diff --git a/.github/prompts/generate-config-tests.prompt.md b/.github/prompts/generate-config-tests.prompt.md
new file mode 100644
index 0000000..dbb13cd
--- /dev/null
+++ b/.github/prompts/generate-config-tests.prompt.md
@@ -0,0 +1,87 @@
+---
+description: Generate PHPUnit snapshot tests for a transformation config. Use when you want to add or update integration tests for a config file by providing 1–2 example input/output pairs per transformation rule.
+argument-hint: "config file path (e.g. config/config-ubs-account.json)"
+agent: agent
+---
+
+# Generate Config Integration Tests
+
+You help the user create PHPUnit snapshot (golden-file) tests for a specific transformation config.
+
+## Workflow
+
+### Step 1 — Identify the config
+
+If the user provided a config path as the argument, use it. Otherwise list all JSON files in `config/` (excluding `config.example.json`) and ask which one to test.
+
+### Step 2 — Read and summarise the config
+
+Read the config file with the read_file tool. Then present a compact table like:
+
+| # | sourceColumn | transformations | outputColumn |
+|---|---|---|---|
+| 1 | Buchungsdatum | dateformat (d.m.Y → Y-m-d) | date |
+| 2 | Buchungstext | trim → replace → lowercase | description |
+| … | … | … | … |
+
+Also note: the `metadata.extractionRules` (which pre-header lines are extracted and under what names), and `csvStructure.headerLine` / `csvStructure.delimiter`.
+
+### Step 3 — Collect examples from the user
+
+For each row in the table, ask the user to provide **1–2 example input cell values** and the **expected output value** after transformation. Present a form like:
+
+```
+Rule 1 — Buchungsdatum → date (dateformat d.m.Y → Y-m-d)
+  Example 1 input:  ___    expected output: ___
+  Example 2 input:  ___    expected output: ___ (optional)
+
+Rule 2 — Buchungstext → description (trim → replace → lowercase)
+  Example 1 input:  ___    expected output: ___
+  …
+```
+
+For `_constant_` source columns (metadata injections), ask the user for the expected metadata value that should appear in the output (e.g. the IBAN string).
+
+For metadata extraction rules, ask for a representative pre-header line string and the expected extracted value.
+
+If the user skips a rule, use a simple passthrough value (copy source → output unchanged).
+
+### Step 4 — Synthesise fixture files
+
+Derive the config name from the filename (e.g. `config-ubs-account.json` → `config-ubs-account`).
+
+**`tests/fixtures/<config-name>/input.csv`**
+
+Build a minimal CSV that satisfies `csvStructure`:
+- Pre-header lines (lines 1 … headerLine-1): one synthetic line per metadata extraction rule that matches its `regex` and returns the example value the user gave. Remaining pre-header lines (if any) can be empty placeholders.
+- Header line (line `headerLine`): the delimiter-separated source column names needed by the config.
+- Data rows: one row per example set. Where the user provided two examples for the same rule, use two data rows; align all other columns to the first example's values.
+
+**`tests/fixtures/<config-name>/expected.csv`**
+
+Header: the output column names in the order they appear after all transformations are applied (new `create` columns appended after existing ones).  
+Rows: the expected output values the user specified, aligned to the data rows above.
+
+### Step 5 — Generate or update `tests/ConfigIntegrationTest.php`
+
+If the file does not exist, create it. If it exists, add or replace only the parts that concern this config's fixture. The class must:
+
+- Use namespace `UbsCsvTransformer\Tests`
+- Extend `PHPUnit\Framework\TestCase`
+- Have a `public static function fixtureProvider(): array` that auto-discovers `tests/fixtures/*/` directories, maps each to `['configName' => ..., 'fixtureDir' => ...]`
+- Have a `@dataProvider fixtureProvider` test method `testConfigProducesExpectedOutput(string $configName, string $fixtureDir)` that:
+  1. Resolves `config/<configName>.json`
+  2. Instantiates `ConfigurationLoader` with that path
+  3. Instantiates `TransformerEngine` with the loader
+  4. Calls `transform()` with `$fixtureDir/input.csv` into a temp file
+  5. Reads the temp file and `$fixtureDir/expected.csv` and asserts they are identical line-by-line with `assertSame`
+  6. Cleans up the temp file in tearDown
+
+Follow all existing project conventions:
+- German docblocks
+- PSR-12, max line length 150
+- No PHPStan suppressions
+
+### Step 6 — Verify
+
+Run `composer test` and confirm the new test passes. If it fails, show the diff and ask the user to correct their expected values, then update `expected.csv`.
diff --git a/.gitignore b/.gitignore
index 464e9ff..2886748 100644
--- a/.gitignore
+++ b/.gitignore
@@ -17,6 +17,7 @@ composer.lock
 # PHP
 .php_cs.cache
 .phpunit.cache
+.phpunit.result.cache
 .phpstan.cache
 .psalm.cache
 
@@ -25,6 +26,7 @@ coverage/
 .coverage/
 build/
 dist/
+example-data/
 
 # Logs
 *.log
@@ -58,3 +60,4 @@ docker-compose.override.yml
 *.bak
 *.backup
 /tmp/
+/~archive/
diff --git a/AGENTS.md b/AGENTS.md
new file mode 100644
index 0000000..6c50c16
--- /dev/null
+++ b/AGENTS.md
@@ -0,0 +1,106 @@
+# Firefly Import Preprocessor — Agent Instructions
+
+PHP 8.1+ CLI ETL tool that transforms bank CSV exports (UBS E-Banking) into Firefly III-compatible format. See [README.md](README.md) for full documentation.
+
+## Build & Test
+
+```bash
+composer test           # PHPUnit tests
+composer lint           # phpcs PSR-12 check (src/ bin/)
+composer lint-fix       # phpcbf auto-fix
+composer analyze        # phpstan level 8
+composer psalm          # Psalm static analysis
+```
+
+### Test Suite Overview
+
+85 tests across 5 test classes:
+
+| File | Tests | Scope |
+|------|-------|-------|
+| `tests/ColumnTransformerTest.php` | 37 | All 13 transformation types, edge cases |
+| `tests/ConfigurationLoaderTest.php` | 18 | JSON loading, dot-notation access, validation |
+| `tests/CsvReaderTest.php` | 15 | CSV parsing, BOM handling, delimiter, encoding |
+| `tests/MetadataExtractorTest.php` | 14 | Pre-header regex extraction, edge cases |
+| `tests/ConfigIntegrationTest.php` | 1× per fixture | Golden-file integration tests (see below) |
+
+### Integration Tests (Golden-File Pattern)
+
+`ConfigIntegrationTest` auto-discovers every subdirectory in `tests/fixtures/` and runs a full transform pipeline against it. For each fixture directory `tests/fixtures/<name>/`:
+
+- `input.csv` — minimal representative CSV input
+- `expected.csv` — exact expected output after transformation
+- `config/<name>.json` must exist in the project root config dir
+
+**Currently active fixtures:** `config-ubs-account`
+
+**Adding a new fixture:** create the directory, add `input.csv` and `expected.csv`, ensure the matching `config/<name>.json` exists. No code changes required — the provider discovers it automatically.
+
+**Regenerating `expected.csv`** after a config change (replace `<name>` accordingly):
+
+```bash
+php -r "
+require 'vendor/autoload.php';
+use UbsCsvTransformer\ConfigurationLoader;
+use UbsCsvTransformer\TransformerEngine;
+\$tmpConfig = sys_get_temp_dir() . '/gen.json';
+\$cfg = json_decode(file_get_contents('config/<name>.json'), true);
+\$cfg['directories']['output'] = 'tests/fixtures/<name>';
+\$cfg['csvStructure']['outputFilename'] = 'expected.csv';
+file_put_contents(\$tmpConfig, json_encode(\$cfg, JSON_UNESCAPED_UNICODE));
+\$loader = new ConfigurationLoader(\$tmpConfig); \$loader->load();
+\$engine = new TransformerEngine(\$loader);
+\$result = \$engine->transform('tests/fixtures/<name>/input.csv');
+unlink(\$tmpConfig);
+echo \$result['success'] ? 'OK' . PHP_EOL : 'ERROR: ' . \$result['error'] . PHP_EOL;
+"
+```
+
+Run the tool:
+
+```bash
+php bin/transformer.php test input.csv config/config.json --rows=5
+php bin/transformer.php transform input.csv config/config.json --output=output.csv
+php bin/transformer.php validate config/config.json --strict
+php bin/transformer.php auto-import config/config.json --watch
+# Add --debug / -d for verbose output
+```
+
+## Architecture
+
+```bash
+bin/transformer.php → TransformerEngine
+                           ├── ConfigurationLoader   (JSON config)
+                           ├── CsvReader             (reads + BOM handling)
+                           ├── MetadataExtractor     (regex on pre-header lines)
+                           ├── ColumnTransformer     (transformation pipeline)
+                           ├── CsvWriter             (output CSV)
+                           └── FireflyImporter       (optional, shells to Firefly CLI)
+```
+
+`DebugLogger` is a static helper used across all components; activated by the `--debug` flag.  
+`TransformerEngine` instantiates `CsvReader` per call (in `transform()`/`validate()`), not in the constructor.
+
+## Conventions
+
+- **PSR-12** enforced via phpcs using `phpcs.xml` (auto-discovered at root). Line length: soft 120, hard 150 chars.
+- **PHPStan level 8** with `checkMissingCallableSignature: true`. `phpstan-baseline.neon` is empty — do not add suppressions without good reason.
+- **All source comments and docblocks are written in German.**
+- Namespace `UbsCsvTransformer\` (PSR-4 → `src/`); tests use `UbsCsvTransformer\Tests\` (→ `tests/`).
+- No runtime package dependencies — only `ext-json` and `ext-mbstring`.
+
+## Config Format
+
+See [config/config.example.json](config/config.example.json) for a full reference. Three top-level sections:
+
+- **`metadata.extractionRules`** — regex rules against 1-based pre-header line numbers
+- **`csvStructure`** — `headerLine`, `delimiter`, `encoding`, `hasBom`
+- **`columnTransformations`** — array of per-column transformation pipelines
+
+### Key patterns in config
+
+- `"sourceColumn": "_constant_"` — injects an extracted metadata value (e.g. IBAN) as a new output column without reading a CSV column
+- `"outputAction": "create"` vs `"overwrite"` — controls whether the result is a new column or replaces an existing one
+- `MetadataExtractor` uses 1-based `lineNumber` in config; it converts to 0-based array index internally
+
+Supported transformation types: `map`, `replace`, `regex`, `regexextract`, `dateformat`, `split`, `trim`, `uppercase`, `lowercase`, `ucwordsfirst`, `truncate`, `constantvalue`, `pipeline`
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..2ffce8e
--- /dev/null
+++ b/README.md
@@ -0,0 +1,1073 @@
+# Firefly Import Preprocessor - Dokumentation
+
+**Version:** 1.0.0  
+**Datum:** 10. Dezember 2025  
+**Status:** Production Ready
+
+---
+
+## 📋 Inhaltsverzeichnis
+
+1. [Überblick](#überblick)
+2. [Installation & Setup](#installation--setup)
+3. [Schnellstart](#schnellstart)
+4. [Konfiguration](#konfiguration)
+5. [Transformationstypen](#transformationstypen)
+6. [CLI-Referenz](#cli-referenz)
+7. [Debug-Modus](#debug-modus)
+8. [Firefly III Integration](#firefly-iii-integration)
+9. [Architektur](#architektur)
+10. [Fehlerbehandlung](#fehlerbehandlung)
+
+---
+
+## Überblick
+
+Der **Firefly Import Preprocessor** ist ein produktionsreifer PHP-Preprocessor für Banken-CSV-Exportdateien. Er transformiert Bankdaten in ein standardisiertes Format und kann sie optional in Firefly III importieren.
+
+### Kernfeatures
+
+✅ **Vollständige CSV-Transformation** mit komplexen Pipelines  
+✅ **Metadaten-Extraktion** mit Regex (IBAN, Währung, Kontoname)  
+✅ **11 Transformationstypen** für flexible Datenverarbeitung  
+✅ **Firefly III Integration** mit Docker-Support  
+✅ **Debug-Modus** für Transparenz bei Verarbeitung  
+✅ **Production Ready** mit vollständiger Fehlerbehandlung  
+✅ **Zero Dependencies** für Core-Funktionalität  
+
+### Workflow
+
+```
+Input CSV
+    ↓
+Metadaten extrahieren (Regex)
+    ↓
+Datenzeilen transformieren (Pipeline)
+    ↓
+Output CSV schreiben
+    ↓
+[Optional] In Firefly III importieren
+```
+
+---
+
+## Installation & Setup
+
+### Voraussetzungen
+
+- PHP 8.1+
+- Composer (empfohlen)
+- [Optional] Docker für Firefly III Integration
+
+### Installation
+
+```bash
+# 1. Repository clonen/kopieren
+cd ff-imp-preprocessor
+
+# 2. Abhängigkeiten installieren (optional)
+composer install
+
+# 3. Konfiguration erstellen
+cp config/config.example.json config/config.json
+# Bearbeite config/config.json mit deinen Einstellungen
+
+# 4. Directories erstellen
+mkdir -p config/import/{source,output,archive,error}
+chmod 755 config/import/{source,output,archive,error}
+
+# 5. Test durchführen
+php bin/transformer.php validate config/config.json input.csv
+```
+
+---
+
+## Schnellstart
+
+### 1. Konfiguration anpassen
+
+Bearbeite `config/config.json` und stelle sicher, dass die Extraction-Rules zu deinem CSV-Format passen:
+
+```json
+{
+  "metadata": {
+    "extractionRules": [
+      {
+        "name": "account_iban",
+        "lineNumber": 2,
+        "regex": "IBAN:\\s*([A-Z0-9 ]+)",
+        "captureGroup": 1
+      }
+    ]
+  },
+  "csvStructure": {
+    "headerLine": 5,
+    "delimiter": ";",
+    "encoding": "UTF-8"
+  }
+}
+```
+
+### 2. CSV validieren
+
+```bash
+php bin/transformer.php validate config/config.json input.csv
+```
+
+Output:
+```
+✓ CSV ist valid
+  IBAN: CH9300762011623852957
+  Währung: CHF
+  Zeilen: 150
+```
+
+### 3. Transformation durchführen
+
+```bash
+php bin/transformer.php process config/config.json input.csv
+
+# Mit Debug-Modus für Fehlersuche
+php bin/transformer.php process config/config.json input.csv --debug
+```
+
+### 4. Output prüfen
+
+```bash
+# Transformierte Datei
+cat config/import/output/transformed.csv
+
+# Oder mit Debug-Ausgabe
+php bin/transformer.php test config/config.json input.csv --debug
+# Zeigt max. 10 transformierte Zeilen und Debug-Logs
+```
+
+---
+
+## Konfiguration
+
+### config.json Struktur
+
+#### `metadata` - Metadaten-Extraktion
+
+```json
+{
+  "metadata": {
+    "extractionRules": [
+      {
+        "name": "account_iban",
+        "lineNumber": 2,
+        "regex": "IBAN:\\s*([A-Z0-9 ]+)",
+        "captureGroup": 1
+      },
+      {
+        "name": "currency_code",
+        "lineNumber": 3,
+        "regex": "Währung:\\s*([A-Z]{3})",
+        "captureGroup": 1
+      }
+    ]
+  }
+}
+```
+
+| Feld | Typ | Beschreibung |
+|------|-----|-------------|
+| `name` | string | Name der Metadaten-Variable (verwendet in constantvalue) |
+| `lineNumber` | int | Zeilennummer in CSV (1-basiert, menschenlesbar) |
+| `regex` | string | Regex-Pattern zur Extraktion (ohne Delimiter) |
+| `captureGroup` | int | Nummer der Klammer-Gruppe (0=komplett, 1=erste Klammer, etc.) |
+
+**Beispiel Regex:**
+- Pattern: `IBAN:\s*([A-Z0-9 ]+)`
+- Input: `IBAN: CH93 0076 2011 6238 5295 7`
+- Capture Group 1: `CH93 0076 2011 6238 5295 7`
+
+#### `csvStructure` - CSV-Format
+
+```json
+{
+  "csvStructure": {
+    "headerLine": 5,
+    "delimiter": ";",
+    "encoding": "UTF-8",
+    "hasBom": false
+  }
+}
+```
+
+| Feld | Typ | Default | Beschreibung |
+|------|-----|---------|-------------|
+| `headerLine` | int | 5 | Zeilennummer der Header (1-basiert) |
+| `delimiter` | string | `;` | CSV-Delimiter |
+| `encoding` | string | `UTF-8` | Zeichenkodierung (UTF-8, ISO-8859-1, CP1252) |
+| `hasBom` | bool | false | Hat die Datei BOM (Byte Order Mark)? |
+
+#### `columnTransformations` - Spalten-Transformationen
+
+```json
+{
+  "columnTransformations": [
+    {
+      "sourceColumn": "Buchungsdatum",
+      "transformations": [
+        {
+          "type": "dateformat",
+          "fromFormat": "d.m.Y",
+          "toFormat": "Y-m-d"
+        }
+      ],
+      "outputColumn": "date",
+      "outputAction": "overwrite"
+    }
+  ]
+}
+```
+
+**outputAction:**
+- `overwrite` - Überschreibe sourceColumn
+- `create` - Erstelle neue Spalte (für Regex-Extract, Split, etc.)
+
+#### `directories` - Dateisystem
+
+```json
+{
+  "directories": {
+    "source": "/opt/ff-imp-preprocessor/import/source",
+    "output": "/opt/ff-imp-preprocessor/import/output",
+    "archive": "/opt/ff-imp-preprocessor/import/archive",
+    "error": "/opt/ff-imp-preprocessor/import/error"
+  }
+}
+```
+
+| Feld | Beschreibung |
+|------|-------------|
+| `source` | Eingabe-Verzeichnis |
+| `output` | Ausgabe-Verzeichnis |
+| `archive` | Archiv für verarbeitete Dateien |
+| `error` | Error-Verzeichnis für ungültige Dateien |
+
+#### `fireflyImport` - Firefly III Integration
+
+```json
+{
+  "fireflyImport": {
+    "jsonConfig": "/opt/firefly/import-config.json",
+    "importerCommand": "docker exec -it firefly-importer php artisan importer:import",
+    "autoImport": false,
+    "deleteAfterImport": false,
+    "timeout": 300,
+    "environment": {
+      "FIREFLY_III_URL": "https://your-firefly.com",
+      "FIREFLY_III_ACCESS_TOKEN": "your-token-here"
+    }
+  }
+}
+```
+
+---
+
+## Transformationstypen
+
+Es gibt **13 unterstützte Transformationstypen**, die als Pipeline kombiniert werden können:
+
+### 1. **trim** - Leerzeichen entfernen
+
+Entfernt Leerzeichen am Anfang und Ende.
+
+```json
+{
+  "type": "trim"
+}
+```
+
+**Beispiel:**
+- Input: `  Coop Pronto  `
+- Output: `Coop Pronto`
+
+---
+
+### 2. **lowercase** - Zu Kleinbuchstaben
+
+Wandelt in Kleinbuchstaben um (UTF-8 safe).
+
+```json
+{
+  "type": "lowercase"
+}
+```
+
+**Beispiel:**
+- Input: `COOP PRONTO CHUR`
+- Output: `coop pronto chur`
+
+---
+
+### 3. **uppercase** - Zu Grossbuchstaben
+
+Wandelt in Grossbuchstaben um (UTF-8 safe).
+
+```json
+{
+  "type": "uppercase"
+}
+```
+
+**Beispiel:**
+- Input: `Coop Pronto Chur`
+- Output: `COOP PRONTO CHUR`
+
+---
+
+### 4. **ucwordsfirst** - Grossschreibung nach Trennzeichen
+
+Grossschreibt ersten Buchstaben nach Worttrennzeichen.
+
+```json
+{
+  "type": "ucwordsfirst"
+}
+```
+
+**Beispiele:**
+- `COOP PRONTO CHUR` → `Coop Pronto Chur`
+- `migros-rail city` → `Migros-Rail City`
+- `O'NEILL STORE` → `O'Neill Store`
+- `SAINT-JEAN-DE-MAURIENNE` → `Saint-Jean-De-Maurienne`
+
+Trennzeichen: Leerzeichen, Bindestrich, Apostroph, Slash, Punkt, Komma, Semikolon, Doppelpunkt, Klammern.
+
+---
+
+### 5. **replace** - String-Replacement
+
+Ersetzt Substring durch anderen String (case-sensitive).
+
+```json
+{
+  "type": "replace",
+  "search": "  ",
+  "replace": " "
+}
+```
+
+**Beispiel:**
+- Input: `Coop  Pronto` (2 Leerzeichen)
+- Output: `Coop Pronto` (1 Leerzeichen)
+
+---
+
+### 6. **split** - Spalte teilen
+
+Teilt einen Wert bei Delimiter und behält einen definierten Teil.
+
+```json
+{
+  "type": "split",
+  "delimiter": ";",
+  "part": 0
+}
+```
+
+**Beispiel:**
+- Input: `Coop Pronto Chur;7007 Chur`
+- Config: `delimiter=";"`, `part=0`
+- Output: `Coop Pronto Chur`
+
+---
+
+### 7. **regex** - Regex-Ersetzung
+
+Ersetzt Teile des Strings per regulärem Ausdruck. Nutzt PHP `preg_replace`.
+
+```json
+{
+  "type": "regex",
+  "pattern": "^(.*?);.*$",
+  "replace": "$1"
+}
+```
+
+**Beispiel — mit Match:**
+- Input: `Friis, Daniela Silvia; Zahlung UBS TWINT`
+- Pattern: `^(.*?);.*$`, Replace: `$1`
+- Output: `Friis, Daniela Silvia`
+
+**Beispiel — kein Match (pass-through):**
+- Input: `Coop Pronto Chur` (kein Semikolon)
+- Output: `Coop Pronto Chur` ← Wert bleibt **unverändert**
+
+**Beispiel — Pattern ohne Anchors (ersetzt nur den gematchten Teil):**
+- Input: `Zahlung UBS TWINT; Referenz 12345`
+- Pattern: `UBS TWINT`, Replace: `TWINT`
+- Output: `Zahlung TWINT; Referenz 12345`
+
+**Hinweise:**
+- **Kein Match → Originalwert wird unverändert weitergegeben** (pipeline-sicher)
+- Capture Groups als `$1`, `$2`, … im `replace` referenzieren
+- Pattern ohne `^`/`$`-Anchors ersetzt nur den gematchten Teilstring, nicht den ganzen Wert
+
+---
+
+### 8. **regexextract** - Regex-Extraktion
+
+Extrahiert eine Capture Group per regulärem Ausdruck und gibt **nur diese** zurück. Nutzt PHP `preg_match`.
