diff --git a/Snippets/ExampleAccumulators.swift b/Snippets/ExampleAccumulators.swift
index 207d16a8..af66bcab 100644
--- a/Snippets/ExampleAccumulators.swift
+++ b/Snippets/ExampleAccumulators.swift
@@ -8,7 +8,7 @@ func ExampleAccumulators()
         $0[.top] = .init
         {
             $0[.output] = "$field"
-            $0[.by] = .init
+            $0[.by, using: Mongo.AnyKeyPath.self]
             {
                 $0["x"] = (+)
                 $0["y"] = (-)
@@ -20,8 +20,8 @@ func ExampleAccumulators()
         $0[.top] = .init
         {
             $0[.output] = "$field"
-            $0[.count] = 5
-            $0[.by] = .init
+            $0[.n] = 5
+            $0[.by, using: Mongo.AnyKeyPath.self]
             {
                 $0["x"] = (+)
                 $0["y"] = (-)
@@ -33,7 +33,7 @@ func ExampleAccumulators()
         $0[.first] = .init
         {
             $0[.input] = "$field"
-            $0[.count] = 5
+            $0[.n] = 5
         }
     }
     let _:Mongo.Accumulator = .init
diff --git a/Snippets/ExampleExpressions.swift b/Snippets/ExampleExpressions.swift
index 4ccf0756..d0fe7563 100644
--- a/Snippets/ExampleExpressions.swift
+++ b/Snippets/ExampleExpressions.swift
@@ -368,7 +368,7 @@ func ExampleExpressions()
             $0[.sortArray] = .init
             {
                 $0[.input] = "$field"
-                $0[.by] = .init
+                $0[.by, using: Mongo.AnyKeyPath.self]
                 {
                     $0["x"] = (+)
                     $0["y"] = (-)
diff --git a/Sources/MongoBuiltins/Accumulators/Mongo.Accumulator.N.swift b/Sources/MongoBuiltins/Accumulators/Mongo.Accumulator.N.swift
new file mode 100644
index 00000000..df507aa5
--- /dev/null
+++ b/Sources/MongoBuiltins/Accumulators/Mongo.Accumulator.N.swift
@@ -0,0 +1,8 @@
+extension Mongo.Accumulator
+{
+    @frozen public
+    enum N:String, Sendable
+    {
+        case n
+    }
+}
diff --git a/Sources/MongoBuiltins/Accumulators/Mongo.Accumulator.SuperlativeDocument.swift b/Sources/MongoBuiltins/Accumulators/Mongo.Accumulator.SuperlativeDocument.swift
index 37db11ef..05fff089 100644
--- a/Sources/MongoBuiltins/Accumulators/Mongo.Accumulator.SuperlativeDocument.swift
+++ b/Sources/MongoBuiltins/Accumulators/Mongo.Accumulator.SuperlativeDocument.swift
@@ -17,8 +17,14 @@ extension Mongo.Accumulator
 }
 extension Mongo.Accumulator.SuperlativeDocument
 {
+    @frozen public
+    enum Input:String, Sendable
+    {
+        case input
+    }
+
     @inlinable public
-    subscript<Encodable>(key:Mongo.SortDocument.Input) -> Encodable?
+    subscript<Encodable>(key:Input) -> Encodable?
         where Encodable:BSONEncodable
     {
         get
@@ -30,8 +36,11 @@ extension Mongo.Accumulator.SuperlativeDocument
             value?.encode(to: &self.bson[with: key])
         }
     }
+}
+extension Mongo.Accumulator.SuperlativeDocument
+{
     @inlinable public
-    subscript<Encodable>(key:Mongo.SortDocument.Count) -> Encodable?
+    subscript<Encodable>(key:Mongo.Accumulator.N) -> Encodable?
         where Encodable:BSONEncodable
     {
         get
diff --git a/Sources/MongoBuiltins/Accumulators/Mongo.Accumulator.SuperlativeSortDocument.swift b/Sources/MongoBuiltins/Accumulators/Mongo.Accumulator.SuperlativeSortDocument.swift
index fd34dca4..50492e1f 100644
--- a/Sources/MongoBuiltins/Accumulators/Mongo.Accumulator.SuperlativeSortDocument.swift
+++ b/Sources/MongoBuiltins/Accumulators/Mongo.Accumulator.SuperlativeSortDocument.swift
@@ -17,36 +17,48 @@ extension Mongo.Accumulator
 }
 extension Mongo.Accumulator.SuperlativeSortDocument
 {
+    @available(*, unavailable)
     @inlinable public
-    subscript(key:Mongo.SortDocument.By) -> Mongo.SortDocument?
+    subscript(key:Mongo.SortBy) -> Mongo.SortDocument<Mongo.AnyKeyPath>?
