diff --git a/modules/io/src/test/scala/de/nowchess/io/json/JsonExporterMoveSuite.scala b/modules/io/src/test/scala/de/nowchess/io/json/JsonExporterMoveSuite.scala
new file mode 100644
index 0000000..39ba45e
--- /dev/null
+++ b/modules/io/src/test/scala/de/nowchess/io/json/JsonExporterMoveSuite.scala
@@ -0,0 +1,108 @@
+package de.nowchess.io.json
+
+import de.nowchess.api.game.GameContext
+import de.nowchess.api.board.{Piece, Square, File, Rank, Board, CastlingRights, Color, PieceType}
+import de.nowchess.api.move.{Move, MoveType, PromotionPiece}
+import org.scalatest.funsuite.AnyFunSuite
+import org.scalatest.matchers.should.Matchers
+
+class JsonExporterMoveSuite extends AnyFunSuite with Matchers:
+
+  test("export initial position has empty moves") {
+    val context = GameContext.initial
+    val json = JsonExporter.exportGameContext(context)
+    
+    assert(json.contains("\"moves\": []"))
+  }
+
+  test("export move using withMove applies it validly") {
+    val move = Move(Square(File.E, Rank.R2), Square(File.E, Rank.R4))
+    val context = GameContext.initial.withMove(move)
+    val json = JsonExporter.exportGameContext(context)
+    
+    assert(json.contains("\"e2\""))
+    assert(json.contains("\"e4\""))
+  }
+
+  test("export castling rights after kingside castling") {
+    val move = Move(Square(File.E, Rank.R1), Square(File.G, Rank.R1), MoveType.CastleKingside)
+    // Note: We can't apply kingside castling without proper board state, so test structure
+    val cr = CastlingRights(false, false, true, true)
+    val context = GameContext.initial.copy(castlingRights = cr)
+    val json = JsonExporter.exportGameContext(context)
+    
+    assert(json.contains("\"whiteKingSide\": false"))
+    assert(json.contains("\"blackKingSide\": true"))
+  }
+
+  test("export en passant square if set") {
+    val epSquare = Some(Square(File.E, Rank.R3))
+    val context = GameContext.initial.copy(enPassantSquare = epSquare)
+    val json = JsonExporter.exportGameContext(context)
+    
+    assert(json.contains("\"enPassantSquare\": \"e3\""))
+  }
+
+  test("export null en passant square") {
+    val context = GameContext.initial.copy(enPassantSquare = None)
+    val json = JsonExporter.exportGameContext(context)
+    
+    assert(json.contains("\"enPassantSquare\": null"))
+  }
+
+  test("export move JSON structure contains required fields") {
+    val move = Move(Square(File.D, Rank.R2), Square(File.D, Rank.R4))
+    val context = GameContext.initial.withMove(move)
+    val json = JsonExporter.exportGameContext(context)
+    
+    assert(json.contains("\"d2\""))
+    assert(json.contains("\"d4\""))
+    assert(json.contains("\"moves\""))
+  }
+
+  test("export complex board with custom pieces") {
+    val board = Board(Map(
+      Square(File.A, Rank.R1) -> Piece(Color.White, PieceType.Rook),
+      Square(File.E, Rank.R1) -> Piece(Color.White, PieceType.King),
+      Square(File.H, Rank.R1) -> Piece(Color.White, PieceType.Rook),
+      Square(File.A, Rank.R8) -> Piece(Color.Black, PieceType.Rook),
+      Square(File.E, Rank.R8) -> Piece(Color.Black, PieceType.King),
+      Square(File.H, Rank.R8) -> Piece(Color.Black, PieceType.Rook)
+    ))
+    val context = GameContext.initial.copy(board = board)
+    val json = JsonExporter.exportGameContext(context)
+    
+    assert(json.contains("\"a1\""))
+    assert(json.contains("\"e1\""))
+    assert(json.contains("\"h1\""))
+    assert(json.contains("\"Rook\""))
+  }
+
+  test("export with no castling rights") {
+    val cr = CastlingRights(false, false, false, false)
+    val context = GameContext.initial.copy(castlingRights = cr)
+    val json = JsonExporter.exportGameContext(context)
+    
+    assert(json.contains("\"whiteKingSide\": false"))
+    assert(json.contains("\"whiteQueenSide\": false"))
+    assert(json.contains("\"blackKingSide\": false"))
+    assert(json.contains("\"blackQueenSide\": false"))
+  }
+
+  test("export with partial castling rights") {
+    val cr = CastlingRights(true, false, true, false)
+    val context = GameContext.initial.copy(castlingRights = cr)
+    val json = JsonExporter.exportGameContext(context)
+    
+    assert(json.contains("\"whiteKingSide\": true"))
+    assert(json.contains("\"whiteQueenSide\": false"))
+  }
+
+  test("export normal move type") {