+
+```json
+{
+  "sourceColumn": "Mitteilungen",
+  "transformations": [
+    {
+      "type": "regexextract",
+      "pattern": "(\\d{4,} [^;]+)"
+    }
+  ],
+  "outputColumn": "location",
+  "outputAction": "create"
+}
+```
+
+**Beispiel — mit Match:**
+- Input: `Coop Pronto Chur, 7007 Chur`
+- Pattern: `(\d{4,} [^;]+)`
+- Output: `7007 Chur` ← nur Capture Group 1
+
+**Beispiel — kein Match:**
+- Input: `Dauerauftrag Miete`
+- Output: `` (leerer String)
+
+**Hinweise:**
+- **Kein Match → leerer String** (vorherige Pipeline-Schritte gehen verloren)
+- Nutzt Capture Group 1 wenn vorhanden, sonst komplettes Match
+- **⚠ Nicht pipeline-sicher:** Nur als einzigen oder letzten Schritt verwenden. Wenn bei Kein-Match der bisherige Wert erhalten bleiben soll, `regex` verwenden.
+
+---
+
+### 9. **dateformat** - Datum-Umformat
+
+Konvertiert zwischen Datum-Formaten.
+
+```json
+{
+  "type": "dateformat",
+  "fromFormat": "d.m.Y",
+  "toFormat": "Y-m-d"
+}
+```
+
+**Beispiel:**
+- Input: `10.12.2025`
+- Output: `2025-12-10`
+
+**Supported Formate:** Alle PHP DateTime-Formate (d, m, Y, H, i, s, etc.)
+
+---
+
+### 10. **truncate** - String kürzen
+
+Kürzt String auf maximale Länge.
+
+```json
+{
+  "type": "truncate",
+  "maxLength": 100
+}
+```
+
+**Beispiel:**
+- Input: `Dieser sehr lange Text...` (150 Zeichen)
+- Output: `Dieser sehr lange Text...` (100 Zeichen)
+
+---
+
+### 11. **constantvalue** - Konstanten-Wert aus Metadaten
+
+Nutzt extrahierte Metadaten als konstanten Wert.
+
+```json
+{
+  "sourceColumn": "_constant_",
+  "transformations": [
+    {
+      "type": "constantvalue",
+      "metadataKey": "account_iban"
+    }
+  ],
+  "outputColumn": "account_iban",
+  "outputAction": "create"
+}
+```
+
+**Beispiel:**
+- metadataKey: `account_iban` (aus Extraktion)
+- Wert: `CH9300762011623852957`
+- Jede Zeile erhält diesen Wert in neuer Spalte
+
+---
+
+### 12. **map** - Spalte kopieren (Standard)
+
+Kopiert oder benannt eine Spalte um.
+
+```json
+{
+  "sourceColumn": "Buchungstext",
+  "transformations": [
+    {
+      "type": "map"
+    }
+  ],
+  "outputColumn": "description",
+  "outputAction": "overwrite"
+}
+```
+
+**Beispiel:**
+- Input Spalte: `Buchungstext`
+- Output Spalte: `description` mit gleichem Inhalt
+
+---
+
+### 13. **pipeline** - Verschachtelte Pipeline
+
+Führt eine Unter-Pipeline innerhalb eines Transformationsschritts aus. Ermöglicht das Gruppieren von Schritten als Einheit.
+
+```json
+{
+  "type": "pipeline",
+  "steps": [
+    { "type": "trim" },
+    { "type": "lowercase" },
+    { "type": "ucwordsfirst" }
+  ]
+}
+```
+
+**Hinweis:** In der Praxis werden mehrere Schritte direkt als `transformations`-Array aufgelistet. `pipeline` als Typ ist nützlich wenn innerhalb einer `transformations`-Liste eine Gruppe von Schritten bedingt oder als Einheit behandelt werden soll.
+
+---
+
+### Pipeline-Beispiel
+
+Mehrere Transformationen hintereinander:
+
+```json
+{
+  "sourceColumn": "Buchungstext",
+  "transformations": [
+    { "type": "trim" },
+    { "type": "replace", "search": "  ", "replace": " " },
+    { "type": "lowercase" },
+    { "type": "ucwordsfirst" }
+  ],
+  "outputColumn": "description",
+  "outputAction": "overwrite"
+}
+```
+
+**Verarbeitung:**
+1. `"  COOP  PRONTO  "` → trim → `"COOP  PRONTO"`
+2. `"COOP  PRONTO"` → replace → `"COOP PRONTO"`
+3. `"COOP PRONTO"` → lowercase → `"coop pronto"`
+4. `"coop pronto"` → ucwordsfirst → `"Coop Pronto"`
+
+---
+
+## CLI-Referenz
+
+Der Transformer wird über `bin/transformer.php` aufgerufen:
+
+```bash
+php bin/transformer.php <command> <config> <input> [options]
+```
+
+### Kommandos
+
+#### `process` - Führe Transformation aus
+
+```bash
+php bin/transformer.php process config/config.json input.csv [--debug]
+```
+
+- Transformiert CSV-Datei komplett
+- Schreibt in `directories.output` (aus config)
+- Optional: `--debug` für Debug-Logs
+
+**Output:**
+```
+✓ Transformation erfolgreich
+  Input:  input.csv
+  Output: config/import/output/transformed.csv
+  Zeilen: 245
+  Sample:
+    - [Datum: 2025-01-10, Beschreibung: ...]
+```
+
+---
+
+#### `validate` - Validiere CSV
+
+```bash
+php bin/transformer.php validate config/config.json input.csv
+```
+
+- Prüft CSV-Format
+- Extrahiert Metadaten
+- Validiert erforderliche Felder
+
+**Output:**
+```
+✓ CSV ist valid
+  Zeilen: 245
+  IBAN: CH9300762011623852957
+  Währung: CHF
+```
+
+---
+
+#### `test` - Test-Run mit Beispieldaten
+
+```bash
+php bin/transformer.php test config/config.json input.csv [--debug]
+```
+
+- Transformiert maximal 10 Zeilen
+- Zeigt Metadaten und Beispiel-Output
+- Schnell zur Prüfung von Konfiguration
+
+**Output:**
+```
+✓ Test erfolgreich
+  Max 10 Zeilen verarbeitet: 10
+  Metadaten:
+    - IBAN: CH93...
+    - Währung: CHF
+  Beispiel (Zeile 1):
+    - date: 2025-01-10
+    - description: coop pronto chur
+    - amount: 25.50
+```
+
+---
+
+#### `help` - Zeige Hilfe
+
+```bash
+php bin/transformer.php help
+```
+
+---
+
+### Optionen
+
+| Option | Beschreibung | Beispiel |
+|--------|-------------|---------|
+| `--debug` | Aktiviere Debug-Modus | `process config.json input.csv --debug` |
+| `--test` | Führe nur Test mit 10 Zeilen aus | `process config.json input.csv --test` |
+
+---
+
+## Debug-Modus
+
+Der Debug-Modus bietet maximale Transparenz über die Verarbeitung.
+
+### Aktivierung
+
+```bash
+php bin/transformer.php process config/config.json input.csv --debug
+```
+
+### Ausgegabene Informationen
+
+Der Debug-Modus protokolliert:
+
+**1. Transformer Level**
+- Transformation gestartet (Input-Datei, maxRows)
+- Transformation abgeschlossen
+- Fehler
+
+**2. CSV Reader Level**
+- Metadaten-Zeilen gelesen (Anzahl)
+- Datenzeilen gelesen (Anzahl)
+
+**3. Metadata Extraction Level**
+- Extraktion-Regel angewendet
+- IBAN extrahiert
+- Währung extrahiert
+- Fehlerhafte Regex
+- Fehlende Zeilen
+
+**4. Transformation Level**
+- Split-Transformation angewendet
+- RegexExtract-Transformation angewendet
+- Fehlerhafte Transformationen
+
+**5. CSV Writer Level**
+- Transformierte Daten geschrieben
+- Output-Datei-Pfad
+
+### JSON-Output mit Debug-Logs
+
+Mit `--debug` wird das Ergebnis erweitert:
+
+```json
+{
+  "success": true,
+  "inputFile": "input.csv",
+  "outputFile": "output/transformed.csv",
+  "rowsProcessed": 245,
+  "metadata": { "account_iban": "CH93...", "currency_code": "CHF" },
+  "debug_logs": [
+    {
+      "timestamp": 1702200120.5432,
+      "category": "transformer",
+      "message": "Transformation started",
+      "data": { "inputFile": "input.csv", "maxRows": 0 }
+    },
+    {
+      "timestamp": 1702200120.5445,
+      "category": "metadata",
+      "message": "Extraction rule applied",
+      "data": { "rule_name": "account_iban", "value": "CH93..." }
+    }
+    // ... weitere Logs
+  ]
+}
+```
+
+### Debug-Log-Kategorien
+
+| Kategorie | Beispiel | Wann |
+|-----------|---------|------|
+| `transformer` | Transformation gestartet | Anfang/Ende Transformation |
+| `csv_reader` | Zeilen gelesen | Beim CSV lesen |
+| `metadata` | IBAN extrahiert | Bei Metadaten-Extraktion |
+| `metadata_warning` | Regex matched nicht | Bei Problemen |
+| `transformation` | Split angewendet | Bei jeder Transformation |
+| `csv_writer` | Daten geschrieben | Beim CSV schreiben |
+
+---
+
+## Firefly III Integration
+
+Der Transformer kann transformierte Daten automatisch in Firefly III importieren.
+
+### Setup
+
+1. **Firefly III laufen lassen**
+
+```bash
+docker-compose up -d firefly-iii
+docker-compose up -d firefly-importer
+```
+
+2. **Konfiguration anpassen**
+
+```json
+{
+  "fireflyImport": {
+    "autoImport": true,
+    "environment": {
+      "FIREFLY_III_URL": "https://your-firefly.local",
+      "FIREFLY_III_ACCESS_TOKEN": "your-personal-access-token"
+    }
+  }
+}
+```
+
+3. **Import-Konfiguration erstellen**
+
+`/opt/firefly/import-config.json`:
+```json
+{
+  "accounts": [
+    {
+      "name": "UBS Checking",
+      "iban": "CH9300762011623852957",
+      "account_type": "asset"
+    }
+  ],
+  "column_mapping": {
+    "date": "date",
+    "amount": "amount",
+    "description": "description"
+  }
+}
+```
+
+4. **Auto-Import aktivieren**
+
+```bash
+php bin/transformer.php process config/config.json input.csv
+# Wenn autoImport=true, wird die transformierte Datei automatisch importiert
+```
+
+### Manueller Import
+
+```bash
+docker exec -it firefly-importer php artisan importer:import
+```
+
+---
+
+## Architektur
+
+### Komponenten
+
+```
+bin/transformer.php (CLI Entry Point)
+  ↓
+TransformerEngine (Orchestrierung)
+  ├─ ConfigurationLoader (Config laden/validieren)
+  ├─ CsvReader (CSV einlesen)
+  ├─ MetadataExtractor (Metadaten mit Regex)
+  ├─ ColumnTransformer (Transformationen anwenden)
+  ├─ CsvWriter (CSV schreiben)
+  ├─ FireflyImporter (Firefly III Integration)
+  └─ DebugLogger (Debug-Protokolle)
+```
+
+### Datenfluss
+
+```
+Input CSV
+  ↓
+CsvReader::readMetadataLines() → Array von Zeilen
+  ↓
+MetadataExtractor::extract() → {iban: "...", currency: "..."}
+  ↓
+CsvReader::readCsvData() → Array von Zeilen
+  ↓
+ColumnTransformer::transformRow() → Transformierte Zeile (Pipeline)
+  ↓
+CsvWriter::write() → Output CSV
+```
+
+### Klassen
+
+| Klasse | Verantwortung |
+|--------|---------------|
+| `TransformerEngine` | Orchestriert gesamten Workflow |
+| `ConfigurationLoader` | Lädt JSON/YAML Konfiguration |
+| `CsvReader` | Liest CSV mit Metadaten |
+| `MetadataExtractor` | Extrahiert mit Regex |
+| `ColumnTransformer` | Transformiert Spalten (Pipeline) |
+| `CsvWriter` | Schreibt CSV |
+| `FireflyImporter` | Importiert in Firefly III |
+| `DebugLogger` | Statischer Logger für Debug |
+
+---
+
+## Fehlerbehandlung
+
+### Häufige Fehler
+
+#### 1. "Input-Datei nicht gefunden"
+
+```bash
+Error: Input-Datei nicht gefunden: input.csv
+```
+
+**Ursache:** Dateipfad falsch oder Datei nicht vorhanden
+
+**Lösung:**
+```bash
+# Prüfe Dateipfad
+ls -la input.csv
+
+# Nutze absoluten Pfad wenn relativ nicht funktioniert
+php bin/transformer.php process config.json /absolute/path/input.csv
+```
+
+---
+
+#### 2. "Fehlende Metadaten: account_iban"
+
+```bash
+Error: Fehlende Metadaten: account_iban
+```
+
+**Ursache:** IBAN konnte nicht extrahiert werden (Regex oder Zeile falsch)
+
+**Lösung:**
+```bash
+# Debugging mit --debug
+php bin/transformer.php validate config.json input.csv
+
+# Prüfe erste 5 Zeilen des CSV
+head -5 input.csv
+
+# Überprüfe lineNumber und regex in config.json
+# lineNumber sollte auf Zeile mit IBAN zeigen
+```
+
+---
+
+#### 3. "Ungültiges JSON"
+
+```bash
+Error: Ungültiges JSON: Syntax error, malformed JSON
+```
+
+**Ursache:** JSON-Syntax-Fehler in config.json
+
+**Lösung:**
+```bash
+# Validiere JSON
+php -r "json_decode(file_get_contents('config/config.json'), true) or die('JSON invalid');"
+
+# Oder nutze online JSON validator
+# https://jsonlint.com/
+```
+
+---
+
+#### 4. "CSV-Struktur-Fehler"
+
+```bash
+Error: 'csvStructure.headerLine' erforderlich
+```
+
+**Ursache:** Erforderliche Konfigurationsfelder fehlen
+
+**Lösung:**
+```bash
+# Vergleiche mit config.example.json
+diff config/config.json config/config.example.json
+
+# Stellen Sie sicher, dass folgende Felder vorhanden sind:
+# - csvStructure.headerLine (Zeilennummer der Kopfzeile)
+# - csvStructure.delimiter (CSV-Trennzeichen)
+# - metadata.extractionRules (mindestens 1)
+# - columnTransformations (mindestens 1)
+```
+
+---
+
+### Exception-Handling
+
+Der Transformer nutzt Try-Catch für robuste Fehlerbehandlung:
+
+```php
+try {
+    $result = $engine->transform($inputFile);
+    if (!$result['success']) {
+        echo "Fehler: " . $result['error'];
+    }
+} catch (Exception $e) {
+    echo "Fatal Error: " . $e->getMessage();
+}
+```
+
+### Debug-Modus für Fehlersuche
+
+Der Debug-Modus zeigt detailliert wo der Fehler liegt:
+
+```bash
+php bin/transformer.php process config/config.json input.csv --debug 2>&1 | tail -50
+```
+
+---
+
+## Besonderheiten & Tipps
+
+### UTF-8 Handling
+
+Der Transformer nutzt UTF-8 safe Funktionen:
+- `mb_strtolower()` statt `strtolower()`
+- `mb_strtoupper()` statt `strtoupper()`
+- `mb_strlen()` für korrektes Character-Counting
+
+Unterstützte Encodings: UTF-8, ISO-8859-1, CP1252
+
+### Regex-Tipps
+
+**Pattern ohne Delimiter:**
+```json
+"pattern": "IBAN:\\s*([A-Z0-9 ]+)"
+// Wird zu: /IBAN:\s*([A-Z0-9 ]+)/u
+```
+
+**Mit Flags:**
+```json
+"pattern": "/IBAN:\\s*([A-Z0-9 ]+)/iu"
+// Case-insensitive
+```
+
+**Spezielle Zeichen escapen:**
+```json
+"pattern": "\\(\\d{4}\\)"
+// Matcht: (1234)
+```
+
+### Performance
+
+- **Max. Dateigröße:** Abhängig von RAM (typically 100MB+)
+- **Optimiert für:** Bis zu 1 Million Zeilen
+- **Typical:** 10-100k Zeilen pro Datei
+
+### Batch-Processing
+
+```bash
+#!/bin/bash
+for file in import/source/*.csv; do
+    php bin/transformer.php process config/config.json "$file"
+    if [ $? -eq 0 ]; then
+        mv "$file" import/archive/
+    else
+        mv "$file" import/error/
+    fi
+done
+```
+
+---
+
+## Support & Troubleshooting
+
+### Logging aktivieren
+
+Nutze den Built-in Debug-Logger:
+
+```bash
+php bin/transformer.php test config/config.json input.csv --debug > debug.log 2>&1
+cat debug.log | grep -i error
+```
+
+### Nützliche Kommandos
+
+```bash
+# Test CSV-Validität
+php bin/transformer.php validate config.json input.csv
+
+# Test nur mit 10 Zeilen
+php bin/transformer.php test config.json input.csv
+
+# Mit voller Debug-Ausgabe
+php bin/transformer.php process config.json input.csv --debug
+
+# Prüfe PHP-Syntax aller Dateien
+php -l bin/transformer.php
+php -l src/*.php
+
+# Validiere Konfiguration
+php -r "require 'src/ConfigurationLoader.php'; new UbsCsvTransformer\ConfigurationLoader('config/config.json');"
+```
+
+---
+
+## Version & Änderungen
+
+**v1.0.0 (10. Dezember 2025)**
+- ✅ Initial Release
+- ✅ 11 Transformationstypen
+- ✅ Metadaten-Extraktion mit Regex
+- ✅ Debug-Modus
+- ✅ Firefly III Integration
+- ✅ Vollständige Dokumentation
+
+---
+
+**Lizenz:** MIT  
+**Author:** PHP CSV Transformer Project  
+**Repository:** https://git.andare.ch/david.reindl/ff-imp-preprocessor
\ No newline at end of file
diff --git a/bin/transformer.php b/bin/transformer.php
new file mode 100755
index 0000000..d62ebf3
--- /dev/null
+++ b/bin/transformer.php
@@ -0,0 +1,543 @@
+#!/usr/bin/env php
+
+<?php
+
+/**
+ * Firefly Import Preprocessor - Kommandozeilen-Einstiegspunkt
+ *
+ * PHP 8.1+ Tool zur Transformation von UBS E-Banking CSV-Exporten
+ * in ein Firefly III kompatibles Format.
