From 9b5185298e9e721e6103ea8372ca29073913775c Mon Sep 17 00:00:00 2001
From: Janis <janis-e@gmx.de>
Date: Tue, 21 Apr 2026 15:38:58 +0200
Subject: [PATCH] feat: NCS-53 changed IO to MicroService for easier scaling
 (#37)

Reviewed-on: https://git.janis-eccarius.de/NowChess/NowChessSystems/pulls/37
Reviewed-by: Shahd Lala <shosho996@blackhole.local>
---
 .idea/scala_compiler.xml                      |   2 +-
 CLAUDE.md                                     |   1 +
 CLAUDE.original.md                            |   1 +
 bruno/{ => board}/draw/01 Offer Draw.bru      |   0
 bruno/{ => board}/draw/02 Accept Draw.bru     |   0
 bruno/{ => board}/draw/03 Decline Draw.bru    |   0
 bruno/{ => board}/draw/04 Claim Draw.bru      |   0
 bruno/{ => board}/draw/folder.bru             |   0
 bruno/{ => board}/export/01 Export FEN.bru    |   0
 bruno/{ => board}/export/02 Export PGN.bru    |   0
 bruno/{ => board}/export/folder.bru           |   0
 bruno/{ => board}/game/01 Create Game.bru     |   0
 bruno/{ => board}/game/02 Get Game.bru        |   0
 bruno/{ => board}/game/03 Stream Game.bru     |   0
 bruno/{ => board}/game/04 Resign.bru          |   0
 bruno/{ => board}/game/folder.bru             |   0
 bruno/{ => board}/import/01 Import FEN.bru    |   0
 bruno/{ => board}/import/02 Import PGN.bru    |   0
 bruno/{ => board}/import/folder.bru           |   0
 bruno/{ => board}/move/01 Make Move.bru       |   0
 bruno/{ => board}/move/02 Get Legal Moves.bru |   0
 bruno/{ => board}/move/03 Undo Move.bru       |   0
 bruno/{ => board}/move/04 Redo Move.bru       |   0
 bruno/{ => board}/move/folder.bru             |   0
 bruno/environments/local.bru                  |   1 +
 bruno/io/export/01 Export FEN.bru             | 100 ++++++++++++++++++
 bruno/io/export/02 Export PGN.bru             | 100 ++++++++++++++++++
 bruno/io/export/folder.bru                    |   4 +
 bruno/io/import/01 Import FEN.bru             |  22 ++++
 bruno/io/import/02 Import PGN.bru             |  22 ++++
 bruno/io/import/folder.bru                    |   4 +
 build.gradle.kts                              |   8 +-
 lint                                          |   3 +
 modules/core/build.gradle.kts                 |   1 +
 .../core/src/main/resources/application.yml   |  11 +-
 .../chess/client/IoServiceClient.scala        |  35 ++++++
 .../nowchess/chess/config/JacksonConfig.scala |   7 ++
 .../chess/config/NativeReflectionConfig.scala |  16 +++
 .../chess/resource/GameResource.scala         |  36 +++----
 .../GameResourceIntegrationTest.scala         |  23 +++-
 modules/io/build.gradle.kts                   |  44 +++++++-
 modules/io/src/main/resources/application.yml |  13 +++
 .../io/json/SquareKeyDeserializer.scala       |   8 ++
 .../io/json/SquareKeySerializer.scala         |   9 ++
 .../io/service/config/JacksonConfig.scala     |  24 +++++
 .../config/NativeReflectionConfig.scala       |  29 +++++
 .../io/service/dto/ImportFenRequest.scala     |   3 +
 .../io/service/dto/ImportPgnRequest.scala     |   3 +
 .../nowchess/io/service/dto/IoErrorDto.scala  |   3 +
 .../io/service/resource/IoResource.scala      |  77 ++++++++++++++
 .../io/json/SquareKeyDeserializerTest.scala   |  62 +++++++++++
 .../io/json/SquareKeySerializerTest.scala     |  50 +++++++++
 .../io/service/resource/IoResourceTest.scala  |  81 ++++++++++++++
 53 files changed, 772 insertions(+), 31 deletions(-)
 rename bruno/{ => board}/draw/01 Offer Draw.bru (100%)
 rename bruno/{ => board}/draw/02 Accept Draw.bru (100%)
 rename bruno/{ => board}/draw/03 Decline Draw.bru (100%)
 rename bruno/{ => board}/draw/04 Claim Draw.bru (100%)
 rename bruno/{ => board}/draw/folder.bru (100%)
 rename bruno/{ => board}/export/01 Export FEN.bru (100%)
 rename bruno/{ => board}/export/02 Export PGN.bru (100%)
 rename bruno/{ => board}/export/folder.bru (100%)
 rename bruno/{ => board}/game/01 Create Game.bru (100%)
 rename bruno/{ => board}/game/02 Get Game.bru (100%)
 rename bruno/{ => board}/game/03 Stream Game.bru (100%)
 rename bruno/{ => board}/game/04 Resign.bru (100%)
 rename bruno/{ => board}/game/folder.bru (100%)
 rename bruno/{ => board}/import/01 Import FEN.bru (100%)
 rename bruno/{ => board}/import/02 Import PGN.bru (100%)
 rename bruno/{ => board}/import/folder.bru (100%)
 rename bruno/{ => board}/move/01 Make Move.bru (100%)
 rename bruno/{ => board}/move/02 Get Legal Moves.bru (100%)
 rename bruno/{ => board}/move/03 Undo Move.bru (100%)
 rename bruno/{ => board}/move/04 Redo Move.bru (100%)
 rename bruno/{ => board}/move/folder.bru (100%)
 create mode 100644 bruno/io/export/01 Export FEN.bru
 create mode 100644 bruno/io/export/02 Export PGN.bru
 create mode 100644 bruno/io/export/folder.bru
 create mode 100644 bruno/io/import/01 Import FEN.bru
 create mode 100644 bruno/io/import/02 Import PGN.bru
 create mode 100644 bruno/io/import/folder.bru
 create mode 100755 lint
 create mode 100644 modules/core/src/main/scala/de/nowchess/chess/client/IoServiceClient.scala
 create mode 100644 modules/io/src/main/resources/application.yml
 create mode 100644 modules/io/src/main/scala/de/nowchess/io/json/SquareKeyDeserializer.scala
 create mode 100644 modules/io/src/main/scala/de/nowchess/io/json/SquareKeySerializer.scala
 create mode 100644 modules/io/src/main/scala/de/nowchess/io/service/config/JacksonConfig.scala
 create mode 100644 modules/io/src/main/scala/de/nowchess/io/service/config/NativeReflectionConfig.scala
 create mode 100644 modules/io/src/main/scala/de/nowchess/io/service/dto/ImportFenRequest.scala
 create mode 100644 modules/io/src/main/scala/de/nowchess/io/service/dto/ImportPgnRequest.scala
 create mode 100644 modules/io/src/main/scala/de/nowchess/io/service/dto/IoErrorDto.scala
 create mode 100644 modules/io/src/main/scala/de/nowchess/io/service/resource/IoResource.scala
 create mode 100644 modules/io/src/test/scala/de/nowchess/io/json/SquareKeyDeserializerTest.scala
 create mode 100644 modules/io/src/test/scala/de/nowchess/io/json/SquareKeySerializerTest.scala
 create mode 100644 modules/io/src/test/scala/de/nowchess/io/service/resource/IoResourceTest.scala

