b, .value, null);
+        try testing.expectEqualSlices(u8, "v3", vals[0]);
+    }
+
+    // Open both (2,4): only key 3.
+    {
+        const b = boundsFor(k2, true, k4, true);
+        try testing.expectEqual(1, try engine.countRange(store_id, b));
+    }
+
+    // Unbounded and point ranges.
+    try testing.expectEqual(5, try engine.countRange(store_id, Engine.Bounds.unbounded()));
+    try testing.expectEqual(1, try engine.countRange(store_id, Engine.Bounds.point(try numKey(arena, 3))));
+
+    // A limit caps the result count.
+    const limited = try engine.getAllRange(arena, store_id, Engine.Bounds.unbounded(), .value, 2);
+    try testing.expectEqual(2, limited.len);
+
+    // The .key column returns encoded keys, sorted.
+    const keys = try engine.getAllRange(arena, store_id, Engine.Bounds.unbounded(), .key, null);
+    try testing.expectEqualSlices(u8, try numKey(arena, 1), keys[0]);
+    try testing.expectEqualSlices(u8, try numKey(arena, 5), keys[4]);
+}
+
+test "IDB - Engine: getRange/getKeyRange first-in-range and deleteRange" {
+    var arena_state = std.heap.ArenaAllocator.init(testing.allocator);
+    defer arena_state.deinit();
+    const arena = arena_state.allocator();
+
+    var engine = try Engine.open(":memory:");
+    defer engine.close();
+    const db_id = try engine.upsertDatabase("app", 1);
+    const store_id = try engine.createObjectStore(db_id, "s", null, false);
+    try seedNumbers(&engine, store_id, arena, &.{ 1, 2, 3, 4, 5 });
+
+    const k2 = try numKey(arena, 2);
+    const k4 = try numKey(arena, 4);
+
+    // First value/key in [2,4] is for key 2.
+    try testing.expectEqualSlices(u8, "v2", (try engine.getRange(arena, store_id, boundsFor(k2, false, k4, false))).?);
+    try testing.expectEqualSlices(u8, k2, (try engine.getKeyRange(arena, store_id, boundsFor(k2, false, k4, false))).?);
+
+    // Open lower skips key 2.
+    try testing.expectEqualSlices(u8, "v3", (try engine.getRange(arena, store_id, boundsFor(k2, true, k4, false))).?);
+
+    // Empty range yields null.
+    try testing.expectEqual(null, try engine.getRange(arena, store_id, Engine.Bounds.point(try numKey(arena, 99))));
+
+    // deleteRange removes [4,5], leaving 1,2,3.
+    try engine.deleteRange(store_id, boundsFor(k4, false, try numKey(arena, 5), false));
+    try testing.expectEqual(3, try engine.countRange(store_id, Engine.Bounds.unbounded()));
+}
 
 test "IDB - Engine: open creates schema" {
     var engine = try Engine.open(":memory:");
@@ -258,3 +454,29 @@ test "IDB - Engine: rollback discards uncommitted writes" {
 
     try testing.expectEqual(null, try engine.get(testing.allocator, store_id, "k"));
 }
+
+const Key = @import("Key.zig");
+
+// Seed a store with numeric keys n and values "v<n>", inserted out of order so
+// the range tests prove ORDER BY rather than insertion order.
+fn seedNumbers(engine: *Engine, store_id: i64, arena: Allocator, ns: []const u8) !void {
+    for (ns) |n| {
+        const enc = try Key.number(@floatFromInt(n)).encode(arena);
+        var buf: [8]u8 = undefined;
+        try engine.add(store_id, enc, try std.fmt.bufPrint(&buf, "v{d}", .{n}));
+    }
+}
+
+fn numKey(arena: Allocator, n: u8) ![]u8 {
+    return Key.number(@floatFromInt(n)).encode(arena);
+}
+
+fn boundsFor(lower: ?[]const u8, lower_open: bool, upper: ?[]const u8, upper_open: bool) Engine.Bounds {
+    return .{
+        .is_point = false,
+        .lower = lower orelse Engine.Bounds.min_sentinel,
+        .upper = upper orelse Engine.Bounds.max_sentinel,
+        .lower_op = if (lower_open) "> " else ">= ",
+        .upper_op = if (upper_open) "< " else "<= ",
+    };
+}
diff --git a/src/browser/webapi/storage/idb/IDBDatabase.zig b/src/browser/webapi/storage/idb/IDBDatabase.zig
index a2ba43c09..01180f5d5 100644
--- a/src/browser/webapi/storage/idb/IDBDatabase.zig
+++ b/src/browser/webapi/storage/idb/IDBDatabase.zig
@@ -81,7 +81,7 @@ pub fn createObjectStore(
 
     const owned_name = try exec.dupeString(name);
     const key_path = if (opts.keyPath) |kp| try exec.dupeString(kp) else null;
-    return IDBObjectStore.init(self._engine, txn, store_id, owned_name, key_path, exec);
+    return IDBObjectStore.init(self._engine, txn, store_id, owned_name, key_path, opts.autoIncrement, exec);
 }
 
