Fix schema properties order

Author: petrukha-ivan

Package.resolved

@@ -13,7 +13,7 @@ let package = Package(
         .package(url: "https://github.com/ml-explore/mlx-swift", from: "0.25.6"),
         .package(url: "https://github.com/ml-explore/mlx-swift-examples", from: "2.25.7"),
         .package(url: "https://github.com/huggingface/swift-transformers", from: "0.1.24"),
-        .package(url: "https://github.com/kevinhermawan/swift-json-schema", from: "2.0.1"),
+        .package(url: "https://github.com/petrukha-ivan/swift-json-schema", from: "2.0.2"),
         .package(url: "https://github.com/apple/swift-argument-parser", from: "1.4.0"),
     ],
     targets: [

Package.swift

@@ -0,0 +1,49 @@
+//
+//  Grammar+Encoding.swift
+//  MLXStructured
+//
+//  Created by Ivan Petrukha on 05.10.2025.
+//
+
+import Foundation
+import JSONSchema
+
+extension JSONEncoder {
+    
+    static let `default` = JSONEncoder()
+    
+    static let sorted: JSONEncoder = {
+        let encoder = JSONEncoder()
+        encoder.outputFormatting = [.sortedKeys, .prettyPrinted]
+        return encoder
+    }()
+}
+
+extension JSONDecoder {
+    
+    static let `default` = JSONDecoder()
+    
+    static func withPropertiesOrderInfo(_ order: [String]) -> JSONDecoder {
+        let decoder = JSONDecoder()
+        decoder.userInfo[JSONSchema.ObjectSchema.Properties.orderInfoKey] = order
+        return decoder
+    }
+}
+
+extension JSONSchema: @retroactive CustomStringConvertible {
+    public var description: String {
+        do {
+            let data = try JSONEncoder.sorted.encode(self)
+            let string = String(decoding: data, as: UTF8.self).sanitizedSchema
+            return string
+        } catch {
+            return "Invalid JSON Schema"
+        }
+    }
+}
+
+extension String {
+    var sanitizedSchema: String {
+        replacingOccurrences(of: "__[0-9]+__", with: "", options: .regularExpression)
+    }
+}

Sources/MLXStructured/Grammar/Grammar+Encoding.swift

@@ -6,6 +6,7 @@
 //
 
 import Foundation
+import JSONSchema
 
 #if canImport(FoundationModels)
 import FoundationModels
@@ -14,10 +15,22 @@ import FoundationModels
 #if compiler(>=6.2)
 @available(macOS 26.0, iOS 26.0, *)
 public extension Grammar {
+    
+    struct OrderContainer: Codable {
+        
+        let order: [String]
+        
+        enum CodingKeys: String, CodingKey {
+            case order = "x-order"
+        }
+    }
+    
     static func generable<Content: Generable>(_ type: Content.Type, indent: Int? = nil) throws -> Grammar {
-        let encoder = JSONEncoder()
-        let data = try encoder.encode(type.generationSchema)
-        let string = String(decoding: data, as: UTF8.self)
+        let generationSchemaData = try JSONEncoder.default.encode(type.generationSchema)
+        let orderContainer = try JSONDecoder.default.decode(OrderContainer.self, from: generationSchemaData)
+        let schema = try JSONDecoder.withPropertiesOrderInfo(orderContainer.order).decode(JSONSchema.self, from: generationSchemaData)
+        let schemaData = try JSONEncoder.sorted.encode(schema)
+        let string = String(decoding: schemaData, as: UTF8.self).sanitizedSchema
         return .schema(string, indent: indent)
     }
 }

Sources/MLXStructured/Grammar/Grammar+Generable.swift

@@ -10,9 +10,8 @@ import JSONSchema
 
 public extension Grammar {
     static func schema(_ schema: JSONSchema = .object(), indent: Int? = nil) throws -> Grammar {
-        let encoder = JSONEncoder()
-        let data = try encoder.encode(schema)
-        let string = String(decoding: data, as: UTF8.self)
+        let data = try JSONEncoder.sorted.encode(schema)
+        let string = String(decoding: data, as: UTF8.self).sanitizedSchema
         return .schema(string, indent: indent)
     }
 }

Sources/MLXStructured/Grammar/Grammar+Schema.swift

@@ -10,9 +10,8 @@ import Foundation
 public extension Grammar {
     init(@FormatBuilder _ content: () -> Encodable) throws {
         let tag = StructuralTag(format: content())
-        let encoder = JSONEncoder()
-        let data = try encoder.encode(tag)
-        let string = String(decoding: data, as: UTF8.self)
+        let data = try JSONEncoder.sorted.encode(tag)
+        let string = String(decoding: data, as: UTF8.self).sanitizedSchema
         self = Grammar.structural(string)
     }
 }

Sources/MLXStructured/Grammar/Grammar+Structural.swift

@@ -26,7 +26,7 @@ struct StructuralExample: AsyncParsableCommand {
         let grammar = try Grammar {
             SequenceFormat {
                 if includePrefix {
-                    ConstTextFormat(text: "According to my knowledge, my answer is ")
+                    ConstTextFormat(text: "Based on the data I was trained on, the answer is ")
                 }
                 OrFormat {
                     ConstTextFormat(text: "YES")

Sources/MLXStructuredCLI/Commands/StructuralExample.swift

@@ -24,7 +24,7 @@ private extension Tool {
             "function": [
                 "name": name,
                 "description": description,
-                "parameters": try! JSONSerialization.jsonObject(with: JSONEncoder().encode(getCurrentTimeTool.parameters))
+                "parameters": try! JSONSerialization.jsonObject(with: JSONEncoder().encode(parameters))
             ]
         ]
     }