diff --git a/.idea/scala_compiler.xml b/.idea/scala_compiler.xml
index a99d21e..5c60cfe 100644
--- a/.idea/scala_compiler.xml
+++ b/.idea/scala_compiler.xml
@@ -5,7 +5,7 @@
       <option name="deprecationWarnings" value="true" />
       <option name="uncheckedWarnings" value="true" />
     </profile>
-    <profile name="Gradle 2" modules="NowChessSystems.modules.bot.main,NowChessSystems.modules.bot.scoverage,NowChessSystems.modules.bot.test,NowChessSystems.modules.core.integrationTest,NowChessSystems.modules.core.main,NowChessSystems.modules.core.native-test,NowChessSystems.modules.core.quarkus-generated-sources,NowChessSystems.modules.core.quarkus-test-generated-sources,NowChessSystems.modules.core.scoverage,NowChessSystems.modules.core.test,NowChessSystems.modules.io.main,NowChessSystems.modules.io.scoverage,NowChessSystems.modules.io.test,NowChessSystems.modules.rule.main,NowChessSystems.modules.rule.scoverage,NowChessSystems.modules.rule.test,NowChessSystems.modules.ui.main,NowChessSystems.modules.ui.scoverage,NowChessSystems.modules.ui.test">
+    <profile name="Gradle 2" modules="NowChessSystems.modules.bot.main,NowChessSystems.modules.bot.scoverage,NowChessSystems.modules.bot.test,NowChessSystems.modules.core.integrationTest,NowChessSystems.modules.core.main,NowChessSystems.modules.core.native-test,NowChessSystems.modules.core.quarkus-generated-sources,NowChessSystems.modules.core.quarkus-test-generated-sources,NowChessSystems.modules.core.scoverage,NowChessSystems.modules.core.test,NowChessSystems.modules.io.integrationTest,NowChessSystems.modules.io.main,NowChessSystems.modules.io.native-test,NowChessSystems.modules.io.quarkus-generated-sources,NowChessSystems.modules.io.quarkus-test-generated-sources,NowChessSystems.modules.io.scoverage,NowChessSystems.modules.io.test,NowChessSystems.modules.rule.main,NowChessSystems.modules.rule.scoverage,NowChessSystems.modules.rule.test,NowChessSystems.modules.ui.main,NowChessSystems.modules.ui.scoverage,NowChessSystems.modules.ui.test">
       <option name="deprecationWarnings" value="true" />
       <option name="uncheckedWarnings" value="true" />
       <parameters>
diff --git a/CLAUDE.md b/CLAUDE.md
index d75a177..dccc202 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -9,6 +9,7 @@ Scala 3.5.1 · Gradle 9
 ./compile    # Compile all modules — always run
 ./test       # Run all tests
 ./coverage   # Check coverage
+./lint       # Run linters
 ```
 Use consistently.
 
diff --git a/CLAUDE.original.md b/CLAUDE.original.md
index b5ab597..8439c5e 100644
--- a/CLAUDE.original.md
+++ b/CLAUDE.original.md
@@ -9,6 +9,7 @@ Scala 3.5.1 · Gradle 9
 ./compile    # Compile all modules — always run
 ./test       # Run all tests
 ./coverage   # Check coverage
+./lint       # Run linters
 ```
 Try to stick to these commands for consistency.
 