 // Only callable during upgradeneeded, hence the _txn check
diff --git a/src/browser/webapi/storage/idb/IDBFactory.zig b/src/browser/webapi/storage/idb/IDBFactory.zig
index bded61047..4fbda4faa 100644
--- a/src/browser/webapi/storage/idb/IDBFactory.zig
+++ b/src/browser/webapi/storage/idb/IDBFactory.zig
@@ -200,8 +200,8 @@ const DeleteContext = struct {
 };
 
 pub fn cmp(_: *IDBFactory, first: js.Value, second: js.Value, exec: *Execution) !i32 {
-    const a = try Key.encodeValue(first, exec.call_arena);
-    const b = try Key.encodeValue(second, exec.call_arena);
+    const a = try Key.encodeValue(exec.call_arena, first);
+    const b = try Key.encodeValue(exec.call_arena, second);
     return switch (std.mem.order(u8, a, b)) {
         .lt => -1,
         .eq => 0,
diff --git a/src/browser/webapi/storage/idb/IDBKeyRange.zig b/src/browser/webapi/storage/idb/IDBKeyRange.zig
new file mode 100644
index 000000000..9132db04d
--- /dev/null
+++ b/src/browser/webapi/storage/idb/IDBKeyRange.zig
@@ -0,0 +1,157 @@
+// Copyright (C) 2023-2026  Lightpanda (Selecy SAS)
+//
+// Francis Bouvier <francis@lightpanda.io>
+// Pierre Tachoire <pierre@lightpanda.io>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as
+// published by the Free Software Foundation, either version 3 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+const std = @import("std");
+
+const js = @import("../../../js/js.zig");
+
+const Key = @import("Key.zig");
+const Engine = @import("Engine.zig");
+
+const Allocator = std.mem.Allocator;
+const Execution = js.Execution;
+
+const IDBKeyRange = @This();
+
+_exec: *Execution,
+// Encoded bound bytes (page-arena lived), null when that side is unbounded.
+_lower: ?[]const u8,
+_upper: ?[]const u8,
+_lower_open: bool,
+_upper_open: bool,
+
+fn create(exec: *Execution, lower: ?[]const u8, upper: ?[]const u8, lower_open: bool, upper_open: bool) !*IDBKeyRange {
+    return exec._factory.create(IDBKeyRange{
+        ._exec = exec,
+        ._lower = lower,
+        ._upper = upper,
+        ._lower_open = lower_open,
+        ._upper_open = upper_open,
+    });
+}
+
+pub fn only(value: js.Value, exec: *Execution) !*IDBKeyRange {
+    const encoded = try Key.encodeValue(exec.arena, value);
+    return create(exec, encoded, encoded, false, false);
+}
+
+pub fn lowerBound(value: js.Value, open: ?bool, exec: *Execution) !*IDBKeyRange {
+    const encoded = try Key.encodeValue(exec.arena, value);
+    return create(exec, encoded, null, open orelse false, false);
+}
+
+pub fn upperBound(value: js.Value, open: ?bool, exec: *Execution) !*IDBKeyRange {
+    const encoded = try Key.encodeValue(exec.arena, value);
+    return create(exec, null, encoded, false, open orelse false);
+}
+
+pub fn bound(lower: js.Value, upper: js.Value, lower_open: ?bool, upper_open: ?bool, exec: *Execution) !*IDBKeyRange {
+    const lo = try Key.encodeValue(exec.arena, lower);
+    const up = try Key.encodeValue(exec.arena, upper);
+    if (std.mem.order(u8, lo, up) == .gt) {
+        return error.DataError;
+    }
+    return create(exec, lo, up, lower_open orelse false, upper_open orelse false);
+}
+
+pub fn getLower(self: *const IDBKeyRange, exec: *Execution) !?js.Value {
+    const encoded = self._lower orelse return null;
+    return try Key.decodeToJs(exec.call_arena, exec.js.local.?, encoded);
+}
+
+pub fn getUpper(self: *const IDBKeyRange, exec: *Execution) !?js.Value {
+    const encoded = self._upper orelse return null;
+    return try Key.decodeToJs(exec.call_arena, exec.js.local.?, encoded);
+}
+
+pub fn getLowerOpen(self: *const IDBKeyRange) bool {
+    return self._lower_open;
+}
+
+pub fn getUpperOpen(self: *const IDBKeyRange) bool {
+    return self._upper_open;
+}
+
+pub fn includes(self: *const IDBKeyRange, key: js.Value, exec: *Execution) !bool {
+    const encoded = try Key.encodeValue(exec.call_arena, key);
+    return self.containsEncoded(encoded);
+}
+
+fn containsEncoded(self: *const IDBKeyRange, encoded: []const u8) bool {
+    if (self._lower) |lo| {
+        switch (std.mem.order(u8, encoded, lo)) {
+            .lt => return false,
+            .eq => if (self._lower_open) return false,
+            .gt => {},
+        }
+    }
+    if (self._upper) |up| {
+        switch (std.mem.order(u8, encoded, up)) {
+            .gt => return false,
+            .eq => if (self._upper_open) return false,
+            .lt => {},
+        }
+    }
+    return true;
+}
+
+// SQL bounds for the engine's ranged queries.
+pub fn toBounds(self: *const IDBKeyRange) Engine.Bounds {
+    return .{
+        .is_point = false,
+        .lower = self._lower orelse Engine.Bounds.min_sentinel,
+        .upper = self._upper orelse Engine.Bounds.max_sentinel,
+        .lower_op = if (self._lower_open) "> " else ">= ",
+        .upper_op = if (self._upper_open) "< " else "<= ",
+    };
+}
+
+// Resolve a get/getAll/count/delete query argument — a key, an IDBKeyRange, or
+// nothing (null/undefined) — into engine bounds. A bare key becomes a point
+// range; the encoded key is allocated in `arena`.
+pub fn resolveQuery(arena: Allocator, query: ?js.Value, exec: *Execution) !Engine.Bounds {
+    const q = query orelse return Engine.Bounds.unbounded();
+    if (q.isNullOrUndefined()) {
+        return Engine.Bounds.unbounded();
+    }
+    if (exec.js.local.?.jsValueToZig(*IDBKeyRange, q)) |range| {
+        return range.toBounds();
+    } else |_| {}
+    return Engine.Bounds.point(try Key.encodeValue(arena, q));
+}
+
+pub const JsApi = struct {
+    pub const bridge = js.Bridge(IDBKeyRange);
+
+    pub const Meta = struct {
+        pub const name = "IDBKeyRange";
+        pub const prototype_chain = bridge.prototypeChain();
+        pub var class_id: bridge.ClassId = undefined;
+    };
+
+    pub const only = bridge.function(IDBKeyRange.only, .{ .static = true, .dom_exception = true });
+    pub const lowerBound = bridge.function(IDBKeyRange.lowerBound, .{ .static = true, .dom_exception = true });
+    pub const upperBound = bridge.function(IDBKeyRange.upperBound, .{ .static = true, .dom_exception = true });
+    pub const bound = bridge.function(IDBKeyRange.bound, .{ .static = true, .dom_exception = true });
+
+    pub const lower = bridge.accessor(IDBKeyRange.getLower, null, .{ .null_as_undefined = true });
+    pub const upper = bridge.accessor(IDBKeyRange.getUpper, null, .{ .null_as_undefined = true });
+    pub const lowerOpen = bridge.accessor(IDBKeyRange.getLowerOpen, null, .{});
+    pub const upperOpen = bridge.accessor(IDBKeyRange.getUpperOpen, null, .{});
+    pub const includes = bridge.function(IDBKeyRange.includes, .{ .dom_exception = true });
+};
diff --git a/src/browser/webapi/storage/idb/IDBObjectStore.zig b/src/browser/webapi/storage/idb/IDBObjectStore.zig
index 1007217f1..cc80560ad 100644
--- a/src/browser/webapi/storage/idb/IDBObjectStore.zig
+++ b/src/browser/webapi/storage/idb/IDBObjectStore.zig
@@ -23,6 +23,7 @@ const js = @import("../../../js/js.zig");
 const Key = @import("Key.zig");
 const Engine = @import("Engine.zig");
 const IDBRequest = @import("IDBRequest.zig");
+const IDBKeyRange = @import("IDBKeyRange.zig");
 const IDBTransaction = @import("IDBTransaction.zig");
 