     {
-        get
-        {
-            nil
-        }
-        set(value)
+        nil
+    }
+
+    @inlinable public
+    subscript<CodingKey>(key:Mongo.SortBy,
+        using _:CodingKey.Type = CodingKey.self,
+        yield:(inout Mongo.SortEncoder<CodingKey>) -> ()) -> Void
+    {
+        mutating get
         {
-            value?.encode(to: &self.bson[with: key])
+            yield(&self.bson[with: key][as: Mongo.SortEncoder<CodingKey>.self])
         }
     }
+}
+extension Mongo.Accumulator.SuperlativeSortDocument
+{
+    @frozen public
+    enum Output:String, Hashable, Sendable
+    {
+        case output
+    }
+
     @inlinable public
-    subscript<Encodable>(key:Mongo.SortDocument.Output) -> Encodable?
+    subscript<Encodable>(key:Output) -> Encodable?
         where Encodable:BSONEncodable
     {
-        get
-        {
-            nil
-        }
-        set(value)
+        get { nil }
+        set (value)
         {
             value?.encode(to: &self.bson[with: key])
         }
     }
 }
-extension Mongo.Accumulator.SuperlativeSortDocument<Mongo.SortDocument.Count>
+extension Mongo.Accumulator.SuperlativeSortDocument<Mongo.Accumulator.N>
 {
+
     @inlinable public
-    subscript<Encodable>(key:Mongo.SortDocument.Count) -> Encodable?
+    subscript<Encodable>(key:Mongo.Accumulator.N) -> Encodable?
         where Encodable:BSONEncodable
     {
         get
diff --git a/Sources/MongoBuiltins/Accumulators/Mongo.Accumulator.swift b/Sources/MongoBuiltins/Accumulators/Mongo.Accumulator.swift
index 27063948..b289bbd5 100644
--- a/Sources/MongoBuiltins/Accumulators/Mongo.Accumulator.swift
+++ b/Sources/MongoBuiltins/Accumulators/Mongo.Accumulator.swift
@@ -81,7 +81,7 @@ extension Mongo.Accumulator
     }
     @_disfavoredOverload
     @inlinable public
-    subscript(key:SuperlativeSort) -> SuperlativeSortDocument<Mongo.SortDocument.Count>?
+    subscript(key:SuperlativeSort) -> SuperlativeSortDocument<N>?
     {
         get
         {
diff --git a/Sources/MongoBuiltins/Documents/Sort/Mongo.SortDocument.By.swift b/Sources/MongoBuiltins/Documents/Sort/Mongo.SortBy.swift
similarity index 63%
rename from Sources/MongoBuiltins/Documents/Sort/Mongo.SortDocument.By.swift
rename to Sources/MongoBuiltins/Documents/Sort/Mongo.SortBy.swift
index 9f7b623e..dbff78e5 100644
--- a/Sources/MongoBuiltins/Documents/Sort/Mongo.SortDocument.By.swift
+++ b/Sources/MongoBuiltins/Documents/Sort/Mongo.SortBy.swift
@@ -1,12 +1,12 @@
-extension Mongo.SortDocument
+extension Mongo
 {
     @frozen public
-    enum By:String, Hashable, Sendable
+    enum SortBy:String, Hashable, Sendable
     {
         case by = "sortBy"
     }
 }
-extension Mongo.SortDocument.By
+extension Mongo.SortBy
 {
     @available(*, unavailable, renamed: "by")
     public static
diff --git a/Sources/MongoBuiltins/Documents/Sort/Mongo.SortDocument.Count.swift b/Sources/MongoBuiltins/Documents/Sort/Mongo.SortDocument.Count.swift
deleted file mode 100644
index f42495cd..00000000
--- a/Sources/MongoBuiltins/Documents/Sort/Mongo.SortDocument.Count.swift
+++ /dev/null
@@ -1,17 +0,0 @@
-extension Mongo.SortDocument
-{
-    @frozen public
-    enum Count:String, Hashable, Sendable
-    {
-        case count = "n"
-    }
-}
-extension Mongo.SortDocument.Count
-{
-    @available(*, unavailable, renamed: "count")
-    public static
-    var n:Self
-    {
-        .count
-    }
-}
diff --git a/Sources/MongoBuiltins/Documents/Sort/Mongo.SortDocument.Input.swift b/Sources/MongoBuiltins/Documents/Sort/Mongo.SortDocument.Input.swift
deleted file mode 100644
index 1c59cdd7..00000000
--- a/Sources/MongoBuiltins/Documents/Sort/Mongo.SortDocument.Input.swift
+++ /dev/null
@@ -1,8 +0,0 @@
-extension Mongo.SortDocument
-{
-    @frozen public
-    enum Input:String, Hashable, Sendable
-    {
-        case input
-    }
-}
diff --git a/Sources/MongoBuiltins/Documents/Sort/Mongo.SortDocument.Output.swift b/Sources/MongoBuiltins/Documents/Sort/Mongo.SortDocument.Output.swift