+ *
+ * Voraussetzung: composer install
+ */
+
+require_once __DIR__ . '/../vendor/autoload.php';
+
+use UbsCsvTransformer\TransformerEngine;
+use UbsCsvTransformer\ConfigurationLoader;
+use UbsCsvTransformer\FireflyImporter;
+
+// ============================================================================
+// CLI-Argument-Verarbeitung
+// ============================================================================
+
+$argc = $_SERVER['argc'] ?? 0;
+$argv = $_SERVER['argv'] ?? [];
+
+if ($argc < 2) {
+    showHelp();
+    exit(0);
+}
+
+// Debug-Modus aktivierbar
+$debug = in_array('--debug', $argv) || in_array('-d', $argv);
+
+// Extrahiere Kommando
+$command = $argv[1];
+
+try {
+    match ($command) {
+        'test' => handleTest($argc, $argv),
+        'transform' => handleTransform($argc, $argv),
+        'validate' => handleValidate($argc, $argv),
+        'auto-import' => handleAutoImport($argc, $argv),
+        'help', '-h', '--help' => showHelp(),
+        default => throw new Exception("Unbekanntes Kommando: $command"),
+    };
+} catch (Exception $e) {
+    fwrite(STDERR, "\n❌ ERROR: " . $e->getMessage() . "\n\n");
+    exit(1);
+}
+
+// ============================================================================
+// COMMAND HANDLERS
+// ============================================================================
+
+/**
+ * Zeige Hilfe und Verwendungsanleitung
+ */
+function showHelp(): void
+{
+    echo <<<'HELP'
+╔════════════════════════════════════════════════════════════════════════════╗
+║ Firefly Import Preprocessor - Kommandozeilen-Tool                        ║
+║                                                                            ║
+║ Ein schlankes PHP 8 Tool zur Transformation von UBS E-Banking Exporten     ║
+║ in ein Firefly III kompatibles Format.                                    ║
+╚════════════════════════════════════════════════════════════════════════════╝
+
+VERWENDUNG:
+  transformer [command] [options]
+
+KOMMANDOS:
+
+  test [input] [config] [options]
+    Testet die Transformation mit limitierter Zeilenzahl
+    Optionen:
+      --rows=N          Nur N Zeilen verarbeiten (Standard: 10)
+      --output=FILE, -o Ergebnis auch in Datei schreiben
+    Beispiel:
+      transformer test ubs-export.csv config.json --rows=5
+      transformer test ubs-export.csv config.json -o test-output.csv
+
+  transform [input] [config] [options]
+    Transformiert eine komplette CSV-Datei
+    Optionen:
+      --output=FILE, -o Output-Pfad (Standard: input-transformed.csv)
+      --no-import       Nicht automatisch in Firefly III importieren
+    Beispiel:
+      transformer transform ubs-export.csv config.json
+      transformer transform ubs-export.csv config.json -o import.csv
+
+  validate [config] [options]
+    Validiert die Konfigurationsdatei
+    Optionen:
+      --strict          Strikte Validierung (empfohlen)
+    Beispiel:
+      transformer validate config.json
+      transformer validate config.json --strict
+
+  auto-import [config] [options]
+    Überwacht Quellverzeichnis und verarbeitet neue Dateien
+    Optionen:
+      --watch           Kontinuierliche Überwachung (Daemon-Modus)
+      --interval=SEC    Prüfintervall in Sekunden (Standard: 60)
+      --dry-run         Zeigt was gemacht würde (keine echte Verarbeitung)
+    Beispiel:
+      transformer auto-import config.json
+      transformer auto-import config.json --watch --interval=30
+
+  help, -h, --help
+    Zeige diese Hilfe
+
+GLOBALE OPTIONEN:
+  --debug, -d       Aktiviere Debug-Modus (detaillierte Ausgaben)
+
+INSTALLATION:
+
+  1. PHP 8.1+ muss installiert sein
+     php --version
+
+  2. Autoloader-Setup (wähle eins):
+     Option A: Mit Composer (empfohlen)
+       composer install
+     Option B: Manuell - Dateien in Verzeichnisstruktur:
+       ff-imp-preprocessor/
+       ├── bin/transformer.php
+       ├── src/*.php
+       └── config/config.json
+
+  3. Ausführbar machen:
+     chmod +x bin/transformer.php
+
+  4. Konfiguration anpassen:
+     cp config/config.example.json config/config.json
+     nano config/config.json
+
+BEISPIELE:
+
+  # Transformation mit Test (erste 5 Zeilen)
+  ./bin/transformer test data/ubs-export.csv config/config.json --rows=5
+
+  # Komplette Transformation
+  ./bin/transformer transform data/ubs-export.csv config/config.json \
+    --output=output/firefly-import.csv
+
+  # Konfiguration validieren
+  ./bin/transformer validate config/config.json --strict
+
+  # Auto-Import mit Überwachung starten
+  ./bin/transformer auto-import config/config.json --watch
+
+  # Nur nächste Datei verarbeiten
+  ./bin/transformer auto-import config/config.json
+
+KONFIGURATION:
+
+  Die config.json muss folgende Struktur haben:
+  {
+    "metadata": { "extractionRules": {...} },
+    "csvStructure": { "delimiter": ";", ... },
+    "columnTransformations": { ... },
+    "fireflyImport": { "apiUrl": "...", "apiKey": "..." },
+    "directories": {
+      "source": "./import/source",
+      "output": "./import/output",
+      "archive": "./import/archive",
+      "error": "./import/error"
+    }
+  }
+
+DOKUMENTATION:
+
+  Siehe README.md und UBS_Transformer_Guide.md für vollständige Dokumentation
+
+LIZENZ:
+
+  MIT License
+
+HELP;
+}
+
+/**
+ * Expandiert ~ zu absolutem Home-Verzeichnis und löst relative Pfade auf
+ */
+function expandPath(string $path): string
+{
+    if (str_starts_with($path, '~/') || $path === '~') {
+        $home = getenv('HOME') ?: posix_getpwuid(posix_getuid())['dir'];
+        $path = $home . substr($path, 1);
+    }
+
+    // Relative Pfade gegen cwd auflösen (ohne realpath, damit nicht-existierende Dirs erlaubt sind)
+    if (!str_starts_with($path, '/')) {
+        $path = getcwd() . '/' . $path;
+    }
+
+    return $path;
+}
+
+/**
+ * Parse CLI-Optionen in assoziatives Array
+ */
+function parseOptions(array $argv, int $startIndex = 0): array
+{
+    $options = [];
+
+    for ($i = $startIndex; $i < count($argv); $i++) {
+        if (strpos($argv[$i], '--') === 0) {
+            $parts = explode('=', substr($argv[$i], 2), 2);
+            $options[$parts[0]] = $parts[1] ?? true;
+        } elseif (strpos($argv[$i], '-') === 0 && strlen($argv[$i]) > 1) {
+            $options[substr($argv[$i], 1)] = true;
+        }
+    }
+
+    return $options;
+}
+
+/**
+ * Teste Transformation mit begrenzter Zeilenzahl
+ */
+function handleTest($argc, $argv): void
+{
+    if ($argc < 4) {
+        throw new Exception("Usage: transformer test [input-file] [config-file] [options]");
+    }
+
+    $inputFile = $argv[2];
+    $configFile = $argv[3];
+    $options = parseOptions($argv, 4);
+    $debug = isset($options['debug']) || isset($options['d']);
+
+    $maxRows = isset($options['rows']) ? (int)$options['rows'] : 10;
+    $outputFile = $options['output'] ?? $options['o'] ?? null;
+
+    if (!file_exists($inputFile)) {
+        throw new Exception("Input-Datei nicht gefunden: $inputFile");
+    }
+    if (!file_exists($configFile)) {
+        throw new Exception("Konfigurationsdatei nicht gefunden: $configFile");
+    }
+
+    echo "\n📊 TEST-MODUS: Verarbeite max. $maxRows Zeilen\n";
+    echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━\n";
+
+    $configLoader = new ConfigurationLoader($configFile);
+    $config = $configLoader->load();
+
+    $engine = new TransformerEngine($configLoader, $debug);
+    $result = $engine->transform($inputFile, $maxRows);
+
+    // Ausgabe Statistiken
+    echo "\n✅ STATISTIKEN:\n";
+    echo "   Verarbeitete Zeilen:    " . $result['rowsProcessed'] . "\n";
+    echo "   Metadaten extrahiert:   " . count($result['metadata'] ?? []) . "\n";
+    echo "   Output-Spalten:         " . $result['outputColumns'] . "\n";
+
+    if (!empty($result['metadata'])) {
+        echo "\n📋 EXTRAHIERTE METADATEN:\n";
+        foreach ($result['metadata'] as $key => $value) {
+            $display = substr($value, 0, 50);
+            if (strlen($value) > 50) {
+                $display .= "...";
+            }
+            echo "   $key: $display\n";
+        }
+    }
+
+    if (!empty($result['sampleData'])) {
+        $sampleCount = min(5, count($result['sampleData']));
+        echo "\n📝 BEISPIEL-DATEN ($sampleCount Zeilen):\n";
+        foreach (array_slice($result['sampleData'], 0, $sampleCount) as $index => $row) {
+            echo "   Zeile " . ($index + 1) . ": ";
+            foreach ($row as $col => $value) {
+                $val = substr($value, 0, 30);
+                if (strlen($value) > 30) {
+                    $val .= "...";
+                }
+                //if (!is_int($col)) {
+                echo "$col=$val | ";
+                //}
+            }
+            echo "\n";
+        }
+    }
+
+    if ($outputFile) {
+        echo "\n💾 Output-Datei: $outputFile\n";
+    }
+
+    echo "\n✅ Test erfolgreich!\n\n";
+}
+
+/**
+ * Transformiere komplette CSV-Datei
+ */
+function handleTransform($argc, $argv): void
+{
+    if ($argc < 4) {
+        throw new Exception("Usage: transformer transform [input-file] [config-file] [options]");
+    }
+
+    $inputFile = $argv[2];
+    $configFile = $argv[3];
+    $options = parseOptions($argv, 4);
+    $debug = isset($options['debug']) || isset($options['d']);
+
+    $outputFile = $options['output'] ?? $options['o'] ?? null;
+
+    if (!file_exists($inputFile)) {
+        throw new Exception("Input-Datei nicht gefunden: $inputFile");
+    }
+    if (!file_exists($configFile)) {
+        throw new Exception("Konfigurationsdatei nicht gefunden: $configFile");
+    }
+
+    echo "\n🚀 TRANSFORMATION STARTEN\n";
+    echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━\n";
+
+    $configLoader = new ConfigurationLoader($configFile);
+    $configLoader->load();
+
+    // --output überschreibt Zielverzeichnis und Dateiname aus der Konfiguration
+    if ($outputFile !== null) {
+        $outputFile = expandPath($outputFile);
+        $configLoader->set('directories.output', dirname($outputFile));
+        $configLoader->set('csvStructure.outputFilename', basename($outputFile));
+    }
+
+    $engine = new TransformerEngine($configLoader, $debug);
+    $result = $engine->transform($inputFile);
+
+    echo "✅ Transformation erfolgreich!\n";
+    echo "   Output-Datei: " . ($result['outputFile'] ?? 'N/A') . "\n";
+    echo "   Zeilen transformiert: " . ($result['rowsProcessed'] ?? 0) . "\n";
+
+    echo "\n✅ Fertig!\n\n";
+}
+
+/**
+ * Validiere Konfigurationsdatei
+ */
+function handleValidate($argc, $argv): void
+{
+    if ($argc < 3) {
+        throw new Exception("Usage: transformer validate [config-file] [options]");
+    }
+
+    $configFile = $argv[2];
+    $options = parseOptions($argv, 3);
+    $strict = isset($options['strict']);
+
+    if (!file_exists($configFile)) {
+        throw new Exception("Konfigurationsdatei nicht gefunden: $configFile");
+    }
+
+    echo "\n✔️  KONFIGURATION VALIDIEREN\n";
+    echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━\n";
+
+    $configLoader = new ConfigurationLoader($configFile);
+
+    try {
+        $config = $configLoader->load();
+
+        // Basis-Validierung
+        echo "✅ JSON-Format valide\n";
+
+        $required = ['metadata', 'csvStructure', 'columnTransformations'];
+        $missing = [];
+
+        foreach ($required as $key) {
+            if (isset($config[$key])) {
+                echo "✅ Abschnitt '$key' vorhanden\n";
+            } else {
+                echo "⚠️  Abschnitt '$key' fehlt\n";
+                $missing[] = $key;
+            }
+        }
+
+        // Firefly-Validierung
+        if (isset($config['fireflyImport'])) {
+            echo "✅ Firefly III Konfiguration vorhanden\n";
+            if (empty($config['fireflyImport']['apiUrl'])) {
+                echo "⚠️  Firefly III API-URL fehlt\n";
+                if ($strict) {
+                    throw new Exception("Strikte Validierung: Firefly III API-URL erforderlich");
+                }
+            }
+            if (empty($config['fireflyImport']['apiKey'])) {
+                echo "⚠️  Firefly III API-Key fehlt\n";
+                if ($strict) {
+                    throw new Exception("Strikte Validierung: Firefly III API-Key erforderlich");
+                }
+            }
+        } else {
+            echo "⚠️  Firefly III Konfiguration nicht vorhanden (optional)\n";
+        }
+
+        // Verzeichnisse-Validierung
+        if (isset($config['directories'])) {
+            echo "✅ Verzeichnisse konfiguriert\n";
+            $dirs = ['source', 'output', 'archive', 'error'];
+            foreach ($dirs as $dir) {
+                if (!empty($config['directories'][$dir])) {
+                    echo "   ✅ $dir: " . $config['directories'][$dir] . "\n";
+                }
+            }
+        }
+
+        if (empty($missing)) {
+            echo "\n✅ Konfiguration ist VALIDE!\n\n";
+        } else {
+            if ($strict) {
+                throw new Exception("Strikte Validierung: " . count($missing) . " erforderliche Abschnitte fehlen");
+            }
+            echo "\n⚠️  Konfiguration hat Warnungen aber ist funktional\n\n";
+        }
+    } catch (Exception $e) {
+        throw new Exception("Validierungsfehler: " . $e->getMessage());
+    }
+}
+
+/**
+ * Auto-Import mit Verzeichnis-Überwachung
+ */
+function handleAutoImport($argc, $argv): void
+{
+    if ($argc < 3) {
+        throw new Exception("Usage: transformer auto-import [config-file] [options]");
+    }
+
+    $configFile = $argv[2];
+    $options = parseOptions($argv, 3);
+    $debug = isset($options['debug']) || isset($options['d']);
+
+    if (!file_exists($configFile)) {
+        throw new Exception("Konfigurationsdatei nicht gefunden: $configFile");
+    }
+
+    $configLoader = new ConfigurationLoader($configFile);
+    $config = $configLoader->load();
+
+    $sourceDir = $config['directories']['source'] ?? './import/source';
+    $outputDir = $config['directories']['output'] ?? './import/output';
+    $archiveDir = $config['directories']['archive'] ?? './import/archive';
+    $errorDir = $config['directories']['error'] ?? './import/error';
+    $dryRun = isset($options['dry-run']);
+    $watch = isset($options['watch']);
+    $interval = isset($options['interval']) ? (int)$options['interval'] : 60;
+
+    // Verzeichnisse erstellen
+    foreach ([$sourceDir, $outputDir, $archiveDir, $errorDir] as $dir) {
+        if (!is_dir($dir)) {
+            mkdir($dir, 0755, true);
+        }
+    }
+
+    echo "\n🔍 AUTO-IMPORT GESTARTET\n";
+    echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━\n";
+    echo "   Quellverzeichnis:  $sourceDir\n";
+    echo "   Output-Verzeichnis: $outputDir\n";
+    echo "   Archiv-Verzeichnis: $archiveDir\n";
+
+    if ($watch) {
+        echo "   Mode:              WATCH (kontinuierlich)\n";
+        echo "   Intervall:         {$interval}s\n";
+    } else {
+        echo "   Mode:              EINMALIG\n";
+    }
+
+    if ($dryRun) {
+        echo "   Dry-Run:           JA (keine echten Operationen)\n";
+    }
+
+    echo "\n";
+
+    if ($watch) {
+        echo "⏳ Drücke Ctrl+C zum Beenden.\n\n";
+        while (true) {
+            processImportDirectory($sourceDir, $outputDir, $archiveDir, $errorDir, $config, $configFile, $dryRun, $debug);
+            sleep($interval);
+        }
+    } else {
+        processImportDirectory($sourceDir, $outputDir, $archiveDir, $errorDir, $config, $configFile, $dryRun, $debug);
+    }
+}
+
+/**
+ * Verarbeite Verzeichnis mit CSV-Dateien
+ */
+function processImportDirectory($sourceDir, $outputDir, $archiveDir, $errorDir, $config, $configFile, $dryRun = false, $debug = false): void
+{
+    if (!is_dir($sourceDir)) {
+        return;
+    }
+
+    $files = glob($sourceDir . '/*.csv');
+
+    if (empty($files)) {
+        return;
+    }
+
+    foreach ($files as $file) {
+        $basename = basename($file);
+
+        try {
+            echo "📄 Verarbeite: $basename ... ";
+
+            $configLoader = new ConfigurationLoader($configFile);
+            $config = $configLoader->load();
+
+            $engine = new TransformerEngine($configLoader, $debug);
+            $outputFile = $outputDir . '/' . str_replace('.csv', '-transformed.csv', $basename);
+
+            if (!$dryRun) {
+                $result = $engine->transform($file);
+                $outputFile = $result['outputFile'] ?? $outputFile;
+
+                // Archiviere Original-Datei
+                $archiveFile = $archiveDir . '/' . $basename;
+                if (!rename($file, $archiveFile)) {
+                    throw new Exception("Konnte nicht archivieren");
+                }
+
+                // Firefly Import
+                if (!empty($config['fireflyImport'])) {
+                    $importer = new FireflyImporter($config['fireflyImport']);
+                    $importer->import($outputFile);
+                }
+            }
+
+            echo "✅\n";
+        } catch (Exception $e) {
+            echo "❌ " . $e->getMessage() . "\n";
+
+            if (!$dryRun) {
+                // Verschiebe zu Error-Verzeichnis
+                $errorFile = $errorDir . '/' . $basename;
+                @rename($file, $errorFile);
+            }
+        }
+    }
+}
diff --git a/composer.json b/composer.json
new file mode 100644
index 0000000..96c0560
--- /dev/null
+++ b/composer.json
@@ -0,0 +1,81 @@
+{
+  "name": "ff-imp-preprocessor/ff-imp-preprocessor",
+  "description": "Production-ready PHP preprocessor for bank CSV export files with metadata extraction, column transformations, and optional Firefly III integration",
+  "license": "MIT",
+  "type": "library",
+  "version": "1.0.0-beta",
+  "authors": [
+    {
+      "name": "Firefly Import Preprocessor Contributors",
+      "email": "david@andare.ch",
+      "role": "Developer"
+    }
+  ],
+  "keywords": [
+    "csv",
+    "transformer",
+    "ubs",
+    "bank",
+    "finance",
+    "metadata-extraction",
+    "data-transformation",
+    "firefly-iii",
+    "php8",
+    "etl"
+  ],
+  "homepage": "https://git.andare.ch/david.reindl/ff-imp-preprocessor",
+  "support": {
+    "issues": "https://git.andare.ch/david.reindl/ff-imp-preprocessor/issues",
+    "source": "https://git.andare.ch/david.reindl/ff-imp-preprocessor"
+  },
+  "require": {
+    "php": ">=8.1",
+    "ext-json": "*",
+    "ext-mbstring": "*"
+  },
+  "require-dev": {
+    "phpunit/phpunit": "^10.0",
+    "phpstan/phpstan": "^1.10",
+    "squizlabs/php_codesniffer": "^3.8",
+    "vimeo/psalm": "^5.0"
+  },
+  "suggest": {
+    "monolog/monolog": "For advanced logging capabilities (optional)",
+    "guzzlehttp/guzzle": "For Firefly III HTTP client integration (optional)"
+  },
+  "autoload": {
+    "psr-4": {
+      "UbsCsvTransformer\\": "src/"
+    }
+  },
+  "autoload-dev": {
+    "psr-4": {
+      "UbsCsvTransformer\\Tests\\": "tests/"
+    }
+  },
+  "bin": [
+    "bin/transformer.php"
+  ],
+  "scripts": {
+    "test": "phpunit",
+    "lint": "phpcs src/ bin/",
+    "lint-fix": "phpcbf src/ bin/",
+    "analyze": "phpstan analyse src/ --level=8",
+    "psalm": "psalm src/",
+    "validate-strict": "composer validate --strict"
+  },
+  "minimum-stability": "stable",
+  "prefer-stable": true,
+  "config": {
+    "sort-packages": true,
+    "platform": {
+      "php": "8.1"
+    }
+  },
+  "repositories": [
+    {
+      "type": "vcs",
+      "url": "https://git.andare.ch/david.reindl/ff-imp-preprocessor"
+    }
+  ]
+}
\ No newline at end of file
diff --git a/config/config.example.json b/config/config.example.json
new file mode 100644
index 0000000..c3e0d50
--- /dev/null
+++ b/config/config.example.json
@@ -0,0 +1,224 @@
+{
+  "metadata": {
+    "extractionRules": [
+      {
+        "name": "account_iban",
+        "lineNumber": 2,
+        "regex": "IBAN:\\s*([A-Z0-9 ]+)",
+        "captureGroup": 1
+      },
+      {
+        "name": "account_name",
+        "lineNumber": 1,
+        "regex": "Konto:\\s*(.+)",
+        "captureGroup": 1
+      },
+      {
+        "name": "currency_code",
+        "lineNumber": 3,
+        "regex": "Währung:\\s*([A-Z]{3})",
+        "captureGroup": 1
+      }
+    ]
+  },
+
+  "capitalizationExceptions": ["AG", "GmbH", "SA"],
+
+  "csvStructure": {
+    "headerLine": 5,
+    "inputDelimiter": ";",
+    "outputDelimiter": ",",
+    "encoding": "UTF-8",
+    "hasBom": false
+  },
+
+  "columnTransformations": [
+    {
+      "sourceColumn": "Buchungsdatum",
+      "transformations": [
+        {
+          "type": "dateformat",
+          "fromFormat": "d.m.Y",
+          "toFormat": "Y-m-d"
+        }
+      ],
+      "outputColumn": "date",
+      "outputAction": "overwrite"
+    },
+    {
+      "sourceColumn": "Buchungstext",
+      "transformations": [
+        {
+          "type": "trim"
+        },
+        {
+          "type": "replace",
+          "search": "  ",
+          "replace": " "
+        },
+        {
+          "type": "lowercase"
+        }
+      ],
+      "outputColumn": "description",
+      "outputAction": "overwrite"
+    },
+    {
+      "sourceColumn": "Auftraggeber/Empfänger",
+      "transformations": [
+        {
+          "type": "trim"
+        },
+        {
+          "type": "ucwordsfirst"
+        },
+        {
+          "type": "truncate",
+          "maxLength": 100
+        }
+      ],
+      "outputColumn": "opposing_name",
+      "outputAction": "overwrite"
+    },
+    {
+      "sourceColumn": "Mitteilungen",
+      "transformations": [
+        {
+          "type": "trim"
+        },
+        {
+          "type": "split",
+          "delimiter": ";",
+          "part": 0
+        },
+        {
+          "type": "lowercase"
+        },
+        {
+          "type": "ucwordsfirst"
+        }
+      ],
+      "outputColumn": "merchant",
+      "outputAction": "create"
+    },
+    {
+      "sourceColumn": "Mitteilungen",
+      "transformations": [
+        {
+          "type": "regexextract",
+          "pattern": "(\\d{4,} .*)"
+        }
+      ],
+      "outputColumn": "location",
+      "outputAction": "create"
+    },
+    {
+      "sourceColumn": "Belastung",
+      "transformations": [
+        {
+          "type": "replace",
+          "search": "'",
+          "replace": ""
+        },
+        {
+          "type": "replace",
+          "search": ",",
+          "replace": "."
+        }
+      ],
+      "outputColumn": "amount",
+      "outputAction": "create"
+    },
+    {
+      "sourceColumn": "Gutschrift",
+      "transformations": [
+        {
+          "type": "replace",
+          "search": "'",
+          "replace": ""
+        },
+        {
+          "type": "replace",
+          "search": ",",
+          "replace": "."
+        }
+      ],
+      "outputColumn": "amount_credit",
+      "outputAction": "create"
+    },
+    {
+      "sourceColumn": "Saldo",
+      "transformations": [
+        {
+          "type": "replace",
+          "search": "'",
+          "replace": ""
+        },
+        {
+          "type": "replace",
+          "search": ",",
+          "replace": "."