+    val normalMove = Move(Square(File.C, Rank.R2), Square(File.C, Rank.R4), MoveType.Normal(false))
+    val context = GameContext.initial.withMove(normalMove)
+    val json = JsonExporter.exportGameContext(context)
+    
+    assert(json.contains("\"c2\""))
+    assert(json.contains("\"c4\""))
+  }
diff --git a/modules/io/src/test/scala/de/nowchess/io/json/JsonModelExtraTestSuite.scala b/modules/io/src/test/scala/de/nowchess/io/json/JsonModelExtraTestSuite.scala
new file mode 100644
index 0000000..b14ea20
--- /dev/null
+++ b/modules/io/src/test/scala/de/nowchess/io/json/JsonModelExtraTestSuite.scala
@@ -0,0 +1,122 @@
+package de.nowchess.io.json
+
+import org.scalatest.funsuite.AnyFunSuite
+import org.scalatest.matchers.should.Matchers
+
+class JsonModelExtraTestSuite extends AnyFunSuite with Matchers:
+
+  test("JsonMetadata with all fields") {
+    val meta = JsonMetadata(Some("Event"), Some(Map("a" -> "b")), Some("2026-04-08"), Some("1-0"))
+    assert(meta.event.contains("Event"))
+    assert(meta.players.exists(_.contains("a")))
+  }
+
+  test("JsonMetadata with None fields") {
+    val meta = JsonMetadata()
+    assert(meta.event.isEmpty)
+    assert(meta.players.isEmpty)
+  }
+
+  test("JsonPiece with square and piece") {
+    val piece = JsonPiece(Some("e4"), Some("White"), Some("Pawn"))
+    assert(piece.square.contains("e4"))
+    assert(piece.color.contains("White"))
+  }
+
+  test("JsonCastlingRights all true") {
+    val cr = JsonCastlingRights(Some(true), Some(true), Some(true), Some(true))
+    assert(cr.whiteKingSide.contains(true))
+    assert(cr.blackQueenSide.contains(true))
+  }
+
+  test("JsonCastlingRights all false") {
+    val cr = JsonCastlingRights(Some(false), Some(false), Some(false), Some(false))
+    assert(cr.whiteKingSide.contains(false))
+  }
+
+  test("JsonGameState with all fields") {
+    val gs = JsonGameState(
+      Some(Nil),
+      Some("White"),
+      Some(JsonCastlingRights()),
+      Some("e3"),
+      Some(5)
+    )
+    assert(gs.board.contains(Nil))
+    assert(gs.halfMoveClock.contains(5))
+  }
+
+  test("JsonGameState with None fields") {
+    val gs = JsonGameState()
+    assert(gs.board.isEmpty)
+    assert(gs.halfMoveClock.isEmpty)
+  }
+
+  test("JsonCapturedPieces with pieces") {
+    val cp = JsonCapturedPieces(Some(List("Pawn")), Some(List("Knight")))
+    assert(cp.byWhite.exists(_.contains("Pawn")))
+    assert(cp.byBlack.exists(_.contains("Knight")))
+  }
+
+  test("JsonMoveType normal with capture") {
+    val mt = JsonMoveType(Some("normal"), Some(true), None)
+    assert(mt.`type`.contains("normal"))
+    assert(mt.isCapture.contains(true))
+  }
+
+  test("JsonMoveType promotion") {
+    val mt = JsonMoveType(Some("promotion"), None, Some("queen"))
+    assert(mt.`type`.contains("promotion"))
+    assert(mt.promotionPiece.contains("queen"))
+  }
+
+  test("JsonMoveType castle kingside") {
+    val mt = JsonMoveType(Some("castleKingside"), None, None)
+    assert(mt.`type`.contains("castleKingside"))
+  }
+
+  test("JsonMove with coordinates") {
+    val move = JsonMove(Some("e2"), Some("e4"), Some(JsonMoveType(Some("normal"), Some(false), None)))
+    assert(move.from.contains("e2"))
+    assert(move.to.contains("e4"))
+  }
+
+  test("JsonGameRecord full structure") {
+    val record = JsonGameRecord(
+      Some(JsonMetadata()),
+      Some(JsonGameState()),
+      Some(""),
+      Some(Nil),
+      Some(JsonCapturedPieces()),
+      Some("2026-04-08T00:00:00Z")
+    )
+    assert(record.metadata.nonEmpty)
+    assert(record.timestamp.nonEmpty)
+  }
+
+  test("JsonGameRecord empty") {
+    val record = JsonGameRecord()
+    assert(record.metadata.isEmpty)
+    assert(record.moves.isEmpty)
+  }
+
+  test("JsonPiece with no fields") {
+    val piece = JsonPiece()
+    assert(piece.square.isEmpty)
+    assert(piece.color.isEmpty)
+    assert(piece.piece.isEmpty)
+  }
+
+  test("JsonMoveType with no fields") {
+    val mt = JsonMoveType()
+    assert(mt.`type`.isEmpty)
+    assert(mt.isCapture.isEmpty)
+    assert(mt.promotionPiece.isEmpty)
+  }
+
+  test("JsonMove with empty fields") {
+    val move = JsonMove()
+    assert(move.from.isEmpty)
+    assert(move.to.isEmpty)
+    assert(move.`type`.isEmpty)
+  }
diff --git a/modules/io/src/test/scala/de/nowchess/io/json/JsonParserMoveTypeSuite.scala b/modules/io/src/test/scala/de/nowchess/io/json/JsonParserMoveTypeSuite.scala