diff --git a/bruno/draw/01 Offer Draw.bru b/bruno/board/draw/01 Offer Draw.bru
similarity index 100%
rename from bruno/draw/01 Offer Draw.bru
rename to bruno/board/draw/01 Offer Draw.bru
diff --git a/bruno/draw/02 Accept Draw.bru b/bruno/board/draw/02 Accept Draw.bru
similarity index 100%
rename from bruno/draw/02 Accept Draw.bru
rename to bruno/board/draw/02 Accept Draw.bru
diff --git a/bruno/draw/03 Decline Draw.bru b/bruno/board/draw/03 Decline Draw.bru
similarity index 100%
rename from bruno/draw/03 Decline Draw.bru
rename to bruno/board/draw/03 Decline Draw.bru
diff --git a/bruno/draw/04 Claim Draw.bru b/bruno/board/draw/04 Claim Draw.bru
similarity index 100%
rename from bruno/draw/04 Claim Draw.bru
rename to bruno/board/draw/04 Claim Draw.bru
diff --git a/bruno/draw/folder.bru b/bruno/board/draw/folder.bru
similarity index 100%
rename from bruno/draw/folder.bru
rename to bruno/board/draw/folder.bru
diff --git a/bruno/export/01 Export FEN.bru b/bruno/board/export/01 Export FEN.bru
similarity index 100%
rename from bruno/export/01 Export FEN.bru
rename to bruno/board/export/01 Export FEN.bru
diff --git a/bruno/export/02 Export PGN.bru b/bruno/board/export/02 Export PGN.bru
similarity index 100%
rename from bruno/export/02 Export PGN.bru
rename to bruno/board/export/02 Export PGN.bru
diff --git a/bruno/export/folder.bru b/bruno/board/export/folder.bru
similarity index 100%
rename from bruno/export/folder.bru
rename to bruno/board/export/folder.bru
diff --git a/bruno/game/01 Create Game.bru b/bruno/board/game/01 Create Game.bru
similarity index 100%
rename from bruno/game/01 Create Game.bru
rename to bruno/board/game/01 Create Game.bru
diff --git a/bruno/game/02 Get Game.bru b/bruno/board/game/02 Get Game.bru
similarity index 100%
rename from bruno/game/02 Get Game.bru
rename to bruno/board/game/02 Get Game.bru
diff --git a/bruno/game/03 Stream Game.bru b/bruno/board/game/03 Stream Game.bru
similarity index 100%
rename from bruno/game/03 Stream Game.bru
rename to bruno/board/game/03 Stream Game.bru
diff --git a/bruno/game/04 Resign.bru b/bruno/board/game/04 Resign.bru
similarity index 100%
rename from bruno/game/04 Resign.bru
rename to bruno/board/game/04 Resign.bru
diff --git a/bruno/game/folder.bru b/bruno/board/game/folder.bru
similarity index 100%
rename from bruno/game/folder.bru
rename to bruno/board/game/folder.bru
diff --git a/bruno/import/01 Import FEN.bru b/bruno/board/import/01 Import FEN.bru
similarity index 100%
rename from bruno/import/01 Import FEN.bru
rename to bruno/board/import/01 Import FEN.bru
diff --git a/bruno/import/02 Import PGN.bru b/bruno/board/import/02 Import PGN.bru
similarity index 100%
rename from bruno/import/02 Import PGN.bru
rename to bruno/board/import/02 Import PGN.bru
diff --git a/bruno/import/folder.bru b/bruno/board/import/folder.bru
similarity index 100%
rename from bruno/import/folder.bru
rename to bruno/board/import/folder.bru
diff --git a/bruno/move/01 Make Move.bru b/bruno/board/move/01 Make Move.bru
similarity index 100%
rename from bruno/move/01 Make Move.bru
rename to bruno/board/move/01 Make Move.bru
diff --git a/bruno/move/02 Get Legal Moves.bru b/bruno/board/move/02 Get Legal Moves.bru
similarity index 100%
rename from bruno/move/02 Get Legal Moves.bru
rename to bruno/board/move/02 Get Legal Moves.bru
diff --git a/bruno/move/03 Undo Move.bru b/bruno/board/move/03 Undo Move.bru
similarity index 100%
rename from bruno/move/03 Undo Move.bru
rename to bruno/board/move/03 Undo Move.bru
diff --git a/bruno/move/04 Redo Move.bru b/bruno/board/move/04 Redo Move.bru
similarity index 100%
rename from bruno/move/04 Redo Move.bru
rename to bruno/board/move/04 Redo Move.bru
diff --git a/bruno/move/folder.bru b/bruno/board/move/folder.bru
similarity index 100%
rename from bruno/move/folder.bru
rename to bruno/board/move/folder.bru
diff --git a/bruno/environments/local.bru b/bruno/environments/local.bru
index 85aff34..d0f7638 100644
--- a/bruno/environments/local.bru
+++ b/bruno/environments/local.bru
@@ -1,3 +1,4 @@
 vars {
   baseUrl: http://localhost:8080
+  ioBaseUrl: http://localhost:8081
 }
diff --git a/bruno/io/export/01 Export FEN.bru b/bruno/io/export/01 Export FEN.bru
new file mode 100644
index 0000000..27ab0d7
--- /dev/null
+++ b/bruno/io/export/01 Export FEN.bru	
@@ -0,0 +1,100 @@
+meta {
+  name: Export FEN
+  type: http
+  seq: 1
+}
+
+http {
+  method: POST
+  url: {{ioBaseUrl}}/io/export/fen
+  body: json
+  auth: none
+}
+
+headers {
+  Content-Type: application/json
+}
+
+body:json {
+  {
+    "board": {
+      "a1": {"color": "White", "pieceType": "Rook"},
+      "b1": {"color": "White", "pieceType": "Knight"},
+      "c1": {"color": "White", "pieceType": "Bishop"},
+      "d1": {"color": "White", "pieceType": "Queen"},
+      "e1": {"color": "White", "pieceType": "King"},
+      "f1": {"color": "White", "pieceType": "Bishop"},
+      "g1": {"color": "White", "pieceType": "Knight"},
+      "h1": {"color": "White", "pieceType": "Rook"},
+      "a2": {"color": "White", "pieceType": "Pawn"},
+      "b2": {"color": "White", "pieceType": "Pawn"},
+      "c2": {"color": "White", "pieceType": "Pawn"},
+      "d2": {"color": "White", "pieceType": "Pawn"},
+      "e2": {"color": "White", "pieceType": "Pawn"},
+      "f2": {"color": "White", "pieceType": "Pawn"},
+      "g2": {"color": "White", "pieceType": "Pawn"},
+      "h2": {"color": "White", "pieceType": "Pawn"},
+      "a7": {"color": "Black", "pieceType": "Pawn"},
+      "b7": {"color": "Black", "pieceType": "Pawn"},
+      "c7": {"color": "Black", "pieceType": "Pawn"},
+      "d7": {"color": "Black", "pieceType": "Pawn"},
+      "e7": {"color": "Black", "pieceType": "Pawn"},
+      "f7": {"color": "Black", "pieceType": "Pawn"},
+      "g7": {"color": "Black", "pieceType": "Pawn"},
+      "h7": {"color": "Black", "pieceType": "Pawn"},
+      "a8": {"color": "Black", "pieceType": "Rook"},
+      "b8": {"color": "Black", "pieceType": "Knight"},
+      "c8": {"color": "Black", "pieceType": "Bishop"},
+      "d8": {"color": "Black", "pieceType": "Queen"},
+      "e8": {"color": "Black", "pieceType": "King"},
+      "f8": {"color": "Black", "pieceType": "Bishop"},
+      "g8": {"color": "Black", "pieceType": "Knight"},
+      "h8": {"color": "Black", "pieceType": "Rook"}
+    },
+    "turn": "White",
+    "castlingRights": {
+      "whiteKingSide": true,
+      "whiteQueenSide": true,
+      "blackKingSide": true,
+      "blackQueenSide": true
+    },
+    "enPassantSquare": null,
+    "halfMoveClock": 0,
+    "moves": [],
+    "result": null,
+    "initialBoard": {
+      "a1": {"color": "White", "pieceType": "Rook"},
+      "b1": {"color": "White", "pieceType": "Knight"},
+      "c1": {"color": "White", "pieceType": "Bishop"},
+      "d1": {"color": "White", "pieceType": "Queen"},
+      "e1": {"color": "White", "pieceType": "King"},
+      "f1": {"color": "White", "pieceType": "Bishop"},
+      "g1": {"color": "White", "pieceType": "Knight"},
+      "h1": {"color": "White", "pieceType": "Rook"},
+      "a2": {"color": "White", "pieceType": "Pawn"},
+      "b2": {"color": "White", "pieceType": "Pawn"},
+      "c2": {"color": "White", "pieceType": "Pawn"},
+      "d2": {"color": "White", "pieceType": "Pawn"},
+      "e2": {"color": "White", "pieceType": "Pawn"},
+      "f2": {"color": "White", "pieceType": "Pawn"},
+      "g2": {"color": "White", "pieceType": "Pawn"},
+      "h2": {"color": "White", "pieceType": "Pawn"},
+      "a7": {"color": "Black", "pieceType": "Pawn"},
+      "b7": {"color": "Black", "pieceType": "Pawn"},
+      "c7": {"color": "Black", "pieceType": "Pawn"},
+      "d7": {"color": "Black", "pieceType": "Pawn"},
+      "e7": {"color": "Black", "pieceType": "Pawn"},
+      "f7": {"color": "Black", "pieceType": "Pawn"},
+      "g7": {"color": "Black", "pieceType": "Pawn"},
+      "h7": {"color": "Black", "pieceType": "Pawn"},
+      "a8": {"color": "Black", "pieceType": "Rook"},
+      "b8": {"color": "Black", "pieceType": "Knight"},
+      "c8": {"color": "Black", "pieceType": "Bishop"},
+      "d8": {"color": "Black", "pieceType": "Queen"},
+      "e8": {"color": "Black", "pieceType": "King"},
+      "f8": {"color": "Black", "pieceType": "Bishop"},
+      "g8": {"color": "Black", "pieceType": "Knight"},
+      "h8": {"color": "Black", "pieceType": "Rook"}
+    }
+  }
+}
diff --git a/bruno/io/export/02 Export PGN.bru b/bruno/io/export/02 Export PGN.bru
new file mode 100644
index 0000000..e1395a3
--- /dev/null
+++ b/bruno/io/export/02 Export PGN.bru	
@@ -0,0 +1,100 @@
+meta {
+  name: Export PGN
+  type: http
+  seq: 2
+}
+
+http {
+  method: POST
+  url: {{ioBaseUrl}}/io/export/pgn
+  body: json
+  auth: none
+}
+
+headers {
+  Content-Type: application/json
+}
+
+body:json {
+  {
+    "board": {
+      "a1": {"color": "White", "pieceType": "Rook"},
+      "b1": {"color": "White", "pieceType": "Knight"},
+      "c1": {"color": "White", "pieceType": "Bishop"},
+      "d1": {"color": "White", "pieceType": "Queen"},
+      "e1": {"color": "White", "pieceType": "King"},
+      "f1": {"color": "White", "pieceType": "Bishop"},
+      "g1": {"color": "White", "pieceType": "Knight"},
+      "h1": {"color": "White", "pieceType": "Rook"},
+      "a2": {"color": "White", "pieceType": "Pawn"},
+      "b2": {"color": "White", "pieceType": "Pawn"},
+      "c2": {"color": "White", "pieceType": "Pawn"},
+      "d2": {"color": "White", "pieceType": "Pawn"},
+      "e2": {"color": "White", "pieceType": "Pawn"},
+      "f2": {"color": "White", "pieceType": "Pawn"},
+      "g2": {"color": "White", "pieceType": "Pawn"},
+      "h2": {"color": "White", "pieceType": "Pawn"},
+      "a7": {"color": "Black", "pieceType": "Pawn"},
+      "b7": {"color": "Black", "pieceType": "Pawn"},
+      "c7": {"color": "Black", "pieceType": "Pawn"},
+      "d7": {"color": "Black", "pieceType": "Pawn"},
+      "e7": {"color": "Black", "pieceType": "Pawn"},
+      "f7": {"color": "Black", "pieceType": "Pawn"},
+      "g7": {"color": "Black", "pieceType": "Pawn"},
+      "h7": {"color": "Black", "pieceType": "Pawn"},
+      "a8": {"color": "Black", "pieceType": "Rook"},
+      "b8": {"color": "Black", "pieceType": "Knight"},
+      "c8": {"color": "Black", "pieceType": "Bishop"},
+      "d8": {"color": "Black", "pieceType": "Queen"},
+      "e8": {"color": "Black", "pieceType": "King"},
+      "f8": {"color": "Black", "pieceType": "Bishop"},
+      "g8": {"color": "Black", "pieceType": "Knight"},
+      "h8": {"color": "Black", "pieceType": "Rook"}
+    },
+    "turn": "White",
+    "castlingRights": {
+      "whiteKingSide": true,
+      "whiteQueenSide": true,
+      "blackKingSide": true,
+      "blackQueenSide": true
+    },
+    "enPassantSquare": null,
+    "halfMoveClock": 0,
+    "moves": [],
+    "result": null,
+    "initialBoard": {
+      "a1": {"color": "White", "pieceType": "Rook"},
+      "b1": {"color": "White", "pieceType": "Knight"},
+      "c1": {"color": "White", "pieceType": "Bishop"},
+      "d1": {"color": "White", "pieceType": "Queen"},
+      "e1": {"color": "White", "pieceType": "King"},
+      "f1": {"color": "White", "pieceType": "Bishop"},
+      "g1": {"color": "White", "pieceType": "Knight"},
+      "h1": {"color": "White", "pieceType": "Rook"},
+      "a2": {"color": "White", "pieceType": "Pawn"},
+      "b2": {"color": "White", "pieceType": "Pawn"},
+      "c2": {"color": "White", "pieceType": "Pawn"},
+      "d2": {"color": "White", "pieceType": "Pawn"},
+      "e2": {"color": "White", "pieceType": "Pawn"},
+      "f2": {"color": "White", "pieceType": "Pawn"},
+      "g2": {"color": "White", "pieceType": "Pawn"},
+      "h2": {"color": "White", "pieceType": "Pawn"},
+      "a7": {"color": "Black", "pieceType": "Pawn"},
+      "b7": {"color": "Black", "pieceType": "Pawn"},
+      "c7": {"color": "Black", "pieceType": "Pawn"},
+      "d7": {"color": "Black", "pieceType": "Pawn"},
+      "e7": {"color": "Black", "pieceType": "Pawn"},
+      "f7": {"color": "Black", "pieceType": "Pawn"},
+      "g7": {"color": "Black", "pieceType": "Pawn"},
+      "h7": {"color": "Black", "pieceType": "Pawn"},
+      "a8": {"color": "Black", "pieceType": "Rook"},
+      "b8": {"color": "Black", "pieceType": "Knight"},
+      "c8": {"color": "Black", "pieceType": "Bishop"},
+      "d8": {"color": "Black", "pieceType": "Queen"},
+      "e8": {"color": "Black", "pieceType": "King"},
+      "f8": {"color": "Black", "pieceType": "Bishop"},
+      "g8": {"color": "Black", "pieceType": "Knight"},
+      "h8": {"color": "Black", "pieceType": "Rook"}
+    }
+  }
+}
diff --git a/bruno/io/export/folder.bru b/bruno/io/export/folder.bru
new file mode 100644
index 0000000..ba07dba
--- /dev/null
+++ b/bruno/io/export/folder.bru
@@ -0,0 +1,4 @@
+meta {
+  name: export
+  seq: 2
+}
diff --git a/bruno/io/import/01 Import FEN.bru b/bruno/io/import/01 Import FEN.bru
new file mode 100644
index 0000000..ec901c6
--- /dev/null
+++ b/bruno/io/import/01 Import FEN.bru	
@@ -0,0 +1,22 @@
+meta {
+  name: Import FEN
+  type: http
+  seq: 1
+}
+
+http {
+  method: POST
+  url: {{ioBaseUrl}}/io/import/fen
+  body: json
+  auth: none
+}
+
+headers {
+  Content-Type: application/json
+}
+
+body:json {
+  {
+    "fen": "rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq e3 0 1"
+  }
+}
diff --git a/bruno/io/import/02 Import PGN.bru b/bruno/io/import/02 Import PGN.bru
new file mode 100644
index 0000000..b7e038d
--- /dev/null
+++ b/bruno/io/import/02 Import PGN.bru	
@@ -0,0 +1,22 @@
+meta {
+  name: Import PGN
+  type: http
+  seq: 2
+}
+
+http {
+  method: POST
+  url: {{ioBaseUrl}}/io/import/pgn
+  body: json
+  auth: none
+}
+
+headers {
+  Content-Type: application/json
+}
+
+body:json {
+  {
+    "pgn": "1. e4 e5 2. Nf3 Nc6 *"
+  }
+}
diff --git a/bruno/io/import/folder.bru b/bruno/io/import/folder.bru
new file mode 100644
index 0000000..86dcb7c
--- /dev/null
+++ b/bruno/io/import/folder.bru
@@ -0,0 +1,4 @@
+meta {
+  name: import
+  seq: 1
+}
diff --git a/build.gradle.kts b/build.gradle.kts
index e8fff64..39ce424 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -36,7 +36,11 @@ val coverageExclusions = listOf(
     "**/core/src/main/scala/de/nowchess/chess/registry/GameEntry.scala",
     "**/core/src/main/scala/de/nowchess/chess/registry/GameRegistryImpl.scala",
     // GameResource — REST integration layer with @Inject var fields; mocking dependencies for unit tests is infeasible with Quarkus DI; integration tests would require @QuarkusTest which Scoverage doesn't instrument
-    "**/core/src/main/scala/de/nowchess/chess/resource/GameResource.scala"
+    "**/core/src/main/scala/de/nowchess/chess/resource/GameResource.scala",
+    // IoResource — same rationale as GameResource; @QuarkusTest not instrumented by Scoverage
+    "**/io/src/main/scala/de/nowchess/io/service/resource/IoResource.scala",
+    // JacksonConfig — Quarkus lifecycle hook, no testable logic beyond ObjectMapper registration
+    "**/io/src/main/scala/de/nowchess/io/service/config/JacksonConfig.scala",
 )
 