 const log = lp.log;
@@ -30,11 +31,11 @@ const Execution = js.Execution;
 
 const IDBObjectStore = @This();
 
-_exec: *Execution,
 _engine: *Engine,
 _store_id: i64,
 _name: []const u8,
 _key_path: ?[]const u8,
+_auto_increment: bool,
 // only null during an upgradeneeded
 _txn: ?*IDBTransaction,
 
@@ -44,37 +45,38 @@ pub fn init(
     store_id: i64,
     name: []const u8,
     key_path: ?[]const u8,
+    auto_increment: bool,
     exec: *Execution,
 ) !*IDBObjectStore {
     return exec._factory.create(IDBObjectStore{
-        ._exec = exec,
         ._engine = engine,
         ._txn = txn,
         ._store_id = store_id,
         ._name = name,
         ._key_path = key_path,
+        ._auto_increment = auto_increment,
     });
 }
 
-pub fn add(self: *IDBObjectStore, value: js.Value, key: ?js.Value) !*IDBRequest {
-    return self.write(value, key, .add);
+pub fn add(self: *IDBObjectStore, value: js.Value, key: ?js.Value, exec: *Execution) !*IDBRequest {
+    return self.write(value, key, .add, exec);
 }
 
-pub fn put(self: *IDBObjectStore, value: js.Value, key: ?js.Value) !*IDBRequest {
-    return self.write(value, key, .put);
+pub fn put(self: *IDBObjectStore, value: js.Value, key: ?js.Value, exec: *Execution) !*IDBRequest {
+    return self.write(value, key, .put, exec);
 }
 
-pub fn get(self: *IDBObjectStore, key: js.Value, exec: *Execution) !*IDBRequest {
+pub fn get(self: *IDBObjectStore, query: js.Value, exec: *Execution) !*IDBRequest {
     const txn = self._txn orelse return error.TransactionInactiveError;
     try txn.ensureBegun();
 
     // Both the encoded key and the fetched bytes are consumed within this call
     // (the bytes are deserialized below), so the per-call scratch arena suffices.
     const arena = exec.call_arena;
-    const encoded = try Key.encodeValue(key, arena);
+    const bounds = try IDBKeyRange.resolveQuery(arena, query, exec);
     const request = try txn.newRequest();
 
-    const bytes = self._engine.get(arena, self._store_id, encoded) catch |err| {
+    const bytes = self._engine.getRange(arena, self._store_id, bounds) catch |err| {
         log.warn(.storage, "idb get", .{ .err = err });
         request.setError(err);
         return request;
@@ -87,17 +89,17 @@ pub fn get(self: *IDBObjectStore, key: js.Value, exec: *Execution) !*IDBRequest
     return request;
 }
 
-pub fn delete(self: *IDBObjectStore, key: js.Value, _: *Execution) !*IDBRequest {
+pub fn delete(self: *IDBObjectStore, query: js.Value, exec: *Execution) !*IDBRequest {
     const txn = self._txn orelse return error.TransactionInactiveError;
     if (txn._mode == .readonly) {
         return error.ReadOnlyError;
     }
     try txn.ensureBegun();
 
-    const encoded = try Key.encodeValue(key, self._exec.call_arena);
+    const bounds = try IDBKeyRange.resolveQuery(exec.call_arena, query, exec);
     const request = try txn.newRequest();
 
-    self._engine.delete(self._store_id, encoded) catch |err| {
+    self._engine.deleteRange(self._store_id, bounds) catch |err| {
         log.warn(.storage, "idb delete", .{ .err = err });
         request.setError(err);
     };
@@ -119,12 +121,13 @@ pub fn clear(self: *IDBObjectStore, _: *Execution) !*IDBRequest {
     return request;
 }
 