deleted file mode 100644
index 18a3dc28..00000000
--- a/Sources/MongoBuiltins/Documents/Sort/Mongo.SortDocument.Output.swift
+++ /dev/null
@@ -1,8 +0,0 @@
-extension Mongo.SortDocument
-{
-    @frozen public
-    enum Output:String, Hashable, Sendable
-    {
-        case output
-    }
-}
diff --git a/Sources/MongoBuiltins/Documents/Sort/Mongo.SortDocument.swift b/Sources/MongoBuiltins/Documents/Sort/Mongo.SortDocument.swift
index 4634b644..44bb6801 100644
--- a/Sources/MongoBuiltins/Documents/Sort/Mongo.SortDocument.swift
+++ b/Sources/MongoBuiltins/Documents/Sort/Mongo.SortDocument.swift
@@ -4,7 +4,7 @@ import MongoABI
 extension Mongo
 {
     @frozen public
-    struct SortDocument:Sendable
+    struct SortDocument<CodingKey>:Sendable where CodingKey:RawRepresentable<String>
     {
         public
         var bson:BSON.Document
@@ -19,5 +19,5 @@ extension Mongo
 extension Mongo.SortDocument:Mongo.EncodableDocument
 {
     public
-    typealias Encoder = Mongo.SortEncoder
+    typealias Encoder = Mongo.SortEncoder<CodingKey>
 }
diff --git a/Sources/MongoBuiltins/Documents/Sort/Mongo.SortEncoder.swift b/Sources/MongoBuiltins/Documents/Sort/Mongo.SortEncoder.swift
index d8bab8f9..0fed0106 100644
--- a/Sources/MongoBuiltins/Documents/Sort/Mongo.SortEncoder.swift
+++ b/Sources/MongoBuiltins/Documents/Sort/Mongo.SortEncoder.swift
@@ -4,13 +4,13 @@ import MongoABI
 extension Mongo
 {
     @frozen public
-    struct SortEncoder:Sendable
+    struct SortEncoder<CodingKey>:Sendable where CodingKey:RawRepresentable<String>
     {
         @usableFromInline
-        var bson:BSON.DocumentEncoder<Mongo.AnyKeyPath>
+        var bson:BSON.DocumentEncoder<CodingKey>
 
         @inlinable internal
-        init(bson:BSON.DocumentEncoder<Mongo.AnyKeyPath>)
+        init(bson:BSON.DocumentEncoder<CodingKey>)
         {
             self.bson = bson
         }
@@ -36,7 +36,7 @@ extension Mongo.SortEncoder
         pass the `(+)` or `(-)` operator functions to specify sort direction.
         """)
     @inlinable public
-    subscript(path:Mongo.AnyKeyPath) -> Int?
+    subscript(path:CodingKey) -> Int?
     {
         get { nil }
         set {     }
@@ -67,7 +67,7 @@ extension Mongo.SortEncoder
 extension Mongo.SortEncoder
 {
     @inlinable public
-    subscript<Direction>(path:Mongo.AnyKeyPath) -> ((Direction) -> Never)?
+    subscript<Direction>(path:CodingKey) -> ((Direction) -> Never)?
         where Direction:Mongo.SortDirection
     {
         get { nil }
@@ -75,7 +75,7 @@ extension Mongo.SortEncoder
         {
             if  case _? = value
             {
-                Direction.code.encode(to: &self.bson[with: path.stem])
+                Direction.code.encode(to: &self.bson[with: path])
             }
         }
     }
@@ -83,11 +83,11 @@ extension Mongo.SortEncoder
 extension Mongo.SortEncoder
 {
     @inlinable public
-    subscript(path:Mongo.AnyKeyPath, yield:(inout Mongo.SortOperatorEncoder) -> ()) -> Void
+    subscript(path:CodingKey, yield:(inout Mongo.SortOperatorEncoder) -> ()) -> Void
     {
         mutating get
         {
-            yield(&self.bson[with: path.stem][as: Mongo.SortOperatorEncoder.self])
+            yield(&self.bson[with: path][as: Mongo.SortOperatorEncoder.self])
         }
     }
 }
diff --git a/Sources/MongoBuiltins/Documents/SortArray/Mongo.SortArrayDocument.swift b/Sources/MongoBuiltins/Documents/SortArray/Mongo.SortArrayDocument.swift
index 90df8f3e..b09cde87 100644
--- a/Sources/MongoBuiltins/Documents/SortArray/Mongo.SortArrayDocument.swift
+++ b/Sources/MongoBuiltins/Documents/SortArray/Mongo.SortArrayDocument.swift
@@ -1,4 +1,5 @@
 import BSON
+import MongoABI
 
 extension Mongo
 {
@@ -17,8 +18,14 @@ extension Mongo
 }
 extension Mongo.SortArrayDocument
 {
+    @frozen public
+    enum Input:String, Sendable
+    {
+        case input
+    }
+
     @inlinable public
-    subscript<Encodable>(key:Mongo.SortDocument.Input) -> Encodable?