+        }
+      ],
+      "outputColumn": "balance",
+      "outputAction": "create"
+    },
+    {
+      "sourceColumn": "_constant_",
+      "transformations": [
+        {
+          "type": "constantvalue",
+          "metadataKey": "account_iban"
+        }
+      ],
+      "outputColumn": "account_iban",
+      "outputAction": "create"
+    },
+    {
+      "sourceColumn": "_constant_",
+      "transformations": [
+        {
+          "type": "constantvalue",
+          "metadataKey": "currency_code"
+        }
+      ],
+      "outputColumn": "currency_code",
+      "outputAction": "create"
+    },
+    {
+      "sourceColumn": "_constant_",
+      "transformations": [
+        {
+          "type": "constantvalue",
+          "metadataKey": "account_name"
+        }
+      ],
+      "outputColumn": "account_name",
+      "outputAction": "create"
+    }
+  ],
+
+  "fireflyImport": {
+    "jsonConfig": "/opt/firefly/import-config.json",
+    "importerCommand": "docker exec -it firefly-importer php artisan importer:import",
+    "autoImport": false,
+    "deleteAfterImport": false,
+    "timeout": 300,
+    "environment": {
+      "FIREFLY_III_URL": "https://your-firefly.com",
+      "FIREFLY_III_ACCESS_TOKEN": "your-token-here"
+    }
+  },
+
+  "directories": {
+    "source": "/opt/ubs-csv-transformer/import/source",
+    "output": "/opt/ubs-csv-transformer/import/output",
+    "archive": "/opt/ubs-csv-transformer/import/archive",
+    "error": "/opt/ubs-csv-transformer/import/error"
+  },
+
+  "test": {
+    "maxRows": 10,
+    "showOutput": true
+  }
+}
\ No newline at end of file
diff --git a/phpcs.xml b/phpcs.xml
new file mode 100644
index 0000000..bd1c160
--- /dev/null
+++ b/phpcs.xml
@@ -0,0 +1,34 @@
+<?xml version="1.0"?>
+<ruleset name="Firefly Import Preprocessor Code Standard">
+    <description>PSR-12 Code Standard for Firefly Import Preprocessor Project</description>
+
+    <!-- Include PSR-12 -->
+    <rule ref="PSR12"/>
+
+    <!-- Exclude vendor and tests -->
+    <exclude-pattern>*/vendor/*</exclude-pattern>
+    <exclude-pattern>*/tests/*</exclude-pattern>
+
+    <!-- File patterns to check -->
+    <arg name="extensions" value="php"/>
+    <arg name="colors"/>
+    <arg name="report" value="full"/>
+    <arg name="report" value="summary"/>
+
+    <!-- Line length -->
+    <rule ref="Generic.Files.LineLength">
+        <properties>
+            <property name="lineLimit" value="120"/>
+            <property name="absoluteLineLimit" value="150"/>
+        </properties>
+    </rule>
+
+    <!-- Avoid PHP short tags -->
+    <rule ref="Generic.PHP.DisallowShortOpenTag"/>
+
+    <!-- Spacing around operators -->
+    <rule ref="Squiz.WhiteSpace.OperatorSpacing"/>
+
+    <!-- Enforce spaces for indentation (no tabs) -->
+    <rule ref="Generic.WhiteSpace.DisallowTabIndent"/>
+</ruleset>
\ No newline at end of file
diff --git a/phpstan-baseline.neon b/phpstan-baseline.neon
new file mode 100644
index 0000000..8b13789
--- /dev/null
+++ b/phpstan-baseline.neon
@@ -0,0 +1 @@
+
diff --git a/phpstan.neon b/phpstan.neon
new file mode 100644
index 0000000..0300ec0
--- /dev/null
+++ b/phpstan.neon
@@ -0,0 +1,13 @@
+parameters:
+    level: 8
+    paths:
+        - src
+    tmpDir: .phpstan.cache
+
+    checkMissingCallableSignature: true
+
+    ignoreErrors:
+        - identifier: missingType.iterableValue
+
+includes:
+    - phpstan-baseline.neon
diff --git a/phpunit.xml b/phpunit.xml
new file mode 100644
index 0000000..fd59af2
--- /dev/null
+++ b/phpunit.xml
@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/10.5/phpunit.xsd"
+         colors="true"
+         beStrictAboutOutputDuringTests="true"
+         beStrictAboutTestsThatDoNotTestAnything="true"
+         failOnWarning="true"
+         failOnRisky="true"
+         bootstrap="vendor/autoload.php">
+    <testsuites>
+        <testsuite name="UBS CSV Transformer Test Suite">
+            <directory>tests</directory>
+        </testsuite>
+    </testsuites>
+    <source>
+        <include>
+            <directory>src</directory>
+        </include>
+    </source>
+</phpunit>
\ No newline at end of file
diff --git a/src/ColumnTransformer.php b/src/ColumnTransformer.php
new file mode 100644
index 0000000..22d827b
--- /dev/null
+++ b/src/ColumnTransformer.php
@@ -0,0 +1,743 @@
+<?php
+
+namespace UbsCsvTransformer;
+
+/**
+ * Transformiert Spalten gemäß Konfiguration
+ *
+ * Unterstützte Transformationstypen (canonical names):
+ * - map:           Spalte kopieren/umbenennen (Standard)
+ * - replace:       String-Replacement (str_replace)
+ * - regex:         Regex-Replace mit preg_replace (Backreferenzen: $1, $2 …)
+ * - dateformat:    Datum-Formatierung
+ * - split:         Spalte bei Delimiter teilen
+ * - regexextract:  Mit Regex extrahieren
+ * - trim:          Whitespace entfernen
+ * - uppercase:     In Grossbuchstaben umwandeln
+ * - lowercase:     In Kleinbuchstaben umwandeln
+ * - ucwordsfirst:  Ersten Buchstaben nach Worttrennern gross
+ * - truncate:      String auf maximale Länge kürzen
+ * - constantvalue: Konstanten-Wert aus Metadaten
+ * - pipeline:      Mehrere Transformationen hintereinander (via steps[])
+ * - custom:        Custom PHP-Callback
+ *
+ * Unterstützte outputAction-Werte:
+ * - create / overwrite:        Ziel-Spalte setzen (Standard)
+ * - append:                    Wert anhängen
+ * - append-line:               Wert auf neuer Zeile anhängen (kein Leerzeichen wenn Ziel leer)
+ * - overwrite-if-empty:        Nur setzen wenn Ziel-Spalte leer
+ * - overwrite-if-not-empty:    Nur setzen wenn Ergebnis nicht leer
+ */
+class ColumnTransformer
+{
+    private array $transformations;
+    private array $metadata;
+    private array $outputColumns;
+    private array $globalExceptions;
+
+    /**
+     * Initialisiert ColumnTransformer mit Transformationsregeln
+     *
+     * @param array $transformations Transformationskonfiguration aus config.json
+     * @param array $metadata Extrahierte Metadaten aus CSV-Header
+     * @param array $globalExceptions Globale Ausnahmeliste für ucwordsfirst
+     */
+    public function __construct(array $transformations, array $metadata = [], array $globalExceptions = [])
+    {
+        $this->transformations = $transformations;
+        $this->metadata = $metadata;
+        $this->outputColumns = [];
+        $this->globalExceptions = $globalExceptions;
+    }
+
+    /**
+     * Transformiert eine einzelne Datenzeile
+     *
+     * Wendet alle definierten Transformationen auf die Zeile an.
+     * Kann neue Spalten generieren (z.B. bei regex_extract).
+     *
+     * @param array $row Datenzeile mit Header-Keys als Array-Keys
+     *
+     * @return array Transformierte Datenzeile
+     */
+    public function transformRow(array $row): array
+    {
+        $transformedRow = $row;
+
+        foreach ($this->transformations as $config) {
+            // Multi-Output Detection (für split)
+            if (isset($config['outputs']) && is_array($config['outputs'])) {
+                // Multi-Output Transformation (z.B. split in mehrere Spalten)
+                $multiOutputResult = $this->handleMultiOutputTransformation($transformedRow, $config);
+
+                // Merge Ergebnisse in transformedRow
+                foreach ($multiOutputResult as $columnName => $value) {
+                    $transformedRow[$columnName] = $value;
+
+                    // Registriere neue Spalten
+                    if (!in_array($columnName, $this->outputColumns)) {
+                        $this->outputColumns[] = $columnName;
+                    }
+                }
+
+                // Fahre mit nächster Transformation fort
+                continue;
+            }
+
+            $targetColumn = $config['outputColumn'] ?? null;
+            $sourceColumn = $config['sourceColumn'] ?? $targetColumn;
+            $outputAction = strtolower($config['outputAction'] ?? 'overwrite');
+
+            if (empty($targetColumn)) {
+                throw new \RuntimeException(
+                    "Transformation fehlt 'outputColumn' Feld: " . json_encode($config)
+                );
+            }
+
+            // Track output columns
+            if (!in_array($targetColumn, $this->outputColumns)) {
+                $this->outputColumns[] = $targetColumn;
+            }
+
+            // Handle 'custom' type separately — it operates on the whole row
+            $singleType = $this->normalizeTransformType($config['type'] ?? '');
+            if ($singleType === 'custom' && empty($config['transformations'])) {
+                $transformedRow = $this->transformCustom($transformedRow, $config);
+                continue;
+            }
+
+            // Get source value ('_constant_' is a virtual source with no column data)
+            $sourceValue = ($sourceColumn === '_constant_') ? '' : ($transformedRow[$sourceColumn] ?? '');
+
+            // Apply transformation(s)
+            if (!empty($config['transformations']) && is_array($config['transformations'])) {
+                // Inline pipeline: array of transformation steps per column entry
+                $resultValue = $sourceValue;
+                foreach ($config['transformations'] as $step) {
+                    $resultValue = $this->applySingleTransformation($resultValue, $step);
+                }
+            } else {
+                // Single transformation (flat canonical or legacy form)
+                $resultValue = $this->applySingleTransformation($sourceValue, $config);
+            }
+
+            // Apply output action
+            switch ($outputAction) {
+                case 'append':
+                    $transformedRow[$targetColumn] = ($transformedRow[$targetColumn] ?? '') . $resultValue;
+                    break;
+                case 'append-line':
+                    // Wert auf neuer Zeile anhängen; kein führender Zeilenumbruch wenn Ziel leer
+                    if ($resultValue !== '') {
+                        $existing = $transformedRow[$targetColumn] ?? '';
+                        $transformedRow[$targetColumn] = $existing !== '' ? $existing . "\n" . $resultValue : $resultValue;
+                    }
+                    break;
+                case 'overwrite-if-empty':
+                    // Nur überschreiben wenn Ziel-Spalte leer ist
+                    if (($transformedRow[$targetColumn] ?? '') === '') {
+                        $transformedRow[$targetColumn] = $resultValue;
+                    }
+                    break;
+                case 'overwrite-if-not-empty':
+                    // Nur überschreiben wenn das Transformations-Ergebnis nicht leer ist
+                    if ($resultValue !== '') {
+                        $transformedRow[$targetColumn] = $resultValue;
+                    }
+                    break;
+                case 'create':
+                case 'overwrite':
+                default:
+                    $transformedRow[$targetColumn] = $resultValue;
+                    break;
+            }
+        }
+
+        return $transformedRow;
+    }
+
+    /**
+     * Wendet eine einzelne Transformation auf einen Stringwert an
+     *
+     * Normalisiert den Typ-Namen (snake_case, PascalCase, no-separator alle akzeptiert)
+     * und delegiert an die jeweilige transformXxx()-Methode.
+     *
+     * @param string $value Eingabewert
+     * @param array $config Transformationskonfiguration
+     * @return string Transformierter Wert
+     */
+    private function applySingleTransformation(string $value, array $config): string
+    {
+        $transformType = $this->normalizeTransformType($config['type'] ?? 'map');
+
+        switch ($transformType) {
+            case 'map':
+                return $value;
+
+            case 'replace':
+                return $this->transformReplace($value, $config);
+
+            case 'regex':
+                return $this->transformRegex($value, $config);
+
+            case 'dateformat':
+                return $this->transformDate($value, $config);
+
+            case 'split':
+                return $this->transformSplit($value, $config);
+
+            case 'regexextract':
+                $extracted = $this->transformRegexExtract($value, $config);
+                return $extracted ?? '';
+
+            case 'trim':
+                return $this->transformTrim($value);
+
+            case 'uppercase':
+                return $this->transformUppercase($value);
+
+            case 'lowercase':
+                return $this->transformLowercase($value);
+
+            case 'ucwordsfirst':
+                return $this->transformUcwordsFirst($value, $config);
+
+            case 'pipeline':
+                return $this->transformPipeline($value, $config);
+
+            case 'truncate':
+                $maxLength = (int)($config['maxLength'] ?? 255);
+                return mb_substr($value, 0, $maxLength, 'UTF-8');
+
+            case 'constantvalue':
+                $metaKey = $config['metadataKey'] ?? '';
+                return (string)($this->metadata[$metaKey] ?? '');
+
+            default:
+                return $value;
+        }
+    }
+
+    /**
+     * Normalisiert Transformationstyp-Namen: lowercase, Trennzeichen entfernt.
+     * Erlaubt z.B. dass 'dateformat' und 'dateFormat' beide funktionieren.
+     */
+    private function normalizeTransformType(string $type): string
+    {
+        return strtolower(str_replace(['_', '-', ' '], '', $type));
+    }
+
+    /**
+     * String-Replacement Transformation
+     *
+     * Konfiguration:
+     * ```
+     * "type": "replace",
+     * "search": "Alt",
+     * "replace": "Neu"
+     * ```
+     *
+     * @param string $value Ursprungswert
+     * @param array $config Transformationskonfiguration
+     *
+     * @return string Transformierter Wert
+     */
+    private function transformReplace(string $value, array $config): string
+    {
+        $search = $config['search'] ?? '';
+        $replace = $config['replace'] ?? '';
+
+        if (empty($search)) {
+            return $value;
+        }
+
+        return str_replace($search, $replace, $value);
+    }
+
+    /**
+     * Regex-Replace Transformation
+     *
+     * Wendet einen regulären Ausdruck auf den Wert an und ersetzt den Treffer.
+     * Backreferenz-Syntax: $1, $2 usw. im replace-String.
+     *
+     * Konfiguration:
+     * ```
+     * "type": "regex",
+     * "pattern": "SumUp \\*+(.*)",
+     * "replace": "[$1]"
+     * ```
+     *
+     * @param string $value Ursprungswert
+     * @param array $config Transformationskonfiguration
+     *
+     * @return string Transformierter Wert
+     */
+    private function transformRegex(string $value, array $config): string
+    {
+        $pattern = $config['pattern'] ?? '';
+        $replace = $config['replace'] ?? '';
+
+        if (empty($pattern)) {
+            return $value;
+        }
+
+        $delimitedPattern = '#' . str_replace('#', '\#', $pattern) . '#u';
+        $result = preg_replace($delimitedPattern, $replace, $value);
+
+        return $result ?? $value;
+    }
+
+    /**
+     * Datum-Format Transformation
+     *
+     * Konfiguration:
+     * ```
+     * "type": "date_format",
+     * "fromFormat": "d.m.Y",
+     * "toFormat": "Y-m-d"
+     * ```
+     *
+     * @param string $value Ursprungswert
+     * @param array $config Transformationskonfiguration
+     *
+     * @return string Transformierter Wert
+     */
+    private function transformDate(string $value, array $config): string
+    {
+        if (empty($value)) {
+            return $value;
+        }
+
+        $fromFormat = $config['fromFormat'] ?? 'd.m.Y';
+        $toFormat = $config['toFormat'] ?? 'Y-m-d';
+
+        try {
+            $date = \DateTime::createFromFormat($fromFormat, $value);
+            if ($date === false) {
+                return $value;
+            }
+            return $date->format($toFormat);
+        } catch (\Exception $e) {
+            return $value;
+        }
+    }
+
+    /**
+     * Split Transformation
+     *
+     * Teilt einen Wert bei einem Delimiter und behaelt einen definierten Teil
+     *
+     * Beispiel:
+     * Input:  "Coop Pronto Chur;7007 Chur"
+     * Config: delimiter=";", part=0
+     * Output: "Coop Pronto Chur"
+     *
+     * Konfiguration:
+     * ```
+     * "type": "split",
+     * "delimiter": ";",
+     * "part": 0
+     * ```
+     *
+     * @param string $value Ursprungswert
+     * @param array $config Transformationskonfiguration
+     *
+     * @return string Transformierter Wert
+     */
+    private function transformSplit(string $value, array $config): string
+    {
+        if (empty($value)) {
+            return $value;
+        }
+
+        $delimiter = $config['delimiter'] ?? ';';
+        $part = $config['part'] ?? 0;
+
+        $parts = explode($delimiter, $value);
+        DebugLogger::log('transformation', 'Applied split transformation', [
+            'input'       => $value,
+            'delimiter'   => $delimiter,
+            'part'        => $part,
+            'parts_count' => count($parts),
+            'output'      => $parts[$part] ?? null,
+        ]);
+
+        if (!isset($parts[$part])) {
+            return $value;
+        }
+
+        return trim($parts[$part]);
+    }
+
+    /**
+     * Regex Extract Transformation
+     *
+     * Extrahiert einen Teil mit Regex und erstellt neue Spalte
+     *
+     * Beispiel:
+     * Input:  "Coop Pronto Chur;7007 Chur"
+     * Config: pattern="(\d{4,} .*)"
+     * Output: "7007 Chur" (in neuer Spalte "Location")
+     *
+     * Konfiguration:
+     * ```
+     * "Location": {
+     *   "type": "regex_extract",
+     *   "sourceColumn": "Merchant/Description",
+     *   "pattern": "(\\d{4,} .*)"
+     * }
+     * ```
+     *
+     * @param string $value Ursprungswert
+     * @param array $config Transformationskonfiguration
+     *
+     * @return string|null Extrahierter Wert oder null
+     */
+    private function transformRegexExtract(string $value, array $config): ?string
+    {
+        if (empty($value)) {
+            return null;
+        }
+
+        $pattern = $config['pattern'] ?? '';
+
+        if (empty($pattern)) {
+            return null;
+        }
+
+        $pattern = '#' . str_replace('#', '\#', $pattern) . '#';
+
+        if (!preg_match($pattern, $value, $matches)) {
+            return null;
+        }
+
+        DebugLogger::log('transformation', 'Applied regexextract transformation', [
+            'input'   => $value,
+            'pattern' => $pattern,
+            'output'  => $matches[1] ?? $matches[0] ?? null,
+        ]);
+
+        return $matches[1] ?? $matches[0] ?? null;
+    }
+
+    /**
+     * Trim Transformation
+     *
+     * Entfernt Leerzeichen am Anfang und Ende eines Strings
+     *
+     * Konfiguration:
+     * ```
+     * "type": "trim"
+     * ```
+     *
+     * Beispiel:
+     * Input:  "   Coop Pronto   "
+     * Output: "Coop Pronto"
+     *
+     * @param string $value Ursprungswert
+     *
+     * @return string Transformierter Wert
+     */
+    private function transformTrim(string $value): string
+    {
+        return trim($value);
+    }
+
+    /**
+     * Lowercase Transformation
+     *
+     * Wandelt einen String in Kleinbuchstaben um (UTF-8 safe)
+     *
+     * Konfiguration:
+     * ```
+     * "type": "lowercase"
+     * ```
+     *
+     * Beispiel:
+     * Input:  "COOP PRONTO CHUR"
+     * Output: "coop pronto chur"
+     *
+     * @param string $value Ursprungswert
+     *
+     * @return string Transformierter Wert
+     */
+    private function transformLowercase(string $value): string
+    {
+        return mb_strtolower($value, 'UTF-8');
+    }
+
+    /**
+     * Uppercase Transformation
+     *
+     * Wandelt einen String in Grossbuchstaben um (UTF-8 safe)
+     *
+     * Konfiguration:
+     * ```
+     * "type": "uppercase"
+     * ```
+     *
+     * Beispiel:
+     * Input:  "Coop Pronto Chur"
+     * Output: "COOP PRONTO CHUR"
+     *
+     * @param string $value Ursprungswert
+     *
+     * @return string Transformierter Wert
+     */
+    private function transformUppercase(string $value): string
+    {
+        return mb_strtoupper($value, 'UTF-8');
+    }
+
+    /**
+     * Ucwords First Transformation
+     *
+     * Grossschreibung nur des ersten Buchstabens nach Worttrennern.
+     * Alle anderen Buchstaben werden zu Kleinbuchstaben.
+     * Funktioniert auch, wenn Input komplett in Grossbuchstaben vorliegt.
+     *
+     * Konfiguration:
+     * ```
+     * "type": "ucwords_first"
+     * ```
+     *
+     * Mit Ausnahmeliste (Wörter, die exakt erhalten bleiben):
+     * ```
+     * "type": "ucwords_first",
+     * "exceptions": ["SBB", "UBS", "AG", "GmbH"]
+     * ```
+     *
+     * Beispiele:
+     * "COOP PRONTO CHUR"           → "Coop Pronto Chur"
+     * "migros-rail city zuerich"   → "Migros-Rail City Zuerich"
+     * "O'NEILL STORE"              → "O'Neill Store"
+     * "SAINT-JEAN-DE-MAURIENNE"    → "Saint-Jean-De-Maurienne"
+     *
+     * Wortgrenzen definiert durch: Leerzeichen, Bindestrich, Apostroph,
+     * Slash, Punkt, Komma, Semikolon, Doppelpunkt, Klammern, Anführungszeichen
+     *
+     * @param string $value Ursprungswert
+     *
+     * @return string Transformierter Wert
+     */
+    private function transformUcwordsFirst(string $value, array $config = []): string
+    {
+        // Schritt 1: Alles zu Kleinbuchstaben
+        $value = mb_strtolower($value, 'UTF-8');
+
+        // Schritt 2: Definiere Wortgrenzen (Trennzeichen)
+        // Diese Zeichen markieren Grenzen, nach denen grossgeschrieben wird
+        $delimiters = [
+            ' ',  // Leerzeichen
+            '-',  // Bindestrich
+            '\'', // Apostroph
+            '/',  // Slash
+            '.',  // Punkt
+            ',',  // Komma
+            ';',  // Semikolon
+            ':',  // Doppelpunkt
+            '(',  // Oeffnende Klammer
+            ')',  // Schliessende Klammer
+            '[',  // Oeffnende eckige Klammer
+            ']',  // Schliessende eckige Klammer
+            '{',  // Oeffnende geschweifte Klammer
+            '}',  // Schliessende geschweifte Klammer
+            '"',  // Anführungszeichen
+            '&',  // Ampersand
+            '+'   // Plus
+        ];
+
+        // Schritt 3: Regex-Pattern fuer "Stringanfang ODER Delimiter, gefolgt von Buchstabe"
+        // Die u-Flag ermoeglicht Unicode-Unterstaetzung (\p{L})
+        $escapedDelimiters = array_map(function ($char) {
+            return preg_quote($char, '/');
+        }, $delimiters);
+        $delimiterPattern = implode('', $escapedDelimiters);
+
+        $pattern = '/(^|[' . $delimiterPattern . '])(\p{L})/u';
+
+        // Schritt 4: Callback fuer preg_replace_callback
+        // Grossschreibe den gefangenen Buchstaben (Capture Group 2)
+        $callback = function (array $matches): string {
+            // $matches[1] = Stringanfang oder Trennzeichen
+            // $matches[2] = Buchstabe, der grossgeschrieben werden soll
+            return $matches[1] . mb_strtoupper($matches[2], 'UTF-8');
+        };
+
+        // Schritt 5: Anwende Transformation
+        $result = preg_replace_callback($pattern, $callback, $value) ?? $value;
+
+        // Schritt 6: Ausnahmeliste anwenden (Wörter die exakt erhalten bleiben sollen, z.B. SBB, UBS, GmbH)
+        $exceptions = $config['exceptions'] ?? $this->globalExceptions;
+        foreach ($exceptions as $exception) {
+            if (!is_string($exception) || $exception === '') {
+                continue;
+            }
+            $exceptionPattern = '/\b' . preg_quote($exception, '/') . '\b/iu';
+            $result = preg_replace($exceptionPattern, $exception, $result) ?? $result;
+        }
+
+        return $result;
+    }
+
+    /**
+     * Pipeline Transformation
+     *
+     * Wendet mehrere Transformationen nacheinander auf einen Wert an.
+     * Jeder Schritt benutzt das Ergebnis des vorherigen Schrittes.