-pub fn count(self: *IDBObjectStore, exec: *Execution) !*IDBRequest {
+pub fn count(self: *IDBObjectStore, query: ?js.Value, exec: *Execution) !*IDBRequest {
     const txn = self._txn orelse return error.TransactionInactiveError;
     try txn.ensureBegun();
 
+    const bounds = try IDBKeyRange.resolveQuery(exec.call_arena, query, exec);
     const request = try txn.newRequest();
-    const n = self._engine.count(self._store_id) catch |err| {
+    const n = self._engine.countRange(self._store_id, bounds) catch |err| {
         log.warn(.storage, "idb count", .{ .err = err });
         request.setError(err);
         return request;
@@ -133,14 +136,16 @@ pub fn count(self: *IDBObjectStore, exec: *Execution) !*IDBRequest {
     return request;
 }
 
-pub fn getAll(self: *IDBObjectStore, exec: *Execution) !*IDBRequest {
+pub fn getAll(self: *IDBObjectStore, query: ?js.Value, count_: ?u32, exec: *Execution) !*IDBRequest {
     const txn = self._txn orelse return error.TransactionInactiveError;
     try txn.ensureBegun();
 
     const local = exec.js.local.?;
+    const arena = exec.call_arena;
+    const bounds = try IDBKeyRange.resolveQuery(arena, query, exec);
     const request = try txn.newRequest();
 
-    const values = self._engine.getAll(exec.call_arena, self._store_id) catch |err| {
+    const values = self._engine.getAllRange(arena, self._store_id, bounds, .value, count_) catch |err| {
         log.warn(.storage, "idb getAll", .{ .err = err });
         request.setError(err);
         return request;
@@ -155,6 +160,48 @@ pub fn getAll(self: *IDBObjectStore, exec: *Execution) !*IDBRequest {
     return request;
 }
 
+pub fn getKey(self: *IDBObjectStore, query: js.Value, exec: *Execution) !*IDBRequest {
+    const txn = self._txn orelse return error.TransactionInactiveError;
+    try txn.ensureBegun();
+
+    const arena = exec.call_arena;
+    const bounds = try IDBKeyRange.resolveQuery(arena, query, exec);
+    const request = try txn.newRequest();
+
+    const found = self._engine.getKeyRange(arena, self._store_id, bounds) catch |err| {
+        log.warn(.storage, "idb getKey", .{ .err = err });
+        request.setError(err);
+        return request;
+    };
+
+    const bytes = found orelse return request; // no record -> undefined
+    try request.setValueResult(try Key.decodeToJs(arena, exec.js.local.?, bytes));
+    return request;
+}
+
+pub fn getAllKeys(self: *IDBObjectStore, query: ?js.Value, count_: ?u32, exec: *Execution) !*IDBRequest {
+    const txn = self._txn orelse return error.TransactionInactiveError;
+    try txn.ensureBegun();
+
+    const arena = exec.call_arena;
+    const bounds = try IDBKeyRange.resolveQuery(arena, query, exec);
+    const request = try txn.newRequest();
+
+    const keys = self._engine.getAllRange(arena, self._store_id, bounds, .key, count_) catch |err| {
+        log.warn(.storage, "idb getAllKeys", .{ .err = err });
+        request.setError(err);
+        return request;
+    };
+
+    const local = exec.js.local.?;
+    const arr = local.newArray(@intCast(keys.len));
+    for (keys, 0..) |bytes, i| {
+        _ = try arr.set(@intCast(i), try Key.decodeToJs(arena, local, bytes), .{});
+    }
+    try request.setValueResult(arr.toValue());
+    return request;
+}
+
 pub fn getName(self: *const IDBObjectStore) []const u8 {
     return self._name;
 }
@@ -163,17 +210,75 @@ pub fn getKeyPath(self: *const IDBObjectStore) ?[]const u8 {
     return self._key_path;
 }
 
+pub fn getAutoIncrement(self: *const IDBObjectStore) bool {
+    return self._auto_increment;
+}
+
+pub fn getTransaction(self: *IDBObjectStore) ?*IDBTransaction {
+    return self._txn;
+}
+
 const WriteKind = enum { add, put };
 
-fn write(self: *IDBObjectStore, value: js.Value, key_: ?js.Value, kind: WriteKind) !*IDBRequest {
+fn write(self: *IDBObjectStore, value: js.Value, key_arg: ?js.Value, kind: WriteKind, exec: *Execution) !*IDBRequest {
     const txn = self._txn orelse return error.TransactionInactiveError;
     if (txn._mode == .readonly) {
         return error.ReadOnlyError;
     }
     try txn.ensureBegun();
 
-    const key = key_ orelse return error.DataError;
-    const encoded = try Key.encodeValue(key, self._exec.call_arena);
+    const local = exec.js.local.?;
+
+    var generated = false;
+    const key_value: js.Value = blk: {
+        if (self._key_path) |kp| {
+            if (key_arg != null) {
+                // can't have an explicit key if we're configured for in-line keys
+                return error.DataError;
+            }
+
+            if (Key.evaluatePath(value, kp)) |extracted| {
+                break :blk extracted;
+            }
+
+            // The keypath wasn't in the value...
+            if (self._auto_increment == false) {
+                // and auto-increment is disabled, no key, error.
+                return error.DataError;
+            }
+
+            if (Key.canInjectKey(value, kp) == false) {
+                return error.DataError;
+            }
+
+            generated = true;
+            const n = try self._engine.nextGeneratedKey(self._store_id);
+            const k = try local.newNumber(@floatFromInt(n));
+            try Key.injectKey(local, value, kp, k);
+            break :blk k;
+        }
+
+        // Out-of-line keys.
+        if (key_arg) |k| {
+            break :blk k;
+        }
+
+        if (self._auto_increment == false) {
+            return error.DataError;
+        }
+
+        generated = true;
+        const n = try self._engine.nextGeneratedKey(self._store_id);
+        break :blk try local.newNumber(@floatFromInt(n));
+    };
+
+    const encoded = try Key.encodeValue(exec.call_arena, key_value);
+
+    if (self._auto_increment and !generated and key_value.isNumber()) {
+        // auto-increment is enabled, but this was NOT a generated key, so we
+        // need to bump the generator so that future generated keys don't collide
+        try self._engine.maybeBumpGenerator(self._store_id, try key_value.toF64());
+    }
 
