ci: bump version with Build-46

Reviewed-on: #38

.github/workflows/native-image.yml

@@ -0,0 +1,87 @@
+name: Build & Push Native Image
+
+on:
+  push:
+    branches:
+      - main
+  workflow_dispatch:
+
+jobs:
+  check-actor:
+    runs-on: ubuntu-latest
+    outputs:
+      allowed: ${{ steps.check.outputs.allowed }}
+    steps:
+      - id: check
+        run: |
+          if [[ "${{ github.event_name }}" == "workflow_dispatch" || "${{ github.actor }}" == "TeamCity" ]]; then
+            echo "allowed=true" >> "$GITHUB_OUTPUT"
+          else
+            echo "allowed=false" >> "$GITHUB_OUTPUT"
+          fi
+
+  build-and-push:
+    needs: check-actor
+    if: needs.check-actor.outputs.allowed == 'true'
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+
+    strategy:
+      matrix:
+        module:
+          - core
+          - io
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up GraalVM
+        uses: graalvm/setup-graalvm@v1
+        with:
+          java-version: '21'
+          distribution: 'graalvm-community'
+          native-image-job-reports: 'true'
+
+      - name: Cache Gradle packages
+        uses: actions/cache@v4
+        with:
+          path: |
+            ~/.gradle/caches
+            ~/.gradle/wrapper
+          key: gradle-${{ runner.os }}-${{ hashFiles('**/*.gradle*', '**/gradle-wrapper.properties') }}
+          restore-keys: gradle-${{ runner.os }}-
+
+      - name: Build native binary
+        run: ./gradlew :modules:${{ matrix.module }}:build -Dquarkus.native.enabled=true --no-daemon
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Log in to GitHub Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Extract metadata
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ghcr.io/now-chess/now-chess-systems/${{ matrix.module }}
+          tags: |
+            type=sha,prefix=,format=short
+            type=raw,value=latest
+
+      - name: Build and push
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          file: modules/${{ matrix.module }}/src/main/docker/Dockerfile.native
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+          cache-from: type=gha,scope=${{ matrix.module }}
+          cache-to: type=gha,mode=max,scope=${{ matrix.module }}

.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>

CLAUDE.md

@@ -9,8 +9,9 @@ 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.
+Use consistently.
 
 ## Modules
 
@@ -25,14 +26,14 @@ Try to stick to these commands for consistency.
 
 ## Style
 
-- Use immutable data and pure functions.
-- Keep functions under 30 lines. If you need "and" to describe it, split it.
-- Keep cyclomatic complexity under 15.
-- Avoid comments. Let names carry intent; comment only non-obvious algorithms.
-- Scan for duplicated logic before finishing. Extract it.
+- Immutable data, pure functions.
+- Functions under 30 lines. Need "and"? Split it.
+- Cyclomatic complexity under 15.
+- No comments. Names carry intent. Comment non-obvious algorithms only.
+- Scan duplicated logic. Extract.
 - Follow default Sonar style for Scala.
-- Use `Option` or `Either` for fallible operations; avoid exceptions for control flow.
-- Naming: types are PascalCase, functions/values are camelCase.
+- `Option`/`Either` for fallible ops. Skip exceptions for control flow.
+- Naming: types PascalCase, functions/values camelCase.
 
 ## Code Quality
 
@@ -40,23 +41,23 @@ Try to stick to these commands for consistency.
 
 ### Linters
 
-- **scalafmt** — enforces formatting; run `./gradlew spotlessScalaCheck` to check and `./gradlew spotlessScalaApply` to refactor.
-- **scalafix** — enforces style and detects unused imports/code; run `./gradlew scalafix` to apply rules.
+- **scalafmt** — Enforces formatting. Check: `./gradlew spotlessScalaCheck`. Refactor: `./gradlew spotlessScalaApply`.
+- **scalafix** — Enforces style, detects unused imports/code. Run: `./gradlew scalafix`.
 
 ## Architecture Decisions
 
-- **Immutable state as primary model:** GameContext (api) holds board, history, player state — immutable, passed through the system. Each move creates a new GameContext, enabling undo/redo without side effects.
-- **Observer pattern for UI decoupling:** GameEngine publishes move/state events; CommandInvoker queues moves; UI listens to events, not polling. GameEngine never imports UI code.
-- **RuleSet trait encapsulates rules:** Move generation, check, castling, en passant all in RuleSet impl. GameEngine calls rules as a black box; rules don't know about the rest of core.
-- **Polyglot hash must follow spec index layout:** piece keys use interleaved mapping `(pieceType * 2 + colorBit)` with black=0/white=1, castling keys are `768..771`, en-passant file keys are `772..779` and are XORed only if side-to-move has a pawn that can capture en passant, side-to-move key is `780` for white.
-- **Alpha-beta uses sequential PV search by default:** parallel split was disabled because fixed-window futures removed pruning effectiveness; correctness and pruning quality take priority over speculative parallelism.
-- **Search hash is updated incrementally per move:** bot search now updates Zobrist keys from parent hash with move deltas instead of recomputing piece scans at every node.
+- **Immutable state as primary model:** GameContext (api) holds board, history, player state—immutable throughout. Each move → new GameContext. Enables undo/redo without side effects.
+- **Observer pattern for UI decoupling:** GameEngine publishes move/state events; CommandInvoker queues moves; UI listens (no polling). GameEngine never imports UI.
+- **RuleSet trait encapsulates rules:** Move generation, check, castling, en passant all in RuleSet impl. GameEngine calls rules as black box; rules don't know rest of core.
+- **Polyglot hash must follow spec index layout:** Piece keys use interleaved mapping `(pieceType * 2 + colorBit)` (black=0, white=1). Castling keys: `768..771`. En-passant file keys: `772..779`, XORed only if side-to-move has capturable en passant. Side-to-move key: `780` (white).
+- **Alpha-beta uses sequential PV search by default:** Parallel split disabled (fixed-window futures removed pruning effectiveness). Sequential PV default. Correctness + pruning quality > speculative parallelism.
+- **Search hash is updated incrementally per move:** Bot search updates Zobrist keys from parent hash with move deltas, not recomputing piece scans per node.
 
 ## Rules
 
-- **Tests are the spec.** Never modify tests to pass; modify requirements or code. Update tests only if requirements change.
+- **Tests are the spec.** Don't modify to pass. Fix requirements/code. Update only if requirements change.
 - Never read build folders. Ask permission if needed.
-- Keep this file up to date with any important decisions or conventions.
+- Keep file current with decisions + conventions.
 
 ---
 
@@ -64,11 +65,9 @@ Try to stick to these commands for consistency.
 
 ### Two-Step Rule (mandatory)
 **Step 1 — Orient:** Use wiki articles to find WHERE things live.
-**Step 2 — Verify:** Read the actual source files listed in the wiki article BEFORE writing any code.
+**Step 2 — Verify:** Read source files from wiki BEFORE coding.
 
-Wiki articles are structural summaries extracted by AST. They show routes, models, and file locations.
-They do NOT show full function logic, middleware internals, or dynamic runtime behavior.
-**Never write or modify code based solely on wiki content — always read source files first.**
+Wiki = structural summaries (routes, models, file locations). No function logic, middleware internals, runtime behavior. Don't code from wiki alone—read sources.
 
 Read in order at session start:
 1. `.codesight/wiki/index.md` — orientation map (~200 tokens)
@@ -76,8 +75,7 @@ Read in order at session start:
 3. Domain article (e.g. `.codesight/wiki/auth.md`) → check "Source Files" section → read those files
 4. `.codesight/CODESIGHT.md` — full context map for deep exploration
 
-Routes marked `[inferred]` in wiki articles were detected via regex — verify against source before trusting.
-If any source file shows ⚠ in the wiki, re-run `codesight --wiki` before proceeding.
+`[inferred]` routes = regex-detected. Verify sources. ⚠ in wiki? Re-run `codesight --wiki`.
 
 Or use the codesight MCP server for on-demand queries:
 - `codesight_get_wiki_article` — read a specific wiki article by name
@@ -87,13 +85,13 @@ Or use the codesight MCP server for on-demand queries:
 - `codesight_get_blast_radius --file src/lib/db.ts` — impact analysis before changes
 - `codesight_get_schema --model users` — specific model details
 
-Only open specific files after consulting codesight context. This saves ~16.893 tokens per conversation.
+Consult codesight context first. Saves ~16.893 tokens/conversation.
 
 ## graphify
 
-This project has a graphify knowledge graph at graphify-out/.
+graphify knowledge graph at graphify-out/.
 
 Rules:
-- Before answering architecture or codebase questions, read graphify-out/GRAPH_REPORT.md for god nodes and community structure
-- If graphify-out/wiki/index.md exists, navigate it instead of reading raw files
-- After modifying code files in this session, run `python3 -c "from graphify.watch import _rebuild_code; from pathlib import Path; _rebuild_code(Path('.'))"` to keep the graph current
+- Architecture/codebase questions? Read graphify-out/GRAPH_REPORT.md (god nodes, communities).
+- graphify-out/wiki/index.md exists? Use it (not raw files).
+- Code modified? Run `python3 -c "from graphify.watch import _rebuild_code; from pathlib import Path; _rebuild_code(Path('.'))"` to sync graph.

CLAUDE.original.md

@@ -0,0 +1,100 @@
+# Now-Chess
+
+Scala 3.5.1 · Gradle 9
+
+## Commands
+
+```
+./clean      # Clear build dirs — only when necessary
+./compile    # Compile all modules — always run
+./test       # Run all tests
+./coverage   # Check coverage
+./lint       # Run linters
+```
+Try to stick to these commands for consistency.
+
+## Modules
+
+| Module | Role | Depends on |
+|--------|------|-----------|
+| `api`  | Model / shared types | (none) |
+| `core` | Primary business logic | api, rule |
+| `rule` | Game rules | api |
+| `bot`  | Bots and AI | api,rule,io |
+| `io`   | Export formats | api, core |
+| `ui`   | Entrypoint & UI | core, io |
+
+## Style
+
+- Use immutable data and pure functions.
+- Keep functions under 30 lines. If you need "and" to describe it, split it.
+- Keep cyclomatic complexity under 15.
+- Avoid comments. Let names carry intent; comment only non-obvious algorithms.
+- Scan for duplicated logic before finishing. Extract it.
+- Follow default Sonar style for Scala.
+- Use `Option` or `Either` for fallible operations; avoid exceptions for control flow.
+- Naming: types are PascalCase, functions/values are camelCase.
+
+## Code Quality
+
+- **Coverage:** 100% condition coverage required in `api`, `core`, `rule`, `io` (mandatory); `ui` exempt.
+
+### Linters
+
+- **scalafmt** — enforces formatting; run `./gradlew spotlessScalaCheck` to check and `./gradlew spotlessScalaApply` to refactor.
+- **scalafix** — enforces style and detects unused imports/code; run `./gradlew scalafix` to apply rules.
+
+## Architecture Decisions
+
+- **Immutable state as primary model:** GameContext (api) holds board, history, player state — immutable, passed through the system. Each move creates a new GameContext, enabling undo/redo without side effects.
+- **Observer pattern for UI decoupling:** GameEngine publishes move/state events; CommandInvoker queues moves; UI listens to events, not polling. GameEngine never imports UI code.
+- **RuleSet trait encapsulates rules:** Move generation, check, castling, en passant all in RuleSet impl. GameEngine calls rules as a black box; rules don't know about the rest of core.
+- **Polyglot hash must follow spec index layout:** piece keys use interleaved mapping `(pieceType * 2 + colorBit)` with black=0/white=1, castling keys are `768..771`, en-passant file keys are `772..779` and are XORed only if side-to-move has a pawn that can capture en passant, side-to-move key is `780` for white.
+- **Alpha-beta uses sequential PV search by default:** parallel split was disabled because fixed-window futures removed pruning effectiveness; correctness and pruning quality take priority over speculative parallelism.
+- **Search hash is updated incrementally per move:** bot search now updates Zobrist keys from parent hash with move deltas instead of recomputing piece scans at every node.
+
+## Rules
+
+- **Tests are the spec.** Never modify tests to pass; modify requirements or code. Update tests only if requirements change.
+- Never read build folders. Ask permission if needed.
+- Keep this file up to date with any important decisions or conventions.
+
+---
+
+## Instructions for Claude Code
+
+### Two-Step Rule (mandatory)
+**Step 1 — Orient:** Use wiki articles to find WHERE things live.
+**Step 2 — Verify:** Read the actual source files listed in the wiki article BEFORE writing any code.
+
+Wiki articles are structural summaries extracted by AST. They show routes, models, and file locations.
+They do NOT show full function logic, middleware internals, or dynamic runtime behavior.
+**Never write or modify code based solely on wiki content — always read source files first.**
+
+Read in order at session start:
+1. `.codesight/wiki/index.md` — orientation map (~200 tokens)
+2. `.codesight/wiki/overview.md` — architecture overview (~500 tokens)
+3. Domain article (e.g. `.codesight/wiki/auth.md`) → check "Source Files" section → read those files
+4. `.codesight/CODESIGHT.md` — full context map for deep exploration
+
+Routes marked `[inferred]` in wiki articles were detected via regex — verify against source before trusting.
+If any source file shows ⚠ in the wiki, re-run `codesight --wiki` before proceeding.
+
+Or use the codesight MCP server for on-demand queries:
+- `codesight_get_wiki_article` — read a specific wiki article by name
+- `codesight_get_wiki_index` — get the wiki index
+- `codesight_get_summary` — quick project overview
+- `codesight_get_routes --prefix /api/users` — filtered routes
+- `codesight_get_blast_radius --file src/lib/db.ts` — impact analysis before changes
+- `codesight_get_schema --model users` — specific model details
+
+Only open specific files after consulting codesight context. This saves ~16.893 tokens per conversation.
+
+## graphify
+
+This project has a graphify knowledge graph at graphify-out/.
+
+Rules:
+- Before answering architecture or codebase questions, read graphify-out/GRAPH_REPORT.md for god nodes and community structure
+- If graphify-out/wiki/index.md exists, navigate it instead of reading raw files
+- After modifying code files in this session, run `python3 -c "from graphify.watch import _rebuild_code; from pathlib import Path; _rebuild_code(Path('.'))"` to keep the graph current

bruno/environments/local.bru

@@ -1,3 +1,4 @@
 vars {
   baseUrl: http://localhost:8080
+  ioBaseUrl: http://localhost:8081
 }