 // Converts a Sonar-style glob to a scoverage regex (matched against full source path).
@@ -72,7 +76,7 @@ sonar {
 val versions = mapOf(
     "QUARKUS_SCALA3"        to "1.0.0",
     "SCALA3"                to "3.5.1",
-    "SCALA_LIBRARY"         to "2.13.18",
+    "SCALA_LIBRARY"         to "2.13.16",
     "SCALATEST"             to "3.2.19",
     "SCALATEST_JUNIT"       to "0.1.11",
     "SCOVERAGE"             to "2.1.1",
diff --git a/lint b/lint
new file mode 100755
index 0000000..848a455
--- /dev/null
+++ b/lint
@@ -0,0 +1,3 @@
+#! /usr/bin/env bash
+
+./gradlew scalafix spotlessCheck
diff --git a/modules/core/build.gradle.kts b/modules/core/build.gradle.kts
index a02a07c..d572500 100644
--- a/modules/core/build.gradle.kts
+++ b/modules/core/build.gradle.kts
@@ -74,6 +74,7 @@ dependencies {
     testImplementation("org.scalatest:scalatest_3:${versions["SCALATEST"]!!}")
     testImplementation("co.helmethair:scalatest-junit-runner:${versions["SCALATEST_JUNIT"]!!}")
     testImplementation("io.quarkus:quarkus-junit5")
+    testImplementation("io.quarkus:quarkus-junit5-mockito")
     testImplementation("io.rest-assured:rest-assured")
 
     testRuntimeOnly("org.junit.platform:junit-platform-launcher")
diff --git a/modules/core/src/main/resources/application.yml b/modules/core/src/main/resources/application.yml
index 0d92446..1663bc0 100644
--- a/modules/core/src/main/resources/application.yml
+++ b/modules/core/src/main/resources/application.yml
@@ -1,3 +1,8 @@
-greeting:
-  message: "hello"
-
+quarkus:
+  http:
+    port: 8080
+  application:
+    name: nowchess-core
+  rest-client:
+    io-service:
+      url: http://localhost:8081
diff --git a/modules/core/src/main/scala/de/nowchess/chess/client/IoServiceClient.scala b/modules/core/src/main/scala/de/nowchess/chess/client/IoServiceClient.scala
new file mode 100644
index 0000000..dac4c3d
--- /dev/null
+++ b/modules/core/src/main/scala/de/nowchess/chess/client/IoServiceClient.scala
@@ -0,0 +1,35 @@
+package de.nowchess.chess.client
+
+import de.nowchess.api.game.GameContext
+import de.nowchess.io.service.dto.{ImportFenRequest, ImportPgnRequest}
+import jakarta.ws.rs.*
+import jakarta.ws.rs.core.MediaType
+import org.eclipse.microprofile.rest.client.inject.RegisterRestClient
+
+@Path("/io")
+@RegisterRestClient(configKey = "io-service")
+trait IoServiceClient:
+
+  @POST
+  @Path("/import/fen")
+  @Consumes(Array(MediaType.APPLICATION_JSON))
+  @Produces(Array(MediaType.APPLICATION_JSON))
+  def importFen(body: ImportFenRequest): GameContext
+
+  @POST
+  @Path("/import/pgn")
+  @Consumes(Array(MediaType.APPLICATION_JSON))
+  @Produces(Array(MediaType.APPLICATION_JSON))
+  def importPgn(body: ImportPgnRequest): GameContext
+
+  @POST
+  @Path("/export/fen")
+  @Consumes(Array(MediaType.APPLICATION_JSON))
+  @Produces(Array(MediaType.TEXT_PLAIN))
+  def exportFen(ctx: GameContext): String
+
+  @POST
+  @Path("/export/pgn")
+  @Consumes(Array(MediaType.APPLICATION_JSON))
+  @Produces(Array("application/x-chess-pgn"))
+  def exportPgn(ctx: GameContext): String
diff --git a/modules/core/src/main/scala/de/nowchess/chess/config/JacksonConfig.scala b/modules/core/src/main/scala/de/nowchess/chess/config/JacksonConfig.scala
index b252cec..816cb0b 100644
--- a/modules/core/src/main/scala/de/nowchess/chess/config/JacksonConfig.scala
+++ b/modules/core/src/main/scala/de/nowchess/chess/config/JacksonConfig.scala
@@ -2,7 +2,10 @@ package de.nowchess.chess.config
 
 import com.fasterxml.jackson.core.Version
 import com.fasterxml.jackson.databind.ObjectMapper
+import com.fasterxml.jackson.databind.module.SimpleModule
 import com.fasterxml.jackson.module.scala.DefaultScalaModule
+import de.nowchess.api.board.Square
+import de.nowchess.io.json.{SquareKeyDeserializer, SquareKeySerializer}
 import io.quarkus.jackson.ObjectMapperCustomizer
 import jakarta.inject.Singleton
 