     const serialized = try value.serialize();
     defer serialized.deinit();
@@ -190,7 +295,7 @@ fn write(self: *IDBObjectStore, value: js.Value, key_: ?js.Value, kind: WriteKin
         return request;
     };
 
-    try request.setValueResult(key);
+    try request.setValueResult(key_value);
     return request;
 }
 
@@ -205,11 +310,15 @@ pub const JsApi = struct {
 
     pub const name = bridge.accessor(IDBObjectStore.getName, null, .{});
     pub const keyPath = bridge.accessor(IDBObjectStore.getKeyPath, null, .{});
+    pub const autoIncrement = bridge.accessor(IDBObjectStore.getAutoIncrement, null, .{});
+    pub const transaction = bridge.accessor(IDBObjectStore.getTransaction, null, .{ .null_as_undefined = true });
     pub const add = bridge.function(IDBObjectStore.add, .{ .dom_exception = true });
     pub const put = bridge.function(IDBObjectStore.put, .{ .dom_exception = true });
     pub const get = bridge.function(IDBObjectStore.get, .{ .dom_exception = true });
+    pub const getKey = bridge.function(IDBObjectStore.getKey, .{ .dom_exception = true });
     pub const delete = bridge.function(IDBObjectStore.delete, .{ .dom_exception = true });
     pub const clear = bridge.function(IDBObjectStore.clear, .{ .dom_exception = true });
     pub const count = bridge.function(IDBObjectStore.count, .{ .dom_exception = true });
     pub const getAll = bridge.function(IDBObjectStore.getAll, .{ .dom_exception = true });
+    pub const getAllKeys = bridge.function(IDBObjectStore.getAllKeys, .{ .dom_exception = true });
 };
diff --git a/src/browser/webapi/storage/idb/IDBTransaction.zig b/src/browser/webapi/storage/idb/IDBTransaction.zig
index 5d5927053..8c02f9836 100644
--- a/src/browser/webapi/storage/idb/IDBTransaction.zig
+++ b/src/browser/webapi/storage/idb/IDBTransaction.zig
@@ -177,12 +177,12 @@ pub fn newRequest(self: *IDBTransaction) !*IDBRequest {
 
 pub fn objectStore(self: *IDBTransaction, name: []const u8, exec: *Execution) !*IDBObjectStore {
     const database_id = self._db._database_id;
-    const store_id = (try self._engine.objectStoreId(database_id, name)) orelse {
+    const info = (try self._engine.objectStoreInfo(exec.arena, database_id, name)) orelse {
         return error.NotFound;
     };
 
     const owned_name = try exec.dupeString(name);
-    return IDBObjectStore.init(self._engine, self, store_id, owned_name, null, exec);
+    return IDBObjectStore.init(self._engine, self, info.id, owned_name, info.key_path, info.auto_increment, exec);
 }
 
 pub fn getMode(self: *const IDBTransaction) Mode {
diff --git a/src/browser/webapi/storage/idb/Key.zig b/src/browser/webapi/storage/idb/Key.zig
index c7fa1d1ef..85e3551f2 100644
--- a/src/browser/webapi/storage/idb/Key.zig
+++ b/src/browser/webapi/storage/idb/Key.zig
@@ -21,23 +21,27 @@ const std = @import("std");
 const js = @import("../../../js/js.zig");
 
 const Allocator = std.mem.Allocator;
+const Local = js.Local;
 
 const Key = @This();
 
-// Type tags are the first encoded byte. The value is for correct sort order.
-const Tag = enum(u8) {
-    number = 10,
-    // date = 20,
-    string = 30,
-    // binary = 40,
-    // array = 50,
-};
+const NUMBER_TAG: u8 = 10;
+const DATE_TAG: u8 = 20;
+const STRING_TAG: u8 = 30;
+const BINARY_TAG: u8 = 40;
+const ARRAY_TAG: u8 = 50;
+
+// Guards against unbounded recursion / cyclic arrays when validating a JS value.
+const MAX_DEPTH = 32;
 
 value: Value,
 
 pub const Value = union(enum) {
     number: f64,
+    date: f64,
     string: []const u8,
+    binary: []const u8,
+    array: []const Value,
 };
 
 pub fn number(n: f64) Key {
@@ -48,42 +52,252 @@ pub fn string(s: []const u8) Key {
     return .{ .value = .{ .string = s } };
 }
 
-pub fn stringBuf(allocator: Allocator, payload_len: usize) ![]u8 {
-    const buf = try allocator.alloc(u8, 1 + payload_len);
-    buf[0] = @intFromEnum(Tag.string);
-    return buf;
+pub fn binary(s: []const u8) Key {
+    return .{ .value = .{ .binary = s } };
 }
 
-pub fn encodeValue(value: js.Value, allocator: Allocator) ![]u8 {
-    if (value.isString()) |s| {
-        const buf = try stringBuf(allocator, s.len());
-        _ = s.toSliceWithBuf(buf[1..]);
-        return buf;
-    }
-    if (value.isNumber()) {
-        return number(try value.toZig(f64)).encode(allocator);
-    }
-    return error.DataError;
+pub fn array(items: []const Value) Key {
+    return .{ .value = .{ .array = items } };
 }
 