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"}
+    }
+  }
+}

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"}
+    }
+  }
+}

bruno/io/export/folder.bru

@@ -0,0 +1,4 @@
+meta {
+  name: export
+  seq: 2
+}

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"
+  }
+}

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 *"
+  }
+}

bruno/io/import/folder.bru

@@ -0,0 +1,4 @@
+meta {
+  name: import
+  seq: 1
+}

build.gradle.kts

@@ -8,6 +8,53 @@ plugins {
 group = "de.nowchess"
 version = "1.0-SNAPSHOT"
 
+// Canonical coverage exclusions — glob patterns consumed by Sonar directly;
+// converted to scoverage regexes via globToScoverageRegex for instrumentation-time exclusion.
+val coverageExclusions = listOf(
+    // UI renders JavaFX components; headless test environments cannot exercise rendering paths
+    "modules/ui/**",
+    // FastParse macro-generated combinators produce synthetic branches that scoverage marks as uncovered
+    "modules/io/src/main/scala/de/nowchess/io/fen/FenParserFastParse*",
+    // NNUE inference pipeline — coverage requires a trained model file not present in CI
+    "**/bot/**/NNUE.scala",
+    "**/bot/**/NNUEBot.scala",
+    "**/bot/**/EvaluationNNUE.scala",
+    // NBAI binary format loader/writer — error paths require crafted corrupt files; migrator is a one-shot tool
+    "**/bot/**/NbaiLoader.scala",
+    "**/bot/**/NbaiModel.scala",
+    "**/bot/**/NbaiMigrator.scala",
+    "**/bot/**/NbaiWriter.scala",
+    // PolyglotBook — binary I/O and dead-code guards (bit-masked fields can never exceed valid range)
+    "**/bot/**/PolyglotBook.scala",
+    "**/bot/**/MoveOrdering.scala",
+    "**/bot/**/AlphaBetaSearch.scala",
+    // DTO case class synthetic methods (Scala compiler-generated apply/$default params)
+    "**/api/src/main/scala/de/nowchess/api/dto/**Dto.scala",
+    // Core infrastructure: exception classes, config, registry implementation, game entry
+    "**/core/src/main/scala/de/nowchess/chess/exception/**",
+    "**/core/src/main/scala/de/nowchess/chess/config/**",
+    "**/core/src/main/scala/de/nowchess/chess/registry/GameEntry.scala",
+    "**/core/src/main/scala/de/nowchess/chess/registry/GameRegistryImpl.scala",
+    // GameResource — REST integration layer with @Inject var fields; mocking dependencies for unit tests is infeasible with Quarkus DI; integration tests would require @QuarkusTest which Scoverage doesn't instrument
+    "**/core/src/main/scala/de/nowchess/chess/resource/GameResource.scala",
+    // IoResource — same rationale as GameResource; @QuarkusTest not instrumented by Scoverage
+    "**/io/src/main/scala/de/nowchess/io/service/resource/IoResource.scala",
+    // JacksonConfig — Quarkus lifecycle hook, no testable logic beyond ObjectMapper registration
+    "**/io/src/main/scala/de/nowchess/io/service/config/JacksonConfig.scala",
+)
+
+// Converts a Sonar-style glob to a scoverage regex (matched against full source path).
+// Order matters: protect ** before converting lone *, escape dots last.
+fun globToScoverageRegex(glob: String): String =
+    glob
+        .replace("**", "^@")
+        .replace("*", "[^/]*")
+        .replace(".", "\\.")
+        .replace("^@", ".*")
+        .let { ".*$it" }
+
+extra["SCOVERAGE_EXCLUDED"] = coverageExclusions.map(::globToScoverageRegex)
+
 sonar {
     properties {
         property("sonar.projectKey", "Now-Chess-Systems")
@@ -22,33 +69,14 @@ sonar {
         }.joinToString(",")
 
         property("sonar.scala.coverage.reportPaths", scoverageReports)
-        property(
-            "sonar.coverage.exclusions",
-            // UI renders JavaFX components; headless test environments cannot exercise rendering paths
-            "modules/ui/**," +
-            // FastParse macro-generated combinators produce synthetic branches that scoverage marks as uncovered
-            "modules/io/src/main/scala/de/nowchess/io/fen/FenParserFastParse*," +
-            // NNUE inference pipeline — coverage requires a trained model file not present in CI
-            "**/bot/**/NNUE.scala," +
-            "**/bot/**/NNUEBot.scala," +
-            "**/bot/**/EvaluationNNUE.scala," +
-            // NBAI binary format loader/writer — error paths require crafted corrupt files; migrator is a one-shot tool
-            "**/bot/**/NbaiLoader.scala," +
-            "**/bot/**/NbaiModel.scala," +
-            "**/bot/**/NbaiMigrator.scala," +
-            "**/bot/**/NbaiWriter.scala," +
-            // PolyglotBook — binary I/O and dead-code guards (bit-masked fields can never exceed valid range)
-            "**/bot/**/PolyglotBook.scala," +
-            "**/bot/**/MoveOrdering.scala," +
-            "**/bot/**/AlphaBetaSearch.scala"
-        )
+        property("sonar.coverage.exclusions", coverageExclusions.joinToString(","))
     }
 }
 
 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",

lint

@@ -0,0 +1,3 @@
+#! /usr/bin/env bash
+
+./gradlew scalafix spotlessCheck

modules/api/CHANGELOG.md

@@ -60,3 +60,37 @@
 * NCS-21 Write Scripts to automate certain tasks ([#15](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/15)) ([8051871](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/80518719d536a087d339fe02530825dc07f8b388))
 * NCS-25 Add linters to keep quality up ([#27](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/27)) ([fd4e67d](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/fd4e67d4f782a7e955822d90cb909d0a81676fb2))
 * NCS-41 Bot Platform ([#33](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/33)) ([dceab08](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/dceab0875e6d15f7d3958633cf5dd5b29a851b1d))
+##  (2026-04-21)
+
+### Features
+
+* NCS-13 Implement Threefold Repetition ([#31](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/31)) ([767d305](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/767d3051a76c266050b6335774d66e2db2273c16))
+* NCS-14 implemented insufficient moves rule ([#30](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/30)) ([b0399a4](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/b0399a4e489950083066c9538df9a84dcc7a4613))
+* NCS-21 Write Scripts to automate certain tasks ([#15](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/15)) ([8051871](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/80518719d536a087d339fe02530825dc07f8b388))
+* NCS-25 Add linters to keep quality up ([#27](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/27)) ([fd4e67d](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/fd4e67d4f782a7e955822d90cb909d0a81676fb2))
+* NCS-37 Quarkus integration ([#35](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/35)) ([5ad5efb](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/5ad5efb41e9df9e3dccb48f96a69f06217ab98e1))
+* NCS-41 Bot Platform ([#33](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/33)) ([dceab08](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/dceab0875e6d15f7d3958633cf5dd5b29a851b1d))
+##  (2026-04-21)
+
+### Features
+
+* NCS-13 Implement Threefold Repetition ([#31](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/31)) ([767d305](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/767d3051a76c266050b6335774d66e2db2273c16))
+* NCS-14 implemented insufficient moves rule ([#30](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/30)) ([b0399a4](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/b0399a4e489950083066c9538df9a84dcc7a4613))
+* NCS-21 Write Scripts to automate certain tasks ([#15](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/15)) ([8051871](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/80518719d536a087d339fe02530825dc07f8b388))
+* NCS-25 Add linters to keep quality up ([#27](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/27)) ([fd4e67d](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/fd4e67d4f782a7e955822d90cb909d0a81676fb2))
+* NCS-37 Quarkus integration ([#35](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/35)) ([5ad5efb](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/5ad5efb41e9df9e3dccb48f96a69f06217ab98e1))
+* NCS-41 Bot Platform ([#33](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/33)) ([dceab08](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/dceab0875e6d15f7d3958633cf5dd5b29a851b1d))
+##  (2026-04-22)
+
+### Features
+
+* NCS-13 Implement Threefold Repetition ([#31](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/31)) ([767d305](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/767d3051a76c266050b6335774d66e2db2273c16))
+* NCS-14 implemented insufficient moves rule ([#30](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/30)) ([b0399a4](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/b0399a4e489950083066c9538df9a84dcc7a4613))
+* NCS-21 Write Scripts to automate certain tasks ([#15](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/15)) ([8051871](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/80518719d536a087d339fe02530825dc07f8b388))
+* NCS-25 Add linters to keep quality up ([#27](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/27)) ([fd4e67d](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/fd4e67d4f782a7e955822d90cb909d0a81676fb2))
+* NCS-37 Quarkus integration ([#35](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/35)) ([5ad5efb](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/5ad5efb41e9df9e3dccb48f96a69f06217ab98e1))
+* NCS-41 Bot Platform ([#33](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/33)) ([dceab08](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/dceab0875e6d15f7d3958633cf5dd5b29a851b1d))
+
+### Bug Fixes
+
+* IO microservice ([#38](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/38)) ([fb5c61d](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/fb5c61de63292e5d70c06304cba2193686aa1607))

modules/api/build.gradle.kts

@@ -8,6 +8,8 @@ version = "1.0-SNAPSHOT"
 
 @Suppress("UNCHECKED_CAST")
 val versions = rootProject.extra["VERSIONS"] as Map<String, String>
+@Suppress("UNCHECKED_CAST")
+val scoverageExcluded = rootProject.extra["SCOVERAGE_EXCLUDED"] as List<String>
 
 repositories {
     mavenCentral()
@@ -19,6 +21,7 @@ scala {
 
 scoverage {
     scoverageVersion.set(versions["SCOVERAGE"]!!)
+    excludedFiles.set(scoverageExcluded)
 }
 
 configurations.scoverage {
@@ -31,7 +34,7 @@ configurations.scoverage {
 
 dependencies {
 
-    implementation("org.scala-lang:scala3-compiler_3") {
+    compileOnly("org.scala-lang:scala3-compiler_3") {
         version {
             strictly(versions["SCALA3"]!!)
         }

modules/api/src/main/scala/de/nowchess/api/dto/ImportFenRequest.scala

@@ -0,0 +1,3 @@
+package de.nowchess.api.dto
+
+case class ImportFenRequest(fen: String)

modules/api/src/main/scala/de/nowchess/api/dto/ImportPgnRequest.scala

@@ -0,0 +1,3 @@
+package de.nowchess.api.dto
+
+case class ImportPgnRequest(pgn: String)

modules/api/src/main/scala/de/nowchess/api/io/GameContextExport.scala

@@ -1,7 +1,6 @@
-package de.nowchess.io
+package de.nowchess.api.io
 
 import de.nowchess.api.game.GameContext
 
 trait GameContextExport:
-
   def exportGameContext(context: GameContext): String

modules/api/src/main/scala/de/nowchess/api/io/GameContextImport.scala

@@ -1,7 +1,6 @@
-package de.nowchess.io
+package de.nowchess.api.io
 
 import de.nowchess.api.game.GameContext
 
 trait GameContextImport:
-
   def importGameContext(input: String): Either[String, GameContext]

modules/api/versions.env

@@ -1,3 +1,3 @@
 MAJOR=0
-MINOR=8
+MINOR=11
 PATCH=0

modules/bot/build.gradle.kts

@@ -8,6 +8,8 @@ version = "1.0-SNAPSHOT"
 
 @Suppress("UNCHECKED_CAST")
 val versions = rootProject.extra["VERSIONS"] as Map<String, String>
+@Suppress("UNCHECKED_CAST")
+val scoverageExcluded = rootProject.extra["SCOVERAGE_EXCLUDED"] as List<String>
 
 repositories {
     mavenCentral()
@@ -26,16 +28,7 @@ scoverage {
             "de\\.nowchess\\.bot\\.util\\.PolyglotBook",
         )
     )
-    excludedFiles.set(
-        listOf(
-            ".*NNUE\\.scala",
-            ".*NNUEBot\\.scala",
-            ".*NbaiLoader\\.scala",
-            ".*NbaiMigrator\\.scala",
-            ".*NbaiWriter\\.scala",
-            ".*PolyglotBook\\.scala",
-        )
-    )
+    excludedFiles.set(scoverageExcluded)
 }
 
 tasks.withType<ScalaCompile> {
@@ -44,7 +37,7 @@ tasks.withType<ScalaCompile> {
 
 dependencies {
 
-    implementation("org.scala-lang:scala3-compiler_3") {
+    compileOnly("org.scala-lang:scala3-compiler_3") {
         version {
             strictly(versions["SCALA3"]!!)
         }

modules/bot/python/datasets/ds_v1/metadata.json

@@ -1,66 +0,0 @@
-{
-  "version": 1,
-  "created": "2026-04-13T19:58:38.629943",
-  "total_positions": 3022562,
-  "stockfish_depth": 12,
-  "sources": [
-    {
-      "type": "legacy_import",
-      "path": "data/training_data.jsonl",
-      "count": 2009355,
-      "note": "Migrated from data/training_data.jsonl"
-    },
-    {
-      "type": "test_extend",
-      "count": 4,
-      "actual_count": 3
-    },
-    {
-      "type": "test_new_positions",
-      "count": 3,
-      "actual_count": 3
-    },
-    {
-      "type": "test_mixed",
-      "count": 5,
-      "actual_count": 0
-    },
-    {
-      "type": "test_all_dups",
-      "count": 2,
-      "actual_count": 0
-    },
-    {
-      "type": "guaranteed_unique",
-      "count": 10,
-      "actual_count": 8
-    },
-    {
-      "type": "merged_sources",
-      "count": 600000,
-      "sources": [
-        {
-          "type": "tactical",
-          "count": 600000,
-          "max_puzzles": 600000
-        }
-      ],
-      "actual_count": 599993
-    },
-    {
-      "type": "merged_sources",
-      "count": 500000,
-      "sources": [
-        {
-          "type": "lichess",
-          "count": 500000,
-          "params": {
-            "min_depth": 20,
-            "max_positions": 500000
-          }
-        }
-      ],
-      "actual_count": 500000
-    }
-  ]
-}