@@ -15,3 +18,7 @@ class JacksonConfig extends ObjectMapperCustomizer:
         new Version(2, 21, 1, null, "com.fasterxml.jackson.module", "jackson-module-scala")
         // scalafix:on DisableSyntax.null
     })
+    val squareModule = new SimpleModule()
+    squareModule.addKeyDeserializer(classOf[Square], new SquareKeyDeserializer())
+    squareModule.addKeySerializer(classOf[Square], new SquareKeySerializer())
+    mapper.registerModule(squareModule)
diff --git a/modules/core/src/main/scala/de/nowchess/chess/config/NativeReflectionConfig.scala b/modules/core/src/main/scala/de/nowchess/chess/config/NativeReflectionConfig.scala
index c8ce0fe..42e4cd4 100644
--- a/modules/core/src/main/scala/de/nowchess/chess/config/NativeReflectionConfig.scala
+++ b/modules/core/src/main/scala/de/nowchess/chess/config/NativeReflectionConfig.scala
@@ -1,6 +1,9 @@
 package de.nowchess.chess.config
 
+import de.nowchess.api.board.{CastlingRights, Color, File, Piece, PieceType, Rank, Square}
 import de.nowchess.api.dto.*
+import de.nowchess.api.game.{DrawReason, GameContext, GameResult}
+import de.nowchess.api.move.{Move, MoveType, PromotionPiece}
 import io.quarkus.runtime.annotations.RegisterForReflection
 
 @RegisterForReflection(
@@ -18,6 +21,19 @@ import io.quarkus.runtime.annotations.RegisterForReflection
     classOf[LegalMovesResponseDto],
     classOf[OkResponseDto],
     classOf[PlayerInfoDto],
+    classOf[GameContext],
+    classOf[Color],
+    classOf[Piece],
+    classOf[PieceType],
+    classOf[CastlingRights],
+    classOf[Square],
+    classOf[File],
+    classOf[Rank],
+    classOf[Move],
+    classOf[MoveType],
+    classOf[PromotionPiece],
+    classOf[GameResult],
+    classOf[DrawReason],
   ),
 )
 class NativeReflectionConfig
diff --git a/modules/core/src/main/scala/de/nowchess/chess/resource/GameResource.scala b/modules/core/src/main/scala/de/nowchess/chess/resource/GameResource.scala
index e8258bb..ece9752 100644
--- a/modules/core/src/main/scala/de/nowchess/chess/resource/GameResource.scala
+++ b/modules/core/src/main/scala/de/nowchess/chess/resource/GameResource.scala
@@ -6,18 +6,21 @@ import de.nowchess.api.dto.*
 import de.nowchess.api.game.{DrawReason, GameContext, GameResult}
 import de.nowchess.api.move.{Move, MoveType, PromotionPiece}
 import de.nowchess.api.player.{PlayerId, PlayerInfo}
+import de.nowchess.chess.client.IoServiceClient
 import de.nowchess.chess.controller.Parser
 import de.nowchess.chess.engine.GameEngine
 import de.nowchess.chess.exception.{BadRequestException, GameNotFoundException}
 import de.nowchess.chess.observer.*
 import de.nowchess.chess.registry.{GameEntry, GameRegistry}
-import de.nowchess.io.fen.{FenExporter, FenParser}
-import de.nowchess.io.pgn.{PgnExporter, PgnParser}
+import de.nowchess.io.fen.FenExporter
+import de.nowchess.io.pgn.PgnExporter
+import de.nowchess.io.service.dto.{ImportFenRequest, ImportPgnRequest}
 import io.smallrye.mutiny.Multi
 import jakarta.enterprise.context.ApplicationScoped
 import jakarta.inject.Inject
 import jakarta.ws.rs.*
 import jakarta.ws.rs.core.{MediaType, Response}
+import org.eclipse.microprofile.rest.client.inject.RestClient
 
 import java.util.concurrent.atomic.AtomicReference
 import scala.compiletime.uninitialized
@@ -32,6 +35,10 @@ class GameResource:
 
   @Inject
   var objectMapper: ObjectMapper = uninitialized
+
+  @Inject
+  @RestClient
+  var ioClient: IoServiceClient = uninitialized
   // scalafix:on DisableSyntax.var
 
   private val DefaultWhite = PlayerInfo(PlayerId("p1"), "Player 1")
@@ -142,7 +149,6 @@ class GameResource:
     val black = playerInfoFrom(req.black, DefaultBlack)
     val entry = newEntry(GameContext.initial, white, black)
     registry.store(entry)
-    println(s"Created game ${entry.gameId}")
     created(toGameFullDto(entry))
 
   @GET
@@ -264,9 +270,7 @@ class GameResource:
   @Consumes(Array(MediaType.APPLICATION_JSON))
   @Produces(Array(MediaType.APPLICATION_JSON))
   def importFen(body: ImportFenRequestDto): Response =
-    val ctx = FenParser.parseFen(body.fen) match
-      case Left(err)  => throw BadRequestException("INVALID_FEN", err, Some("fen"))
-      case Right(ctx) => ctx
+    val ctx   = ioClient.importFen(ImportFenRequest(body.fen))
     val white = playerInfoFrom(body.white, DefaultWhite)
     val black = playerInfoFrom(body.black, DefaultBlack)
     val entry = newEntry(ctx, white, black)
@@ -278,11 +282,8 @@ class GameResource:
   @Consumes(Array(MediaType.APPLICATION_JSON))
   @Produces(Array(MediaType.APPLICATION_JSON))
   def importPgn(body: ImportPgnRequestDto): Response =
-    val engine = GameEngine()
-    engine.loadGame(PgnParser, body.pgn) match
-      case Left(err) => throw BadRequestException("INVALID_PGN", err, Some("pgn"))
-      case Right(_)  => ()
-    val entry = GameEntry(registry.generateId(), engine, DefaultWhite, DefaultBlack)
+    val ctx   = ioClient.importPgn(ImportPgnRequest(body.pgn))
+    val entry = newEntry(ctx, DefaultWhite, DefaultBlack)
     registry.store(entry)
     created(toGameFullDto(entry))
 
@@ -291,21 +292,12 @@ class GameResource:
   @Produces(Array(MediaType.TEXT_PLAIN))
   def exportFen(@PathParam("gameId") gameId: String): Response =
     val entry = registry.get(gameId).getOrElse(throw GameNotFoundException(gameId))
-    ok(FenExporter.exportGameContext(entry.engine.context))
+    ok(ioClient.exportFen(entry.engine.context))
 
   @GET
   @Path("/{gameId}/export/pgn")
   @Produces(Array("application/x-chess-pgn"))
   def exportPgn(@PathParam("gameId") gameId: String): Response =
     val entry = registry.get(gameId).getOrElse(throw GameNotFoundException(gameId))
-    val pgn = PgnExporter.exportGame(
-      Map(
-        "Event"  -> "NowChess game",
-        "White"  -> entry.white.displayName,
-        "Black"  -> entry.black.displayName,
-        "Result" -> "*",
-      ),
-      entry.engine.context.moves,
-    )
-    ok(pgn)
+    ok(ioClient.exportPgn(entry.engine.context))
   // scalafix:on DisableSyntax.throw
diff --git a/modules/core/src/test/scala/de/nowchess/chess/resource/GameResourceIntegrationTest.scala b/modules/core/src/test/scala/de/nowchess/chess/resource/GameResourceIntegrationTest.scala
index bf165cc..1ee458e 100644
--- a/modules/core/src/test/scala/de/nowchess/chess/resource/GameResourceIntegrationTest.scala
+++ b/modules/core/src/test/scala/de/nowchess/chess/resource/GameResourceIntegrationTest.scala
@@ -1,11 +1,19 @@
 package de.nowchess.chess.resource
 
 import de.nowchess.api.dto.*
+import de.nowchess.api.game.GameContext
+import de.nowchess.chess.client.IoServiceClient
 import de.nowchess.chess.exception.BadRequestException
+import de.nowchess.io.fen.FenExporter
+import de.nowchess.io.pgn.PgnParser
+import io.quarkus.test.InjectMock
 import io.quarkus.test.junit.QuarkusTest
 import jakarta.inject.Inject
-import org.junit.jupiter.api.{DisplayName, Test}
+import org.eclipse.microprofile.rest.client.inject.RestClient
+import org.junit.jupiter.api.{BeforeEach, DisplayName, Test}
 import org.junit.jupiter.api.Assertions.*
+import org.mockito.ArgumentMatchers.any
+import org.mockito.Mockito.when
 
 import scala.compiletime.uninitialized
 
@@ -17,6 +25,19 @@ class GameResourceIntegrationTest:
   @Inject
   var resource: GameResource = uninitialized
 