 // Encode into an order-preserving byte slice, allocated by `allocator`.
 // Caller owns the returned memory.
-fn encode(self: Key, allocator: Allocator) ![]u8 {
-    switch (self.value) {
-        .number => |n| {
-            var buf = try allocator.alloc(u8, 1 + 8);
-            buf[0] = @intFromEnum(Tag.number);
-            writeOrderedF64(buf[1..9], n);
-            return buf;
-        },
-        .string => |s| {
-            const buf = try stringBuf(allocator, s.len);
-            @memcpy(buf[1..], s);
-            return buf;
+pub fn encode(self: Key, allocator: Allocator) ![]u8 {
+    var list: std.ArrayList(u8) = .empty;
+    try encodeInto(allocator, self.value, &list);
+    return list.toOwnedSlice(allocator);
+}
+
+fn encodeInto(allocator: Allocator, value: Value, list: *std.ArrayList(u8)) !void {
+    switch (value) {
+        .number => |n| try encodeF64(allocator, list, NUMBER_TAG, n),
+        .date => |n| try encodeF64(allocator, list, DATE_TAG, n),
+        .string => |s| try encodeBytes(allocator, list, STRING_TAG, s),
+        .binary => |s| try encodeBytes(allocator, list, BINARY_TAG, s),
+        .array => |items| {
+            try list.append(allocator, ARRAY_TAG);
+            for (items) |item| {
+                try encodeInto(allocator, item, list);
+            }
+            try list.append(allocator, 0x00); // array terminator
         },
     }
 }
 