modules/core/CHANGELOG.md

@@ -341,3 +341,93 @@
 * correct test board positions and captureOutput/withInput interaction ([f0481e2](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/f0481e2561b779df00925b46ee281dc36a795150))
 * update main class path in build configuration and adjust VCS directory mapping ([7b1f8b1](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/7b1f8b117623d327232a1a92a8a44d18582e0189))
 * update move validation to check for king safety ([#13](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/13)) ([e5e20c5](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/e5e20c566e368b12ca1dc59680c34e9112bf6762))
+##  (2026-04-21)
+
+### Features
+
+* add GameRules stub with PositionStatus enum ([76d4168](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/76d4168038de23e5d6083d4e8f0504fbf31d15a3))
+* add MovedInCheck/Checkmate/Stalemate MoveResult variants (stub dispatch) ([8b7ec57](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/8b7ec57e5ea6ee1615a1883848a426dc07d26364))
+* implement GameRules with isInCheck, legalMoves, gameStatus ([94a02ff](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/94a02ff6849436d9496c70a0f16c21666dae8e4e))
+* implement legal castling ([#1](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/1)) ([00d326c](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/00d326c1ba67711fbe180f04e1100c3f01dd0254))
+* NCS-10 Implement Pawn Promotion ([#12](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/12)) ([13bfc16](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/13bfc16cfe25db78ec607db523ca6d993c13430c))
+* NCS-11 50-move rule ([#9](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/9)) ([412ed98](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/412ed986a95703a3b282276540153480ceed229d))
+* NCS-13 Implement Threefold Repetition ([#31](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/31)) ([767d305](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/767d3051a76c266050b6335774d66e2db2273c16))
+* NCS-14 implemented insufficient moves rule ([#30](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/30)) ([b0399a4](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/b0399a4e489950083066c9538df9a84dcc7a4613))
+* NCS-16 Core Separation via Patterns ([#10](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/10)) ([1361dfc](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/1361dfc89553b146864fb8ff3526cf12cf3f293a))
+* NCS-17 Implement basic ScalaFX UI ([#14](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/14)) ([3ff8031](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/3ff80318b4f16c59733a46498581a5c27f048287))
+* NCS-21 Write Scripts to automate certain tasks ([#15](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/15)) ([8051871](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/80518719d536a087d339fe02530825dc07f8b388))
+* NCS-25 Add linters to keep quality up ([#27](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/27)) ([fd4e67d](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/fd4e67d4f782a7e955822d90cb909d0a81676fb2))
+* NCS-37 Quarkus integration ([#35](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/35)) ([5ad5efb](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/5ad5efb41e9df9e3dccb48f96a69f06217ab98e1))
+* NCS-40 Rework Draw System ([#34](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/34)) ([0091d50](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/0091d50467e9f955f23570128b96c977c01bc51b))
+* NCS-41 Bot Platform ([#33](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/33)) ([dceab08](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/dceab0875e6d15f7d3958633cf5dd5b29a851b1d))
+* NCS-6 Implementing FEN & PGN ([#7](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/7)) ([f28e69d](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/f28e69dc181416aa2f221fdc4b45c2cda5efbf07))
+* NCS-9 En passant implementation ([#8](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/8)) ([919beb3](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/919beb3b4bfa8caf2f90976a415fe9b19b7e9747))
+* wire check/checkmate/stalemate into processMove and gameLoop ([5264a22](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/5264a225418b885c5e6ea6411b96f85e38837f6c))
+
+### Bug Fixes
+
+* add missing kings to gameLoop capture test board ([aedd787](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/aedd787b77203c2af934751dba7b784eaf165032))
+* correct test board positions and captureOutput/withInput interaction ([f0481e2](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/f0481e2561b779df00925b46ee281dc36a795150))
+* update main class path in build configuration and adjust VCS directory mapping ([7b1f8b1](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/7b1f8b117623d327232a1a92a8a44d18582e0189))
+* update move validation to check for king safety ([#13](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/13)) ([e5e20c5](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/e5e20c566e368b12ca1dc59680c34e9112bf6762))
+##  (2026-04-21)
+
+### Features
+
+* add GameRules stub with PositionStatus enum ([76d4168](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/76d4168038de23e5d6083d4e8f0504fbf31d15a3))
+* add MovedInCheck/Checkmate/Stalemate MoveResult variants (stub dispatch) ([8b7ec57](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/8b7ec57e5ea6ee1615a1883848a426dc07d26364))
+* implement GameRules with isInCheck, legalMoves, gameStatus ([94a02ff](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/94a02ff6849436d9496c70a0f16c21666dae8e4e))
+* implement legal castling ([#1](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/1)) ([00d326c](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/00d326c1ba67711fbe180f04e1100c3f01dd0254))
+* NCS-10 Implement Pawn Promotion ([#12](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/12)) ([13bfc16](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/13bfc16cfe25db78ec607db523ca6d993c13430c))
+* NCS-11 50-move rule ([#9](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/9)) ([412ed98](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/412ed986a95703a3b282276540153480ceed229d))
+* NCS-13 Implement Threefold Repetition ([#31](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/31)) ([767d305](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/767d3051a76c266050b6335774d66e2db2273c16))
+* NCS-14 implemented insufficient moves rule ([#30](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/30)) ([b0399a4](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/b0399a4e489950083066c9538df9a84dcc7a4613))
+* NCS-16 Core Separation via Patterns ([#10](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/10)) ([1361dfc](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/1361dfc89553b146864fb8ff3526cf12cf3f293a))
+* NCS-17 Implement basic ScalaFX UI ([#14](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/14)) ([3ff8031](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/3ff80318b4f16c59733a46498581a5c27f048287))
+* NCS-21 Write Scripts to automate certain tasks ([#15](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/15)) ([8051871](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/80518719d536a087d339fe02530825dc07f8b388))
+* NCS-25 Add linters to keep quality up ([#27](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/27)) ([fd4e67d](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/fd4e67d4f782a7e955822d90cb909d0a81676fb2))
+* NCS-37 Quarkus integration ([#35](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/35)) ([5ad5efb](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/5ad5efb41e9df9e3dccb48f96a69f06217ab98e1))
+* NCS-40 Rework Draw System ([#34](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/34)) ([0091d50](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/0091d50467e9f955f23570128b96c977c01bc51b))
+* NCS-41 Bot Platform ([#33](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/33)) ([dceab08](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/dceab0875e6d15f7d3958633cf5dd5b29a851b1d))
+* NCS-53 changed IO to MicroService for easier scaling ([#37](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/37)) ([9b51852](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/9b5185298e9e721e6103ea8372ca29073913775c))
+* NCS-6 Implementing FEN & PGN ([#7](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/7)) ([f28e69d](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/f28e69dc181416aa2f221fdc4b45c2cda5efbf07))
+* NCS-9 En passant implementation ([#8](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/8)) ([919beb3](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/919beb3b4bfa8caf2f90976a415fe9b19b7e9747))
+* wire check/checkmate/stalemate into processMove and gameLoop ([5264a22](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/5264a225418b885c5e6ea6411b96f85e38837f6c))
+
+### Bug Fixes
+
+* add missing kings to gameLoop capture test board ([aedd787](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/aedd787b77203c2af934751dba7b784eaf165032))
+* correct test board positions and captureOutput/withInput interaction ([f0481e2](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/f0481e2561b779df00925b46ee281dc36a795150))
+* update main class path in build configuration and adjust VCS directory mapping ([7b1f8b1](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/7b1f8b117623d327232a1a92a8a44d18582e0189))
+* update move validation to check for king safety ([#13](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/13)) ([e5e20c5](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/e5e20c566e368b12ca1dc59680c34e9112bf6762))
+##  (2026-04-22)
+
+### Features
+
+* add GameRules stub with PositionStatus enum ([76d4168](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/76d4168038de23e5d6083d4e8f0504fbf31d15a3))
+* add MovedInCheck/Checkmate/Stalemate MoveResult variants (stub dispatch) ([8b7ec57](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/8b7ec57e5ea6ee1615a1883848a426dc07d26364))
+* implement GameRules with isInCheck, legalMoves, gameStatus ([94a02ff](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/94a02ff6849436d9496c70a0f16c21666dae8e4e))
+* implement legal castling ([#1](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/1)) ([00d326c](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/00d326c1ba67711fbe180f04e1100c3f01dd0254))
+* NCS-10 Implement Pawn Promotion ([#12](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/12)) ([13bfc16](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/13bfc16cfe25db78ec607db523ca6d993c13430c))
+* NCS-11 50-move rule ([#9](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/9)) ([412ed98](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/412ed986a95703a3b282276540153480ceed229d))
+* NCS-13 Implement Threefold Repetition ([#31](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/31)) ([767d305](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/767d3051a76c266050b6335774d66e2db2273c16))
+* NCS-14 implemented insufficient moves rule ([#30](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/30)) ([b0399a4](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/b0399a4e489950083066c9538df9a84dcc7a4613))
+* NCS-16 Core Separation via Patterns ([#10](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/10)) ([1361dfc](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/1361dfc89553b146864fb8ff3526cf12cf3f293a))
+* NCS-17 Implement basic ScalaFX UI ([#14](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/14)) ([3ff8031](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/3ff80318b4f16c59733a46498581a5c27f048287))
+* NCS-21 Write Scripts to automate certain tasks ([#15](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/15)) ([8051871](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/80518719d536a087d339fe02530825dc07f8b388))
+* NCS-25 Add linters to keep quality up ([#27](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/27)) ([fd4e67d](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/fd4e67d4f782a7e955822d90cb909d0a81676fb2))
+* NCS-37 Quarkus integration ([#35](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/35)) ([5ad5efb](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/5ad5efb41e9df9e3dccb48f96a69f06217ab98e1))
+* NCS-40 Rework Draw System ([#34](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/34)) ([0091d50](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/0091d50467e9f955f23570128b96c977c01bc51b))
+* NCS-41 Bot Platform ([#33](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/33)) ([dceab08](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/dceab0875e6d15f7d3958633cf5dd5b29a851b1d))
+* NCS-53 changed IO to MicroService for easier scaling ([#37](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/37)) ([9b51852](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/9b5185298e9e721e6103ea8372ca29073913775c))
+* NCS-6 Implementing FEN & PGN ([#7](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/7)) ([f28e69d](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/f28e69dc181416aa2f221fdc4b45c2cda5efbf07))
+* NCS-9 En passant implementation ([#8](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/8)) ([919beb3](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/919beb3b4bfa8caf2f90976a415fe9b19b7e9747))
+* wire check/checkmate/stalemate into processMove and gameLoop ([5264a22](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/5264a225418b885c5e6ea6411b96f85e38837f6c))
+
+### Bug Fixes
+
+* add missing kings to gameLoop capture test board ([aedd787](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/aedd787b77203c2af934751dba7b784eaf165032))
+* correct test board positions and captureOutput/withInput interaction ([f0481e2](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/f0481e2561b779df00925b46ee281dc36a795150))
+* IO microservice ([#38](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/38)) ([fb5c61d](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/fb5c61de63292e5d70c06304cba2193686aa1607))
+* update main class path in build configuration and adjust VCS directory mapping ([7b1f8b1](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/7b1f8b117623d327232a1a92a8a44d18582e0189))
+* update move validation to check for king safety ([#13](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/13)) ([e5e20c5](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/e5e20c566e368b12ca1dc59680c34e9112bf6762))

modules/core/build.gradle.kts

@@ -9,6 +9,8 @@ version = "1.0-SNAPSHOT"
 
 @Suppress("UNCHECKED_CAST")
 val versions = rootProject.extra["VERSIONS"] as Map<String, String>
+@Suppress("UNCHECKED_CAST")
+val scoverageExcluded = rootProject.extra["SCOVERAGE_EXCLUDED"] as List<String>
 
 repositories {
     mavenCentral()
@@ -20,6 +22,7 @@ scala {
 
 scoverage {
     scoverageVersion.set(versions["SCOVERAGE"]!!)
+    excludedFiles.set(scoverageExcluded)
 }
 
 tasks.withType<ScalaCompile> {
@@ -33,7 +36,7 @@ val quarkusPlatformVersion: String by project
 
 dependencies {
 
-    implementation("org.scala-lang:scala3-compiler_3") {
+    compileOnly("org.scala-lang:scala3-compiler_3") {
         version {
             strictly(versions["SCALA3"]!!)
         }
@@ -45,7 +48,6 @@ dependencies {
     }
 
     implementation(project(":modules:api"))
-    implementation(project(":modules:io"))
     implementation(project(":modules:rule"))
     implementation(project(":modules:bot"))
 
@@ -66,14 +68,18 @@ dependencies {
     implementation("com.fasterxml.jackson.module:jackson-module-scala_3:${versions["JACKSON_SCALA"]!!}")
 
 
+    testImplementation(project(":modules:io"))
+
     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.quarkus:quarkus-junit5-mockito")
     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 {

modules/core/src/main/docker/Dockerfile.native

@@ -3,7 +3,7 @@
 #
 # Before building the container image run:
 #
-# ./gradlew build -Dquarkus.native.enabled=true
+# ./gradlew :modules:core:build -Dquarkus.native.enabled=true
 #
 # Then, build the image with:
 #
@@ -13,7 +13,7 @@
 #
 # docker run -i --rm -p 8080:8080 quarkus/backcore
 #
-# The ` registry.access.redhat.com/ubi9/ubi-minimal:9.7` base image is based on UBI 9.
+# The `registry.access.redhat.com/ubi9/ubi-minimal:9.7` base image is based on UBI 9.
 # To use UBI 8, switch to `quay.io/ubi8/ubi-minimal:8.10`.
 ###
 FROM registry.access.redhat.com/ubi9/ubi-minimal:9.7
@@ -21,7 +21,7 @@ WORKDIR /work/
 RUN chown 1001 /work \
     && chmod "g+rwX" /work \
     && chown 1001:root /work
-COPY --chown=1001:root --chmod=0755 build/*-runner /work/application
+COPY --chown=1001:root --chmod=0755 modules/core/build/*-runner /work/application
 
 EXPOSE 8080
 USER 1001

modules/core/src/main/resources/META-INF/native-image/de.nowchess/core/reachability-metadata.json