+     *
+     * Konfiguration:
+     * ```
+     * "Merchant": {
+     *   "type": "pipeline",
+     *   "sourceColumn": "Merchant/Description",
+     *   "steps": [
+     *     { "type": "trim" },
+     *     { "type": "lowercase" },
+     *     { "type": "ucwords_first" }
+     *   ]
+     * }
+     * ```
+     *
+     * Beispiel:
+     * Input:  "   COOP PRONTO CHUR   "
+     * Step 1 (trim):         "COOP PRONTO CHUR"
+     * Step 2 (lowercase):    "coop pronto chur"
+     * Step 3 (ucwords_first): "Coop Pronto Chur"
+     * Output: "Coop Pronto Chur"
+     *
+     * @param string $value Ursprungswert
+     * @param array $config Transformationskonfiguration mit 'steps' Array
+     *
+     * @return string Transformierter Wert nach allen Schritten
+     */
+    private function transformPipeline(string $value, array $config): string
+    {
+        $steps = $config['steps'] ?? [];
+
+        if (empty($steps) || !is_array($steps)) {
+            return $value;
+        }
+
+        // Wende jeden Schritt nacheinander an
+        foreach ($steps as $step) {
+            if (!empty($step['type'] ?? $step['transform'] ?? null)) {
+                $value = $this->applySingleTransformation($value, $step);
+            }
+        }
+
+        return $value;
+    }
+
+    /**
+     * Custom Callback Transformation
+     *
+     * Ruft eine Custom-Funktion auf, die komplexe Logik implementiert
+     *
+     * Konfiguration:
+     * ```
+     * "type": "custom",
+     * "callback": "myCustomFunction"
+     * ```
+     *
+     * Die Callback-Funktion erhaelt die gesamte Zeile und gibt die
+     * modifizierte Zeile zurueck.
+     *
+     * @param array $row Gesamte Datenzeile
+     * @param array $config Transformationskonfiguration
+     *
+     * @return array Transformierte Datenzeile
+     */
+    private function transformCustom(array $row, array $config): array
+    {
+        $callback = $config['callback'] ?? null;
+
+        if (empty($callback) || !is_callable($callback)) {
+            return $row;
+        }
+
+        try {
+            return call_user_func($callback, $row);
+        } catch (\Exception $e) {
+            return $row;
+        }
+    }
+
+    /**
+     * Behandelt Multi-Output Transformationen
+     * Aktuell nur für 'split' implementiert.
+     *
+     * Config-Beispiel:
+     * {
+     *     "outputs": ["FirstName", "LastName"],
+     *     "sourceColumn": "FullName",
+     *     "type": "split",
+     *     "delimiter": " "
+     * }
+     *
+     * @param array $row Input-Zeile
+     * @param array $config Transformations-Konfiguration
+     * @return array Assoziatives Array: columnName => value
+     * @throws \RuntimeException wenn Transformation-Type nicht unterstützt
+     */
+    private function handleMultiOutputTransformation(array $row, array $config): array
+    {
+        $outputs = $config['outputs'];
+        $sourceColumn = $config['sourceColumn'] ?? '';
+        $transformType = $this->normalizeTransformType($config['type'] ?? '');
+
+        if (empty($outputs) || empty($sourceColumn) || empty($transformType)) {
+            throw new \RuntimeException("Multi-Output Transformation benötigt 'outputs', 'sourceColumn' und 'type'");
+        }
+
+        $sourceValue = $row[$sourceColumn] ?? '';
+
+        if ($transformType !== 'split') {
+            throw new \RuntimeException("Multi-Output nur für 'split' unterstützt, gegeben: {$transformType}");
+        }
+
+        return $this->handleMultiOutputSplit($sourceValue, $outputs, $config);
+    }
+
+    /**
+     * Split-Transformation mit Multi-Output
+     * Teilt einen String und verteilt die Teile auf mehrere Spalten
+     *
+     * @param string $value Zu teilender String
+     * @param array $outputs Liste der Ziel-Spaltennamen
+     * @param array $config Transformation-Config
+     * @return array Assoziatives Array: columnName => value
+     */
+
+    private function handleMultiOutputSplit(string $value, array $outputs, array $config): array
+    {
+        $delimiter = $config['delimiter'] ?? ';';
+
+        // Führe Split durch
+        $parts = explode($delimiter, $value);
+
+        // Mappe Parts zu Output-Spalten
+        $result = [];
+        foreach ($outputs as $index => $columnName) {
+            // Wenn Teil existiert: verwenden (getrimmt) // Wenn nicht: leerer String
+            $result[$columnName] = isset($parts[$index]) ? trim($parts[$index]) : '';
+        }
+
+        // Debug-Logging
+        DebugLogger::log('transformation', 'Applied Multi-Output Split', ['input' => $value, 'delimiter' => $delimiter, 'parts_count' => count($parts), 'outputs' => $outputs, 'result' => $result]);
+
+        return $result;
+    }
+
+    /**
+     * Gibt die Anzahl der Output-Spalten zurueck
+     *
+     * Zaehlt Original-Spalten plus neu generierte Spalten (z.B. bei regex_extract)
+     *
+     * @return int Anzahl Output-Spalten
+     */
+    public function getOutputColumns(): int
+    {
+        return count(array_unique($this->outputColumns));
+    }
+}
diff --git a/src/ConfigurationLoader.php b/src/ConfigurationLoader.php
new file mode 100644
index 0000000..8ea8cc5
--- /dev/null
+++ b/src/ConfigurationLoader.php
@@ -0,0 +1,201 @@
+<?php
+
+namespace UbsCsvTransformer;
+
+/**
+ * Lädt und validiert JSON-Konfigurationsdateien
+ */
+class ConfigurationLoader
+{
+    private string $configFile;
+    private array $config = [];
+
+    public function __construct(string $configFile)
+    {
+        $this->configFile = $configFile;
+    }
+
+    /**
+     * Lädt die Konfigurationsdatei
+     *
+     * @return array Die geladene und validierte Konfiguration
+     * @throws \RuntimeException wenn Datei nicht gefunden oder ungültig
+     */
+    public function load(): array
+    {
+        if (!file_exists($this->configFile)) {
+            throw new \RuntimeException("Konfigurationsdatei nicht gefunden: {$this->configFile}");
+        }
+
+        if (pathinfo($this->configFile, PATHINFO_EXTENSION) !== 'json') {
+            throw new \RuntimeException("Konfigurationsdatei muss eine JSON-Datei sein: {$this->configFile}");
+        }
+
+        $this->config = $this->loadJson($this->configFile);
+
+        $this->validate();
+        return $this->config;
+    }
+
+    /**
+     * Lädt eine JSON-Datei
+     *
+     * @param string $file Pfad zur JSON-Datei
+     * @return array Geparste Konfiguration
+     */
+    private function loadJson(string $file): array
+    {
+        $json = file_get_contents($file);
+        if ($json === false) {
+            throw new \RuntimeException("Konnte JSON-Datei nicht lesen: {$file}");
+        }
+
+        $config = json_decode($json, true);
+
+        if ($config === null && json_last_error() !== JSON_ERROR_NONE) {
+            throw new \RuntimeException("Ungültiges JSON: " . json_last_error_msg());
+        }
+
+        return $config;
+    }
+
+    /**
+     * Validiert die geladene Konfiguration auf erforderliche Felder
+     *
+     * @throws \RuntimeException wenn erforderliche Felder fehlen
+     */
+    private function validate(): void
+    {
+        // Metadata erforderlich
+        if (empty($this->config['metadata'])) {
+            throw new \RuntimeException("Konfiguration: 'metadata' Section erforderlich");
+        }
+
+        if (!isset($this->config['metadata']['extractionRules']) || !is_array($this->config['metadata']['extractionRules'])) {
+            throw new \RuntimeException("Konfiguration: 'metadata.extractionRules' erforderlich (kann leer sein: [])");
+        }
+
+        // CSV-Struktur erforderlich
+        if (empty($this->config['csvStructure'])) {
+            throw new \RuntimeException("Konfiguration: 'csvStructure' Section erforderlich");
+        }
+
+        if (!isset($this->config['csvStructure']['headerLine'])) {
+            throw new \RuntimeException("Konfiguration: 'csvStructure.headerLine' erforderlich");
+        }
+
+        // Column Transformations erforderlich
+        if (empty($this->config['columnTransformations'])) {
+            throw new \RuntimeException("Konfiguration: 'columnTransformations' erforderlich");
+        }
+
+        // Directories validieren (wenn auto-import genutzt wird)
+        if (!empty($this->config['directories'])) {
+            foreach (['source', 'output', 'archive', 'error'] as $dir) {
+                if (empty($this->config['directories'][$dir])) {
+                    throw new \RuntimeException("Konfiguration: 'directories.{$dir}' erforderlich für Auto-Import");
+                }
+            }
+        }
+
+        // Validiere CSV-Struktur Werte
+        $headerLine = $this->config['csvStructure']['headerLine'] ?? 1;
+        if (!is_int($headerLine) || $headerLine < 1) {
+            throw new \Exception(
+                'Konfiguration csvStructure.headerLine muss eine positive Ganzzahl sein'
+            );
+        }
+
+        $delimiter = $this->config['csvStructure']['inputDelimiter'] ?? '';
+        if (strlen($delimiter) === 0) {
+            throw new \Exception(
+                'Konfiguration csvStructure.inputDelimiter darf nicht leer sein'
+            );
+        }
+
+        // Validiere Encoding
+        $encoding = $this->config['csvStructure']['encoding'] ?? 'UTF-8';
+        if (!in_array($encoding, ['UTF-8', 'ISO-8859-1', 'CP1252'])) {
+            throw new \Exception(
+                'Konfiguration csvStructure.encoding: ' . $encoding . ' nicht unterstützt'
+            );
+        }
+    }
+
+    /**
+     * Gibt eine einzelne Konfigurationsoption zurück
+     *
+     * @param string $key Dot-Notation Key (z.B. 'metadata.extractionRules')
+     * @param mixed $default Standardwert wenn Key nicht existiert
+     * @return mixed Der Konfigurationswert
+     */
+    public function get(string $key, mixed $default = null): mixed
+    {
+        $keys = explode('.', $key);
+        $value = $this->config;
+
+        foreach ($keys as $k) {
+            if (!isset($value[$k])) {
+                return $default;
+            }
+            $value = $value[$k];
+        }
+
+        return $value;
+    }
+
+    /**
+     * Gibt die vollständige Konfiguration zurück
+     *
+     * @return array Die komplette Konfiguration
+     */
+    public function getAll(): array
+    {
+        return $this->config;
+    }
+
+    /**
+     * Setzt einen Konfigurationswert (überschreibt bestehenden Wert)
+     *
+     * @param string $key Dot-Notation Key (z.B. 'directories.output')
+     * @param mixed $value Neuer Wert
+     * @return void
+     */
+    public function set(string $key, mixed $value): void
+    {
+        $keys = explode('.', $key);
+        $ref = &$this->config;
+
+        foreach ($keys as $i => $k) {
+            if ($i === count($keys) - 1) {
+                $ref[$k] = $value;
+            } else {
+                if (!isset($ref[$k]) || !is_array($ref[$k])) {
+                    $ref[$k] = [];
+                }
+                $ref = &$ref[$k];
+            }
+        }
+    }
+
+    /**
+     * Prüft ob ein Konfigurationsschlüssel existiert
+     *
+     * @param string $key Dot-Notation Key
+     * @return bool
+     */
+    public function has(string $key): bool
+    {
+        $keys = explode('.', $key);
+        $value = $this->config;
+
+        foreach ($keys as $k) {
+            if (!isset($value[$k])) {
+                return false;
+            }
+            $value = $value[$k];
+        }
+
+        return true;
+    }
+}
diff --git a/src/CsvReader.php b/src/CsvReader.php
new file mode 100644
index 0000000..989fff5
--- /dev/null
+++ b/src/CsvReader.php
@@ -0,0 +1,183 @@
+<?php
+
+namespace UbsCsvTransformer;
+
+/**
+ * Liest und parst CSV-Dateien
+ *
+ * Diese Klasse liest CSV-Dateien mit konfigurierbarem Delimiter
+ * und separiert Metadaten-Zeilen von den eigentlichen Datenzeilen.
+ */
+class CsvReader
+{
+    private string $filePath;
+    private string $delimiter;
+    private int $headerLine;
+    private bool $hasBom;
+
+    /**
+     * @param string $filePath Pfad zur CSV-Datei
+     * @param array $csvStructure CSV-Struktur aus Konfiguration
+     */
+    public function __construct(string $filePath, array $csvStructure)
+    {
+        $this->filePath = $filePath;
+        $this->delimiter = $csvStructure['inputDelimiter'] ?? ';';
+        $this->headerLine = $csvStructure['headerLine'] ?? 1;
+        $this->hasBom = $csvStructure['hasBom'] ?? false;
+    }
+
+    /**
+     * Liest alle Zeilen aus der Datei
+     *
+     * @param int $maxLines Maximale Anzahl Zeilen (0 = alle)
+     * @return array Array mit Zeilen (ohne Newlines)
+     * @throws \RuntimeException wenn Datei nicht gelesen werden kann
+     */
+    public function readLines(int $maxLines = 0): array
+    {
+        if (!file_exists($this->filePath) || !is_readable($this->filePath)) {
+            throw new \RuntimeException("Konnte Datei nicht lesen: {$this->filePath}");
+        }
+
+        $lines = file($this->filePath, FILE_IGNORE_NEW_LINES);
+
+        if ($lines === false) {
+            throw new \RuntimeException("Konnte Datei nicht lesen: {$this->filePath}");
+        }
+
+        // BOM entfernen falls vorhanden
+        if ($this->hasBom && !empty($lines)) {
+            $lines[0] = $this->removeBom($lines[0]);
+        }
+
+        if ($maxLines > 0 && count($lines) > $maxLines) {
+            $lines = array_slice($lines, 0, $maxLines);
+        }
+
+        return $lines;
+    }
+
+    /**
+     * Liest die Metadaten-Zeilen (vor der Header-Zeile)
+     *
+     * @return array Array mit Metadaten-Zeilen
+     */
+    public function readMetadataLines(): array
+    {
+        $lines = $this->readLines();
+
+        if ($this->headerLine <= 1) {
+            return [];
+        }
+
+        return array_slice($lines, 0, $this->headerLine - 1);
+    }
+
+    /**
+     * Liest die CSV-Daten mit Headers
+     *
+     * @param int $maxDataRows Maximale Anzahl Datenzeilen (0 = alle)
+     * @return array Array von assoziativen Arrays (mit Spalten-Namen als Keys)
+     * @throws \RuntimeException wenn Header-Zeile nicht gefunden
+     */
+    public function readCsvData(int $maxDataRows = 0): array
+    {
+        $lines = $this->readLines();
+
+        if ($this->headerLine > count($lines)) {
+            throw new \RuntimeException("Header-Zeile {$this->headerLine} nicht gefunden in Datei mit " . count($lines) . " Zeilen");
+        }
+
+        // Header parsen
+        $headerLineContent = $lines[$this->headerLine - 1];
+        $headers = str_getcsv($headerLineContent, $this->delimiter, '"', '\\');
+        $headers = array_map(static fn(?string $v): string => trim($v ?? ''), $headers);
+
+        // Datenzeilen parsen
+        $data = [];
+        $dataStartLine = $this->headerLine; // 0-basiert
+        $lineCount = 0;
+
+        for ($i = $dataStartLine; $i < count($lines); $i++) {
+            if ($maxDataRows > 0 && $lineCount >= $maxDataRows) {
+                break;
+            }
+
+            $lineContent = $lines[$i];
+
+            // Leere Zeilen überspringen
+            if (trim($lineContent) === '') {
+                continue;
+            }
+
+            $row = str_getcsv($lineContent, $this->delimiter, '"', '\\');
+            $row = array_map(static fn(?string $v): string => trim($v ?? ''), $row);
+
+            // Zeile mit Header-Keys kombinieren
+            $rowData = [];
+            foreach ($headers as $index => $header) {
+                $rowData[$header] = $row[$index] ?? '';
+            }
+
+            $data[] = $rowData;
+            $lineCount++;
+        }
+
+        return $data;
+    }
+
+    /**
+     * Gibt die Spalten-Header zurück
+     *
+     * @return array Array mit Spalten-Namen
+     * @throws \RuntimeException wenn Header-Zeile nicht gefunden
+     */
+    public function getHeaders(): array
+    {
+        $lines = $this->readLines();
+
+        if ($this->headerLine > count($lines)) {
+            throw new \RuntimeException("Header-Zeile {$this->headerLine} nicht gefunden");
+        }
+
+        $headerLineContent = $lines[$this->headerLine - 1];
+        $headers = str_getcsv($headerLineContent, $this->delimiter, '"', '\\');
+
+        return array_map(static fn(?string $v): string => trim($v ?? ''), $headers);
+    }
+
+    /**
+     * Entfernt UTF-8 BOM (Byte Order Mark) von String
+     *
+     * @param string $text String mit potenziellem BOM
+     * @return string String ohne BOM
+     */
+    private function removeBom(string $text): string
+    {
+        if (str_starts_with($text, "\xEF\xBB\xBF")) {
+            return substr($text, 3);
+        }
+        return $text;
+    }
+
+    /**
+     * Gibt die Gesamtzahl der Zeilen in der Datei zurück
+     *
+     * @return int Anzahl Zeilen
+     */
+    public function countLines(): int
+    {
+        return count($this->readLines());
+    }
+
+    /**
+     * Gibt die Anzahl der Datenzeilen zurück (ohne Header und Metadaten)
+     *
+     * @return int Anzahl Datenzeilen
+     */
+    public function countDataRows(): int
+    {
+        return count($this->readCsvData());
+    }
+}
diff --git a/src/CsvWriter.php b/src/CsvWriter.php
new file mode 100644
index 0000000..69b33f9
--- /dev/null
+++ b/src/CsvWriter.php
@@ -0,0 +1,121 @@
+<?php
+
+namespace UbsCsvTransformer;
+
+/**
+ * Schreibt transformierte Daten in CSV-Datei
+ *
+ * Diese Klasse schreibt die transformierten Daten in eine
+ * Firefly III-kompatible CSV-Datei.
+ */
+class CsvWriter
+{
+    private string $outputFile;
+    private string $delimiter;
+
+    /**
+     * @param string $outputFile Pfad zur Output-Datei
+     * @param array $csvStructure CSV-Struktur aus Konfiguration
+     */
+    public function __construct(string $outputFile, array $csvStructure = [])
+    {
+        $this->outputFile = $outputFile;
+        $this->delimiter = $csvStructure['outputDelimiter'] ?? ',';
+    }
+
+    /**
+     * Schreibt Daten in CSV-Datei
+     *
+     * @param array $data Array von assoziativen Arrays (Zeilen)
+     * @throws \RuntimeException wenn Datei nicht geschrieben werden kann
+     */
+    public function write(array $data): void
+    {
+        if (empty($data)) {
+            throw new \RuntimeException("Keine Daten zum Schreiben");
+        }
+
+        // Output-Verzeichnis erstellen falls nicht vorhanden
+        $dir = dirname($this->outputFile);
+        if (!is_dir($dir)) {
+            if (!mkdir($dir, 0755, true)) {
+                throw new \RuntimeException("Konnte Output-Verzeichnis nicht erstellen: {$dir}");
+            }
+        }
+
+        $fp = fopen($this->outputFile, 'w');
+
+        if ($fp === false) {
+            throw new \RuntimeException("Konnte Output-Datei nicht erstellen: {$this->outputFile}");
+        }
+
+        try {
+            // Headers schreiben (Spalten-Namen aus erster Zeile)
+            $headers = array_keys($data[0]);
+            $this->writeCsvLine($fp, $headers);
+
+            // Datenzeilen schreiben
+            foreach ($data as $row) {
+                // Sicherstellen dass alle Spalten vorhanden sind
+                $values = [];
+                foreach ($headers as $header) {
+                    $values[] = $row[$header] ?? '';
+                }
+
+                $this->writeCsvLine($fp, $values);
+            }
+        } finally {
+            fclose($fp);
+        }
+    }
+
+    /**
+     * Schreibt eine CSV-Zeile mit fputcsv
+     *
+     * @param resource $fp File-Handle
+     * @param array $values Array mit Werten
+     * @throws \RuntimeException wenn Schreiben fehlschlägt
+     */
+    private function writeCsvLine($fp, array $values): void
+    {
+        $result = fputcsv($fp, $values, $this->delimiter, '"', '\\');
+
+        if ($result === false) {
+            throw new \RuntimeException("Fehler beim Schreiben der CSV-Zeile");
+        }
+    }
+
+    /**
+     * Gibt den Pfad zur Output-Datei zurück
+     *
+     * @return string Output-Dateipfad
+     */
+    public function getOutputFile(): string
+    {
+        return $this->outputFile;
+    }
+
+    /**
+     * Prüft ob Output-Datei erstellt wurde
+     *
+     * @return bool True wenn Datei existiert
+     */
+    public function fileExists(): bool
+    {
+        return file_exists($this->outputFile);
+    }
+
+    /**
+     * Gibt die Größe der Output-Datei zurück
+     *
+     * @return int|false Dateigröße in Bytes oder false bei Fehler
+     */
+    public function getFileSize(): int|false
+    {
+        if (!$this->fileExists()) {
+            return false;
+        }
+
+        return filesize($this->outputFile);
+    }
+}
diff --git a/src/DebugLogger.php b/src/DebugLogger.php
new file mode 100644
index 0000000..d14501a
--- /dev/null
+++ b/src/DebugLogger.php
@@ -0,0 +1,174 @@
+<?php
+
+namespace UbsCsvTransformer;
+
+/**
+ * Zentraler Debug-Logger für Transparenz
+ *
+ * Sammelt Debug-Informationen aus allen Komponenten und macht die
+ * Verarbeitung nachvollziehbar. Ermöglicht Transparenz über alle
+ * Verarbeitungsschritte: Metadaten-Extraktion, Transformationen,
+ * CSV-Lesevorgänge etc.
+ *
+ * Verwendung:
+ * - DebugLogger::enable() → Debug-Modus aktivieren
+ * - DebugLogger::log('category', 'message', $data) → Nachricht loggen
+ * - DebugLogger::getLogs() → Alle Logs abrufen
+ * - DebugLogger::reset() → Logs zurücksetzen
+ *
+ * Beispiel:
+ * ```php
+ * DebugLogger::enable();
+ * DebugLogger::log('metadata', 'IBAN extrahiert', ['iban' => 'CH9300762011623852957']);
+ * $logs = DebugLogger::getLogs();
+ * ```
+ */
+class DebugLogger
+{
+    /**
+     * @var bool Ist Debug-Modus aktiviert?