+    subscript<Encodable>(key:Input) -> Encodable?
         where Encodable:BSONEncodable
     {
         get
@@ -30,16 +37,22 @@ extension Mongo.SortArrayDocument
             value?.encode(to: &self.bson[with: key])
         }
     }
+
     @inlinable public
-    subscript(key:Mongo.SortDocument.By) -> Mongo.SortDocument?
+    subscript<CodingKey>(key:Mongo.SortBy,
+        using _:CodingKey.Type = CodingKey.self,
+        yield:(inout Mongo.SortEncoder<CodingKey>) -> ()) -> Void
     {
-        get
+        mutating get
         {
-            nil
-        }
-        set(value)
-        {
-            value?.encode(to: &self.bson[with: key])
+            yield(&self.bson[with: key][as: Mongo.SortEncoder<CodingKey>.self])
         }
     }
+
+    @available(*, unavailable)
+    @inlinable public
+    subscript(key:Mongo.SortBy) -> Mongo.SortDocument<Mongo.AnyKeyPath>?
+    {
+        nil
+    }
 }
diff --git a/Sources/MongoBuiltins/Documents/Update/Mongo.UpdateArrayEncoder.swift b/Sources/MongoBuiltins/Documents/Update/Mongo.UpdateArrayEncoder.swift
index 61a0d994..0c28d7e2 100644
--- a/Sources/MongoBuiltins/Documents/Update/Mongo.UpdateArrayEncoder.swift
+++ b/Sources/MongoBuiltins/Documents/Update/Mongo.UpdateArrayEncoder.swift
@@ -82,11 +82,13 @@ extension Mongo.UpdateArrayEncoder
     }
 
     @inlinable public
-    subscript(key:Sort, yield:(inout Mongo.SortEncoder) -> ()) -> Void
+    subscript<CodingKey>(key:Sort,
+        using _:CodingKey.Type = CodingKey.self,
+        yield:(inout Mongo.SortEncoder<CodingKey>) -> ()) -> Void
     {
         mutating get
         {
-            yield(&self.bson[with: key][as: Mongo.SortEncoder.self])
+            yield(&self.bson[with: key][as: Mongo.SortEncoder<CodingKey>.self])
         }
     }
 }
diff --git a/Sources/MongoBuiltins/Pipelines/Mongo.PipelineEncoder.swift b/Sources/MongoBuiltins/Pipelines/Mongo.PipelineEncoder.swift
index 412b7705..9788b978 100644
--- a/Sources/MongoBuiltins/Pipelines/Mongo.PipelineEncoder.swift
+++ b/Sources/MongoBuiltins/Pipelines/Mongo.PipelineEncoder.swift
@@ -712,24 +712,25 @@ extension Mongo.PipelineEncoder
 extension Mongo.PipelineEncoder
 {
     @inlinable public
-    subscript(stage key:Mongo.Pipeline.Sort) -> Mongo.SortDocument?
+    subscript<CodingKey>(stage sort:Mongo.Pipeline.Sort,
+        using _:CodingKey.Type = CodingKey.self,
+        yield:(inout Mongo.SortEncoder<CodingKey>) -> ()) -> Void
     {
-        get { nil }
-        set (value)
+        mutating get
         {
-            guard
-            let value:Mongo.SortDocument
-            else
-            {
-                return
-            }
-
             self.list(Mongo.Pipeline.Sort.self)
             {
-                $0[.sort] = value
+                yield(&$0[with: sort][as: Mongo.SortEncoder<CodingKey>.self])
             }
         }
     }
+
+    @available(*, unavailable)
+    @inlinable public
+    subscript(stage key:Mongo.Pipeline.Sort) -> Mongo.SortDocument<Mongo.AnyKeyPath>?