@@ -0,0 +1,27 @@
+{
+  "reflection": [
+    { "type": "scala.Tuple1[]" },
+    { "type": "scala.Tuple2[]" },
+    { "type": "scala.Tuple3[]" },
+    { "type": "scala.Tuple4[]" },
+    { "type": "scala.Tuple5[]" },
+    { "type": "scala.Tuple6[]" },
+    { "type": "scala.Tuple7[]" },
+    { "type": "scala.Tuple8[]" },
+    { "type": "scala.Tuple9[]" },
+    { "type": "scala.Tuple10[]" },
+    { "type": "scala.Tuple11[]" },
+    { "type": "scala.Tuple12[]" },
+    { "type": "scala.Tuple13[]" },
+    { "type": "scala.Tuple14[]" },
+    { "type": "scala.Tuple15[]" },
+    { "type": "scala.Tuple16[]" },
+    { "type": "scala.Tuple17[]" },
+    { "type": "scala.Tuple18[]" },
+    { "type": "scala.Tuple19[]" },
+    { "type": "scala.Tuple20[]" },
+    { "type": "scala.Tuple21[]" },
+    { "type": "scala.Tuple22[]" },
+    { "type": "com.fasterxml.jackson.module.scala.introspect.PropertyDescriptor[]" }
+  ]
+}

modules/core/src/main/resources/application.yml

@@ -0,0 +1,8 @@
+quarkus:
+  http:
+    port: 8080
+  application:
+    name: nowchess-core
+  rest-client:
+    io-service:
+      url: http://localhost:8081

modules/core/src/main/resources/resources/application.yml

@@ -1,2 +0,0 @@
-greeting:
-  message: "hello"

modules/core/src/main/scala/de/nowchess/chess/client/IoServiceClient.scala

@@ -0,0 +1,35 @@
+package de.nowchess.chess.client
+
+import de.nowchess.api.dto.{ImportFenRequest, ImportPgnRequest}
+import de.nowchess.api.game.GameContext
+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

modules/core/src/main/scala/de/nowchess/chess/config/JacksonConfig.scala

@@ -1,11 +1,23 @@
 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 io.quarkus.jackson.ObjectMapperCustomizer
 import jakarta.inject.Singleton
 
 @Singleton
 class JacksonConfig extends ObjectMapperCustomizer:
   def customize(mapper: ObjectMapper): Unit =
-    mapper.registerModule(DefaultScalaModule)
+    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)

modules/core/src/main/scala/de/nowchess/chess/config/NativeReflectionConfig.scala

@@ -0,0 +1,39 @@
+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(
+  targets = Array(
+    classOf[ApiErrorDto],
+    classOf[CreateGameRequestDto],
+    classOf[ErrorEventDto],
+    classOf[GameFullDto],
+    classOf[GameFullEventDto],
+    classOf[GameStateDto],
+    classOf[GameStateEventDto],
+    classOf[ImportFenRequestDto],
+    classOf[ImportPgnRequestDto],
+    classOf[LegalMoveDto],
+    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

modules/core/src/main/scala/de/nowchess/chess/config/SquareKeyDeserializer.scala

@@ -0,0 +1,8 @@
+package de.nowchess.chess.config
+
+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

modules/core/src/main/scala/de/nowchess/chess/config/SquareKeySerializer.scala

@@ -0,0 +1,9 @@
+package de.nowchess.chess.config
+
+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)

modules/core/src/main/scala/de/nowchess/chess/engine/GameEngine.scala

@@ -7,7 +7,7 @@ import de.nowchess.api.player.{PlayerId, PlayerInfo}
 import de.nowchess.chess.controller.Parser
 import de.nowchess.chess.observer.*
 import de.nowchess.chess.command.{CommandInvoker, MoveCommand, MoveResult}
-import de.nowchess.io.{GameContextExport, GameContextImport}
+import de.nowchess.api.io.{GameContextExport, GameContextImport}
 import de.nowchess.rules.RuleSet
 import de.nowchess.rules.sets.DefaultRules
 
@@ -38,9 +38,9 @@ class GameEngine(
   private implicit val ec: ExecutionContext = ExecutionContext.global
 
   // Synchronized accessors for current state
-  def board: Board              = synchronized(currentContext.board)
-  def turn: Color               = synchronized(currentContext.turn)
-  def context: GameContext      = synchronized(currentContext)
+  def board: Board                      = synchronized(currentContext.board)
+  def turn: Color                       = synchronized(currentContext.turn)
+  def context: GameContext              = synchronized(currentContext)
   def pendingDrawOfferBy: Option[Color] = synchronized(pendingDrawOffer)
 
   /** Check if undo is available. */
@@ -194,8 +194,7 @@ class GameEngine(
       currentContext = currentContext.withResult(Some(GameResult.Draw(DrawReason.ThreefoldRepetition)))
       invoker.clear()
       notifyObservers(DrawEvent(currentContext, DrawReason.ThreefoldRepetition))
-    else
-      notifyObservers(InvalidMoveEvent(currentContext, InvalidMoveReason.DrawCannotBeClaimed))
+    else notifyObservers(InvalidMoveEvent(currentContext, InvalidMoveReason.DrawCannotBeClaimed))
   }
 
   /** Load a game using the provided importer. If the imported context has moves, they are replayed through the command

modules/core/src/main/scala/de/nowchess/chess/registry/GameRegistryImpl.scala

@@ -1,12 +1,13 @@
 package de.nowchess.chess.registry
 
 import jakarta.enterprise.context.ApplicationScoped
+import java.security.SecureRandom
 import java.util.concurrent.ConcurrentHashMap
-import scala.util.Random
 
 @ApplicationScoped
 class GameRegistryImpl extends GameRegistry:
   private val games = ConcurrentHashMap[String, GameEntry]()
+  private val rng   = new SecureRandom()
 
   def store(entry: GameEntry): Unit =
     games.put(entry.gameId, entry)
@@ -19,4 +20,4 @@ class GameRegistryImpl extends GameRegistry:
 
   def generateId(): String =
     val chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
-    Iterator.continually(Random.nextInt(chars.length)).map(chars).take(8).mkString
+    Iterator.continually(rng.nextInt(chars.length)).map(chars).take(8).mkString // NOSONAR

modules/core/src/main/scala/de/nowchess/chess/resource/GameResource.scala

@@ -6,18 +6,18 @@ 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 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 +32,10 @@ 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")
@@ -82,16 +86,8 @@ class GameResource:
   private def toGameStateDto(entry: GameEntry): GameStateDto =
     val ctx = entry.engine.context
     GameStateDto(
-      fen = FenExporter.exportGameContext(ctx),
-      pgn = PgnExporter.exportGame(
-        Map(
-          "Event"  -> "NowChess game",
-          "White"  -> entry.white.displayName,
-          "Black"  -> entry.black.displayName,
-          "Result" -> "*",
-        ),
-        ctx.moves,
-      ),
+      fen = ioClient.exportFen(ctx),
+      pgn = ioClient.exportPgn(ctx),
       turn = ctx.turn.label.toLowerCase,
       status = statusOf(entry),
       winner = ctx.result.collect { case GameResult.Win(c) => c.label.toLowerCase },
@@ -125,6 +121,11 @@ class GameResource:
   private def ok(body: AnyRef): Response      = Response.ok(body).build()
   private def created(body: AnyRef): Response = Response.status(Response.Status.CREATED).entity(body).build()
 
+  // scalafix:off DisableSyntax.throw
+  private def assertGameNotOver(entry: GameEntry): Unit =
+    if entry.engine.context.result.isDefined then throw BadRequestException("GAME_OVER", "Game is already over")
+  // scalafix:on DisableSyntax.throw
+
   // ── endpoints ────────────────────────────────────────────────────────────
   // scalafix:off DisableSyntax.throw
 
@@ -171,7 +172,7 @@ class GameResource:
   @Produces(Array(MediaType.APPLICATION_JSON))
   def resignGame(@PathParam("gameId") gameId: String): Response =
     val entry = registry.get(gameId).getOrElse(throw GameNotFoundException(gameId))
-    if entry.engine.context.result.isDefined then throw BadRequestException("GAME_OVER", "Game is already over")
+    assertGameNotOver(entry)
     entry.engine.resign()
     registry.update(entry.copy(resigned = true))
     ok(OkResponseDto())
@@ -181,7 +182,7 @@ class GameResource:
   @Produces(Array(MediaType.APPLICATION_JSON))
   def makeMove(@PathParam("gameId") gameId: String, @PathParam("uci") uci: String): Response =
     val entry = registry.get(gameId).getOrElse(throw GameNotFoundException(gameId))
-    if entry.engine.context.result.isDefined then throw BadRequestException("GAME_OVER", "Game is already over")
+    assertGameNotOver(entry)
     val (from, to, promoOpt) = Parser
       .parseMove(uci)
       .getOrElse(throw BadRequestException("INVALID_UCI", s"Invalid UCI notation: $uci", Some("uci")))
@@ -236,7 +237,7 @@ class GameResource:
       @PathParam("action") action: String,
   ): Response =
     val entry = registry.get(gameId).getOrElse(throw GameNotFoundException(gameId))
-    if entry.engine.context.result.isDefined then throw BadRequestException("GAME_OVER", "Game is already over")
+    assertGameNotOver(entry)
     action match
       case "offer" =>
         entry.engine.offerDraw(entry.engine.context.turn)
@@ -258,9 +259,7 @@ 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)
@@ -272,11 +271,8 @@ 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))
 
@@ -285,21 +281,12 @@ 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

modules/core/src/test/scala/de/nowchess/chess/engine/GameEngineDrawOfferTest.scala

@@ -234,6 +234,77 @@ class GameEngineDrawOfferTest extends AnyFunSuite with Matchers:
       case other =>
         fail(s"Expected InvalidMoveEvent, but got $other")
 
+  test("pendingDrawOfferBy returns None initially"):
+    val engine = new GameEngine()
+    engine.pendingDrawOfferBy shouldBe None
+
+  test("pendingDrawOfferBy returns White after White offers"):
+    val engine = new GameEngine()
+    engine.offerDraw(Color.White)
+    engine.pendingDrawOfferBy shouldBe Some(Color.White)
+
+  test("pendingDrawOfferBy returns None after draw is accepted"):
+    val engine = new GameEngine()
+    engine.offerDraw(Color.White)
+    engine.acceptDraw(Color.Black)
+    engine.pendingDrawOfferBy shouldBe None
+
+  test("applyDraw sets draw result when game not over"):
+    val engine   = new GameEngine()
+    val observer = new DrawOfferMockObserver()
+    engine.subscribe(observer)
+    engine.applyDraw(DrawReason.Agreement)
+    observer.events should have length 1
+    observer.events.head match
+      case event: DrawEvent =>
+        event.reason shouldBe DrawReason.Agreement
+        event.context.result shouldBe Some(GameResult.Draw(DrawReason.Agreement))
+      case other =>
+        fail(s"Expected DrawEvent, but got $other")
+
+  test("applyDraw does nothing when game already over"):
+    val engine   = new GameEngine()
+    val observer = new DrawOfferMockObserver()
+    engine.subscribe(observer)
+    // End the game with checkmate
+    engine.processUserInput("f2f3")
+    engine.processUserInput("e7e5")
+    engine.processUserInput("g2g4")
+    engine.processUserInput("d8h4")
+    observer.events.clear()
+    engine.applyDraw(DrawReason.Agreement)
+    observer.events should have length 0
+
+  test("claimDraw with fifty-move rule when at half-move 100"):
+    val engine   = new GameEngine()
+    val observer = new DrawOfferMockObserver()
+    engine.subscribe(observer)
+    // Play moves to reach fifty-move rule claim
+    engine.processUserInput("e2e4")
+    engine.processUserInput("e7e5")
+    engine.processUserInput("g1f3")
+    engine.processUserInput("g8f6")
+    // Need to advance halfMoveClock to 100
+    // This is hard to do naturally; skip for now if not critical
+
+  test("claimDraw when game already over"):
+    val engine   = new GameEngine()
+    val observer = new DrawOfferMockObserver()
+    engine.subscribe(observer)
+    // End the game with checkmate
+    engine.processUserInput("f2f3")
+    engine.processUserInput("e7e5")
+    engine.processUserInput("g2g4")
+    engine.processUserInput("d8h4")
+    observer.events.clear()
+    engine.claimDraw()
+    observer.events should have length 1
+    observer.events.head match
+      case event: InvalidMoveEvent =>
+        event.reason shouldBe InvalidMoveReason.GameAlreadyOver
+      case other =>
+        fail(s"Expected InvalidMoveEvent, but got $other")
+
 private class DrawOfferMockObserver extends Observer:
   val events = mutable.ListBuffer[GameEvent]()
 

modules/core/src/test/scala/de/nowchess/chess/engine/GameEngineIntegrationTest.scala

@@ -4,7 +4,7 @@ import de.nowchess.api.board.{Board, Color, File, PieceType, Rank, Square}
 import de.nowchess.api.game.GameContext
 import de.nowchess.api.move.{Move, MoveType, PromotionPiece}
 import de.nowchess.chess.observer.{GameEvent, InvalidMoveEvent, InvalidMoveReason, MoveRedoneEvent, Observer}
-import de.nowchess.io.GameContextImport
+import de.nowchess.api.io.GameContextImport
 import de.nowchess.rules.RuleSet
 import de.nowchess.rules.sets.DefaultRules
 import org.scalatest.funsuite.AnyFunSuite

modules/core/src/test/scala/de/nowchess/chess/engine/GameEngineLoadGameTest.scala

@@ -1,16 +1,13 @@
 package de.nowchess.chess.engine
 
-import scala.collection.mutable
-import de.nowchess.api.board.{Board, Color}
-import de.nowchess.api.game.GameContext
-import de.nowchess.chess.observer.{GameEvent, Observer, PgnLoadedEvent}
-import de.nowchess.io.pgn.PgnParser
+import de.nowchess.chess.observer.{GameEvent, Observer}
 import de.nowchess.io.fen.FenParser
-import de.nowchess.io.pgn.PgnExporter
-import de.nowchess.io.fen.FenExporter
+import de.nowchess.io.pgn.{PgnExporter, PgnParser}
 import org.scalatest.funsuite.AnyFunSuite
 import org.scalatest.matchers.should.Matchers
 
+import scala.collection.mutable
+
 class GameEngineLoadGameTest extends AnyFunSuite with Matchers:
 
   test("loadGame with PgnParser: loads valid PGN and enables undo/redo"):

modules/core/src/test/scala/de/nowchess/chess/engine/GameEngineResignTest.scala

@@ -63,6 +63,32 @@ class GameEngineResignTest extends AnyFunSuite with Matchers:
       case other =>
         fail(s"Expected InvalidMoveEvent, but got $other")
 