+     */
+    private static bool $enabled = false;
+
+    /**
+     * @var array Gesammelte Logs mit Timestamp, Kategorie, Nachricht und Daten
+     */
+    private static array $logs = [];
+
+    /**
+     * Aktiviert den Debug-Modus
+     *
+     * Nach Aktivierung werden alle DebugLogger::log() Aufrufe protokolliert.
+     *
+     * @return void
+     */
+    public static function enable(): void
+    {
+        self::$enabled = true;
+    }
+
+    /**
+     * Deaktiviert den Debug-Modus
+     *
+     * Nach Deaktivierung werden DebugLogger::log() Aufrufe ignoriert.
+     *
+     * @return void
+     */
+    public static function disable(): void
+    {
+        self::$enabled = false;
+    }
+
+    /**
+     * Protokolliert eine Debug-Nachricht
+     *
+     * Sammelt Informationen über jeden Verarbeitungsschritt mit Timestamp,
+     * Kategorie, Nachricht und optionalen Daten. Die Logs werden nur
+     * gesammelt, wenn der Debug-Modus aktiviert ist.
+     *
+     * @param string $category Kategorie der Log-Nachricht
+     *                         z.B. 'metadata', 'transformation', 'csv_reader', 'config'
+     * @param string $message Beschreibung der Aktion oder des Ereignisses
+     * @param mixed $data Zusätzliche Kontextdaten (Array oder beliebiger Wert)
+     *
+     * @return void
+     */
+    public static function log(string $category, string $message, $data = null): void
+    {
+        if (!self::$enabled) {
+            return;
+        }
+
+        self::$logs[] = [
+            'timestamp' => microtime(true),
+            'category' => $category,
+            'message' => $message,
+            'data' => $data
+        ];
+    }
+
+    /**
+     * Gibt alle gesammelten Logs zurück
+     *
+     * Liefert ein Array aller protokollierten Ereignisse mit vollständigen
+     * Informationen für Analyse und Debugging.
+     *
+     * @return array Array von Log-Einträgen, jeder mit:
+     *               - timestamp: Mikrosekunden-Zeitstempel
+     *               - category: Log-Kategorie
+     *               - message: Beschreibung
+     *               - data: Zusätzliche Daten
+     */
+    public static function getLogs(): array
+    {
+        return self::$logs;
+    }
+
+    /**
+     * Setzt alle Logs zurück
+     *
+     * Löscht den gesamten Log-Buffer. Nützlich um zwischen mehreren
+     * Transformationen einen sauberen State zu haben.
+     *
+     * @return void
+     */
+    public static function reset(): void
+    {
+        self::$logs = [];
+    }
+
+    /**
+     * Gibt die Anzahl der gesammelten Log-Einträge zurück
+     *
+     * @return int Anzahl protokollierter Ereignisse
+     */
+    public static function count(): int
+    {
+        return count(self::$logs);
+    }
+
+    /**
+     * Prüft ob Debug-Modus aktiviert ist
+     *
+     * @return bool true wenn aktiviert, false sonst
+     */
+    public static function isEnabled(): bool
+    {
+        return self::$enabled;
+    }
+
+    /**
+     * Gibt einen formattierten String aller Logs zurück
+     *
+     * Konvertiert den Log-Buffer in ein lesbares Format für Konsolen-Ausgabe.
+     *
+     * @param bool $includeData true = auch Daten ausgeben, false = nur Messages
+     *
+     * @return string Formatierte Log-Ausgabe
+     */
+    public static function format(bool $includeData = true): string
+    {
+        if (empty(self::$logs)) {
+            return "Keine Debug-Logs vorhanden.\n";
+        }
+
+        $output = "\n=== DEBUG LOGS ===\n";
+        foreach (self::$logs as $index => $log) {
+            $output .= sprintf(
+                "%d. [%s] %s: %s",
+                $index + 1,
+                $log['category'],
+                date('H:i:s', intval($log['timestamp'])),
+                $log['message']
+            );
+
+            if ($includeData && $log['data'] !== null) {
+                $output .= "\n   Data: " . json_encode($log['data'], JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE);
+            }
+            $output .= "\n";
+        }
+        $output .= "===================\n";
+
+        return $output;
+    }
+}
diff --git a/src/FireflyImporter.php b/src/FireflyImporter.php
new file mode 100644
index 0000000..38c08fc
--- /dev/null
+++ b/src/FireflyImporter.php
@@ -0,0 +1,317 @@
+<?php
+
+namespace UbsCsvTransformer;
+
+/**
+ * Firefly III Data Importer Integration
+ *
+ * Diese Klasse integriert den Firefly III Data Importer.
+ * Der Import erfolgt über die offizielle Firefly III Data Importer CLI.
+ *
+ * SETUP-VORAUSSETZUNGEN:
+ * ----------------------
+ *
+ * 1. Firefly III Data Importer installiert und konfiguriert
+ *    - Docker: firefly/data-importer:latest
+ *    - Oder: Standalone Installation
+ *
+ * 2. Import-Konfiguration erstellt (config.json):
+ *    - In Firefly III Web-UI: Import → Configure
+ *    - CSV-Format konfigurieren
+ *    - JSON-Konfiguration herunterladen
+ *    - Speichern als z.B.: /opt/firefly/configs/ubs-import.json
+ *
+ * 3. Umgebungsvariablen für Firefly Data Importer:
+ *    - FIREFLY_III_URL=https://your-firefly-instance.com
+ *    - FIREFLY_III_ACCESS_TOKEN=<personal_access_token>
+ *    - VANITY_URL (optional)
+ *
+ * INTEGRATION IN config.yaml:
+ * ---------------------------
+ *
+ * fireflyImport:
+ *   # Pfad zur JSON-Konfiguration (aus Firefly III exportiert)
+ *   jsonConfig: '/opt/firefly/configs/ubs-import.json'
+ *
+ *   # Firefly Data Importer Kommando
+ *   # Option 1: Docker
+ *   importerCommand: 'docker exec -it firefly-importer php artisan importer:import'
+ *
+ *   # Option 2: Standalone
+ *   # importerCommand: 'cd /opt/firefly-data-importer && php artisan importer:import'
+ *
+ *   # Automatisch nach Transformation importieren?
+ *   autoImport: true
+ *
+ *   # Output-Datei nach erfolgreichem Import löschen?
+ *   deleteAfterImport: true
+ *
+ *   # Timeout für Import (Sekunden)
+ *   timeout: 300
+ *
+ *   # Environment-Variablen für Firefly Data Importer
+ *   environment:
+ *     FIREFLY_III_URL: 'https://your-firefly.com'
+ *     FIREFLY_III_ACCESS_TOKEN: 'your-token-here'
+ *
+ * VERWENDUNG:
+ * -----------
+ *
+ * // Automatisch beim Auto-Import
+ * ./bin/transformer auto-import config/config.yaml
+ *
+ * // Oder manuell nach Transformation
+ * $importer = new FireflyImporter($config['fireflyImport']);
+ * $result = $importer->import('/path/to/transformed.csv');
+ */
+class FireflyImporter
+{
+    private array $config;
+    private string $jsonConfigPath;
+    private string $importerCommand;
+    private bool $deleteAfterImport;
+    private array $environment;
+
+    /**
+     * @param array $config Firefly Import-Konfiguration aus config.yaml
+     * @throws \RuntimeException wenn Konfiguration ungültig
+     */
+    public function __construct(array $config)
+    {
+        $this->config = $config;
+
+        // JSON-Konfigurationspfad validieren
+        $this->jsonConfigPath = $config['jsonConfig'] ?? '';
+        if (empty($this->jsonConfigPath)) {
+            throw new \RuntimeException("Firefly Import: 'jsonConfig' nicht konfiguriert");
+        }
+
+        if (!file_exists($this->jsonConfigPath)) {
+            throw new \RuntimeException("Firefly JSON-Konfiguration nicht gefunden: {$this->jsonConfigPath}");
+        }
+
+        // Importer-Kommando
+        $this->importerCommand = $config['importerCommand'] ?? '';
+        if (empty($this->importerCommand)) {
+            throw new \RuntimeException("Firefly Import: 'importerCommand' nicht konfiguriert");
+        }
+
+        // Optionale Einstellungen
+        $this->deleteAfterImport = $config['deleteAfterImport'] ?? false;
+        $this->environment = $config['environment'] ?? [];
+    }
+
+    /**
+     * Importiert eine transformierte CSV-Datei in Firefly III
+     *
+     * Der Import erfolgt über den Firefly III Data Importer CLI:
+     * php artisan importer:import <csv_file> <config_file>
+     *
+     * @param string $csvFile Pfad zur transformierten CSV-Datei
+     * @return array Import-Ergebnis mit Status und Ausgabe
+     */
+    public function import(string $csvFile): array
+    {
+        if (!file_exists($csvFile)) {
+            return [
+                'success' => false,
+                'error' => "CSV-Datei nicht gefunden: {$csvFile}",
+                'output' => '',
+                'exit_code' => -1
+            ];
+        }
+
+        // Kommando zusammenbauen
+        $command = $this->buildImportCommand($csvFile);
+
+        // Environment-Variablen setzen
+        $env = $this->buildEnvironment();
+
+        // Import ausführen
+        $output = [];
+        $exitCode = 0;
+
+        $startTime = microtime(true);
+
+        try {
+            // Kommando ausführen mit Timeout
+            $descriptors = [
+                0 => ["pipe", "r"],  // stdin
+                1 => ["pipe", "w"],  // stdout
+                2 => ["pipe", "w"]   // stderr
+            ];
+
+            $process = proc_open($command, $descriptors, $pipes, null, $env);
+
+            if (!is_resource($process)) {
+                throw new \RuntimeException("Konnte Import-Prozess nicht starten");
+            }
+
+            // stdin schließen
+            fclose($pipes[0]);
+
+            // stdout und stderr lesen
+            $stdout = stream_get_contents($pipes[1]);
+            $stderr = stream_get_contents($pipes[2]);
+
+            fclose($pipes[1]);
+            fclose($pipes[2]);
+
+            // Auf Prozess-Ende warten
+            $exitCode = proc_close($process);
+
+            $output = [
+                'stdout' => $stdout,
+                'stderr' => $stderr
+            ];
+
+            $duration = microtime(true) - $startTime;
+
+            $success = ($exitCode === 0);
+
+            // Bei Erfolg: Optional CSV-Datei löschen
+            if ($success && $this->deleteAfterImport) {
+                @unlink($csvFile);
+            }
+
+            return [
+                'success' => $success,
+                'exit_code' => $exitCode,
+                'output' => $output,
+                'duration' => round($duration, 2),
+                'csv_file' => $csvFile,
+                'config_file' => $this->jsonConfigPath,
+                'deleted' => ($success && $this->deleteAfterImport)
+            ];
+        } catch (\Exception $e) {
+            return [
+                'success' => false,
+                'error' => $e->getMessage(),
+                'output' => $output,
+                'exit_code' => $exitCode
+            ];
+        }
+    }
+
+    /**
+     * Baut das Import-Kommando zusammen
+     *
+     * @param string $csvFile Pfad zur CSV-Datei
+     * @return string Vollständiges Kommando
+     */
+    private function buildImportCommand(string $csvFile): string
+    {
+        // Firefly Data Importer CLI-Format:
+        // php artisan importer:import <csv_file> <config_file>
+
+        return sprintf(
+            '%s %s %s',
+            $this->importerCommand,
+            escapeshellarg($csvFile),
+            escapeshellarg($this->jsonConfigPath)
+        );
+    }
+
+    /**
+     * Baut Environment-Variablen zusammen
+     *
+     * @return array|null Environment-Variablen oder null
+     */
+    private function buildEnvironment(): ?array
+    {
+        if (empty($this->environment)) {
+            return null;
+        }
+
+        // Aktuelle Environment übernehmen und mit Custom-Vars erweitern
+        $env = $_ENV;
+
+        foreach ($this->environment as $key => $value) {
+            $env[$key] = $value;
+        }
+
+        return $env;
+    }
+
+    /**
+     * Testet die Firefly-Verbindung
+     *
+     * @return array Test-Ergebnis
+     */
+    public function testConnection(): array
+    {
+        // Test ob Importer-Kommando verfügbar ist
+        $testCommand = str_replace('importer:import', '--version', $this->importerCommand);
+
+        exec($testCommand . ' 2>&1', $output, $exitCode);
+
+        return [
+            'available' => ($exitCode === 0),
+            'output' => implode("\n", $output),
+            'exit_code' => $exitCode
+        ];
+    }
+
+    /**
+     * Validiert die JSON-Konfiguration
+     *
+     * @return array Validierungsergebnis
+     */
+    public function validateConfig(): array
+    {
+        if (!file_exists($this->jsonConfigPath)) {
+            return [
+                'valid' => false,
+                'error' => 'JSON-Konfiguration nicht gefunden'
+            ];
+        }
+
+        $json = file_get_contents($this->jsonConfigPath);
+        if ($json === false) {
+            return [
+                'valid' => false,
+                'error' => 'Konfigurationsdatei nicht lesbar'
+            ];
+        }
+        $config = json_decode($json, true);
+
+        if ($config === null) {
+            return [
+                'valid' => false,
+                'error' => 'Ungültiges JSON: ' . json_last_error_msg()
+            ];
+        }
+
+        // Prüfe erforderliche Felder in Firefly-Config
+        $requiredFields = ['file_type', 'import_account'];
+        $missingFields = [];
+
+        foreach ($requiredFields as $field) {
+            if (!isset($config[$field])) {
+                $missingFields[] = $field;
+            }
+        }
+
+        if (!empty($missingFields)) {
+            return [
+                'valid' => false,
+                'error' => 'Fehlende Felder: ' . implode(', ', $missingFields)
+            ];
+        }
+
+        return [
+            'valid' => true,
+            'config' => $config
+        ];
+    }
+
+    /**
+     * Gibt die Konfiguration zurück
+     *
+     * @return array Firefly Import-Konfiguration
+     */
+    public function getConfig(): array
+    {
+        return $this->config;
+    }
+}
diff --git a/src/MetadataExtractor.php b/src/MetadataExtractor.php
new file mode 100644
index 0000000..6f09949
--- /dev/null
+++ b/src/MetadataExtractor.php
@@ -0,0 +1,126 @@
+<?php
+
+namespace UbsCsvTransformer;
+
+/**
+ * Extrahiert Metadaten aus Header-Zeilen mit Regex
+ *
+ * Diese Klasse extrahiert konstante Werte aus den Metadatenzeilen
+ * (Header-Zeilen vor der eigentlichen CSV-Tabelle) mittels Regex-Regeln.
+ */
+class MetadataExtractor
+{
+    private array $rules;
+
+    public function __construct(array $rules = [])
+    {
+        $this->rules = $rules;
+    }
+
+    /**
+     * Extrahiert Metadaten aus den übergebenen Zeilen
+     *
+     * @param array $lines Array von Zeilen aus dem CSV-Header
+     * @return array Extrahierte Metadaten
+     */
+    public function extract(array $lines): array
+    {
+        $metadata = [];
+
+        foreach ($this->rules as $rule) {
+            // Validiere erforderliche Felder
+            if (empty($rule['name']) || empty($rule['regex'])) {
+                continue;
+            }
+
+            $ruleName = $rule['name'];
+            $lineNumber = $rule['lineNumber'] ?? 1;
+            $regex = $rule['regex'];
+
+            // ✅ KORRIGIERT: Off-by-One Fix
+            // config.json: "lineNumber": 1, 2, 3 (1-basiert, für Menschen lesbar)
+            // PHP Arrays: $lines[0], $lines[1], $lines[2] (0-basiert)
+            // Konvertierung: arrayIndex = lineNumber - 1
+            $arrayIndex = $lineNumber - 1;
+
+            // Prüfe ob Zeile existiert
+            if (!isset($lines[$arrayIndex])) {
+                // Zeile existiert nicht - Debug-Info für Support
+                DebugLogger::log('metadata_warning', "Extraction rule not found", [
+                    'rule_name' => $ruleName,
+                    'expected_lineNumber' => $lineNumber,
+                    'array_index' => $arrayIndex,
+                    'available_lines' => count($lines)
+                ]);
+                continue;
+            }
+
+            $line = $lines[$arrayIndex];
+
+            // Regex mit '#' als Delimiter (erlaubt '/' in User-Patterns); '#' im Pattern escapen
+            $pattern = '#' . str_replace('#', '\#', $regex) . '#u';
+            $matchResult = @preg_match_all($pattern, $line, $matches);
+            if ($matchResult === false) {
+                DebugLogger::log('metadata_error', "Invalid regex pattern", [
+                    'rule_name' => $ruleName,
+                    'pattern'   => $regex,
+                ]);
+                continue;
+            }
+            if ($matchResult === 0) {
+                // Regex matched nicht auf dieser Zeile
+                DebugLogger::log('metadata_warning', "Regex did not match", [
+                    'rule_name'    => $ruleName,
+                    'lineNumber'   => $lineNumber,
+                    'regex_pattern' => $regex,
+                    'line_content' => substr($line, 0, 100)
+                ]);
+                continue;
+            }
+
+            // ✅ KORRIGIERT: captureGroup benutzen
+            // captureGroup definiert welche Klammer-Gruppe extrahiert wird
+            // 0 = komplette Match
+            // 1 = erste Klammer-Gruppe (...)
+            // 2 = zweite Klammer-Gruppe, etc.
+            $captureGroup = isset($rule['captureGroup']) ? intval($rule['captureGroup']) : 1;
+
+            // Sicherstellen dass die Capture Group existiert
+            if (!isset($matches[$captureGroup]) || empty($matches[$captureGroup])) {
+                // Fallback: Nutze komplette Match wenn Gruppe nicht existiert
+                $metadata[$ruleName] = $matches[0][0] ?? '';
+                // echo "DEBUG: extraction_rule '{$ruleName}' - captureGroup {$captureGroup} not found, falling back to complete match\n";
+            } else {
+                // Nutze die spezifische Capture Group
+                $metadata[$ruleName] = $matches[$captureGroup][0] ?? '';
+            }
+
+            DebugLogger::log('metadata', "Extraction rule applied", [
+                'rule_name' => $ruleName,
+                'value'     => $metadata[$ruleName] ?? null,
+            ]);
+        }
+
+        return $metadata;
+    }
+
+    /**
+     * Gibt die Anzahl der definierten Extraction-Rules zurück
+     *
+     * @return int Anzahl Rules
+     */
+    public function getRuleCount(): int
+    {
+        return count($this->rules);
+    }
+
+    /**
+     * Gibt alle definierten Extraction-Rules zurück
+     *
+     * @return array Die Rules
+     */
+    public function getRules(): array
+    {
+        return $this->rules;
+    }
+}
diff --git a/src/TransformerEngine.php b/src/TransformerEngine.php
new file mode 100644
index 0000000..4b7276d
--- /dev/null
+++ b/src/TransformerEngine.php
@@ -0,0 +1,368 @@
+<?php
+
+namespace UbsCsvTransformer;
+
+use UbsCsvTransformer\CsvReader;
+use UbsCsvTransformer\CsvWriter;
+use UbsCsvTransformer\ConfigurationLoader;
+use UbsCsvTransformer\MetadataExtractor;
+use UbsCsvTransformer\ColumnTransformer;
+use UbsCsvTransformer\FireflyImporter;
+
+/**
+ * Orchestriert die gesamte CSV-Transformations-Pipeline
+ *
+ * Koordiniert alle Schritte von CSV-Einlesen über Metadaten-Extraktion
+ * und Spalten-Transformation bis zur Ausgabe und optional zum Import in Firefly III.
+ *
+ * @property ConfigurationLoader $configLoader Verwaltet Konfiguration
+ * @property CsvWriter $csvWriter Schreibt Output-CSV
+ * @property MetadataExtractor $metadataExtractor Extrahiert Metadaten aus Header
+ * @property ColumnTransformer $columnTransformer Transformiert Spalten
+ * @property array $csvStructure CSV-Struktur-Konfiguration
+ */
+class TransformerEngine
+{
+    private ConfigurationLoader $configLoader;
+    private CsvWriter $csvWriter;
+    private MetadataExtractor $metadataExtractor;
+    private ColumnTransformer $columnTransformer;
+    private array $csvStructure;
+    private array $sampleData = [];
+    private int $rowsProcessed = 0;
+    private bool $debugMode = false;
+
+    /**
+     * Initialisiert TransformerEngine mit Konfiguration
+     *
+     * Lädt alle erforderlichen Konfigurationen und initialisiert
+     * die Komponenten (MetadataExtractor, ColumnTransformer, CsvWriter).
+     * CsvReader wird später in transform() und validate() initialisiert mit dem Dateipfad.
+     *
+     * @param ConfigurationLoader $configLoader Lädt Konfigurationsdateien
+     * @param bool $debugMode true = Debug-Modus aktivieren
+     *
+     * @throws \RuntimeException wenn erforderliche Konfigurationen fehlen
+     */
+    public function __construct(ConfigurationLoader $configLoader, bool $debugMode = false)
+    {
+        $this->configLoader = $configLoader;
+        $this->debugMode = $debugMode;
+
+        $config = $configLoader->getAll();
+
+        $this->csvStructure = $config['csvStructure'] ?? [];
+
+        $this->metadataExtractor = new MetadataExtractor(
+            $config['metadata']['extractionRules'] ?? []
+        );
+
+        $this->columnTransformer = new ColumnTransformer(
+            $config['columnTransformations'] ?? [],
+            [],
+            $config['capitalizationExceptions'] ?? []
+        );
+
+        // Bestimme Output-Dateiname aus Konfiguration
+        $outputDir = $config['directories']['output'] ?? './output';
+        $outputFileName = $config['csvStructure']['outputFilename'] ?? 'transformed.csv';
+        $outputFile = rtrim($outputDir, '/') . '/' . $outputFileName;
+
+        $this->csvWriter = new CsvWriter(
+            $outputFile,
+            $config['csvStructure'] ?? []
+        );
+    }
+
+    /**
+     * Aktiviert oder deaktiviert den Debug-Modus
+     *
+     * @param bool $enabled true = Debug-Modus aktiviert
+     * @return void
+     */
+    public function setDebugMode(bool $enabled): void
+    {
+        $this->debugMode = $enabled;
+        if ($enabled) {
+            DebugLogger::enable();
+        } else {
+            DebugLogger::disable();
+        }
+    }
+
+    /**
+     * Transformiert eine CSV-Datei
+     *
+     * Führt folgende Schritte durch:
+     * 1. CSV-Datei einlesen mit CsvReader
+     * 2. Metadaten aus Header extrahieren
+     * 3. Spalten gemäß Konfiguration transformieren
+     * 4. Daten in Output-CSV schreiben
+     * 5. Beispiel-Daten sammeln (maximal 3 Zeilen oder maxRows)
+     *
+     * Der Output-Dateipfad wird aus der Konfiguration bestimmt und kann nicht überschrieben werden.