+fn encodeF64(allocator: Allocator, list: *std.ArrayList(u8), tag: u8, n: f64) !void {
+    try list.append(allocator, tag);
+    var buf: [8]u8 = undefined;
+    writeOrderedF64(&buf, n);
+    try list.appendSlice(allocator, &buf);
+}
+
+fn encodeBytes(allocator: Allocator, list: *std.ArrayList(u8), tag: u8, data: []const u8) !void {
+    try list.append(allocator, tag);
+    for (data) |b| {
+        if (b == 0x00) {
+            try list.appendSlice(allocator, &.{ 0x00, 0xFF });
+        } else {
+            try list.append(allocator, b);
+        }
+    }
+    try list.append(allocator, 0x00); // field terminator
+}
+
+// Decode an encoded key back into a Key.Value. All sub-allocations (strings,
+// binary, array backing) come from `allocator` — use an arena and free as a unit.
+pub fn decode(allocator: Allocator, bytes: []const u8) !Value {
+    var pos: usize = 0;
+    const value = try decodeOne(allocator, bytes, &pos);
+    return value;
+}
+
+fn decodeOne(allocator: Allocator, bytes: []const u8, pos: *usize) !Value {
+    if (pos.* >= bytes.len) return error.InvalidKeyEncoding;
+    const tag = bytes[pos.*];
+    pos.* += 1;
+    switch (tag) {
+        NUMBER_TAG, DATE_TAG => {
+            if (pos.* + 8 > bytes.len) return error.InvalidKeyEncoding;
+            const n = readOrderedF64(bytes[pos.*..][0..8]);
+            pos.* += 8;
+            return if (tag == NUMBER_TAG) .{ .number = n } else .{ .date = n };
+        },
+        STRING_TAG => return .{ .string = try decodeBytes(allocator, bytes, pos) },
+        BINARY_TAG => return .{ .binary = try decodeBytes(allocator, bytes, pos) },
+        ARRAY_TAG => {
+            var items: std.ArrayList(Value) = .empty;
+            while (pos.* < bytes.len and bytes[pos.*] != 0x00) {
+                try items.append(allocator, try decodeOne(allocator, bytes, pos));
+            }
+            if (pos.* >= bytes.len) return error.InvalidKeyEncoding;
+            pos.* += 1; // consume array terminator
+            return .{ .array = try items.toOwnedSlice(allocator) };
+        },
+        else => return error.InvalidKeyEncoding,
+    }
+}
+
+fn decodeBytes(allocator: Allocator, bytes: []const u8, pos: *usize) ![]u8 {
+    var out: std.ArrayList(u8) = .empty;
+    while (true) {
+        if (pos.* >= bytes.len) return error.InvalidKeyEncoding;
+        const b = bytes[pos.*];
+        pos.* += 1;
+        if (b != 0x00) {
+            try out.append(allocator, b);
+            continue;
+        }
+        // 0x00: an escaped content byte (0x00 0xFF) or the field terminator.
+        if (pos.* < bytes.len and bytes[pos.*] == 0xFF) {
+            pos.* += 1;
+            try out.append(allocator, 0x00);
+        } else {
+            break; // terminator
+        }
+    }
+    return out.toOwnedSlice(allocator);
+}
+
+// Build a Key.Value from a JS value, validating that it is a structurally valid
+// IDB key. Invalid keys (booleans, null/undefined, objects, NaN, ±Inf, and —
+// until the binding supports it — Date) produce error.DataError.
+pub fn fromJs(value: js.Value, allocator: Allocator) !Value {
+    return fromJsDepth(value, allocator, 0);
+}
+
+fn fromJsDepth(value: js.Value, allocator: Allocator, depth: usize) !Value {
+    if (depth > MAX_DEPTH) return error.DataError;
+
+    if (value.isString()) |s| {
+        return .{ .string = try s.toSliceWithAlloc(allocator) };
+    }
+    if (value.isNumber()) {
+        var n = try value.toF64();
+        if (std.math.isNan(n) or std.math.isInf(n)) return error.DataError;
+        if (n == 0) n = 0; // normalize -0 to +0
+        return .{ .number = n };
+    }
+    if (value.isDate()) {
+        // A Date coerces to its time value; an invalid Date (NaN) is not a key.
+        const n = try value.toF64();
+        if (std.math.isNan(n)) return error.DataError;
+        return .{ .date = n };
+    }
+    if (value.isArrayBuffer() or value.isArrayBufferView()) {
+        // toStringSmart returns the raw bytes for a confirmed binary value.
+        const bytes = try value.toStringSmart();
+        return .{ .binary = try allocator.dupe(u8, bytes) };
+    }
+    if (value.isArray()) {
+        const arr = value.toArray();
+        const len = arr.len();
+        const items = try allocator.alloc(Value, len);
+        for (0..len) |i| {
+            const element = try arr.get(@intCast(i));
+            items[i] = try fromJsDepth(element, allocator, depth + 1);
+        }
+        return .{ .array = items };
+    }
+    return error.DataError;
+}
+
+// Build a JS value (in `local`) from a decoded Key.Value. Binary keys surface as
+// ArrayBuffer, arrays as Array, matching the spec's key-to-value conversion.
+pub fn toJs(value: Value, local: *const Local) !js.Value {
+    switch (value) {
+        .number => |n| return local.zigValueToJs(n, .{}),
+        .date => |n| return local.newDate(n),
+        .string => |s| return local.newString(s).toValue(),
+        .binary => |s| return local.zigValueToJs(js.ArrayBuffer{ .values = s }, .{}),
+        .array => |items| {
+            const arr = local.newArray(@intCast(items.len));
+            for (items, 0..) |item, i| {
+                _ = try arr.set(@intCast(i), try toJs(item, local), .{});
+            }
+            return arr.toValue();
+        },
+    }
+}
+
+// Given a key path , "manager.id", extract that from an object
+pub fn evaluatePath(value: js.Value, key_path: []const u8) ?js.Value {
+    if (key_path.len == 0) {
+        return value;
+    }
+
+    var current = value;
+    var it = std.mem.splitScalar(u8, key_path, '.');
+    while (it.next()) |component| {
+        if (!current.isObject()) {
+            return null;
+        }
+        const next = current.toObject().get(component) catch return null;
+        if (next.isUndefined()) {
+            return null;
+        }
+        current = next;
+    }
+    return current;
+}
+
+// Whether a generated key can be injected at `key_path` (the spec's "check that
+// a key could be injected into a value"). Each existing path segment must be an
+// object; a missing segment is fine since injectKey creates it. Callers check
+// this before consuming a generated key so a doomed write doesn't advance the
+// key generator.
+pub fn canInjectKey(value: js.Value, key_path: []const u8) bool {
+    const last_dot = std.mem.lastIndexOfScalar(u8, key_path, '.') orelse return value.isObject();
+
+    var current = value;
+    var it = std.mem.splitScalar(u8, key_path[0..last_dot], '.');
+    while (it.next()) |component| {
+        if (!current.isObject()) {
+            return false;
+        }
+        const next = current.toObject().get(component) catch return false;
+        if (next.isUndefined()) {
+            // injectKey will create the rest
+            return true;
+        }
+        current = next;
+    }
+    return current.isObject();
+}
+
+// Inject a key into a value at a (non-empty) key path, creating intermediate
+// objects as needed. Requires canInjectKey(value, key_path).
+pub fn injectKey(local: *const Local, value: js.Value, key_path: []const u8, key: js.Value) !void {
+    const last_dot = std.mem.lastIndexOfScalar(u8, key_path, '.');
+    const final = if (last_dot) |i| key_path[i + 1 ..] else key_path;
+
+    var current = value.toObject();
+    if (last_dot) |i| {
+        var it = std.mem.splitScalar(u8, key_path[0..i], '.');
+        while (it.next()) |component| {
+            const next = try current.get(component);
+            if (next.isUndefined()) {
+                const created = local.newObject();
+                _ = try current.set(component, created.toValue(), .{});
+                current = created;
+            } else {
+                current = next.toObject();
+            }
+        }
+    }
+    _ = try current.set(final, key, .{});
+}
+
+// Convenience: validate+encode a JS value straight to its byte key.
+pub fn encodeValue(allocator: Allocator, value: js.Value) ![]u8 {
+    const key: Key = .{ .value = try fromJs(value, allocator) };
+    return key.encode(allocator);
+}
+
+// Convenience: decode a byte key straight to a JS value.
+pub fn decodeToJs(allocator: Allocator, local: *const Local, bytes: []const u8) !js.Value {
+    return toJs(try decode(allocator, bytes), local);
+}
+
 // Map an f64 to 8 big-endian bytes whose unsigned ordering matches IEEE-754
 // numeric ordering. For positive numbers flip only the sign bit; for negative
 // numbers flip every bit. NaN is not a valid IDB key, so it is not handled.
@@ -97,8 +311,36 @@ fn writeOrderedF64(out: *[8]u8, n: f64) void {
     std.mem.writeInt(u64, out, bits, .big);
 }
 
+// Inverse of writeOrderedF64.
+fn readOrderedF64(in: *const [8]u8) f64 {
+    var bits = std.mem.readInt(u64, in, .big);
+    if (bits & (1 << 63) != 0) {
+        bits &= ~@as(u64, 1 << 63); // was positive: we set the sign bit
+    } else {
+        bits = ~bits; // was negative: we flipped every bit
+    }
+    return @bitCast(bits);
+}
+
 const testing = @import("../../../../testing.zig");
 