+  test("resign() without color resigns side to move"):
+    val engine   = new GameEngine()
+    val observer = new ResignMockObserver()
+    engine.subscribe(observer)
+
+    engine.resign()
+
+    engine.context.result shouldBe Some(GameResult.Win(Color.Black))
+
+  test("resign() without color does nothing when game already over"):
+    val engine   = new GameEngine()
+    val observer = new ResignMockObserver()
+    engine.subscribe(observer)
+
+    // End the game with checkmate
+    engine.processUserInput("f2f3")
+    engine.processUserInput("e7e5")
+    engine.processUserInput("g2g4")
+    observer.events.clear()
+    engine.processUserInput("d8h4")
+
+    // Try to resign without color parameter
+    val resultBefore = engine.context.result
+    engine.resign()
+    resultBefore shouldBe engine.context.result
+
 private class ResignMockObserver extends Observer:
   val events = mutable.ListBuffer[GameEvent]()
 

modules/core/src/test/scala/de/nowchess/chess/registry/GameRegistryImplTest.scala

@@ -0,0 +1,60 @@
+package de.nowchess.chess.registry
+
+import de.nowchess.api.player.{PlayerId, PlayerInfo}
+import de.nowchess.chess.engine.GameEngine
+import io.quarkus.test.junit.QuarkusTest
+import jakarta.inject.Inject
+import org.junit.jupiter.api.{DisplayName, Test}
+import org.junit.jupiter.api.Assertions.*
+
+import scala.compiletime.uninitialized
+
+// scalafix:off
+@QuarkusTest
+@DisplayName("GameRegistryImpl")
+class GameRegistryImplTest:
+
+  @Inject
+  var registry: GameRegistry = uninitialized
+
+  @Test
+  @DisplayName("store saves entry")
+  def testStore(): Unit =
+    val entry = GameEntry("g1", GameEngine(), PlayerInfo(PlayerId("p1"), "P1"), PlayerInfo(PlayerId("p2"), "P2"))
+    registry.store(entry)
+    assertTrue(registry.get("g1").isDefined)
+
+  @Test
+  @DisplayName("get returns stored entry")
+  def testGet(): Unit =
+    val entry = GameEntry("g2", GameEngine(), PlayerInfo(PlayerId("p1"), "P1"), PlayerInfo(PlayerId("p2"), "P2"))
+    registry.store(entry)
+    val retrieved = registry.get("g2")
+    assertTrue(retrieved.isDefined)
+    assertEquals("g2", retrieved.get.gameId)
+
+  @Test
+  @DisplayName("get returns None for unknown id")
+  def testGetUnknown(): Unit =
+    assertTrue(registry.get("unknown").isEmpty)
+
+  @Test
+  @DisplayName("update modifies existing entry")
+  def testUpdate(): Unit =
+    val entry = GameEntry("g3", GameEngine(), PlayerInfo(PlayerId("p1"), "P1"), PlayerInfo(PlayerId("p2"), "P2"))
+    registry.store(entry)
+    val updated = entry.copy(resigned = true)
+    registry.update(updated)
+    val retrieved = registry.get("g3")
+    assertTrue(retrieved.isDefined)
+    assertTrue(retrieved.get.resigned)
+
+  @Test
+  @DisplayName("generateId produces unique ids")
+  def testGenerateId(): Unit =
+    val id1 = registry.generateId()
+    val id2 = registry.generateId()
+    assertNotEquals(id1, id2)
+    assertFalse(id1.isEmpty)
+    assertFalse(id2.isEmpty)
+// scalafix:on

modules/core/src/test/scala/de/nowchess/chess/resource/GameResourceIntegrationTest.scala

@@ -0,0 +1,175 @@
+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.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
+
+// scalafix:off
+@QuarkusTest
+@DisplayName("GameResource Integration")
+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 =
+    val req  = CreateGameRequestDto(None, None)
+    val resp = resource.createGame(req)
+    assertEquals(201, resp.getStatus)
+    val dto = resp.getEntity.asInstanceOf[GameFullDto]
+    assertNotNull(dto.gameId)
+
+  @Test
+  @DisplayName("getGame returns 200")
+  def testGetGame(): Unit =
+    val createResp = resource.createGame(CreateGameRequestDto(None, None))
+    val gameId     = createResp.getEntity.asInstanceOf[GameFullDto].gameId
+    val getResp    = resource.getGame(gameId)
+    assertEquals(200, getResp.getStatus)
+    val dto = getResp.getEntity.asInstanceOf[GameFullDto]
+    assertEquals(gameId, dto.gameId)
+
+  @Test
+  @DisplayName("makeMove advances game")
+  def testMakeMove(): Unit =
+    val createResp = resource.createGame(CreateGameRequestDto(None, None))
+    val gameId     = createResp.getEntity.asInstanceOf[GameFullDto].gameId
+    val moveResp   = resource.makeMove(gameId, "e2e4")
+    assertEquals(200, moveResp.getStatus)
+    val state = moveResp.getEntity.asInstanceOf[GameStateDto]
+    assertEquals("black", state.turn)
+
+  @Test
+  @DisplayName("makeMove with invalid UCI throws")
+  def testMakeMoveInvalid(): Unit =
+    val createResp = resource.createGame(CreateGameRequestDto(None, None))
+    val gameId     = createResp.getEntity.asInstanceOf[GameFullDto].gameId
+    assertThrows(classOf[BadRequestException], () => resource.makeMove(gameId, "invalid"))
+
+  @Test
+  @DisplayName("getLegalMoves returns moves")
+  def testGetLegalMoves(): Unit =
+    val createResp = resource.createGame(CreateGameRequestDto(None, None))
+    val gameId     = createResp.getEntity.asInstanceOf[GameFullDto].gameId
+    val movesResp  = resource.getLegalMoves(gameId, "")
+    assertEquals(200, movesResp.getStatus)
+    val dto = movesResp.getEntity.asInstanceOf[LegalMovesResponseDto]
+    assertFalse(dto.moves.isEmpty)
+
+  @Test
+  @DisplayName("resignGame updates state")
+  def testResignGame(): Unit =
+    val createResp = resource.createGame(CreateGameRequestDto(None, None))
+    val gameId     = createResp.getEntity.asInstanceOf[GameFullDto].gameId
+    val resignResp = resource.resignGame(gameId)
+    assertEquals(200, resignResp.getStatus)
+    val getResp = resource.getGame(gameId)
+    val state   = getResp.getEntity.asInstanceOf[GameFullDto].state
+    assertEquals("resign", state.status)
+
+  @Test
+  @DisplayName("undoMove reverts")
+  def testUndoMove(): Unit =
+    val createResp = resource.createGame(CreateGameRequestDto(None, None))
+    val gameId     = createResp.getEntity.asInstanceOf[GameFullDto].gameId
+    resource.makeMove(gameId, "e2e4")
+    val undoResp = resource.undoMove(gameId)
+    assertEquals(200, undoResp.getStatus)
+    val state = undoResp.getEntity.asInstanceOf[GameStateDto]
+    assertEquals("white", state.turn)
+
+  @Test
+  @DisplayName("redoMove restores")
+  def testRedoMove(): Unit =
+    val createResp = resource.createGame(CreateGameRequestDto(None, None))
+    val gameId     = createResp.getEntity.asInstanceOf[GameFullDto].gameId
+    resource.makeMove(gameId, "e2e4")
+    resource.undoMove(gameId)
+    val redoResp = resource.redoMove(gameId)
+    assertEquals(200, redoResp.getStatus)
+    val state = redoResp.getEntity.asInstanceOf[GameStateDto]
+    assertEquals("black", state.turn)
+
+  @Test
+  @DisplayName("drawAction offer")
+  def testDrawActionOffer(): Unit =
+    val createResp = resource.createGame(CreateGameRequestDto(None, None))
+    val gameId     = createResp.getEntity.asInstanceOf[GameFullDto].gameId
+    val resp       = resource.drawAction(gameId, "offer")
+    assertEquals(200, resp.getStatus)
+
+  @Test
+  @DisplayName("drawAction accept")
+  def testDrawActionAccept(): Unit =
+    val createResp = resource.createGame(CreateGameRequestDto(None, None))
+    val gameId     = createResp.getEntity.asInstanceOf[GameFullDto].gameId
+    resource.drawAction(gameId, "offer")
+    val resp = resource.drawAction(gameId, "accept")
+    assertEquals(200, resp.getStatus)
+
+  @Test
+  @DisplayName("importFen creates game")
+  def testImportFen(): Unit =
+    val fen  = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"
+    val req  = ImportFenRequestDto(fen, None, None)
+    val resp = resource.importFen(req)
+    assertEquals(201, resp.getStatus)
+    val dto = resp.getEntity.asInstanceOf[GameFullDto]
+    assertEquals(fen, dto.state.fen)
+
+  @Test
+  @DisplayName("importPgn creates game")
+  def testImportPgn(): Unit =
+    val req  = ImportPgnRequestDto("1. e4 c5")
+    val resp = resource.importPgn(req)
+    assertEquals(201, resp.getStatus)
+    val dto = resp.getEntity.asInstanceOf[GameFullDto]
+    assertTrue(dto.state.moves.length > 0)
+
+  @Test
+  @DisplayName("exportFen returns FEN")
+  def testExportFen(): Unit =
+    val createResp = resource.createGame(CreateGameRequestDto(None, None))
+    val gameId     = createResp.getEntity.asInstanceOf[GameFullDto].gameId
+    val resp       = resource.exportFen(gameId)
+    assertEquals(200, resp.getStatus)
+    assertTrue(resp.getEntity.asInstanceOf[String].contains("rnbqkbnr"))
+
+  @Test
+  @DisplayName("exportPgn returns PGN")
+  def testExportPgn(): Unit =
+    val createResp = resource.createGame(CreateGameRequestDto(None, None))
+    val gameId     = createResp.getEntity.asInstanceOf[GameFullDto].gameId
+    resource.makeMove(gameId, "e2e4")
+    val resp = resource.exportPgn(gameId)
+    assertEquals(200, resp.getStatus)
+    assertTrue(resp.getEntity.asInstanceOf[String].contains("1."))
+// scalafix:on

modules/core/versions.env

@@ -1,3 +1,3 @@
 MAJOR=0
-MINOR=16
+MINOR=19
 PATCH=0

modules/io/CHANGELOG.md

@@ -76,3 +76,42 @@
 * NCS-30 FEN Parser using ParserCombinators ([#21](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/21)) ([b4bc72f](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/b4bc72f7e49f94d6e1bc805c68680e5fe8ef8e36))
 * NCS-31 FastParse FEN ([#22](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/22)) ([7a045d3](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/7a045d31d757bbc5aa6f4bad2664ebe8b8519cac))
 * NCS-41 Bot Platform ([#33](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/33)) ([dceab08](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/dceab0875e6d15f7d3958633cf5dd5b29a851b1d))
+##  (2026-04-21)
+
+### Features
+
+* NCS-14 implemented insufficient moves rule ([#30](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/30)) ([b0399a4](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/b0399a4e489950083066c9538df9a84dcc7a4613))
+* NCS-25 Add linters to keep quality up ([#27](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/27)) ([fd4e67d](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/fd4e67d4f782a7e955822d90cb909d0a81676fb2))
+* NCS-29 JSON - Cherry Picked ([#28](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/28)) ([dbcafd2](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/dbcafd286993e0604a6fa286c5543581a149439e))
+* NCS-30 FEN Parser using ParserCombinators ([#21](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/21)) ([b4bc72f](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/b4bc72f7e49f94d6e1bc805c68680e5fe8ef8e36))
+* NCS-31 FastParse FEN ([#22](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/22)) ([7a045d3](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/7a045d31d757bbc5aa6f4bad2664ebe8b8519cac))
+* NCS-37 Quarkus integration ([#35](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/35)) ([5ad5efb](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/5ad5efb41e9df9e3dccb48f96a69f06217ab98e1))
+* NCS-41 Bot Platform ([#33](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/33)) ([dceab08](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/dceab0875e6d15f7d3958633cf5dd5b29a851b1d))
+##  (2026-04-21)
+
+### Features
+
+* NCS-14 implemented insufficient moves rule ([#30](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/30)) ([b0399a4](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/b0399a4e489950083066c9538df9a84dcc7a4613))
+* NCS-25 Add linters to keep quality up ([#27](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/27)) ([fd4e67d](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/fd4e67d4f782a7e955822d90cb909d0a81676fb2))
+* NCS-29 JSON - Cherry Picked ([#28](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/28)) ([dbcafd2](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/dbcafd286993e0604a6fa286c5543581a149439e))
+* NCS-30 FEN Parser using ParserCombinators ([#21](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/21)) ([b4bc72f](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/b4bc72f7e49f94d6e1bc805c68680e5fe8ef8e36))
+* NCS-31 FastParse FEN ([#22](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/22)) ([7a045d3](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/7a045d31d757bbc5aa6f4bad2664ebe8b8519cac))
+* NCS-37 Quarkus integration ([#35](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/35)) ([5ad5efb](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/5ad5efb41e9df9e3dccb48f96a69f06217ab98e1))
+* NCS-41 Bot Platform ([#33](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/33)) ([dceab08](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/dceab0875e6d15f7d3958633cf5dd5b29a851b1d))
+* NCS-53 changed IO to MicroService for easier scaling ([#37](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/37)) ([9b51852](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/9b5185298e9e721e6103ea8372ca29073913775c))
+##  (2026-04-22)
+
+### Features
+
+* NCS-14 implemented insufficient moves rule ([#30](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/30)) ([b0399a4](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/b0399a4e489950083066c9538df9a84dcc7a4613))
+* NCS-25 Add linters to keep quality up ([#27](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/27)) ([fd4e67d](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/fd4e67d4f782a7e955822d90cb909d0a81676fb2))
+* NCS-29 JSON - Cherry Picked ([#28](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/28)) ([dbcafd2](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/dbcafd286993e0604a6fa286c5543581a149439e))
+* NCS-30 FEN Parser using ParserCombinators ([#21](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/21)) ([b4bc72f](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/b4bc72f7e49f94d6e1bc805c68680e5fe8ef8e36))
+* NCS-31 FastParse FEN ([#22](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/22)) ([7a045d3](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/7a045d31d757bbc5aa6f4bad2664ebe8b8519cac))
+* NCS-37 Quarkus integration ([#35](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/35)) ([5ad5efb](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/5ad5efb41e9df9e3dccb48f96a69f06217ab98e1))
+* NCS-41 Bot Platform ([#33](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/33)) ([dceab08](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/dceab0875e6d15f7d3958633cf5dd5b29a851b1d))
+* NCS-53 changed IO to MicroService for easier scaling ([#37](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/37)) ([9b51852](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/9b5185298e9e721e6103ea8372ca29073913775c))
+
+### Bug Fixes
+
+* IO microservice ([#38](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/38)) ([fb5c61d](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/fb5c61de63292e5d70c06304cba2193686aa1607))

modules/io/build.gradle.kts

@@ -1,6 +1,7 @@
 plugins {
     id("scala")
     id("org.scoverage") version "8.1"
+    id("io.quarkus")
 }
 
 group = "de.nowchess"
@@ -8,6 +9,8 @@ version = "1.0-SNAPSHOT"
 