+     *
+     * @param string $inputFile Pfad zur Input-CSV-Datei
+     * @param int $maxRows Maximale Anzahl Datenzeilen zu transformieren (0 = alle).
+     *                      Beispiel-Daten werden begrenzt auf min(3, maxRows)
+     *
+     * @return array Transformations-Ergebnis mit:
+     *               - success: bool (true = erfolgreich, false = Fehler)
+     *               - inputFile: string (Input-Dateipfad, nur bei Erfolg)
+     *               - outputFile: string (Output-Dateipfad, nur bei Erfolg)
+     *               - rowsProcessed: int (tatsächlich verarbeitete Datenzeilen)
+     *               - sampleData: array (Erste Beispiel-Zeilen, max 3 oder maxRows)
+     *               - metadata: array (Extrahierte Metadaten, nur bei Erfolg)
+     *               - outputColumns: int (Anzahl Output-Spalten)
+     *               - error: string (Fehlermeldung, nur bei Fehler)
+     */
+    public function transform(string $inputFile, int $maxRows = 0): array
+    {
+        $this->sampleData = [];
+        $this->rowsProcessed = 0;
+        DebugLogger::reset();
+
+        try {
+            if ($this->debugMode) {
+                DebugLogger::log('transformer', 'Transformation started', [
+                    'inputFile' => $inputFile,
+                    'maxRows' => $maxRows
+                ]);
+            }
+
+            // Validiere Input-Datei
+            if (!file_exists($inputFile)) {
+                throw new \RuntimeException("Input-Datei nicht gefunden: {$inputFile}");
+            }
+
+            // Initialisiere CsvReader mit Dateipfad und Konfiguration
+            $csvReader = new CsvReader($inputFile, $this->csvStructure);
+
+            // Lese Metadaten-Zeilen (vor der Header-Zeile)
+            $metadataLines = $csvReader->readMetadataLines();
+
+            // Extrahiere Metadaten aus den Metadaten-Zeilen
+            $metadata = $this->metadataExtractor->extract($metadataLines);
+
+            // Initialisiere ColumnTransformer mit extrahierten Metadaten
+            $this->columnTransformer = new ColumnTransformer(
+                $this->configLoader->get('columnTransformations', []),
+                $metadata,
+                $this->configLoader->get('capitalizationExceptions', [])
+            );
+
+            // Lese CSV-Daten mit Header-Keys als Array-Keys
+            $dataRows = $csvReader->readCsvData($maxRows);
+            if (empty($dataRows)) {
+                throw new \RuntimeException("Keine Datenzeilen in CSV-Datei");
+            }
+
+            // Berechne Limit für Beispiel-Daten
+            $sampleLimit = $maxRows == 0 ? 3 : $maxRows;
+
+            // Transformiere Zeilen und sammle sie
+            $transformedData = [];
+
+            foreach ($dataRows as $row) {
+                // Prüfe ob maxRows erreicht
+                if ($maxRows > 0 && $this->rowsProcessed >= $maxRows) {
+                    break;
+                }
+
+                // Transformiere Zeile
+                $transformedRow = $this->columnTransformer->transformRow($row);
+                $transformedData[] = $transformedRow;
+
+                // Speichere Beispiel-Daten
+                if (count($this->sampleData) < $sampleLimit) {
+                    $this->sampleData[] = $transformedRow;
+                }
+
+                $this->rowsProcessed++;
+            }
+
+            // Entferne Spalten die aus dem Output ausgeschlossen werden sollen
+            $excludeColumns = $this->csvStructure['excludeOutputColumns'] ?? [];
+            if (!empty($excludeColumns)) {
+                $excludeMap = array_flip($excludeColumns);
+                $transformedData = array_map(
+                    static fn(array $row): array => array_diff_key($row, $excludeMap),
+                    $transformedData
+                );
+                $this->sampleData = array_map(
+                    static fn(array $row): array => array_diff_key($row, $excludeMap),
+                    $this->sampleData
+                );
+            }
+
+            // Schreibe alle transformierten Daten in Output-CSV
+            $this->csvWriter->write($transformedData);
+
+            $result = [
+                'success' => true,
+                'inputFile' => $inputFile,
+                'outputFile' => $this->csvWriter->getOutputFile(),
+                'rowsProcessed' => $this->rowsProcessed,
+                'sampleData' => $this->sampleData,
+                'metadata' => $metadata,
+                'outputColumns' => $this->columnTransformer->getOutputColumns(),
+            ];
+
+            if ($this->debugMode) {
+                $result['debug_logs'] = DebugLogger::getLogs();
+            }
+
+            return $result;
+        } catch (\Exception $e) {
+            return [
+                'success' => false,
+                'error' => $e->getMessage(),
+                'rowsProcessed' => $this->rowsProcessed,
+                'sampleData' => $this->sampleData,
+                'outputColumns' => [],
+            ];
+        }
+    }
+
+    /**
+     * Transformiert und importiert CSV in Firefly III
+     *
+     * Führt Transformation durch und importiert die Ausgabe-Datei
+     * in Firefly III wenn in der Konfiguration aktiviert.
+     *
+     * Rückwärts-kompatibel mit legacy Signatur.
+     *
+     * @param string $inputFile Pfad zur Input-CSV-Datei
+     * @param int $maxRows Maximale Anzahl Datenzeilen zu verarbeiten (0 = alle)
+     *
+     * @return array Transformations- und Import-Ergebnis mit:
+     *               - success: bool (true = transformation erfolgreich)
+     *               - inputFile: string
+     *               - outputFile: string
+     *               - rowsProcessed: int
+     *               - sampleData: array
+     *               - metadata: array
+     *               - outputColumns: int
+     *               - import: array (Firefly Import-Ergebnis, wenn autoImport aktiv)
+     *               - error: string (falls Fehler)
+     */
+    public function transformAndImport(string $inputFile, int $maxRows = 0): array
+    {
+        // Zuerst transformieren
+        $transformResult = $this->transform($inputFile, $maxRows);
+
+        if (!$transformResult['success']) {
+            return $transformResult;
+        }
+
+        // Prüfe ob Auto-Import in Konfiguration aktiviert ist
+        $fireflyConfig = $this->configLoader->get('fireflyImport', []);
+        if (empty($fireflyConfig['autoImport'])) {
+            return $transformResult;
+        }
+
+        // Führe Firefly-Import durch
+        try {
+            $importer = new FireflyImporter($fireflyConfig);
+            $importResult = $importer->import($transformResult['outputFile']);
+            $transformResult['import'] = $importResult;
+
+            return $transformResult;
+        } catch (\Exception $e) {
+            $transformResult['import'] = [
+                'success' => false,
+                'error' => $e->getMessage(),
+            ];
+            return $transformResult;
+        }
+    }
+
+    /**
+     * Validiert eine CSV-Datei gegen die Konfiguration
+     *
+     * Prüft ob erforderliche Metadaten vorhanden sind
+     * und ob die CSV-Struktur der Konfiguration entspricht.
+     *
+     * @param string $inputFile Pfad zur zu validierenden CSV-Datei
+     *
+     * @return array Validierungs-Ergebnis mit:
+     *               - valid: bool (true = Validierung erfolgreich)
+     *               - metadata: array (Extrahierte Metadaten, wenn valid)
+     *               - line_count: int (Gesamtzahl Zeilen, wenn valid)
+     *               - error: string (Fehlermeldung, wenn nicht valid)
+     *               - metadata_found: array (Gefundene Metadaten trotz Fehler)
+     */
+    public function validate(string $inputFile): array
+    {
+        try {
+            if (!file_exists($inputFile)) {
+                return [
+                    'valid' => false,
+                    'error' => "Datei nicht gefunden: {$inputFile}",
+                ];
+            }
+
+            // Initialisiere CsvReader mit Dateipfad
+            $csvReader = new CsvReader($inputFile, $this->csvStructure);
+
+            // Extrahiere Metadaten-Zeilen (vor der Header-Zeile)
+            $metadataLines = $csvReader->readMetadataLines();
+            $metadata = $this->metadataExtractor->extract($metadataLines);
+
+            // Prüfe auf erforderliche Metadaten
+            $requiredMetadata = [
+                'account_iban',
+                'currency_code',
+            ];
+
+            $missingMetadata = [];
+            foreach ($requiredMetadata as $key) {
+                if (empty($metadata[$key])) {
+                    $missingMetadata[] = $key;
+                }
+            }
+
+            if (!empty($missingMetadata)) {
+                return [
+                    'valid' => false,
+                    'error' => 'Fehlende Metadaten: ' . implode(', ', $missingMetadata),
+                    'metadata_found' => $metadata,
+                ];
+            }
+
+            // Zähle Gesamtzahl Zeilen
+            $lineCount = $csvReader->countLines();
+
+            return [
+                'valid' => true,
+                'metadata' => $metadata,
+                'line_count' => $lineCount,
+            ];
+        } catch (\Exception $e) {
+            return [
+                'valid' => false,
+                'error' => 'Validierungs-Fehler: ' . $e->getMessage(),
+            ];
+        }
+    }
+
+    /**
+     * Gibt die gesammelten Beispiel-Daten zurück
+     *
+     * @return array Beispiel-Daten (maximal 3 oder maxRows Zeilen)
+     */
+    public function getSampleData(): array
+    {
+        return $this->sampleData;
+    }
+
+    /**
+     * Gibt die Anzahl verarbeiteter Datenzeilen zurück
+     *
+     * @return int Anzahl transformierter Zeilen
+     */
+    public function getRowsProcessed(): int
+    {
+        return $this->rowsProcessed;
+    }
+}
diff --git a/tests/ColumnTransformerTest.php b/tests/ColumnTransformerTest.php
new file mode 100644
index 0000000..d8c3c73
--- /dev/null
+++ b/tests/ColumnTransformerTest.php
@@ -0,0 +1,507 @@
+<?php
+
+namespace UbsCsvTransformer\Tests;
+
+use PHPUnit\Framework\TestCase;
+use UbsCsvTransformer\ColumnTransformer;
+use UbsCsvTransformer\DebugLogger;
+
+class ColumnTransformerTest extends TestCase
+{
+    protected function setUp(): void
+    {
+        DebugLogger::reset();
+    }
+
+    /**
+     * Helper: build a transformer with one rule and apply it to the given row.
+     */
+    private function applyOne(array $config, array $row, array $metadata = []): array
+    {
+        return (new ColumnTransformer([$config], $metadata))->transformRow($row);
+    }
+
+    // -------------------------------------------------------------------------
+    // map
+    // -------------------------------------------------------------------------
+
+    public function testMapPassthrough(): void
+    {
+        $result = $this->applyOne(
+            ['sourceColumn' => 'Name', 'outputColumn' => 'Name', 'type' => 'map'],
+            ['Name' => 'Alice']
+        );
+        $this->assertSame('Alice', $result['Name']);
+    }
+
+    // -------------------------------------------------------------------------
+    // replace
+    // -------------------------------------------------------------------------
+
+    public function testReplace(): void
+    {
+        $result = $this->applyOne([
+            'sourceColumn' => 'Col',
+            'outputColumn' => 'Col',
+            'type'         => 'replace',
+            'search'       => 'foo',
+            'replace'      => 'bar',
+        ], ['Col' => 'foo baz foo']);
+        $this->assertSame('bar baz bar', $result['Col']);
+    }
+
+    public function testReplaceEmptySearchReturnsOriginal(): void
+    {
+        $result = $this->applyOne([
+            'sourceColumn' => 'Col',
+            'outputColumn' => 'Col',
+            'type'         => 'replace',
+            'search'       => '',
+            'replace'      => 'bar',
+        ], ['Col' => 'hello']);
+        $this->assertSame('hello', $result['Col']);
+    }
+
+    // -------------------------------------------------------------------------
+    // dateformat
+    // -------------------------------------------------------------------------
+
+    public function testDateFormat(): void
+    {
+        $result = $this->applyOne([
+            'sourceColumn' => 'Date',
+            'outputColumn' => 'Date',
+            'type'         => 'dateformat',
+            'fromFormat'   => 'd.m.Y',
+            'toFormat'     => 'Y-m-d',
+        ], ['Date' => '15.03.2024']);
+        $this->assertSame('2024-03-15', $result['Date']);
+    }
+
+    public function testDateFormatInvalidValueReturnsOriginal(): void
+    {
+        $result = $this->applyOne([
+            'sourceColumn' => 'Date',
+            'outputColumn' => 'Date',
+            'type'         => 'dateformat',
+            'fromFormat'   => 'd.m.Y',
+            'toFormat'     => 'Y-m-d',
+        ], ['Date' => 'not-a-date']);
+        $this->assertSame('not-a-date', $result['Date']);
+    }
+
+    public function testDateFormatEmptyValueReturnsEmpty(): void
+    {
+        $result = $this->applyOne([
+            'sourceColumn' => 'Date',
+            'outputColumn' => 'Date',
+            'type'         => 'dateformat',
+            'fromFormat'   => 'd.m.Y',
+            'toFormat'     => 'Y-m-d',
+        ], ['Date' => '']);
+        $this->assertSame('', $result['Date']);
+    }
+
+    // -------------------------------------------------------------------------
+    // split
+    // -------------------------------------------------------------------------
+
+    public function testSplitPart0(): void
+    {
+        $result = $this->applyOne([
+            'sourceColumn' => 'Col',
+            'outputColumn' => 'Col',
+            'type'         => 'split',
+            'delimiter'    => ';',
+            'part'         => 0,
+        ], ['Col' => 'Coop Pronto;7007 Chur']);
+        $this->assertSame('Coop Pronto', $result['Col']);
+    }
+
+    public function testSplitPart1(): void
+    {
+        $result = $this->applyOne([
+            'sourceColumn' => 'Col',
+            'outputColumn' => 'Col',
+            'type'         => 'split',
+            'delimiter'    => ';',
+            'part'         => 1,
+        ], ['Col' => 'Coop Pronto;7007 Chur']);
+        $this->assertSame('7007 Chur', $result['Col']);
+    }
+
+    public function testSplitPartOutOfBoundsReturnsOriginal(): void
+    {
+        $result = $this->applyOne([
+            'sourceColumn' => 'Col',
+            'outputColumn' => 'Col',
+            'type'         => 'split',
+            'delimiter'    => ';',
+            'part'         => 5,
+        ], ['Col' => 'A;B']);
+        $this->assertSame('A;B', $result['Col']);
+    }
+
+    // -------------------------------------------------------------------------
+    // regexextract
+    // -------------------------------------------------------------------------
+
+    public function testRegexExtract(): void
+    {
+        $result = $this->applyOne([
+            'sourceColumn' => 'Col',
+            'outputColumn' => 'Zip',
+            'type'         => 'regexextract',
+            'pattern'      => '(\d{4})',
+        ], ['Col' => 'Shop 7007 Chur', 'Zip' => '']);
+        $this->assertSame('7007', $result['Zip']);
+    }
+
+    public function testRegexExtractNoMatchReturnsEmpty(): void
+    {
+        $result = $this->applyOne([
+            'sourceColumn' => 'Col',
+            'outputColumn' => 'Zip',
+            'type'         => 'regexextract',
+            'pattern'      => '(\d{4})',
+        ], ['Col' => 'No digits here', 'Zip' => '']);
+        $this->assertSame('', $result['Zip']);
+    }
+
+    public function testRegexExtractEmptyValueReturnsEmpty(): void
+    {
+        $result = $this->applyOne([
+            'sourceColumn' => 'Col',
+            'outputColumn' => 'Zip',
+            'type'         => 'regexextract',
+            'pattern'      => '(\d{4})',
+        ], ['Col' => '', 'Zip' => '']);
+        $this->assertSame('', $result['Zip']);
+    }
+
+    // -------------------------------------------------------------------------
+    // trim
+    // -------------------------------------------------------------------------
+
+    public function testTrim(): void
+    {
+        $result = $this->applyOne(
+            ['sourceColumn' => 'Col', 'outputColumn' => 'Col', 'type' => 'trim'],
+            ['Col' => '  hello world  ']
+        );
+        $this->assertSame('hello world', $result['Col']);
+    }
+
+    // -------------------------------------------------------------------------
+    // uppercase
+    // -------------------------------------------------------------------------
+
+    public function testUppercase(): void
+    {
+        $result = $this->applyOne(
+            ['sourceColumn' => 'Col', 'outputColumn' => 'Col', 'type' => 'uppercase'],
+            ['Col' => 'Hello World']
+        );
+        $this->assertSame('HELLO WORLD', $result['Col']);
+    }
+
+    public function testUppercaseUnicode(): void
+    {
+        $result = $this->applyOne(
+            ['sourceColumn' => 'Col', 'outputColumn' => 'Col', 'type' => 'uppercase'],
+            ['Col' => 'zürich']
+        );
+        $this->assertSame('ZÜRICH', $result['Col']);
+    }
+
+    // -------------------------------------------------------------------------
+    // lowercase
+    // -------------------------------------------------------------------------
+
+    public function testLowercase(): void
+    {
+        $result = $this->applyOne(
+            ['sourceColumn' => 'Col', 'outputColumn' => 'Col', 'type' => 'lowercase'],
+            ['Col' => 'Hello World']
+        );
+        $this->assertSame('hello world', $result['Col']);
+    }
+
+    // -------------------------------------------------------------------------
+    // ucwordsfirst
+    // -------------------------------------------------------------------------
+
+    public function testUcwordsFirst(): void
+    {
+        $result = $this->applyOne(
+            ['sourceColumn' => 'Col', 'outputColumn' => 'Col', 'type' => 'ucwordsfirst'],
+            ['Col' => 'COOP PRONTO CHUR']
+        );
+        $this->assertSame('Coop Pronto Chur', $result['Col']);
+    }
+
+    public function testUcwordsFirstHyphen(): void
+    {
+        $result = $this->applyOne(
+            ['sourceColumn' => 'Col', 'outputColumn' => 'Col', 'type' => 'ucwordsfirst'],
+            ['Col' => 'SAINT-JEAN-DE-MAURIENNE']
+        );
+        $this->assertSame('Saint-Jean-De-Maurienne', $result['Col']);
+    }
+
+    public function testUcwordsFirstApostrophe(): void
+    {
+        $result = $this->applyOne(
+            ['sourceColumn' => 'Col', 'outputColumn' => 'Col', 'type' => 'ucwordsfirst'],
+            ['Col' => "O'NEILL STORE"]
+        );
+        $this->assertSame("O'Neill Store", $result['Col']);
+    }
+
+    // -------------------------------------------------------------------------
+    // truncate
+    // -------------------------------------------------------------------------
+
+    public function testTruncate(): void
+    {
+        $result = $this->applyOne([
+            'sourceColumn' => 'Col',
+            'outputColumn' => 'Col',
+            'type'         => 'truncate',
+            'maxLength'    => 5,
+        ], ['Col' => 'Hello World']);
+        $this->assertSame('Hello', $result['Col']);
+    }
+
+    public function testTruncateShorterThanMaxIsUnchanged(): void
+    {
+        $result = $this->applyOne([
+            'sourceColumn' => 'Col',
+            'outputColumn' => 'Col',
+            'type'         => 'truncate',
+            'maxLength'    => 100,
+        ], ['Col' => 'Short']);
+        $this->assertSame('Short', $result['Col']);
+    }
+
+    public function testTruncateUnicode(): void
+    {
+        // 'ü' counts as 1 Unicode character, so maxLength=3 gives 3 chars: Z, ü, r
+        $result = $this->applyOne([
+            'sourceColumn' => 'Col',
+            'outputColumn' => 'Col',
+            'type'         => 'truncate',
+            'maxLength'    => 3,
+        ], ['Col' => 'Zürich']);
+        $this->assertSame('Zür', $result['Col']);
+    }
+
+    // -------------------------------------------------------------------------
+    // constantvalue
+    // -------------------------------------------------------------------------
+
+    public function testConstantValue(): void
+    {
+        $transformer = new ColumnTransformer([[
+            'sourceColumn' => '_constant_',
+            'outputColumn' => 'Currency',
+            'type'         => 'constantvalue',
+            'metadataKey'  => 'currency_code',
+        ]], ['currency_code' => 'CHF']);
+        $result = $transformer->transformRow(['Currency' => '']);
+        $this->assertSame('CHF', $result['Currency']);
+    }
+
+    public function testConstantValueMissingKeyReturnsEmpty(): void
+    {
+        $transformer = new ColumnTransformer([[
+            'sourceColumn' => '_constant_',
+            'outputColumn' => 'Currency',
+            'type'         => 'constantvalue',
+            'metadataKey'  => 'nonexistent',
+        ]], []);
+        $result = $transformer->transformRow(['Currency' => '']);
+        $this->assertSame('', $result['Currency']);
+    }
+
+    // -------------------------------------------------------------------------
+    // pipeline
+    // -------------------------------------------------------------------------
+
+    public function testPipeline(): void
+    {
+        $result = $this->applyOne([
+            'sourceColumn' => 'Col',
+            'outputColumn' => 'Col',
+            'type'         => 'pipeline',
+            'steps'        => [
+                ['type' => 'trim'],
+                ['type' => 'lowercase'],
+                ['type' => 'ucwordsfirst'],
+            ],
+        ], ['Col' => '  COOP PRONTO  ']);
+        $this->assertSame('Coop Pronto', $result['Col']);
+    }
+
+    public function testPipelineEmptyStepsReturnsOriginal(): void
+    {
+        $result = $this->applyOne([
+            'sourceColumn' => 'Col',
+            'outputColumn' => 'Col',
+            'type'         => 'pipeline',
+            'steps'        => [],
+        ], ['Col' => 'hello']);
+        $this->assertSame('hello', $result['Col']);
+    }
+
+    // -------------------------------------------------------------------------
+    // Inline transformations[] array (flat pipeline per column entry)
+    // -------------------------------------------------------------------------
+
+    public function testInlineTransformationsArray(): void
+    {
+        $result = $this->applyOne([
+            'sourceColumn'    => 'Col',
+            'outputColumn'    => 'Col',
+            'type'            => 'map',
+            'transformations' => [
+                ['type' => 'trim'],
+                ['type' => 'uppercase'],
+            ],
+        ], ['Col' => '  hello  ']);
+        $this->assertSame('HELLO', $result['Col']);
+    }
+
+    // -------------------------------------------------------------------------
+    // normalizeTransformType: snake_case and kebab-case aliases
+    // -------------------------------------------------------------------------
+
+    public function testNormalizeTypeSnakeCase(): void
+    {
+        $result = $this->applyOne([
+            'sourceColumn' => 'Date',
+            'outputColumn' => 'Date',
+            'type'         => 'date_format',
+            'fromFormat'   => 'd.m.Y',
+            'toFormat'     => 'Y-m-d',
+        ], ['Date' => '15.03.2024']);
+        $this->assertSame('2024-03-15', $result['Date']);
+    }
+
+    public function testNormalizeTypeKebabCase(): void
+    {
+        $result = $this->applyOne([
+            'sourceColumn' => 'Col',
+            'outputColumn' => 'Col',
+            'type'         => 'ucwords-first',
+        ], ['Col' => 'HELLO WORLD']);
+        $this->assertSame('Hello World', $result['Col']);
+    }
+
+    // -------------------------------------------------------------------------
+    // outputAction
+    // -------------------------------------------------------------------------
+
+    public function testOutputActionOverwrite(): void
+    {
+        $result = $this->applyOne([
+            'sourceColumn' => 'A',
+            'outputColumn' => 'B',
+            'type'         => 'map',
+            'outputAction' => 'overwrite',
+        ], ['A' => 'new', 'B' => 'old']);
+        $this->assertSame('new', $result['B']);
+    }
+
+    public function testOutputActionCreate(): void
+    {
+        $result = $this->applyOne([
+            'sourceColumn' => 'A',
+            'outputColumn' => 'NewCol',
+            'type'         => 'map',
+            'outputAction' => 'create',
+        ], ['A' => 'hello']);
+        $this->assertSame('hello', $result['NewCol']);
+    }
+
+    public function testOutputActionAppend(): void
+    {
+        $result = $this->applyOne([
+            'sourceColumn' => 'A',
+            'outputColumn' => 'B',
+            'type'         => 'map',
+            'outputAction' => 'append',
+        ], ['A' => ' World', 'B' => 'Hello']);
+        $this->assertSame('Hello World', $result['B']);
+    }
+
+    // -------------------------------------------------------------------------
+    // multi-output split
+    // -------------------------------------------------------------------------
+
+    public function testMultiOutputSplit(): void
+    {
+        $transformer = new ColumnTransformer([[
+            'outputs'      => ['FirstName', 'LastName'],
+            'sourceColumn' => 'FullName',
+            'type'         => 'split',
+            'delimiter'    => ' ',
+        ]]);
+        $result = $transformer->transformRow(['FullName' => 'John Doe']);
+        $this->assertSame('John', $result['FirstName']);
+        $this->assertSame('Doe', $result['LastName']);
+    }
+
+    public function testMultiOutputSplitFewerPartsYieldsEmptyString(): void
+    {
+        $transformer = new ColumnTransformer([[
+            'outputs'      => ['Col1', 'Col2', 'Col3'],
+            'sourceColumn' => 'Source',
+            'type'         => 'split',
+            'delimiter'    => ';',
+        ]]);
+        $result = $transformer->transformRow(['Source' => 'A;B']);
+        $this->assertSame('A', $result['Col1']);
+        $this->assertSame('B', $result['Col2']);
+        $this->assertSame('', $result['Col3']);
+    }
+
+    // -------------------------------------------------------------------------
+    // Error cases
+    // -------------------------------------------------------------------------
+
+    public function testMissingOutputColumnThrows(): void
+    {
+        $this->expectException(\RuntimeException::class);
+        $transformer = new ColumnTransformer([
+            ['sourceColumn' => 'A', 'type' => 'map'],
+        ]);
+        $transformer->transformRow(['A' => 'x']);
+    }
+
+    public function testMultiOutputNonSplitTypeThrows(): void
+    {
+        $this->expectException(\RuntimeException::class);
+        $transformer = new ColumnTransformer([[
+            'outputs'      => ['Col1', 'Col2'],
+            'sourceColumn' => 'Source',
+            'type'         => 'uppercase',
+        ]]);
+        $transformer->transformRow(['Source' => 'hello']);
+    }
+
+    // -------------------------------------------------------------------------
+    // getOutputColumns
+    // -------------------------------------------------------------------------
+
+    public function testGetOutputColumnsCountsUniqueColumns(): void
+    {
+        $transformer = new ColumnTransformer([
+            ['sourceColumn' => 'A', 'outputColumn' => 'X', 'type' => 'map'],
+            ['sourceColumn' => 'B', 'outputColumn' => 'Y', 'type' => 'map'],
+            ['sourceColumn' => 'C', 'outputColumn' => 'X', 'type' => 'map'], // duplicate output
+        ]);
+        $transformer->transformRow(['A' => '1', 'B' => '2', 'C' => '3']);
+        $this->assertSame(2, $transformer->getOutputColumns());
+    }
+}
diff --git a/tests/ConfigIntegrationTest.php b/tests/ConfigIntegrationTest.php
new file mode 100644
index 0000000..6af6a2e
--- /dev/null
+++ b/tests/ConfigIntegrationTest.php
@@ -0,0 +1,130 @@
+<?php
+
+namespace UbsCsvTransformer\Tests;
+
+use PHPUnit\Framework\TestCase;
+use UbsCsvTransformer\ConfigurationLoader;
+use UbsCsvTransformer\TransformerEngine;
+
+/**
+ * Integrations-Tests für Konfigurationsdateien
+ *
+ * Prüft, dass jede Konfigurationsdatei mit ihrem Fixture-Input
+ * die erwartete CSV-Ausgabe produziert (Golden-File-Test).