+    {
+        nil
+    }
 }
 
 extension Mongo.PipelineEncoder
diff --git a/Sources/MongoDBTests/CausalConsistency/CausalConsistency.swift b/Sources/MongoDBTests/CausalConsistency/CausalConsistency.swift
index 9b2e2ad2..7c2bf32d 100644
--- a/Sources/MongoDBTests/CausalConsistency/CausalConsistency.swift
+++ b/Sources/MongoDBTests/CausalConsistency/CausalConsistency.swift
@@ -174,9 +174,9 @@ struct CausalConsistency<Configuration>:MongoTestBattery
                 command: Mongo.Find<Mongo.SingleBatch<Letter>>.init(collection,
                     limit: 10)
                 {
-                    $0[.sort]
+                    $0[.sort, using: Letter.CodingKey.self]
                     {
-                        $0["_id"] = (+)
+                        $0[.id] = (+)
                     }
                 },
                 against: database,
@@ -214,9 +214,9 @@ struct CausalConsistency<Configuration>:MongoTestBattery
                 command: Mongo.Find<Mongo.SingleBatch<Letter>>.init(collection,
                     limit: 10)
                 {
-                    $0[.sort]
+                    $0[.sort, using: Letter.CodingKey.self]
                     {
-                        $0["_id"] = (+)
+                        $0[.id] = (+)
                     }
                 },
                 against: database,
diff --git a/Sources/MongoDBTests/Delete/Delete.swift b/Sources/MongoDBTests/Delete/Delete.swift
index 98606908..c3a5c75a 100644
--- a/Sources/MongoDBTests/Delete/Delete.swift
+++ b/Sources/MongoDBTests/Delete/Delete.swift
@@ -134,9 +134,9 @@ struct Delete<Configuration>:MongoTestBattery where Configuration:MongoTestConfi
                         .init
                         {
                             $0[.name] = "points_index"
-                            $0[.key] = .init
+                            $0[.key, using: Cake.CodingKey.self]
                             {
-                                $0["points"] = (+)
+                                $0[.points] = (+)
                             }
                         },
                     ]),
diff --git a/Sources/MongoDBTests/Find/Find.swift b/Sources/MongoDBTests/Find/Find.swift
index 4e4d0c6f..d4c55d25 100644
--- a/Sources/MongoDBTests/Find/Find.swift
+++ b/Sources/MongoDBTests/Find/Find.swift
@@ -56,9 +56,9 @@ struct Find<Configuration>:MongoTestBattery where Configuration:MongoTestConfigu
                         limit: 5,
                         skip: 10)
                     {
-                        $0[.hint]
+                        $0[.hint, using: Record<Int64>.CodingKey.self]
                         {
-                            $0["_id"] = (+)
+                            $0[.id] = (+)
                         }
                     },
                     against: database)
@@ -75,9 +75,9 @@ struct Find<Configuration>:MongoTestBattery where Configuration:MongoTestConfigu
                         limit: 5,
                         skip: 10)
                     {
-                        $0[.sort]
+                        $0[.sort, using: Record<Int64>.CodingKey.self]
                         {
-                            $0["value"] = (-)
+                            $0[.value] = (-)
                         }
                     },
                     against: database)
diff --git a/Sources/MongoDBTests/FindAndModify/FindAndModify.swift b/Sources/MongoDBTests/FindAndModify/FindAndModify.swift
index a98ec324..1769a2de 100644
--- a/Sources/MongoDBTests/FindAndModify/FindAndModify.swift
+++ b/Sources/MongoDBTests/FindAndModify/FindAndModify.swift
@@ -186,9 +186,9 @@ struct FindAndModify<Configuration>:MongoTestBattery where Configuration:MongoTe
                         writeConcern: .majority,
                         returning: .deleted)
                         {
-                            $0[.sort]
+                            $0[.sort, using: Ruler.CodingKey.self]
                             {
-                                $0["since"] = (+)
+                                $0[.since] = (+)
                             }
                         },
                     against: database)
diff --git a/Sources/MongoDBTests/Indexes/Indexes.swift b/Sources/MongoDBTests/Indexes/Indexes.swift
index 522c6f3f..6fdc2040 100644
--- a/Sources/MongoDBTests/Indexes/Indexes.swift
+++ b/Sources/MongoDBTests/Indexes/Indexes.swift
@@ -61,22 +61,22 @@ struct Indexes<Configuration>:MongoTestBattery where Configuration:MongoTestConf
                             {
                                 $0[.unique] = true
                                 $0[.name] = "item_manufacturer_model"
-                                $0[.key] = .init
+                                $0[.key, using: Product.CodingKey.self]
                                 {
-                                    $0["item"] = (+)
-                                    $0["manufacturer"] = (+)
-                                    $0["model"] = (+)
+                                    $0[.item] = (+)
+                                    $0[.manufacturer] = (+)
+                                    $0[.model] = (+)
                                 }
                             },
                             .init
                             {
                                 $0[.unique] = true
                                 $0[.name] = "item_supplier_model"