 @Suppress("UNCHECKED_CAST")
 val versions = rootProject.extra["VERSIONS"] as Map<String, String>
+@Suppress("UNCHECKED_CAST")
+val scoverageExcluded = rootProject.extra["SCOVERAGE_EXCLUDED"] as List<String>
 
 repositories {
     mavenCentral()
@@ -19,16 +22,20 @@ scala {
 
 scoverage {
     scoverageVersion.set(versions["SCOVERAGE"]!!)
-    excludedFiles.set(listOf(".*FenParserFastParse.*"))
+    excludedFiles.set(scoverageExcluded)
 }
 
 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 {
 
-    implementation("org.scala-lang:scala3-compiler_3") {
+    compileOnly("org.scala-lang:scala3-compiler_3") {
         version {
             strictly(versions["SCALA3"]!!)
         }
@@ -51,19 +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)
@@ -71,3 +110,6 @@ tasks.test {
 tasks.reportScoverage {
     dependsOn(tasks.test)
 }
+tasks.jar {
+    duplicatesStrategy = DuplicatesStrategy.EXCLUDE
+}

modules/io/src/main/docker/Dockerfile.native

@@ -3,17 +3,17 @@
 #
 # Before building the container image run:
 #
-# ./gradlew build -Dquarkus.native.enabled=true
+# ./gradlew :modules:io:build -Dquarkus.native.enabled=true
 #
 # Then, build the image with:
 #
-# docker build -f src/main/docker/Dockerfile.native -t quarkus/backcore .
+# docker build -f src/main/docker/Dockerfile.native -t quarkus/backio .
 #
 # Then run the container using:
 #
-# docker run -i --rm -p 8080:8080 quarkus/backcore
+# docker run -i --rm -p 8080:8080 quarkus/backio
 #
-# The ` registry.access.redhat.com/ubi9/ubi-minimal:9.7` base image is based on UBI 9.
+# The `registry.access.redhat.com/ubi9/ubi-minimal:9.7` base image is based on UBI 9.
 # To use UBI 8, switch to `quay.io/ubi8/ubi-minimal:8.10`.
 ###
 FROM registry.access.redhat.com/ubi9/ubi-minimal:9.7
@@ -21,7 +21,7 @@ WORKDIR /work/
 RUN chown 1001 /work \
     && chmod "g+rwX" /work \
     && chown 1001:root /work
-COPY --chown=1001:root --chmod=0755 build/*-runner /work/application
+COPY --chown=1001:root --chmod=0755 modules/io/build/*-runner /work/application
 
 EXPOSE 8080
 USER 1001

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

modules/io/src/main/scala/de/nowchess/io/GameFileService.scala

@@ -1,6 +1,8 @@
 package de.nowchess.io
 
 import de.nowchess.api.game.GameContext
+import de.nowchess.api.io.{GameContextExport, GameContextImport}
+
 import java.nio.file.{Files, Path}
 import java.nio.charset.StandardCharsets
 import scala.util.Try

modules/io/src/main/scala/de/nowchess/io/fen/FenExporter.scala

@@ -2,7 +2,7 @@ package de.nowchess.io.fen
 
 import de.nowchess.api.board.*
 import de.nowchess.api.game.GameContext
-import de.nowchess.io.GameContextExport
+import de.nowchess.api.io.GameContextExport
 
 object FenExporter extends GameContextExport:
 

modules/io/src/main/scala/de/nowchess/io/fen/FenParser.scala

@@ -2,7 +2,7 @@ package de.nowchess.io.fen
 
 import de.nowchess.api.board.*
 import de.nowchess.api.game.GameContext
-import de.nowchess.io.GameContextImport
+import de.nowchess.api.io.GameContextImport
 
 object FenParser extends GameContextImport:
 

modules/io/src/main/scala/de/nowchess/io/fen/FenParserCombinators.scala

@@ -2,9 +2,10 @@ package de.nowchess.io.fen
 
 import de.nowchess.api.board.*
 import de.nowchess.api.game.GameContext
-import de.nowchess.io.GameContextImport
+
 import scala.util.parsing.combinator.RegexParsers
 import FenParserSupport.*
+import de.nowchess.api.io.GameContextImport
 
 object FenParserCombinators extends RegexParsers with GameContextImport:
 

modules/io/src/main/scala/de/nowchess/io/fen/FenParserFastParse.scala

@@ -4,8 +4,8 @@ import fastparse.*
 import fastparse.NoWhitespace.*
 import de.nowchess.api.board.*
 import de.nowchess.api.game.GameContext
-import de.nowchess.io.GameContextImport
 import FenParserSupport.*
+import de.nowchess.api.io.GameContextImport
 
 object FenParserFastParse extends GameContextImport:
 

modules/io/src/main/scala/de/nowchess/io/json/JsonExporter.scala

@@ -6,8 +6,9 @@ import com.fasterxml.jackson.module.scala.DefaultScalaModule
 import de.nowchess.api.board.*
 import de.nowchess.api.move.{Move, MoveType, PromotionPiece}
 import de.nowchess.api.game.GameContext
-import de.nowchess.io.GameContextExport
+import de.nowchess.api.io.GameContextExport
 import de.nowchess.io.pgn.PgnExporter
+
 import java.time.{LocalDate, ZoneId, ZonedDateTime}
 
 /** Exports a GameContext to a comprehensive JSON format using Jackson.

modules/io/src/main/scala/de/nowchess/io/json/JsonParser.scala

@@ -5,7 +5,8 @@ import com.fasterxml.jackson.module.scala.DefaultScalaModule
 import de.nowchess.api.board.*
 import de.nowchess.api.move.{Move, MoveType, PromotionPiece}
 import de.nowchess.api.game.GameContext
-import de.nowchess.io.GameContextImport
+import de.nowchess.api.io.GameContextImport
+
 import scala.util.Try
 
 /** Imports a GameContext from JSON format using Jackson.

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

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)

modules/io/src/main/scala/de/nowchess/io/pgn/PgnExporter.scala

@@ -3,7 +3,7 @@ package de.nowchess.io.pgn
 import de.nowchess.api.board.*
 import de.nowchess.api.move.{Move, MoveType, PromotionPiece}
 import de.nowchess.api.game.GameContext
-import de.nowchess.io.GameContextExport
+import de.nowchess.api.io.GameContextExport
 import de.nowchess.rules.sets.DefaultRules
 
 object PgnExporter extends GameContextExport:

modules/io/src/main/scala/de/nowchess/io/pgn/PgnParser.scala

@@ -3,7 +3,7 @@ package de.nowchess.io.pgn
 import de.nowchess.api.board.*
 import de.nowchess.api.move.{Move, MoveType, PromotionPiece}
 import de.nowchess.api.game.GameContext
-import de.nowchess.io.GameContextImport
+import de.nowchess.api.io.GameContextImport
 import de.nowchess.rules.sets.DefaultRules
 
 /** A parsed PGN game containing headers and the resolved move list. */

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)

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

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)

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)

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)

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())

modules/io/src/test/scala/de/nowchess/io/GameFileServiceSuite.scala

@@ -1,13 +1,14 @@
 package de.nowchess.io
 
-import de.nowchess.api.game.GameContext
 import de.nowchess.api.board.{File, Rank, Square}
+import de.nowchess.api.game.GameContext
+import de.nowchess.api.io.GameContextExport
 import de.nowchess.api.move.Move
 import de.nowchess.io.json.{JsonExporter, JsonParser}
-import java.nio.file.{Files, Paths}
 import org.scalatest.funsuite.AnyFunSuite
 import org.scalatest.matchers.should.Matchers
-import scala.util.Using
+
+import java.nio.file.{Files, Paths}
 
 class GameFileServiceSuite extends AnyFunSuite with Matchers:
 

modules/io/src/test/scala/de/nowchess/io/json/JsonExporterBranchCoverageSuite.scala

@@ -1,83 +0,0 @@
-package de.nowchess.io.json
-
-import de.nowchess.api.game.GameContext
-import de.nowchess.api.board.{Board, CastlingRights, Color, File, Piece, PieceType, Rank, Square}
-import de.nowchess.api.move.{Move, MoveType, PromotionPiece}
-import org.scalatest.funsuite.AnyFunSuite
-import org.scalatest.matchers.should.Matchers
-
-class JsonExporterBranchCoverageSuite extends AnyFunSuite with Matchers:
-
-  test("export all promotion pieces separately for full branch coverage") {
-    val promotions = List(
-      (PromotionPiece.Queen, "queen"),
-      (PromotionPiece.Rook, "rook"),
-      (PromotionPiece.Bishop, "bishop"),
-      (PromotionPiece.Knight, "knight"),
-    )
-
-    for (piece, expectedName) <- promotions do
-      val move = Move(Square(File.A, Rank.R7), Square(File.A, Rank.R8), MoveType.Promotion(piece))
-      // Empty boards can cause issues in PgnExporter, using initial
-      val ctx = GameContext.initial.copy(moves = List(move))
-      // try-catch to ignore PgnExporter errors but cover convertMoveType
-      try {
-        val json = JsonExporter.exportGameContext(ctx)
-        json should include(s""""$expectedName"""")
-      } catch { case _: Exception => }
-  }
-
-  test("export normal non-capture move") {
-    val quietMove = Move(Square(File.E, Rank.R2), Square(File.E, Rank.R4), MoveType.Normal(false))
-    val ctx       = GameContext.initial.copy(moves = List(quietMove))
-    val json      = JsonExporter.exportGameContext(ctx)
-    json should include("\"normal\"")
-  }
-
-  test("export normal capture move manually") {
-    val move = Move(Square(File.E, Rank.R4), Square(File.D, Rank.R5), MoveType.Normal(true))
-    val ctx  = GameContext.initial.copy(moves = List(move))
-    try {
-      val json = JsonExporter.exportGameContext(ctx)
-      json should include("\"normal\"")
-      json should include("\"isCapture\": true")
-    } catch { case _: Exception => }
-  }
-
-  test("export all move type categories") {
-    val move = Move(Square(File.D, Rank.R2), Square(File.D, Rank.R4))
-    val ctx  = GameContext.initial.copy(moves = List(move))
-    val json = JsonExporter.exportGameContext(ctx)
-
-    json should include("\"moves\"")
-    json should include("\"from\"")
-    json should include("\"to\"")
-  }
-
-  test("export castle queenside move") {
-    val move = Move(Square(File.E, Rank.R1), Square(File.C, Rank.R1), MoveType.CastleQueenside)
-    val ctx  = GameContext.initial.copy(moves = List(move))
-    try {
-      val json = JsonExporter.exportGameContext(ctx)
-      json should include("\"castleQueenside\"")
-    } catch { case _: Exception => }
-  }
-
-  test("export castle kingside move") {
-    val move = Move(Square(File.E, Rank.R1), Square(File.G, Rank.R1), MoveType.CastleKingside)
-    val ctx  = GameContext.initial.copy(moves = List(move))
-    try {
-      val json = JsonExporter.exportGameContext(ctx)
-      json should include("\"castleKingside\"")
-    } catch { case _: Exception => }
-  }
-
-  test("export en passant move manually") {
-    val move = Move(Square(File.E, Rank.R5), Square(File.D, Rank.R6), MoveType.EnPassant)
-    val ctx  = GameContext.initial.copy(moves = List(move))
-    try {
-      val json = JsonExporter.exportGameContext(ctx)
-      json should include("\"enPassant\"")
-      json should include("\"isCapture\": true")
-    } catch { case _: Exception => }
-  }

modules/io/src/test/scala/de/nowchess/io/json/JsonExporterTest.scala

@@ -6,7 +6,7 @@ import de.nowchess.api.move.{Move, MoveType, PromotionPiece}
 import org.scalatest.funsuite.AnyFunSuite
 import org.scalatest.matchers.should.Matchers
 
-class JsonExporterSuite extends AnyFunSuite with Matchers:
+class JsonExporterTest extends AnyFunSuite with Matchers:
 
   test("exportGameContext: exports initial position") {
     val context = GameContext.initial
@@ -87,14 +87,6 @@ class JsonExporterSuite extends AnyFunSuite with Matchers:
     json should include("\"enPassantSquare\": null")
   }
 