+fn eql(a: Value, b: Value) bool {
+    if (std.meta.activeTag(a) != std.meta.activeTag(b)) return false;
+    return switch (a) {
+        .number => |n| n == b.number,
+        .date => |n| n == b.date,
+        .string => |s| std.mem.eql(u8, s, b.string),
+        .binary => |s| std.mem.eql(u8, s, b.binary),
+        .array => |items| blk: {
+            if (items.len != b.array.len) break :blk false;
+            for (items, b.array) |x, y| {
+                if (!eql(x, y)) break :blk false;
+            }
+            break :blk true;
+        },
+    };
+}
+
 test "IDB - Key: number encoding round-trips ordering" {
     const cases = [_]f64{ -1e308, -100.5, -1, -0.0001, 0, 0.0001, 1, 100.5, 1e308 };
     var prev: ?[]u8 = null;
@@ -114,18 +356,71 @@ test "IDB - Key: number encoding round-trips ordering" {
     }
 }
 
-test "IDB - Key: numbers sort before strings" {
+test "IDB - Key: cross-type ordering number < date < string < binary < array" {
     const num = try Key.number(1e308).encode(testing.allocator);
     defer testing.allocator.free(num);
-    const str = try Key.string("").encode(testing.allocator);
+    const date = try (Key{ .value = .{ .date = -1e308 } }).encode(testing.allocator);
+    defer testing.allocator.free(date);
+    const str = try Key.string("zzz").encode(testing.allocator);
     defer testing.allocator.free(str);
-    try testing.expect(std.mem.order(u8, num, str) == .lt);
+    const bin = try Key.binary(&.{0xFF}).encode(testing.allocator);
+    defer testing.allocator.free(bin);
+    const arr = try Key.array(&.{.{ .number = 0 }}).encode(testing.allocator);
+    defer testing.allocator.free(arr);
+
+    try testing.expect(std.mem.order(u8, num, date) == .lt);
+    try testing.expect(std.mem.order(u8, date, str) == .lt);
+    try testing.expect(std.mem.order(u8, str, bin) == .lt);
+    try testing.expect(std.mem.order(u8, bin, arr) == .lt);
 }
 
-test "IDB - Key: string encoding preserves byte order" {
+test "IDB - Key: string encoding preserves byte order and handles NUL" {
     const a = try Key.string("apple").encode(testing.allocator);
     defer testing.allocator.free(a);
     const b = try Key.string("banana").encode(testing.allocator);
     defer testing.allocator.free(b);
     try testing.expect(std.mem.order(u8, a, b) == .lt);
+
+    // A prefix sorts before a longer string, and an embedded NUL sorts after.
+    const empty = try Key.string("").encode(testing.allocator);
+    defer testing.allocator.free(empty);
+    const x = try Key.string("x").encode(testing.allocator);
+    defer testing.allocator.free(x);
+    const x_nul = try Key.string("x\x00").encode(testing.allocator);
+    defer testing.allocator.free(x_nul);
+    try testing.expect(std.mem.order(u8, empty, x) == .lt);
+    try testing.expect(std.mem.order(u8, x, x_nul) == .lt);
+}
+
+test "IDB - Key: array ordering — shorter prefix sorts first, element order dominates" {
+    const a1 = try Key.array(&.{.{ .number = 1 }}).encode(testing.allocator);
+    defer testing.allocator.free(a1);
+    const a12 = try Key.array(&.{ .{ .number = 1 }, .{ .number = 2 } }).encode(testing.allocator);
+    defer testing.allocator.free(a12);
+    const a2 = try Key.array(&.{.{ .number = 2 }}).encode(testing.allocator);
+    defer testing.allocator.free(a2);
+
+    try testing.expect(std.mem.order(u8, a1, a12) == .lt); // [1] < [1,2]
+    try testing.expect(std.mem.order(u8, a12, a2) == .lt); // [1,2] < [2]
+}
+
+test "IDB - Key: encode/decode round-trip for every key type" {
+    var arena_state = std.heap.ArenaAllocator.init(testing.allocator);
+    defer arena_state.deinit();
+    const arena = arena_state.allocator();
+
+    const cases = [_]Value{
+        .{ .number = -42.5 },
+        .{ .number = 0 },
+        .{ .date = 1_700_000_000_000 },
+        .{ .string = "héllo\x00world" },
+        .{ .binary = &.{ 0x00, 0x01, 0xFF, 0x00 } },
+        .{ .array = &.{ .{ .number = 1 }, .{ .string = "a" }, .{ .array = &.{.{ .number = 2 }} } } },
+    };
+
+    for (cases) |case| {
+        const enc = try (Key{ .value = case }).encode(arena);
+        const dec = try Key.decode(arena, enc);
+        try testing.expect(eql(case, dec));
+    }
 }
diff --git a/src/browser/webapi/storage/idb/idb.zig b/src/browser/webapi/storage/idb/idb.zig
index eef0c94ee..af572617f 100644
--- a/src/browser/webapi/storage/idb/idb.zig
+++ b/src/browser/webapi/storage/idb/idb.zig
@@ -25,6 +25,7 @@ pub const Manager = @import("Manager.zig");
 pub const IDBFactory = @import("IDBFactory.zig");
 pub const IDBRequest = @import("IDBRequest.zig");
 pub const IDBDatabase = @import("IDBDatabase.zig");
+pub const IDBKeyRange = @import("IDBKeyRange.zig");
 pub const IDBTransaction = @import("IDBTransaction.zig");
 pub const IDBObjectStore = @import("IDBObjectStore.zig");
 pub const IDBVersionChangeEvent = @import("IDBVersionChangeEvent.zig");
@@ -34,6 +35,7 @@ pub fn registerTypes() []const type {
         IDBFactory,
         IDBRequest,
         IDBDatabase,
+        IDBKeyRange,
         IDBTransaction,
         IDBObjectStore,
         IDBVersionChangeEvent,