-                                $0[.key] = .init
+                                $0[.key, using: Product.CodingKey.self]
                                 {
-                                    $0["item"] = (+)
-                                    $0["supplier"] = (+)
-                                    $0["model"] = (+)
+                                    $0[.item] = (+)
+                                    $0[.supplier] = (+)
+                                    $0[.model] = (+)
                                 }
                             },
                         ]),
@@ -102,11 +102,11 @@ struct Indexes<Configuration>:MongoTestBattery where Configuration:MongoTestConf
                             {
                                 $0[.unique] = true
                                 $0[.name] = "item_supplier_model"
-                                $0[.key] = .init
+                                $0[.key, using: Product.CodingKey.self]
                                 {
-                                    $0["item"] = (+)
-                                    $0["supplier"] = (+)
-                                    $0["model"] = (+)
+                                    $0[.item] = (+)
+                                    $0[.supplier] = (+)
+                                    $0[.model] = (+)
                                 }
                             },
                         ]),
diff --git a/Sources/MongoDBTests/Letter.swift b/Sources/MongoDBTests/Letter.swift
index 140f4e4d..efe59705 100644
--- a/Sources/MongoDBTests/Letter.swift
+++ b/Sources/MongoDBTests/Letter.swift
@@ -1,4 +1,5 @@
 import BSON
+import MongoQL
 
 struct Letter:Hashable, Sendable
 {
@@ -11,7 +12,7 @@ extension Letter:ExpressibleByUnicodeScalarLiteral
         self.init(id: unicodeScalarLiteral)
     }
 }
-extension Letter
+extension Letter:Mongo.MasterCodingModel
 {
     enum CodingKey:String, Sendable
     {
diff --git a/Sources/MongoQL/Commands/Aggregate/Mongo.Aggregate.swift b/Sources/MongoQL/Commands/Aggregate/Mongo.Aggregate.swift
index 81cfcdc0..99df3bbf 100644
--- a/Sources/MongoQL/Commands/Aggregate/Mongo.Aggregate.swift
+++ b/Sources/MongoQL/Commands/Aggregate/Mongo.Aggregate.swift
@@ -182,10 +182,10 @@ extension Mongo.Aggregate
         }
     }
 }
-extension Mongo.Aggregate
+extension Mongo.Aggregate:Mongo.HintableEncoder
 {
     @frozen public
-    enum Hint:String, Hashable, Sendable
+    enum Hint:String, Sendable
     {
         case hint
     }
@@ -193,22 +193,18 @@ extension Mongo.Aggregate
     @inlinable public
     subscript(key:Hint) -> String?
     {
-        get
-        {
-            nil
-        }
-        set(value)
-        {
-            value?.encode(to: &self.fields[with: key])
-        }
+        get { nil }
+        set (value) { value?.encode(to: &self.fields[with: key]) }
     }
 
     @inlinable public
-    subscript(key:Hint, yield:(inout Mongo.SortEncoder) -> ()) -> Void
+    subscript<IndexKey>(key:Hint,
+        using _:IndexKey.Type = IndexKey.self,
+        yield:(inout Mongo.SortEncoder<IndexKey>) -> ()) -> Void
     {
         mutating get
         {
-            yield(&self.fields[with: key][as: Mongo.SortEncoder.self])
+            yield(&self.fields[with: key][as: Mongo.SortEncoder<IndexKey>.self])
         }
     }
 }
diff --git a/Sources/MongoQL/Commands/CreateIndexes/Mongo.CreateIndexStatementEncoder.swift b/Sources/MongoQL/Commands/CreateIndexes/Mongo.CreateIndexStatementEncoder.swift
index 7cae2908..6343503e 100644
--- a/Sources/MongoQL/Commands/CreateIndexes/Mongo.CreateIndexStatementEncoder.swift
+++ b/Sources/MongoQL/Commands/CreateIndexes/Mongo.CreateIndexStatementEncoder.swift
@@ -74,8 +74,11 @@ extension Mongo.CreateIndexStatementEncoder
         }
     }
 }
-extension Mongo.CreateIndexStatementEncoder
+extension Mongo.CreateIndexStatementEncoder:Mongo.SortableEncoder
 {
+    public
+    typealias Sort = Key
+
     @frozen public
     enum Key:String, Hashable, Sendable
     {
@@ -83,15 +86,13 @@ extension Mongo.CreateIndexStatementEncoder
     }
 
     @inlinable public
-    subscript(key:Key) -> Mongo.SortDocument?
+    subscript<IndexKey>(key:Key,
+        using _:IndexKey.Type = IndexKey.self,
+        yield:(inout Mongo.SortEncoder<IndexKey>) -> ()) -> Void
     {
-        get
-        {
-            nil
-        }
-        set(value)
+        mutating get
         {
-            value?.encode(to: &self.bson[with: key])
+            yield(&self.bson[with: key][as: Mongo.SortEncoder<IndexKey>.self])
         }
     }
 }
diff --git a/Sources/MongoQL/Commands/Delete/Mongo.DeleteStatementEncoder.swift b/Sources/MongoQL/Commands/Delete/Mongo.DeleteStatementEncoder.swift
index 875b0ccf..e141ab9a 100644
--- a/Sources/MongoQL/Commands/Delete/Mongo.DeleteStatementEncoder.swift
+++ b/Sources/MongoQL/Commands/Delete/Mongo.DeleteStatementEncoder.swift
@@ -75,10 +75,10 @@ extension Mongo.DeleteStatementEncoder
         set (value) { value?.encode(to: &self.bson[with: key]) }
     }
 }
-extension Mongo.DeleteStatementEncoder
+extension Mongo.DeleteStatementEncoder:Mongo.HintableEncoder
 {
     @frozen public
-    enum Hint:String, Hashable, Sendable
+    enum Hint:String, Sendable
     {
         case hint
     }
@@ -91,9 +91,13 @@ extension Mongo.DeleteStatementEncoder
     }
 
     @inlinable public
-    subscript(key:Hint) -> Mongo.SortDocument?