+  @InjectMock
+  @RestClient
+  var ioClient: IoServiceClient = uninitialized
+
+  @BeforeEach
+  def setupMocks(): Unit =
+    when(ioClient.importFen(any())).thenReturn(GameContext.initial)
+    when(ioClient.importPgn(any())).thenReturn(
+      PgnParser.importGameContext("1. e4 c5").toOption.get,
+    )
+    when(ioClient.exportFen(any())).thenReturn(FenExporter.exportGameContext(GameContext.initial))
+    when(ioClient.exportPgn(any())).thenReturn("1. e4 c5")
+
   @Test
   @DisplayName("createGame returns 201")
   def testCreateGame(): Unit =
diff --git a/modules/io/build.gradle.kts b/modules/io/build.gradle.kts
index 84475e4..61ea69d 100644
--- a/modules/io/build.gradle.kts
+++ b/modules/io/build.gradle.kts
@@ -1,6 +1,7 @@
 plugins {
     id("scala")
     id("org.scoverage") version "8.1"
+    id("io.quarkus")
 }
 
 group = "de.nowchess"
@@ -28,6 +29,10 @@ tasks.withType<ScalaCompile> {
     scalaCompileOptions.additionalParameters = listOf("-encoding", "UTF-8")
 }
 
+val quarkusPlatformGroupId: String by project
+val quarkusPlatformArtifactId: String by project
+val quarkusPlatformVersion: String by project
+
 dependencies {
 
     compileOnly("org.scala-lang:scala3-compiler_3") {
@@ -53,19 +58,51 @@ dependencies {
     implementation("com.fasterxml.jackson.module:jackson-module-scala_3:${versions["JACKSON_SCALA"]!!}")
     implementation("com.fasterxml.jackson.datatype:jackson-datatype-jsr310:${versions["JACKSON"]!!}")
 
+    implementation(enforcedPlatform("${quarkusPlatformGroupId}:${quarkusPlatformArtifactId}:${quarkusPlatformVersion}"))
+    implementation("io.quarkus:quarkus-rest")
+    implementation("io.quarkus:quarkus-rest-jackson")
+    implementation("io.quarkus:quarkus-arc")
+    implementation("io.quarkus:quarkus-config-yaml")
+    implementation("io.quarkus:quarkus-smallrye-health")
+    implementation("io.quarkus:quarkus-smallrye-openapi")
+
     testImplementation(platform("org.junit:junit-bom:5.13.4"))
     testImplementation("org.junit.jupiter:junit-jupiter")
     testImplementation("org.scalatest:scalatest_3:${versions["SCALATEST"]!!}")
     testImplementation("co.helmethair:scalatest-junit-runner:${versions["SCALATEST_JUNIT"]!!}")
+    testImplementation("io.quarkus:quarkus-junit5")
+    testImplementation("io.rest-assured:rest-assured")
 
     testRuntimeOnly("org.junit.platform:junit-platform-launcher")
+    testRuntimeOnly("org.junit.jupiter:junit-jupiter-engine")
+}
+
+
+configurations.matching { !it.name.startsWith("scoverage") }.configureEach {
+    resolutionStrategy.force("org.scala-lang:scala-library:${versions["SCALA_LIBRARY"]!!}")
+}
+configurations.scoverage {
+    resolutionStrategy.eachDependency {
+        if (requested.group == "org.scoverage" && requested.name.startsWith("scalac-scoverage-plugin_")) {
+            useTarget("${requested.group}:scalac-scoverage-plugin_2.13.16:2.3.0")
+        }
+    }
+}
+
+tasks.withType<JavaCompile> {
+    options.encoding = "UTF-8"
+    options.compilerArgs.add("-parameters")
+}
+
+tasks.withType<Jar>().configureEach {
+    duplicatesStrategy = DuplicatesStrategy.EXCLUDE
 }
 