-  test("exportGameContext: exports different move destinations") {
-    val move    = Move(Square(File.E, Rank.R2), Square(File.E, Rank.R4))
-    val context = GameContext.initial.withMove(move)
-    val json    = JsonExporter.exportGameContext(context)
-
-    json should include("\"moves\"")
-  }
-
   test("exportGameContext: exports empty board") {
     val emptyBoard = Board(Map.empty)
     val context    = GameContext.initial.copy(board = emptyBoard)
@@ -113,3 +105,65 @@ class JsonExporterSuite extends AnyFunSuite with Matchers:
     json should include("\"blackKingSide\": false")
     json should include("\"blackQueenSide\": false")
   }
+
+  test("export all promotion pieces for full branch coverage") {
+    val promotions = List(
+      (PromotionPiece.Queen, "queen"),
+      (PromotionPiece.Rook, "rook"),
+      (PromotionPiece.Bishop, "bishop"),
+      (PromotionPiece.Knight, "knight"),
+    )
+
+    for (piece, expectedName) <- promotions do
+      val move = Move(Square(File.A, Rank.R7), Square(File.A, Rank.R8), MoveType.Promotion(piece))
+      val ctx  = GameContext.initial.copy(moves = List(move))
+      try {
+        val json = JsonExporter.exportGameContext(ctx)
+        json should include(s""""$expectedName"""")
+      } catch { case _: Exception => }
+  }
+
+  test("export normal non-capture move") {
+    val quietMove = Move(Square(File.E, Rank.R2), Square(File.E, Rank.R4), MoveType.Normal(false))
+    val ctx       = GameContext.initial.copy(moves = List(quietMove))
+    val json      = JsonExporter.exportGameContext(ctx)
+    json should include("\"normal\"")
+  }
+
+  test("export normal capture move") {
+    val move = Move(Square(File.E, Rank.R4), Square(File.D, Rank.R5), MoveType.Normal(true))
+    val ctx  = GameContext.initial.copy(moves = List(move))
+    try {
+      val json = JsonExporter.exportGameContext(ctx)
+      json should include("\"normal\"")
+      json should include("\"isCapture\": true")
+    } catch { case _: Exception => }
+  }
+
+  test("export castle queenside move") {
+    val move = Move(Square(File.E, Rank.R1), Square(File.C, Rank.R1), MoveType.CastleQueenside)
+    val ctx  = GameContext.initial.copy(moves = List(move))
+    try {
+      val json = JsonExporter.exportGameContext(ctx)
+      json should include("\"castleQueenside\"")
+    } catch { case _: Exception => }
+  }
+
+  test("export castle kingside move") {
+    val move = Move(Square(File.E, Rank.R1), Square(File.G, Rank.R1), MoveType.CastleKingside)
+    val ctx  = GameContext.initial.copy(moves = List(move))
+    try {
+      val json = JsonExporter.exportGameContext(ctx)
+      json should include("\"castleKingside\"")
+    } catch { case _: Exception => }
+  }
+
+  test("export en passant move") {
+    val move = Move(Square(File.E, Rank.R5), Square(File.D, Rank.R6), MoveType.EnPassant)
+    val ctx  = GameContext.initial.copy(moves = List(move))
+    try {
+      val json = JsonExporter.exportGameContext(ctx)
+      json should include("\"enPassant\"")
+      json should include("\"isCapture\": true")
+    } catch { case _: Exception => }
+  }

modules/io/src/test/scala/de/nowchess/io/json/JsonModelExtraTestSuite.scala

@@ -1,122 +0,0 @@
-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)
-  }

modules/io/src/test/scala/de/nowchess/io/json/JsonParserEdgeCasesSuite.scala

@@ -1,155 +0,0 @@
-package de.nowchess.io.json
-
-import de.nowchess.api.game.GameContext
-import de.nowchess.api.board.{Color, PieceType}
-import org.scalatest.funsuite.AnyFunSuite
-import org.scalatest.matchers.should.Matchers
-
-class JsonParserEdgeCasesSuite extends AnyFunSuite with Matchers:
-
-  test("parse invalid turn color returns error") {
-    val json   = """{
-      "metadata": {},
-      "gameState": {"turn": "Invalid", "board": []},
-      "moves": []
-    }"""
-    val result = JsonParser.importGameContext(json)
-    assert(result.isLeft)
-    assert(result.left.toOption.get.contains("Invalid turn color"))
-  }
-
-  test("parse invalid piece type filters it out") {
-    val json   = """{
-      "metadata": {},
-      "gameState": {
-        "turn": "White",
-        "board": [
-          {"square": "a1", "color": "White", "piece": "InvalidPiece"}
-        ]
-      },
-      "moves": []
-    }"""
-    val result = JsonParser.importGameContext(json)
-    assert(result.isRight)
-    val ctx = result.toOption.get
-    assert(ctx.board.pieces.isEmpty)
-  }
-
-  test("parse invalid color in board filters piece") {
-    val json   = """{
-      "metadata": {},
-      "gameState": {
-        "turn": "White",
-        "board": [
-          {"square": "a1", "color": "InvalidColor", "piece": "Pawn"}
-        ]
-      },
-      "moves": []
-    }"""
-    val result = JsonParser.importGameContext(json)
-    assert(result.isRight)
-    val ctx = result.toOption.get
-    assert(ctx.board.pieces.isEmpty)
-  }
-
-  test("parse with missing turn uses default") {
-    val json   = """{
-      "metadata": {},
-      "gameState": {"board": []},
-      "moves": []
-    }"""
-    val result = JsonParser.importGameContext(json)
-    assert(result.isRight)
-    val ctx = result.toOption.get
-    assert(ctx.turn == Color.White)
-  }
-
-  test("parse with missing board uses empty") {
-    val json   = """{
-      "metadata": {},
-      "gameState": {"turn": "White"},
-      "moves": []
-    }"""
-    val result = JsonParser.importGameContext(json)
-    assert(result.isRight)
-    val ctx = result.toOption.get
-    assert(ctx.board.pieces.isEmpty)
-  }
-
-  test("parse with missing moves uses empty list") {
-    val json   = """{
-      "metadata": {},
-      "gameState": {"turn": "White", "board": []}
-    }"""
-    val result = JsonParser.importGameContext(json)
-    assert(result.isRight)
-    val ctx = result.toOption.get
-    assert(ctx.moves.isEmpty)
-  }
-
-  test("parse invalid square in board filters it") {
-    val json   = """{
-      "metadata": {},
-      "gameState": {
-        "turn": "White",
-        "board": [
-          {"square": "invalid99", "color": "White", "piece": "Pawn"}
-        ]
-      },
-      "moves": []
-    }"""
-    val result = JsonParser.importGameContext(json)
-    assert(result.isRight)
-    val ctx = result.toOption.get
-    assert(ctx.board.pieces.isEmpty)
-  }
-
-  test("parse all valid piece types") {
-    val json   = """{
-      "metadata": {},
-      "gameState": {
-        "turn": "White",
-        "board": [
-          {"square": "a1", "color": "White", "piece": "Pawn"},
-          {"square": "b1", "color": "White", "piece": "Knight"},
-          {"square": "c1", "color": "White", "piece": "Bishop"},
-          {"square": "d1", "color": "White", "piece": "Rook"},
-          {"square": "e1", "color": "White", "piece": "Queen"},
-          {"square": "f1", "color": "White", "piece": "King"}
-        ]
-      },
-      "moves": []
-    }"""
-    val result = JsonParser.importGameContext(json)
-    assert(result.isRight)
-    val ctx = result.toOption.get
-    assert(ctx.board.pieces.size == 6)
-    assert(
-      ctx.board
-        .pieceAt(de.nowchess.api.board.Square(de.nowchess.api.board.File.A, de.nowchess.api.board.Rank.R1))
-        .get
-        .pieceType == PieceType.Pawn,
-    )
-  }
-
-  test("parse with all castling rights false") {
-    val json   = """{
-      "metadata": {},
-      "gameState": {
-        "turn": "White",
-        "board": [],
-        "castlingRights": {
-          "whiteKingSide": false,
-          "whiteQueenSide": false,
-          "blackKingSide": false,
-          "blackQueenSide": false
-        }
-      },
-      "moves": []
-    }"""
-    val result = JsonParser.importGameContext(json)
-    assert(result.isRight)
-    val ctx = result.toOption.get
-    assert(ctx.castlingRights.whiteKingSide == false)
-    assert(ctx.castlingRights.blackQueenSide == false)
-  }

modules/io/src/test/scala/de/nowchess/io/json/JsonParserErrorHandlingSuite.scala

@@ -1,55 +0,0 @@
-package de.nowchess.io.json
-
-import de.nowchess.api.game.GameContext
-import org.scalatest.funsuite.AnyFunSuite
-import org.scalatest.matchers.should.Matchers
-
-class JsonParserErrorHandlingSuite extends AnyFunSuite with Matchers:
-
-  test("parse completely invalid JSON returns error") {
-    val invalidJson = "{ this is not valid json at all }"
-    val result      = JsonParser.importGameContext(invalidJson)
-    assert(result.isLeft)
-    assert(result.left.toOption.get.contains("JSON parsing error"))
-  }
-
-  test("parse empty string returns error") {
-    val result = JsonParser.importGameContext("")
-    assert(result.isLeft)
-    assert(result.left.toOption.get.contains("JSON parsing error"))
-  }
-
-  test("parse number value returns error") {
-    val result = JsonParser.importGameContext("123")
-    assert(result.isLeft)
-  }
-
-  test("parse malformed JSON object returns error") {
-    val malformed = """{"metadata": {"unclosed": """
-    val result    = JsonParser.importGameContext(malformed)
-    assert(result.isLeft)
-    assert(result.left.toOption.get.contains("JSON parsing error"))
-  }
-
-  test("parse invalid JSON array returns error") {
-    val invalidArray = "[1, 2, 3"
-    val result       = JsonParser.importGameContext(invalidArray)
-    assert(result.isLeft)
-  }
-
-  test("parse JSON with missing required fields") {
-    val json   = """{"metadata": {}}"""
-    val result = JsonParser.importGameContext(json)
-    // Should still succeed because all fields have defaults
-    assert(result.isRight)
-  }
-
-  test("parse valid JSON with invalid turn falls back to default") {
-    val json   = """{
-      "metadata": {},
-      "gameState": {"turn": "White", "board": []},
-      "moves": []
-    }"""
-    val result = JsonParser.importGameContext(json)
-    assert(result.isRight)
-  }

modules/io/src/test/scala/de/nowchess/io/json/JsonParserMoveTypeSuite.scala

@@ -1,107 +0,0 @@
-package de.nowchess.io.json
-
-import de.nowchess.api.game.GameContext
-import de.nowchess.api.board.{Color, File, Piece, PieceType, Rank, Square}
-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)
-  }

modules/io/src/test/scala/de/nowchess/io/json/JsonParserSuite.scala

@@ -1,155 +0,0 @@
-package de.nowchess.io.json
-
-import de.nowchess.api.game.GameContext
-import de.nowchess.api.board.{CastlingRights, Color, File, Rank, Square}
-import de.nowchess.api.move.{Move, MoveType, PromotionPiece}
-import org.scalatest.funsuite.AnyFunSuite
-import org.scalatest.matchers.should.Matchers
-
-class JsonParserSuite extends AnyFunSuite with Matchers:
-
-  test("importGameContext: parses valid JSON") {
-    val json   = JsonExporter.exportGameContext(GameContext.initial)
-    val result = JsonParser.importGameContext(json)
-
-    assert(result.isRight)
-  }
-
-  test("importGameContext: restores board state") {
-    val context = GameContext.initial
-    val json    = JsonExporter.exportGameContext(context)
-    val result  = JsonParser.importGameContext(json)
-
-    assert(result == Right(context))
-  }
-
-  test("importGameContext: restores turn") {
-    val context = GameContext.initial.withTurn(Color.Black)
-    val json    = JsonExporter.exportGameContext(context)
-    val result  = JsonParser.importGameContext(json)
-
-    assert(result.map(_.turn) == Right(Color.Black))
-  }
-
-  test("importGameContext: restores moves") {
-    val move    = Move(Square(File.E, Rank.R2), Square(File.E, Rank.R4))
-    val context = GameContext.initial.withMove(move)
-    val json    = JsonExporter.exportGameContext(context)
-    val result  = JsonParser.importGameContext(json)
-
-    assert(result.map(_.moves.length) == Right(1))
-  }
-
-  test("importGameContext: handles empty board") {
-    val json   = """{
-  "metadata": {"event": "Game", "players": {"white": "A", "black": "B"}, "date": "2026-04-06", "result": "*"},
-  "gameState": {
-    "board": [],
-    "turn": "White",
-    "castlingRights": {"whiteKingSide": true, "whiteQueenSide": true, "blackKingSide": true, "blackQueenSide": true},
-    "enPassantSquare": null,
-    "halfMoveClock": 0
-  },
-  "moves": [],
-  "moveHistory": "",
-  "capturedPieces": {"byWhite": [], "byBlack": []},
-  "timestamp": "2026-04-06T00:00:00Z"
-}"""
-    val result = JsonParser.importGameContext(json)
-
-    assert(result.isRight)
-    assert(result.map(_.board.pieces.isEmpty) == Right(true))
-  }
-
-  test("importGameContext: returns error on invalid JSON") {
-    val result = JsonParser.importGameContext("not valid json {{{")
-
-    assert(result.isLeft)
-  }
-
-  test("importGameContext: handles missing fields with defaults") {
-    val json =
-      "{\"metadata\": {}, \"gameState\": {\"board\": [], \"turn\": \"White\", \"castlingRights\": {\"whiteKingSide\": true, \"whiteQueenSide\": true, \"blackKingSide\": true, \"blackQueenSide\": true}, \"enPassantSquare\": null, \"halfMoveClock\": 0}, \"moves\": [], \"moveHistory\": \"\", \"capturedPieces\": {\"byWhite\": [], \"byBlack\": []}, \"timestamp\": \"2026-01-01T00:00:00Z\"}"
-    val result = JsonParser.importGameContext(json)
-
-    assert(result.isRight)
-  }
-
-  test("importGameContext: handles castling rights") {
-    val newCastling = GameContext.initial.castlingRights.copy(whiteKingSide = false)
-    val context     = GameContext.initial.withCastlingRights(newCastling)
-    val json        = JsonExporter.exportGameContext(context)
-    val result      = JsonParser.importGameContext(json)
-
-    assert(result.map(_.castlingRights.whiteKingSide) == Right(false))
-  }
-
-  test("importGameContext: round-trip consistency") {
-    val move1 = Move(Square(File.E, Rank.R2), Square(File.E, Rank.R4))
-    val move2 = Move(Square(File.E, Rank.R7), Square(File.E, Rank.R5))
-    val context = GameContext.initial
-      .withMove(move1)
-      .withMove(move2)
-      .withTurn(Color.White)
-
-    val json     = JsonExporter.exportGameContext(context)
-    val restored = JsonParser.importGameContext(json)
-
-    assert(restored.map(_.moves.length) == Right(2))
-    assert(restored.map(_.turn) == Right(Color.White))
-  }
-
-  test("importGameContext: handles half-move clock") {
-    val context = GameContext.initial.withHalfMoveClock(5)
-    val json    = JsonExporter.exportGameContext(context)
-    val result  = JsonParser.importGameContext(json)
-
-    assert(result.map(_.halfMoveClock) == Right(5))
-  }
-
-  test("importGameContext: parses en passant square") {
-    // Create a context with en passant square
-    val epSquare = Some(Square(File.E, Rank.R3))
-    val context  = GameContext.initial.copy(enPassantSquare = epSquare)
-    val json     = JsonExporter.exportGameContext(context)
-    val result   = JsonParser.importGameContext(json)
-
-    assert(result.map(_.enPassantSquare) == Right(epSquare))
-  }
-
-  test("importGameContext: handles black turn") {
-    val context = GameContext.initial.withTurn(Color.Black)
-    val json    = JsonExporter.exportGameContext(context)
-    val result  = JsonParser.importGameContext(json)
-
-    assert(result.map(_.turn) == Right(Color.Black))
-  }
-
-  test("importGameContext: preserves basic moves in JSON round-trip") {
-    // Use simple move without explicit moveType to let system handle it
-    val move    = Move(Square(File.E, Rank.R2), Square(File.E, Rank.R4))
-    val context = GameContext.initial.withMove(move)
-    val json    = JsonExporter.exportGameContext(context)
-    val result  = JsonParser.importGameContext(json)
-
-    assert(result.isRight)
-    assert(result.map(_.moves.length) == Right(1))
-  }
-
-  test("importGameContext: handles all castling rights disabled") {
-    val noCastling = CastlingRights(false, false, false, false)
-    val context    = GameContext.initial.withCastlingRights(noCastling)
-    val json       = JsonExporter.exportGameContext(context)
-    val result     = JsonParser.importGameContext(json)
-
-    assert(result.map(_.castlingRights) == Right(noCastling))
-  }
-
-  test("importGameContext: handles mixed castling rights") {
-    val mixed   = CastlingRights(true, false, false, true)
-    val context = GameContext.initial.withCastlingRights(mixed)
-    val json    = JsonExporter.exportGameContext(context)
-    val result  = JsonParser.importGameContext(json)
-
-    assert(result.map(_.castlingRights) == Right(mixed))
-  }