+    subscript<IndexKey>(key:Hint,
+        using _:IndexKey.Type = IndexKey.self,
+        yield:(inout Mongo.SortEncoder<IndexKey>) -> ()) -> Void
     {
-        get { nil }
-        set (value) { value?.encode(to: &self.bson[with: key]) }
+        mutating get
+        {
+            yield(&self.bson[with: key][as: Mongo.SortEncoder<IndexKey>.self])
+        }
     }
-}
+}
\ No newline at end of file
diff --git a/Sources/MongoQL/Commands/Find/Mongo.Find.swift b/Sources/MongoQL/Commands/Find/Mongo.Find.swift
index 015aad42..aa50cee7 100644
--- a/Sources/MongoQL/Commands/Find/Mongo.Find.swift
+++ b/Sources/MongoQL/Commands/Find/Mongo.Find.swift
@@ -193,10 +193,10 @@ extension Mongo.Find
         }
     }
 }
-extension Mongo.Find
+extension Mongo.Find:Mongo.HintableEncoder
 {
     @frozen public
-    enum Hint:String, Hashable, Sendable
+    enum Hint:String, Sendable
     {
         case hint
     }
@@ -204,22 +204,18 @@ extension Mongo.Find
     @inlinable public
     subscript(key:Hint) -> String?
     {
-        get
-        {
-            nil
-        }
-        set(value)
-        {
-            value?.encode(to: &self.fields[with: key])
-        }
+        get { nil }
+        set (value) { value?.encode(to: &self.fields[with: key]) }
     }
 
     @inlinable public
-    subscript(key:Hint, yield:(inout Mongo.SortEncoder) -> ()) -> Void
+    subscript<IndexKey>(key:Hint,
+        using _:IndexKey.Type = IndexKey.self,
+        yield:(inout Mongo.SortEncoder<IndexKey>) -> ()) -> Void
     {
         mutating get
         {
-            yield(&self.fields[with: key][as: Mongo.SortEncoder.self])
+            yield(&self.fields[with: key][as: Mongo.SortEncoder<IndexKey>.self])
         }
     }
 }
@@ -302,20 +298,22 @@ extension Mongo.Find
         }
     }
 }
-extension Mongo.Find
+extension Mongo.Find:Mongo.SortableEncoder
 {
     @frozen public
-    enum Sort:String, Hashable, Sendable
+    enum Sort:String, Sendable
     {
         case sort
     }
 
     @inlinable public
-    subscript(key:Sort, yield:(inout Mongo.SortEncoder) -> ()) -> Void
+    subscript<CodingKey>(key:Sort,
+        using _:CodingKey.Type = CodingKey.self,
+        yield:(inout Mongo.SortEncoder<CodingKey>) -> ()) -> Void
     {
         mutating get
         {
-            yield(&self.fields[with: key][as: Mongo.SortEncoder.self])
+            yield(&self.fields[with: key][as: Mongo.SortEncoder<CodingKey>.self])
         }
     }
 }
diff --git a/Sources/MongoQL/Commands/FindAndModify/Mongo.FindAndModify.swift b/Sources/MongoQL/Commands/FindAndModify/Mongo.FindAndModify.swift
index 9df2f39e..de47edcf 100644
--- a/Sources/MongoQL/Commands/FindAndModify/Mongo.FindAndModify.swift
+++ b/Sources/MongoQL/Commands/FindAndModify/Mongo.FindAndModify.swift
@@ -144,10 +144,10 @@ extension Mongo.FindAndModify
         }
     }
 }
-extension Mongo.FindAndModify
+extension Mongo.FindAndModify:Mongo.HintableEncoder
 {
     @frozen public
-    enum Hint:String, Hashable, Sendable
+    enum Hint:String, Sendable
     {
         case hint
     }
@@ -155,22 +155,18 @@ extension Mongo.FindAndModify
     @inlinable public
     subscript(key:Hint) -> String?