 tasks.test {
     useJUnitPlatform {
-        includeEngines("scalatest")
+        includeEngines("scalatest", "junit-jupiter")
         testLogging {
-            events("skipped", "failed")
+            events("passed", "skipped", "failed")
         }
     }
     finalizedBy(tasks.reportScoverage)
@@ -73,3 +110,6 @@ tasks.test {
 tasks.reportScoverage {
     dependsOn(tasks.test)
 }
+tasks.jar {
+    duplicatesStrategy = DuplicatesStrategy.EXCLUDE
+}
diff --git a/modules/io/src/main/resources/application.yml b/modules/io/src/main/resources/application.yml
new file mode 100644
index 0000000..b80a867
--- /dev/null
+++ b/modules/io/src/main/resources/application.yml
@@ -0,0 +1,13 @@
+quarkus:
+  http:
+    port: 8081
+  application:
+    name: nowchess-io
+  smallrye-openapi:
+    info-title: NowChess IO Service
+    info-version: 1.0.0
+    info-description: Chess notation import and export — FEN and PGN
+    path: /openapi
+  swagger-ui:
+    always-include: true
+    path: /swagger-ui
diff --git a/modules/io/src/main/scala/de/nowchess/io/json/SquareKeyDeserializer.scala b/modules/io/src/main/scala/de/nowchess/io/json/SquareKeyDeserializer.scala
new file mode 100644
index 0000000..223f077
--- /dev/null
+++ b/modules/io/src/main/scala/de/nowchess/io/json/SquareKeyDeserializer.scala
@@ -0,0 +1,8 @@
+package de.nowchess.io.json
+
+import com.fasterxml.jackson.databind.{DeserializationContext, KeyDeserializer}
+import de.nowchess.api.board.Square
+
+class SquareKeyDeserializer extends KeyDeserializer:
+  override def deserializeKey(key: String, ctx: DeserializationContext): AnyRef =
+    Square.fromAlgebraic(key).orNull
diff --git a/modules/io/src/main/scala/de/nowchess/io/json/SquareKeySerializer.scala b/modules/io/src/main/scala/de/nowchess/io/json/SquareKeySerializer.scala
new file mode 100644
index 0000000..93bcbad
--- /dev/null
+++ b/modules/io/src/main/scala/de/nowchess/io/json/SquareKeySerializer.scala
@@ -0,0 +1,9 @@
+package de.nowchess.io.json
+
+import com.fasterxml.jackson.core.JsonGenerator
+import com.fasterxml.jackson.databind.{JsonSerializer, SerializerProvider}
+import de.nowchess.api.board.Square
+
+class SquareKeySerializer extends JsonSerializer[Square]:
+  override def serialize(value: Square, gen: JsonGenerator, provider: SerializerProvider): Unit =
+    gen.writeFieldName(value.toString)
diff --git a/modules/io/src/main/scala/de/nowchess/io/service/config/JacksonConfig.scala b/modules/io/src/main/scala/de/nowchess/io/service/config/JacksonConfig.scala
new file mode 100644
index 0000000..b0a0c5c
--- /dev/null
+++ b/modules/io/src/main/scala/de/nowchess/io/service/config/JacksonConfig.scala
@@ -0,0 +1,24 @@
+package de.nowchess.io.service.config
+
+import com.fasterxml.jackson.core.Version
+import com.fasterxml.jackson.databind.ObjectMapper
+import com.fasterxml.jackson.databind.module.SimpleModule
+import com.fasterxml.jackson.module.scala.DefaultScalaModule
+import de.nowchess.api.board.Square
+import de.nowchess.io.json.{SquareKeyDeserializer, SquareKeySerializer}
+import io.quarkus.jackson.ObjectMapperCustomizer
+import jakarta.inject.Singleton
+
+@Singleton
+class JacksonConfig extends ObjectMapperCustomizer:
+  def customize(mapper: ObjectMapper): Unit =
+    mapper.registerModule(new DefaultScalaModule() {
+      override def version(): Version =
+        // scalafix:off DisableSyntax.null
+        new Version(2, 21, 1, null, "com.fasterxml.jackson.module", "jackson-module-scala")
+        // scalafix:on DisableSyntax.null
+    })
+    val squareModule = new SimpleModule()
+    squareModule.addKeyDeserializer(classOf[Square], new SquareKeyDeserializer())
+    squareModule.addKeySerializer(classOf[Square], new SquareKeySerializer())
+    mapper.registerModule(squareModule)
diff --git a/modules/io/src/main/scala/de/nowchess/io/service/config/NativeReflectionConfig.scala b/modules/io/src/main/scala/de/nowchess/io/service/config/NativeReflectionConfig.scala
new file mode 100644
index 0000000..a9a15e8
--- /dev/null
+++ b/modules/io/src/main/scala/de/nowchess/io/service/config/NativeReflectionConfig.scala
@@ -0,0 +1,29 @@
+package de.nowchess.io.service.config
+
+import de.nowchess.api.board.{CastlingRights, Color, File, Piece, PieceType, Rank, Square}
+import de.nowchess.api.game.{DrawReason, GameContext, GameResult}
+import de.nowchess.api.move.{Move, MoveType, PromotionPiece}
+import de.nowchess.io.service.dto.{ImportFenRequest, ImportPgnRequest, IoErrorDto}
+import io.quarkus.runtime.annotations.RegisterForReflection
+
+@RegisterForReflection(
+  targets = Array(
+    classOf[ImportFenRequest],
+    classOf[ImportPgnRequest],
+    classOf[IoErrorDto],
+    classOf[GameContext],
+    classOf[GameResult],
+    classOf[DrawReason],
+    classOf[Color],
+    classOf[Piece],
+    classOf[PieceType],
+    classOf[CastlingRights],
+    classOf[Square],
+    classOf[File],
+    classOf[Rank],
+    classOf[Move],
+    classOf[MoveType],
+    classOf[PromotionPiece],
+  ),
+)
+class NativeReflectionConfig
diff --git a/modules/io/src/main/scala/de/nowchess/io/service/dto/ImportFenRequest.scala b/modules/io/src/main/scala/de/nowchess/io/service/dto/ImportFenRequest.scala
new file mode 100644
index 0000000..fe7a139
--- /dev/null
+++ b/modules/io/src/main/scala/de/nowchess/io/service/dto/ImportFenRequest.scala
@@ -0,0 +1,3 @@
+package de.nowchess.io.service.dto
+
+case class ImportFenRequest(fen: String)
diff --git a/modules/io/src/main/scala/de/nowchess/io/service/dto/ImportPgnRequest.scala b/modules/io/src/main/scala/de/nowchess/io/service/dto/ImportPgnRequest.scala
new file mode 100644
index 0000000..83ed7f7
--- /dev/null
+++ b/modules/io/src/main/scala/de/nowchess/io/service/dto/ImportPgnRequest.scala
@@ -0,0 +1,3 @@
+package de.nowchess.io.service.dto
+
+case class ImportPgnRequest(pgn: String)
diff --git a/modules/io/src/main/scala/de/nowchess/io/service/dto/IoErrorDto.scala b/modules/io/src/main/scala/de/nowchess/io/service/dto/IoErrorDto.scala
new file mode 100644
index 0000000..04c9805
--- /dev/null
+++ b/modules/io/src/main/scala/de/nowchess/io/service/dto/IoErrorDto.scala
@@ -0,0 +1,3 @@
+package de.nowchess.io.service.dto
+
+case class IoErrorDto(code: String, message: String)
diff --git a/modules/io/src/main/scala/de/nowchess/io/service/resource/IoResource.scala b/modules/io/src/main/scala/de/nowchess/io/service/resource/IoResource.scala
new file mode 100644
index 0000000..393d74e
--- /dev/null
+++ b/modules/io/src/main/scala/de/nowchess/io/service/resource/IoResource.scala
@@ -0,0 +1,77 @@
+package de.nowchess.io.service.resource
+
+import de.nowchess.api.game.GameContext
+import de.nowchess.io.fen.{FenExporter, FenParser}
+import de.nowchess.io.pgn.{PgnExporter, PgnParser}
+import de.nowchess.io.service.dto.{ImportFenRequest, ImportPgnRequest, IoErrorDto}
+import io.smallrye.mutiny.Uni
+import jakarta.enterprise.context.ApplicationScoped
+import jakarta.ws.rs.*
+import jakarta.ws.rs.core.{MediaType, Response}
+import org.eclipse.microprofile.openapi.annotations.Operation
+import org.eclipse.microprofile.openapi.annotations.media.{Content, Schema}
+import org.eclipse.microprofile.openapi.annotations.responses.{APIResponse, APIResponses}
+import org.eclipse.microprofile.openapi.annotations.tags.Tag
+
+@Path("/io")
+@ApplicationScoped
+@Tag(name = "IO", description = "Chess notation import and export")
+class IoResource:
+
+  @POST
+  @Path("/import/fen")
+  @Consumes(Array(MediaType.APPLICATION_JSON))
+  @Produces(Array(MediaType.APPLICATION_JSON))
+  @Operation(summary = "Import FEN", description = "Parse a FEN string into a GameContext")
+  @APIResponses(
+    Array(
+      new APIResponse(responseCode = "200", description = "Parsed GameContext"),
+      new APIResponse(responseCode = "400", description = "Invalid FEN"),
+    ),
+  )
+  def importFen(body: ImportFenRequest): Uni[Response] =
+    Uni.createFrom().item {
+      FenParser.parseFen(body.fen) match
+        case Left(err) =>
+          Response.status(400).entity(IoErrorDto("INVALID_FEN", err)).build()
+        case Right(ctx) =>
+          Response.ok(ctx).build()
+    }
+
+  @POST
+  @Path("/import/pgn")
+  @Consumes(Array(MediaType.APPLICATION_JSON))
+  @Produces(Array(MediaType.APPLICATION_JSON))
+  @Operation(summary = "Import PGN", description = "Parse a PGN string into a GameContext")
+  @APIResponses(
+    Array(
+      new APIResponse(responseCode = "200", description = "Parsed GameContext"),
+      new APIResponse(responseCode = "400", description = "Invalid PGN"),
+    ),
+  )
+  def importPgn(body: ImportPgnRequest): Uni[Response] =
+    Uni.createFrom().item {
+      PgnParser.importGameContext(body.pgn) match