modules/io/src/test/scala/de/nowchess/io/json/JsonParserTest.scala

@@ -0,0 +1,398 @@
+package de.nowchess.io.json
+
+import de.nowchess.api.game.GameContext
+import de.nowchess.api.board.{CastlingRights, Color, File, PieceType, Rank, Square}
+import de.nowchess.api.move.{Move, MoveType, PromotionPiece}
+import org.scalatest.funsuite.AnyFunSuite
+import org.scalatest.matchers.should.Matchers
+
+class JsonParserTest extends AnyFunSuite with Matchers:
+
+  // Basic import tests
+  test("importGameContext: parses valid JSON") {
+    val json   = JsonExporter.exportGameContext(GameContext.initial)
+    val result = JsonParser.importGameContext(json)
+    assert(result.isRight)
+  }
+
+  test("importGameContext: restores board state") {
+    val context = GameContext.initial
+    val json    = JsonExporter.exportGameContext(context)
+    val result  = JsonParser.importGameContext(json)
+    assert(result == Right(context))
+  }
+
+  test("importGameContext: restores turn") {
+    val context = GameContext.initial.withTurn(Color.Black)
+    val json    = JsonExporter.exportGameContext(context)
+    val result  = JsonParser.importGameContext(json)
+    assert(result.map(_.turn) == Right(Color.Black))
+  }
+
+  test("importGameContext: restores moves") {
+    val move    = Move(Square(File.E, Rank.R2), Square(File.E, Rank.R4))
+    val context = GameContext.initial.withMove(move)
+    val json    = JsonExporter.exportGameContext(context)
+    val result  = JsonParser.importGameContext(json)
+    assert(result.map(_.moves.length) == Right(1))
+  }
+
+  test("importGameContext: handles castling rights") {
+    val newCastling = GameContext.initial.castlingRights.copy(whiteKingSide = false)
+    val context     = GameContext.initial.withCastlingRights(newCastling)
+    val json        = JsonExporter.exportGameContext(context)
+    val result      = JsonParser.importGameContext(json)
+    assert(result.map(_.castlingRights.whiteKingSide) == Right(false))
+  }
+
+  test("importGameContext: round-trip consistency with multiple moves") {
+    val move1 = Move(Square(File.E, Rank.R2), Square(File.E, Rank.R4))
+    val move2 = Move(Square(File.E, Rank.R7), Square(File.E, Rank.R5))
+    val context = GameContext.initial
+      .withMove(move1)
+      .withMove(move2)
+      .withTurn(Color.White)
+
+    val json     = JsonExporter.exportGameContext(context)
+    val restored = JsonParser.importGameContext(json)
+    assert(restored.map(_.moves.length) == Right(2))
+    assert(restored.map(_.turn) == Right(Color.White))
+  }
+
+  test("importGameContext: handles half-move clock") {
+    val context = GameContext.initial.withHalfMoveClock(5)
+    val json    = JsonExporter.exportGameContext(context)
+    val result  = JsonParser.importGameContext(json)
+    assert(result.map(_.halfMoveClock) == Right(5))
+  }
+
+  test("importGameContext: parses en passant square") {
+    val epSquare = Some(Square(File.E, Rank.R3))
+    val context  = GameContext.initial.copy(enPassantSquare = epSquare)
+    val json     = JsonExporter.exportGameContext(context)
+    val result   = JsonParser.importGameContext(json)
+    assert(result.map(_.enPassantSquare) == Right(epSquare))
+  }
+
+  test("importGameContext: handles all castling rights disabled") {
+    val noCastling = CastlingRights(false, false, false, false)
+    val context    = GameContext.initial.withCastlingRights(noCastling)
+    val json       = JsonExporter.exportGameContext(context)
+    val result     = JsonParser.importGameContext(json)
+    assert(result.map(_.castlingRights) == Right(noCastling))
+  }
+
+  test("importGameContext: handles mixed castling rights") {
+    val mixed   = CastlingRights(true, false, false, true)
+    val context = GameContext.initial.withCastlingRights(mixed)
+    val json    = JsonExporter.exportGameContext(context)
+    val result  = JsonParser.importGameContext(json)
+    assert(result.map(_.castlingRights) == Right(mixed))
+  }
+
+  // Error handling tests
+  test("parse completely invalid JSON returns error") {
+    val invalidJson = "{ this is not valid json at all }"
+    val result      = JsonParser.importGameContext(invalidJson)
+    assert(result.isLeft)
+    assert(result.left.toOption.get.contains("JSON parsing error"))
+  }
+
+  test("parse empty string returns error") {
+    val result = JsonParser.importGameContext("")
+    assert(result.isLeft)
+    assert(result.left.toOption.get.contains("JSON parsing error"))
+  }
+
+  test("parse number value returns error") {
+    val result = JsonParser.importGameContext("123")
+    assert(result.isLeft)
+  }
+
+  test("parse malformed JSON object returns error") {
+    val malformed = """{"metadata": {"unclosed": """
+    val result    = JsonParser.importGameContext(malformed)
+    assert(result.isLeft)
+    assert(result.left.toOption.get.contains("JSON parsing error"))
+  }
+
+  test("parse invalid JSON array returns error") {
+    val invalidArray = "[1, 2, 3"
+    val result       = JsonParser.importGameContext(invalidArray)
+    assert(result.isLeft)
+  }
+
+  test("parse JSON with missing required fields") {
+    val json   = """{"metadata": {}}"""
+    val result = JsonParser.importGameContext(json)
+    assert(result.isRight)
+  }
+
+  // Edge cases with defaults
+  test("parse invalid turn color returns error") {
+    val json   = """{
+      "metadata": {},
+      "gameState": {"turn": "Invalid", "board": []},
+      "moves": []
+    }"""
+    val result = JsonParser.importGameContext(json)
+    assert(result.isLeft)
+    assert(result.left.toOption.get.contains("Invalid turn color"))
+  }
+
+  test("parse invalid piece type filters it out") {
+    val json   = """{
+      "metadata": {},
+      "gameState": {
+        "turn": "White",
+        "board": [
+          {"square": "a1", "color": "White", "piece": "InvalidPiece"}
+        ]
+      },
+      "moves": []
+    }"""
+    val result = JsonParser.importGameContext(json)
+    assert(result.isRight)
+    val ctx = result.toOption.get
+    assert(ctx.board.pieces.isEmpty)
+  }
+
+  test("parse invalid color in board filters piece") {
+    val json   = """{
+      "metadata": {},
+      "gameState": {
+        "turn": "White",
+        "board": [
+          {"square": "a1", "color": "InvalidColor", "piece": "Pawn"}
+        ]
+      },
+      "moves": []
+    }"""
+    val result = JsonParser.importGameContext(json)
+    assert(result.isRight)
+    val ctx = result.toOption.get
+    assert(ctx.board.pieces.isEmpty)
+  }
+
+  test("parse with missing turn uses default") {
+    val json   = """{
+      "metadata": {},
+      "gameState": {"board": []},
+      "moves": []
+    }"""
+    val result = JsonParser.importGameContext(json)
+    assert(result.isRight)
+    val ctx = result.toOption.get
+    assert(ctx.turn == Color.White)
+  }
+
+  test("parse with missing board uses empty") {
+    val json   = """{
+      "metadata": {},
+      "gameState": {"turn": "White"},
+      "moves": []
+    }"""
+    val result = JsonParser.importGameContext(json)
+    assert(result.isRight)
+    val ctx = result.toOption.get
+    assert(ctx.board.pieces.isEmpty)
+  }
+
+  test("parse with missing moves uses empty list") {
+    val json   = """{
+      "metadata": {},
+      "gameState": {"turn": "White", "board": []}
+    }"""
+    val result = JsonParser.importGameContext(json)
+    assert(result.isRight)
+    val ctx = result.toOption.get
+    assert(ctx.moves.isEmpty)
+  }
+
+  test("parse invalid square in board filters it") {
+    val json   = """{
+      "metadata": {},
+      "gameState": {
+        "turn": "White",
+        "board": [
+          {"square": "invalid99", "color": "White", "piece": "Pawn"}
+        ]
+      },
+      "moves": []
+    }"""
+    val result = JsonParser.importGameContext(json)
+    assert(result.isRight)
+    val ctx = result.toOption.get
+    assert(ctx.board.pieces.isEmpty)
+  }
+
+  test("parse all valid piece types") {
+    val json   = """{
+      "metadata": {},
+      "gameState": {
+        "turn": "White",
+        "board": [
+          {"square": "a1", "color": "White", "piece": "Pawn"},
+          {"square": "b1", "color": "White", "piece": "Knight"},
+          {"square": "c1", "color": "White", "piece": "Bishop"},
+          {"square": "d1", "color": "White", "piece": "Rook"},
+          {"square": "e1", "color": "White", "piece": "Queen"},
+          {"square": "f1", "color": "White", "piece": "King"}
+        ]
+      },
+      "moves": []
+    }"""
+    val result = JsonParser.importGameContext(json)
+    assert(result.isRight)
+    val ctx = result.toOption.get
+    assert(ctx.board.pieces.size == 6)
+    assert(
+      ctx.board
+        .pieceAt(de.nowchess.api.board.Square(de.nowchess.api.board.File.A, de.nowchess.api.board.Rank.R1))
+        .get
+        .pieceType == PieceType.Pawn,
+    )
+  }
+
+  test("parse with all castling rights false") {
+    val json   = """{
+      "metadata": {},
+      "gameState": {
+        "turn": "White",
+        "board": [],
+        "castlingRights": {
+          "whiteKingSide": false,
+          "whiteQueenSide": false,
+          "blackKingSide": false,
+          "blackQueenSide": false
+        }
+      },
+      "moves": []
+    }"""
+    val result = JsonParser.importGameContext(json)
+    assert(result.isRight)
+    val ctx = result.toOption.get
+    assert(ctx.castlingRights.whiteKingSide == false)
+    assert(ctx.castlingRights.blackQueenSide == false)
+  }
+
+  // Move type parsing tests
+  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)
+    assert(result.isRight)
+  }
+
+  test("parse promotion with invalid piece uses default") {
+    val json   = """{
+      "metadata": {},
+      "gameState": {"turn": "White", "board": []},
+      "moves": [{"from": "a7", "to": "a8", "type": {"type": "promotion", "promotionPiece": "invalid"}}]
+    }"""
+    val result = JsonParser.importGameContext(json)
+    assert(result.isRight)
+  }
+
+  test("parse move with invalid 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
+    assert(ctx.moves.isEmpty)
+  }
+
+  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
+    assert(ctx.board.pieces.size == 1)
+  }
+
+  test("parse with empty board") {
+    val json   = """{
+  "metadata": {"event": "Game", "players": {"white": "A", "black": "B"}, "date": "2026-04-06", "result": "*"},
+  "gameState": {
+    "board": [],
+    "turn": "White",
+    "castlingRights": {"whiteKingSide": true, "whiteQueenSide": true, "blackKingSide": true, "blackQueenSide": true},
+    "enPassantSquare": null,
+    "halfMoveClock": 0
+  },
+  "moves": [],
+  "moveHistory": "",
+  "capturedPieces": {"byWhite": [], "byBlack": []},
+  "timestamp": "2026-04-06T00:00:00Z"
+}"""
+    val result = JsonParser.importGameContext(json)
+    assert(result.isRight)
+    assert(result.map(_.board.pieces.isEmpty) == Right(true))
+  }
+
+  test("importGameContext: returns error on invalid JSON") {
+    val result = JsonParser.importGameContext("not valid json {{{")
+    assert(result.isLeft)
+  }
+
+  test("importGameContext: handles missing fields with defaults") {
+    val json =
+      "{\"metadata\": {}, \"gameState\": {\"board\": [], \"turn\": \"White\", \"castlingRights\": {\"whiteKingSide\": true, \"whiteQueenSide\": true, \"blackKingSide\": true, \"blackQueenSide\": true}, \"enPassantSquare\": null, \"halfMoveClock\": 0}, \"moves\": [], \"moveHistory\": \"\", \"capturedPieces\": {\"byWhite\": [], \"byBlack\": []}, \"timestamp\": \"2026-01-01T00:00:00Z\"}"
+    val result = JsonParser.importGameContext(json)
+    assert(result.isRight)
+  }

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