     {
-        get
-        {
-            nil
-        }
-        set(value)
-        {
-            value?.encode(to: &self.fields[with: key])
-        }
+        get { nil }
+        set (value) { value?.encode(to: &self.fields[with: key]) }
     }
 
     @inlinable public
-    subscript(key:Hint, yield:(inout Mongo.SortEncoder) -> ()) -> Void
+    subscript<IndexKey>(key:Hint,
+        using _:IndexKey.Type = IndexKey.self,
+        yield:(inout Mongo.SortEncoder<IndexKey>) -> ()) -> Void
     {
         mutating get
         {
-            yield(&self.fields[with: key][as: Mongo.SortEncoder.self])
+            yield(&self.fields[with: key][as: Mongo.SortEncoder<IndexKey>.self])
         }
     }
 }
@@ -215,20 +211,22 @@ extension Mongo.FindAndModify
         }
     }
 }
-extension Mongo.FindAndModify
+extension Mongo.FindAndModify:Mongo.SortableEncoder
 {
     @frozen public
-    enum Sort:String, Hashable, Sendable
+    enum Sort:String, Sendable
     {
         case sort
     }
 
     @inlinable public
-    subscript(key:Sort, yield:(inout Mongo.SortEncoder) -> ()) -> Void
+    subscript<CodingKey>(key:Sort,
+        using _:CodingKey.Type = CodingKey.self,
+        yield:(inout Mongo.SortEncoder<CodingKey>) -> ()) -> Void
     {
         mutating get
         {
-            yield(&self.fields[with: key][as: Mongo.SortEncoder.self])
+            yield(&self.fields[with: key][as: Mongo.SortEncoder<CodingKey>.self])
         }
     }
 }
diff --git a/Sources/MongoQL/Commands/Mongo.HintableEncoder.swift b/Sources/MongoQL/Commands/Mongo.HintableEncoder.swift
new file mode 100644
index 00000000..2553fb63
--- /dev/null
+++ b/Sources/MongoQL/Commands/Mongo.HintableEncoder.swift
@@ -0,0 +1,23 @@
+extension Mongo
+{
+    public
+    protocol HintableEncoder<Hint>
+    {
+        associatedtype Hint:RawRepresentable<String>
+
+        subscript(key:Hint) -> String? { get set }
+
+        subscript<IndexKey>(key:Hint,
+            using _:IndexKey.Type,
+            yield:(inout Mongo.SortEncoder<IndexKey>) -> ()) -> Void { mutating get }
+    }
+}
+extension Mongo.HintableEncoder
+{
+    @available(*, unavailable)
+    @inlinable public
+    subscript(key:Hint) -> Mongo.SortDocument<Mongo.AnyKeyPath>?
+    {
+        nil
+    }
+}
diff --git a/Sources/MongoQL/Commands/Mongo.SortableEncoder.swift b/Sources/MongoQL/Commands/Mongo.SortableEncoder.swift
new file mode 100644
index 00000000..46fab6da
--- /dev/null
+++ b/Sources/MongoQL/Commands/Mongo.SortableEncoder.swift
@@ -0,0 +1,21 @@
+extension Mongo
+{
+    public
+    protocol SortableEncoder<Sort>
+    {
+        associatedtype Sort:RawRepresentable<String>
+
+        subscript<IndexKey>(key:Sort,
+            using _:IndexKey.Type,
+            yield:(inout Mongo.SortEncoder<IndexKey>) -> ()) -> Void { mutating get }
+    }
+}
+extension Mongo.SortableEncoder
+{
+    @available(*, unavailable)
+    @inlinable public
+    subscript(key:Sort) -> Mongo.SortDocument<Mongo.AnyKeyPath>?
+    {
+        nil
+    }
+}
diff --git a/Sources/MongoQL/Commands/Update/Mongo.UpdateStatementEncoder.swift b/Sources/MongoQL/Commands/Update/Mongo.UpdateStatementEncoder.swift
index 8e88b566..8c40bd24 100644
--- a/Sources/MongoQL/Commands/Update/Mongo.UpdateStatementEncoder.swift
+++ b/Sources/MongoQL/Commands/Update/Mongo.UpdateStatementEncoder.swift
@@ -156,10 +156,10 @@ extension Mongo.UpdateStatementEncoder
         set (value) { value?.encode(to: &self.bson[with: key]) }
     }
 }
-extension Mongo.UpdateStatementEncoder
+extension Mongo.UpdateStatementEncoder:Mongo.HintableEncoder
 {
     @frozen public
-    enum Hint:String, Hashable, Sendable
+    enum Hint:String, Sendable
     {
         case hint
     }
@@ -172,10 +172,14 @@ extension Mongo.UpdateStatementEncoder
     }
 
     @inlinable public
-    subscript(key:Hint) -> Mongo.SortDocument?
+    subscript<CodingKey>(key:Hint,
+        using _:CodingKey.Type = CodingKey.self,
+        yield:(inout Mongo.SortEncoder<CodingKey>) -> ()) -> Void
     {
-        get { nil }
-        set (value) { value?.encode(to: &self.bson[with: key]) }
+        mutating get
+        {
+            yield(&self.bson[with: key][as: Mongo.SortEncoder<CodingKey>.self])
+        }
     }
 }
 extension Mongo.UpdateStatementEncoder