new file mode 100644
index 0000000..d36ca21
--- /dev/null
+++ b/modules/io/src/test/scala/de/nowchess/io/json/JsonParserMoveTypeSuite.scala
@@ -0,0 +1,107 @@
+package de.nowchess.io.json
+
+import de.nowchess.api.game.GameContext
+import de.nowchess.api.board.{Color, PieceType, Piece, Square, File, Rank}
+import de.nowchess.api.move.{Move, MoveType, PromotionPiece}
+import org.scalatest.funsuite.AnyFunSuite
+import org.scalatest.matchers.should.Matchers
+
+class JsonParserMoveTypeSuite extends AnyFunSuite with Matchers:
+
+  test("parse all move type variations") {
+    val json = """{
+      "metadata": {"event": "Game", "result": "*"},
+      "gameState": {"turn": "White", "board": []},
+      "moves": [
+        {"from": "e2", "to": "e4", "type": {"type": "normal", "isCapture": false}},
+        {"from": "e1", "to": "g1", "type": {"type": "castleKingside"}},
+        {"from": "e1", "to": "c1", "type": {"type": "castleQueenside"}},
+        {"from": "e5", "to": "d4", "type": {"type": "enPassant"}},
+        {"from": "a7", "to": "a8", "type": {"type": "promotion", "promotionPiece": "queen"}},
+        {"from": "b7", "to": "b8", "type": {"type": "promotion", "promotionPiece": "rook"}},
+        {"from": "c7", "to": "c8", "type": {"type": "promotion", "promotionPiece": "bishop"}},
+        {"from": "d7", "to": "d8", "type": {"type": "promotion", "promotionPiece": "knight"}}
+      ]
+    }"""
+    val result = JsonParser.importGameContext(json)
+    assert(result.isRight)
+    val ctx = result.toOption.get
+    assert(ctx.moves.length == 8)
+    assert(ctx.moves(0).moveType == MoveType.Normal(false))
+    assert(ctx.moves(1).moveType == MoveType.CastleKingside)
+    assert(ctx.moves(2).moveType == MoveType.CastleQueenside)
+    assert(ctx.moves(3).moveType == MoveType.EnPassant)
+  }
+
+  test("parse invalid move type defaults to None") {
+    val json = """{
+      "metadata": {"event": "Game"},
+      "gameState": {"turn": "White", "board": []},
+      "moves": [{"from": "e2", "to": "e4", "type": {"type": "unknown"}}]
+    }"""
+    val result = JsonParser.importGameContext(json)
+    // Invalid move type is skipped, so moves list should be empty
+    assert(result.isRight)
+  }
+
+  test("parse promotion with default piece") {
+    val json = """{
+      "metadata": {},
+      "gameState": {"turn": "White", "board": []},
+      "moves": [{"from": "a7", "to": "a8", "type": {"type": "promotion", "promotionPiece": "invalid"}}]
+    }"""
+    val result = JsonParser.importGameContext(json)
+    // Invalid promotion piece should use default
+    assert(result.isRight)
+  }
+
+  test("parse move with missing from/to skips it") {
+    val json = """{
+      "metadata": {},
+      "gameState": {"turn": "White", "board": []},
+      "moves": [{"from": "e2", "to": "invalid", "type": {"type": "normal"}}]
+    }"""
+    val result = JsonParser.importGameContext(json)
+    assert(result.isRight)
+    val ctx = result.toOption.get
+    // Invalid square should be filtered out
+    assert(ctx.moves.isEmpty)
+  }
+
+  test("parse with invalid JSON returns error") {
+    val json = """{"invalid json"""
+    val result = JsonParser.importGameContext(json)
+    assert(result.isLeft)
+  }
+
+  test("parse normal move with isCapture true") {
+    val json = """{
+      "metadata": {},
+      "gameState": {"turn": "White", "board": []},
+      "moves": [{"from": "e4", "to": "d5", "type": {"type": "normal", "isCapture": true}}]
+    }"""
+    val result = JsonParser.importGameContext(json)
+    assert(result.isRight)
+    val ctx = result.toOption.get
+    val move = ctx.moves.head
+    assert(move.moveType == MoveType.Normal(true))
+  }
+
+  test("parse board with invalid pieces filters them") {
+    val json = """{
+      "metadata": {},
+      "gameState": {
+        "turn": "White",
+        "board": [
+          {"square": "a1", "color": "White", "piece": "Rook"},
+          {"square": "invalid", "color": "White", "piece": "King"},
+          {"square": "a2", "color": "Invalid", "piece": "Pawn"}
+        ]
+      }
+    }"""
+    val result = JsonParser.importGameContext(json)
+    assert(result.isRight)
+    val ctx = result.toOption.get
+    // Only valid piece should be in board
+    assert(ctx.board.pieces.size == 1)
+  }