+        case Left(err) =>
+          Response.status(400).entity(IoErrorDto("INVALID_PGN", err)).build()
+        case Right(ctx) =>
+          Response.ok(ctx).build()
+    }
+
+  @POST
+  @Path("/export/fen")
+  @Consumes(Array(MediaType.APPLICATION_JSON))
+  @Produces(Array(MediaType.TEXT_PLAIN))
+  @Operation(summary = "Export FEN", description = "Serialize a GameContext to FEN notation")
+  @APIResponse(responseCode = "200", description = "FEN string")
+  def exportFen(ctx: GameContext): Uni[Response] =
+    Uni.createFrom().item(Response.ok(FenExporter.exportGameContext(ctx)).build())
+
+  @POST
+  @Path("/export/pgn")
+  @Consumes(Array(MediaType.APPLICATION_JSON))
+  @Produces(Array("application/x-chess-pgn"))
+  @Operation(summary = "Export PGN", description = "Serialize a GameContext to PGN notation")
+  @APIResponse(responseCode = "200", description = "PGN text")
+  def exportPgn(ctx: GameContext): Uni[Response] =
+    Uni.createFrom().item(Response.ok(PgnExporter.exportGameContext(ctx)).build())
diff --git a/modules/io/src/test/scala/de/nowchess/io/json/SquareKeyDeserializerTest.scala b/modules/io/src/test/scala/de/nowchess/io/json/SquareKeyDeserializerTest.scala
new file mode 100644
index 0000000..70908d2
--- /dev/null
+++ b/modules/io/src/test/scala/de/nowchess/io/json/SquareKeyDeserializerTest.scala
@@ -0,0 +1,62 @@
+package de.nowchess.io.json
+
+import com.fasterxml.jackson.core.`type`.TypeReference
+import com.fasterxml.jackson.databind.ObjectMapper
+import com.fasterxml.jackson.databind.module.SimpleModule
+import com.fasterxml.jackson.module.scala.DefaultScalaModule
+import de.nowchess.api.board.{File, Rank, Square}
+import org.scalatest.funsuite.AnyFunSuite
+import org.scalatest.matchers.should.Matchers
+
+class SquareKeyDeserializerTest extends AnyFunSuite with Matchers:
+
+  private def mapper: ObjectMapper =
+    val m   = new ObjectMapper()
+    val mod = new SimpleModule()
+    mod.addKeyDeserializer(classOf[Square], new SquareKeyDeserializer())
+    m.registerModule(DefaultScalaModule)
+    m.registerModule(mod)
+    m
+
+  private def readMap(json: String): Map[Square, Int] =
+    mapper.readValue(json, new TypeReference[Map[Square, Int]] {})
+
+  test("deserializes valid algebraic key") {
+    val result = readMap("""{"e4":1}""")
+    result(Square(File.E, Rank.R4)) shouldBe 1
+  }
+
+  test("deserializes a1 corner") {
+    val result = readMap("""{"a1":1}""")
+    result(Square(File.A, Rank.R1)) shouldBe 1
+  }
+
+  test("deserializes h8 corner") {
+    val result = readMap("""{"h8":1}""")
+    result(Square(File.H, Rank.R8)) shouldBe 1
+  }
+
+  test("deserializes multiple squares") {
+    val result = readMap("""{"a1":1,"h8":2,"e4":3}""")
+    result(Square(File.A, Rank.R1)) shouldBe 1
+    result(Square(File.H, Rank.R8)) shouldBe 2
+    result(Square(File.E, Rank.R4)) shouldBe 3
+  }
+
+  // scalafix:off DisableSyntax.null
+  test("deserializeKey returns null for invalid square") {
+    new SquareKeyDeserializer().deserializeKey("invalid", null) shouldBe null
+  }
+
+  test("deserializeKey returns null for wrong-length key") {
+    new SquareKeyDeserializer().deserializeKey("e44", null) shouldBe null
+  }
+
+  test("deserializeKey returns null for bad file") {
+    new SquareKeyDeserializer().deserializeKey("z4", null) shouldBe null
+  }
+
+  test("deserializeKey returns null for bad rank") {
+    new SquareKeyDeserializer().deserializeKey("e9", null) shouldBe null
+  }
+  // scalafix:on DisableSyntax.null
diff --git a/modules/io/src/test/scala/de/nowchess/io/json/SquareKeySerializerTest.scala b/modules/io/src/test/scala/de/nowchess/io/json/SquareKeySerializerTest.scala
new file mode 100644
index 0000000..bcc2f0f
--- /dev/null
+++ b/modules/io/src/test/scala/de/nowchess/io/json/SquareKeySerializerTest.scala
@@ -0,0 +1,50 @@
+package de.nowchess.io.json
+
+import com.fasterxml.jackson.core.`type`.TypeReference
+import com.fasterxml.jackson.databind.ObjectMapper
+import com.fasterxml.jackson.databind.module.SimpleModule
+import com.fasterxml.jackson.module.scala.DefaultScalaModule
+import de.nowchess.api.board.{File, Rank, Square}
+import org.scalatest.funsuite.AnyFunSuite
+import org.scalatest.matchers.should.Matchers
+
+class SquareKeySerializerTest extends AnyFunSuite with Matchers:
+
+  private def mapper: ObjectMapper =
+    val m   = new ObjectMapper()
+    val mod = new SimpleModule()
+    mod.addKeySerializer(classOf[Square], new SquareKeySerializer())
+    m.registerModule(DefaultScalaModule)
+    m.registerModule(mod)
+    m
+
+  test("serializes square as algebraic notation") {
+    val json = mapper.writeValueAsString(Map(Square(File.E, Rank.R4) -> 1))
+    json should include("\"e4\"")
+  }
+
+  test("serializes a1 corner") {
+    val json = mapper.writeValueAsString(Map(Square(File.A, Rank.R1) -> 1))
+    json should include("\"a1\"")
+  }
+
+  test("serializes h8 corner") {
+    val json = mapper.writeValueAsString(Map(Square(File.H, Rank.R8) -> 1))
+    json should include("\"h8\"")
+  }
+
+  test("round-trips with SquareKeyDeserializer") {
+    val rt = {
+      val m   = new ObjectMapper()
+      val mod = new SimpleModule()
+      mod.addKeySerializer(classOf[Square], new SquareKeySerializer())
+      mod.addKeyDeserializer(classOf[Square], new SquareKeyDeserializer())
+      m.registerModule(DefaultScalaModule)
+      m.registerModule(mod)
+      m
+    }
+    val original = Map(Square(File.D, Rank.R5) -> 99)
+    val json     = rt.writeValueAsString(original)
+    val result   = rt.readValue(json, new TypeReference[Map[Square, Int]] {})
+    result shouldBe original
+  }
diff --git a/modules/io/src/test/scala/de/nowchess/io/service/resource/IoResourceTest.scala b/modules/io/src/test/scala/de/nowchess/io/service/resource/IoResourceTest.scala
new file mode 100644
index 0000000..2091794
--- /dev/null
+++ b/modules/io/src/test/scala/de/nowchess/io/service/resource/IoResourceTest.scala
@@ -0,0 +1,81 @@
+package de.nowchess.io.service.resource
+
+import com.fasterxml.jackson.databind.ObjectMapper
+import com.fasterxml.jackson.databind.module.SimpleModule
+import com.fasterxml.jackson.module.scala.DefaultScalaModule
+import de.nowchess.api.board.Square
+import de.nowchess.api.game.GameContext
+import de.nowchess.io.json.{SquareKeyDeserializer, SquareKeySerializer}
+import io.quarkus.test.junit.QuarkusTest
+import io.restassured.RestAssured
+import io.restassured.http.ContentType
+import org.junit.jupiter.api.Assertions.*
+import org.junit.jupiter.api.Test
+
+@QuarkusTest
+class IoResourceTest:
+  private lazy val testMapper: ObjectMapper =
+    val m   = new ObjectMapper()
+    val mod = new SimpleModule()
+    mod.addKeySerializer(classOf[Square], new SquareKeySerializer())
+    mod.addKeyDeserializer(classOf[Square], new SquareKeyDeserializer())
+    m.registerModule(new DefaultScalaModule())
+    m.registerModule(mod)
+    m
+
+  private def contextJson(ctx: GameContext): String = testMapper.writeValueAsString(ctx)
+
+  @Test
+  def importFenReturns200(): Unit =
+    val resp = RestAssured
+      .`given`()
+      .contentType(ContentType.JSON)
+      .body("""{"fen":"rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq e3 0 1"}""")
+      .post("/io/import/fen")
+    assertEquals(200, resp.statusCode())
+
+  @Test
+  def importFenInvalidReturns400(): Unit =
+    val resp = RestAssured
+      .`given`()
+      .contentType(ContentType.JSON)
+      .body("""{"fen":"not-a-fen"}""")
+      .post("/io/import/fen")
+    assertEquals(400, resp.statusCode())
+
+  @Test
+  def importPgnReturns200(): Unit =
+    val resp = RestAssured
+      .`given`()
+      .contentType(ContentType.JSON)
+      .body("""{"pgn":"1. e4 e5"}""")
+      .post("/io/import/pgn")
+    assertEquals(200, resp.statusCode())
+
+  @Test
+  def importPgnInvalidReturns400(): Unit =
+    val resp = RestAssured
+      .`given`()
+      .contentType(ContentType.JSON)
+      .body("""{"pgn":"not valid pgn !!!###"}""")
+      .post("/io/import/pgn")
+    assertEquals(400, resp.statusCode())
+
+  @Test
+  def exportFenReturns200WithFen(): Unit =
+    val resp = RestAssured
+      .`given`()
+      .contentType(ContentType.JSON)
+      .body(contextJson(GameContext.initial))
+      .post("/io/export/fen")
+    assertEquals(200, resp.statusCode())
+    assertTrue(resp.getBody.asString().contains("rnbqkbnr"))
+
+  @Test
+  def exportPgnReturns200(): Unit =
+    val resp = RestAssured
+      .`given`()
+      .contentType(ContentType.JSON)
+      .body(contextJson(GameContext.initial))
+      .post("/io/export/pgn")
+    assertEquals(200, resp.statusCode())