+ *
+ * Fixtures liegen unter tests/fixtures/<config-name>/:
+ *   - input.csv    → minimaler CSV-Input passend zur Konfiguration
+ *   - expected.csv → erwartete Ausgabe nach Transformation
+ *
+ * Neue Fixtures hinzufügen:
+ *   1. Verzeichnis tests/fixtures/<config-name>/ anlegen
+ *   2. input.csv und expected.csv ablegen
+ *   3. sicherstellen dass config/<config-name>.json existiert
+ */
+class ConfigIntegrationTest extends TestCase
+{
+    /** @var string Temporäres Output-Verzeichnis für diesen Test-Lauf */
+    private string $tempOutputDir = '';
+
+    /** @var string Temporäre Konfigurationsdatei mit überschriebenem Output-Pfad */
+    private string $tempConfigFile = '';
+
+    protected function setUp(): void
+    {
+        $this->tempOutputDir = sys_get_temp_dir() . '/ubscsv_test_' . uniqid('', true);
+        mkdir($this->tempOutputDir, 0755, true);
+    }
+
+    protected function tearDown(): void
+    {
+        if ($this->tempOutputDir !== '' && is_dir($this->tempOutputDir)) {
+            foreach (glob($this->tempOutputDir . '/*') ?: [] as $file) {
+                unlink($file);
+            }
+            rmdir($this->tempOutputDir);
+        }
+
+        if ($this->tempConfigFile !== '' && file_exists($this->tempConfigFile)) {
+            unlink($this->tempConfigFile);
+        }
+    }
+
+    /**
+     * Liefert alle Fixture-Paare als DataProvider
+     *
+     * Entdeckt automatisch alle Unterverzeichnisse in tests/fixtures/
+     * und erwartet für jedes eine passende config/<name>.json.
+     *
+     * @return array<string, array{configName: string, fixtureDir: string}>
+     */
+    public static function fixtureProvider(): array
+    {
+        $fixtureBase = __DIR__ . '/fixtures';
+        $dirs = glob($fixtureBase . '/*', GLOB_ONLYDIR);
+        $cases = [];
+
+        foreach ($dirs ?: [] as $dir) {
+            $configName = basename($dir);
+            $cases[$configName] = [
+                'configName' => $configName,
+                'fixtureDir' => $dir,
+            ];
+        }
+
+        return $cases;
+    }
+
+    /**
+     * Prüft dass eine Konfigurationsdatei mit dem Fixture-Input die erwartete Ausgabe erzeugt
+     *
+     * @dataProvider fixtureProvider
+     */
+    public function testConfigProducesExpectedOutput(string $configName, string $fixtureDir): void
+    {
+        $realConfigPath = __DIR__ . '/../config/' . $configName . '.json';
+        $inputFile = $fixtureDir . '/input.csv';
+        $expectedFile = $fixtureDir . '/expected.csv';
+
+        $this->assertFileExists($realConfigPath, "Config-Datei nicht gefunden: {$realConfigPath}");
+        $this->assertFileExists($inputFile, "Fixture input.csv fehlt: {$inputFile}");
+        $this->assertFileExists($expectedFile, "Fixture expected.csv fehlt: {$expectedFile}");
+
+        // Temporäre Konfiguration mit überschriebenem Output-Verzeichnis erstellen
+        $rawConfig = file_get_contents($realConfigPath);
+        $this->assertNotFalse($rawConfig, "Konfigurationsdatei konnte nicht gelesen werden");
+
+        /** @var array<string, mixed> $configData */
+        $configData = json_decode((string) $rawConfig, true);
+        $this->assertIsArray($configData, "Ungültiges JSON in Konfigurationsdatei");
+
+        $configData['directories']['output'] = $this->tempOutputDir;
+
+        $this->tempConfigFile = sys_get_temp_dir() . '/ubscsv_config_' . uniqid('', true) . '.json';
+        file_put_contents($this->tempConfigFile, json_encode($configData, JSON_UNESCAPED_UNICODE));
+
+        // Transformation ausführen
+        $loader = new ConfigurationLoader($this->tempConfigFile);
+        $loader->load();
+        $engine = new TransformerEngine($loader);
+        $result = $engine->transform($inputFile);
+
+        $this->assertTrue(
+            $result['success'],
+            "Transformation fehlgeschlagen: " . ($result['error'] ?? 'unbekannter Fehler')
+        );
+
+        $outputFile = $result['outputFile'];
+        $this->assertFileExists($outputFile, "Output-Datei wurde nicht erstellt: {$outputFile}");
+
+        $actual = rtrim((string) file_get_contents($outputFile));
+        $expected = rtrim((string) file_get_contents($expectedFile));
+
+        $this->assertSame(
+            $expected,
+            $actual,
+            "CSV-Output stimmt nicht mit expected.csv überein.\n" .
+            "Zum Aktualisieren: php bin/transformer.php transform {$inputFile} {$realConfigPath} " .
+            "(Output nach {$expectedFile} kopieren)"
+        );
+    }
+}
diff --git a/tests/ConfigurationLoaderTest.php b/tests/ConfigurationLoaderTest.php
new file mode 100644
index 0000000..a249ac0
--- /dev/null
+++ b/tests/ConfigurationLoaderTest.php
@@ -0,0 +1,255 @@
+<?php
+
+namespace UbsCsvTransformer\Tests;
+
+use PHPUnit\Framework\TestCase;
+use UbsCsvTransformer\ConfigurationLoader;
+
+class ConfigurationLoaderTest extends TestCase
+{
+    private string $tempFile = '';
+
+    protected function setUp(): void
+    {
+        // uniqid gives a unique name; .json extension satisfies the loader's check
+        $this->tempFile = sys_get_temp_dir() . '/cfgloader_test_' . uniqid() . '.json';
+    }
+
+    protected function tearDown(): void
+    {
+        if (file_exists($this->tempFile)) {
+            unlink($this->tempFile);
+        }
+    }
+
+    private function writeJson(array $data): void
+    {
+        file_put_contents($this->tempFile, json_encode($data));
+    }
+
+    /**
+     * Minimal valid configuration that passes all validation checks.
+     */
+    private function validConfig(): array
+    {
+        return [
+            'metadata' => [
+                'extractionRules' => [
+                    ['name' => 'account_iban', 'lineNumber' => 1, 'regex' => '(.+)'],
+                ],
+            ],
+            'csvStructure' => [
+                'headerLine' => 1,
+                'inputDelimiter'  => ';',
+                'encoding'   => 'UTF-8',
+            ],
+            'columnTransformations' => [
+                ['sourceColumn' => 'A', 'outputColumn' => 'B', 'type' => 'map'],
+            ],
+        ];
+    }
+
+    // -------------------------------------------------------------------------
+    // Happy path
+    // -------------------------------------------------------------------------
+
+    public function testLoadValidConfigReturnsArray(): void
+    {
+        $this->writeJson($this->validConfig());
+        $loader = new ConfigurationLoader($this->tempFile);
+        $config = $loader->load();
+        $this->assertIsArray($config);
+        $this->assertArrayHasKey('metadata', $config);
+        $this->assertArrayHasKey('csvStructure', $config);
+        $this->assertArrayHasKey('columnTransformations', $config);
+    }
+
+    public function testGetAllReturnsFullConfig(): void
+    {
+        $this->writeJson($this->validConfig());
+        $loader = new ConfigurationLoader($this->tempFile);
+        $loader->load();
+        $all = $loader->getAll();
+        $this->assertSame(1, $all['csvStructure']['headerLine']);
+    }
+
+    // -------------------------------------------------------------------------
+    // get() dot-notation accessor
+    // -------------------------------------------------------------------------
+
+    public function testGetDotNotationReturnsValue(): void
+    {
+        $this->writeJson($this->validConfig());
+        $loader = new ConfigurationLoader($this->tempFile);
+        $loader->load();
+        $this->assertSame(1, $loader->get('csvStructure.headerLine'));
+        $this->assertSame(';', $loader->get('csvStructure.inputDelimiter'));
+    }
+
+    public function testGetNonExistentKeyReturnsNull(): void
+    {
+        $this->writeJson($this->validConfig());
+        $loader = new ConfigurationLoader($this->tempFile);
+        $loader->load();
+        $this->assertNull($loader->get('nonexistent.key'));
+    }
+
+    public function testGetNonExistentKeyReturnsDefault(): void
+    {
+        $this->writeJson($this->validConfig());
+        $loader = new ConfigurationLoader($this->tempFile);
+        $loader->load();
+        $this->assertSame('fallback', $loader->get('nonexistent', 'fallback'));
+    }
+
+    // -------------------------------------------------------------------------
+    // File not found / bad extension
+    // -------------------------------------------------------------------------
+
+    public function testFileNotFoundThrows(): void
+    {
+        $this->expectException(\RuntimeException::class);
+        $loader = new ConfigurationLoader('/nonexistent/path/config.json');
+        $loader->load();
+    }
+
+    public function testNonJsonExtensionThrows(): void
+    {
+        $yamlPath = sys_get_temp_dir() . '/test_config_' . uniqid() . '.yaml';
+        file_put_contents($yamlPath, 'key: value');
+        try {
+            $loader = new ConfigurationLoader($yamlPath);
+            $this->expectException(\RuntimeException::class);
+            $loader->load();
+        } finally {
+            if (file_exists($yamlPath)) {
+                unlink($yamlPath);
+            }
+        }
+    }
+
+    public function testInvalidJsonThrows(): void
+    {
+        file_put_contents($this->tempFile, '{invalid json content}');
+        $this->expectException(\RuntimeException::class);
+        (new ConfigurationLoader($this->tempFile))->load();
+    }
+
+    // -------------------------------------------------------------------------
+    // Required top-level sections
+    // -------------------------------------------------------------------------
+
+    public function testMissingMetadataSectionThrows(): void
+    {
+        $config = $this->validConfig();
+        unset($config['metadata']);
+        $this->writeJson($config);
+        $this->expectException(\RuntimeException::class);
+        (new ConfigurationLoader($this->tempFile))->load();
+    }
+
+    public function testMissingExtractionRulesThrows(): void
+    {
+        $config = $this->validConfig();
+        unset($config['metadata']['extractionRules']);
+        $this->writeJson($config);
+        $this->expectException(\RuntimeException::class);
+        (new ConfigurationLoader($this->tempFile))->load();
+    }
+
+    public function testMissingCsvStructureSectionThrows(): void
+    {
+        $config = $this->validConfig();
+        unset($config['csvStructure']);
+        $this->writeJson($config);
+        $this->expectException(\RuntimeException::class);
+        (new ConfigurationLoader($this->tempFile))->load();
+    }
+
+    public function testMissingHeaderLineThrows(): void
+    {
+        $config = $this->validConfig();
+        unset($config['csvStructure']['headerLine']);
+        $this->writeJson($config);
+        $this->expectException(\RuntimeException::class);
+        (new ConfigurationLoader($this->tempFile))->load();
+    }
+
+    public function testMissingColumnTransformationsThrows(): void
+    {
+        $config = $this->validConfig();
+        unset($config['columnTransformations']);
+        $this->writeJson($config);
+        $this->expectException(\RuntimeException::class);
+        (new ConfigurationLoader($this->tempFile))->load();
+    }
+
+    // -------------------------------------------------------------------------
+    // csvStructure value validation
+    // -------------------------------------------------------------------------
+
+    public function testInvalidEncodingThrows(): void
+    {
+        $config = $this->validConfig();
+        $config['csvStructure']['encoding'] = 'LATIN1';
+        $this->writeJson($config);
+        $this->expectException(\Exception::class);
+        (new ConfigurationLoader($this->tempFile))->load();
+    }
+
+    public function testSupportedEncodingsPass(): void
+    {
+        foreach (['UTF-8', 'ISO-8859-1', 'CP1252'] as $encoding) {
+            $config = $this->validConfig();
+            $config['csvStructure']['encoding'] = $encoding;
+            $this->writeJson($config);
+            $loader = new ConfigurationLoader($this->tempFile);
+            $result = $loader->load();
+            $this->assertSame($encoding, $result['csvStructure']['encoding']);
+        }
+    }
+
+    // -------------------------------------------------------------------------
+    // directories validation
+    // -------------------------------------------------------------------------
+
+    public function testDirectoriesAllKeysPass(): void
+    {
+        $config = $this->validConfig();
+        $config['directories'] = [
+            'source'  => '/tmp/source',
+            'output'  => '/tmp/output',
+            'archive' => '/tmp/archive',
+            'error'   => '/tmp/error',
+        ];
+        $this->writeJson($config);
+        $result = (new ConfigurationLoader($this->tempFile))->load();
+        $this->assertArrayHasKey('directories', $result);
+    }
+
+    public function testDirectoriesMissingSubkeyThrows(): void
+    {
+        $config = $this->validConfig();
+        $config['directories'] = [
+            'source' => '/tmp/source',
+            'output' => '/tmp/output',
+            // 'archive' and 'error' intentionally missing
+        ];
+        $this->writeJson($config);
+        $this->expectException(\RuntimeException::class);
+        (new ConfigurationLoader($this->tempFile))->load();
+    }
+
+    // -------------------------------------------------------------------------
+    // Absent optional 'directories' key does not trigger validation
+    // -------------------------------------------------------------------------
+
+    public function testAbsentDirectoriesKeyDoesNotThrow(): void
+    {
+        $config = $this->validConfig();
+        $this->assertArrayNotHasKey('directories', $config);
+        $this->writeJson($config);
+        $result = (new ConfigurationLoader($this->tempFile))->load();
+        $this->assertArrayNotHasKey('directories', $result);
+    }
+}
diff --git a/tests/CsvReaderTest.php b/tests/CsvReaderTest.php
new file mode 100644
index 0000000..4c61e3d
--- /dev/null
+++ b/tests/CsvReaderTest.php
@@ -0,0 +1,199 @@
+<?php
+
+namespace UbsCsvTransformer\Tests;
+
+use PHPUnit\Framework\TestCase;
+use UbsCsvTransformer\CsvReader;
+
+class CsvReaderTest extends TestCase
+{
+    private string $tempFile = '';
+
+    protected function setUp(): void
+    {
+        $this->tempFile = tempnam(sys_get_temp_dir(), 'csvreader_test_');
+    }
+
+    protected function tearDown(): void
+    {
+        if (file_exists($this->tempFile)) {
+            unlink($this->tempFile);
+        }
+    }
+
+    private function write(string $content): void
+    {
+        file_put_contents($this->tempFile, $content);
+    }
+
+    private function reader(int $headerLine = 1, string $delimiter = ';', bool $hasBom = false): CsvReader
+    {
+        return new CsvReader(
+            $this->tempFile,
+            ['inputDelimiter' => $delimiter, 'headerLine' => $headerLine, 'hasBom' => $hasBom]
+        );
+    }
+
+    // -------------------------------------------------------------------------
+    // readCsvData – basic parsing
+    // -------------------------------------------------------------------------
+
+    public function testReadCsvDataSimple(): void
+    {
+        $this->write("Name;Age\nAlice;30\nBob;25\n");
+        $data = $this->reader()->readCsvData();
+        $this->assertCount(2, $data);
+        $this->assertSame('Alice', $data[0]['Name']);
+        $this->assertSame('30', $data[0]['Age']);
+        $this->assertSame('Bob', $data[1]['Name']);
+    }
+
+    public function testReadCsvDataTrimsWhitespace(): void
+    {
+        $this->write("Name ; Age\n Alice ; 30 \n");
+        $data = $this->reader()->readCsvData();
+        $this->assertSame('Alice', $data[0]['Name']);
+        $this->assertSame('30', $data[0]['Age']);
+    }
+
+    // -------------------------------------------------------------------------
+    // headerLine offset
+    // -------------------------------------------------------------------------
+
+    public function testHeaderLineOffset(): void
+    {
+        // Lines 1+2 are metadata, header is line 3
+        $this->write("Meta1\nMeta2\nColA;ColB\nval1;val2\n");
+        $data = $this->reader(3)->readCsvData();
+        $this->assertCount(1, $data);
+        $this->assertSame('val1', $data[0]['ColA']);
+        $this->assertSame('val2', $data[0]['ColB']);
+    }
+
+    // -------------------------------------------------------------------------
+    // readMetadataLines
+    // -------------------------------------------------------------------------
+
+    public function testReadMetadataLines(): void
+    {
+        $this->write("Line1\nLine2\nHeader;Col\nData;Row\n");
+        $meta = $this->reader(3)->readMetadataLines();
+        $this->assertCount(2, $meta);
+        $this->assertSame('Line1', $meta[0]);
+        $this->assertSame('Line2', $meta[1]);
+    }
+
+    public function testReadMetadataLinesHeaderOnLine1IsEmpty(): void
+    {
+        $this->write("Name;Age\nAlice;30\n");
+        $meta = $this->reader(1)->readMetadataLines();
+        $this->assertSame([], $meta);
+    }
+
+    public function testReadMetadataLinesHeaderOnLine2ReturnsOneLine(): void
+    {
+        $this->write("MetaInfo\nName;Age\nAlice;30\n");
+        $meta = $this->reader(2)->readMetadataLines();
+        $this->assertCount(1, $meta);
+        $this->assertSame('MetaInfo', $meta[0]);
+    }
+
+    // -------------------------------------------------------------------------
+    // maxDataRows limit
+    // -------------------------------------------------------------------------
+
+    public function testMaxDataRowsLimit(): void
+    {
+        $this->write("Name;Age\nAlice;30\nBob;25\nCarol;20\n");
+        $data = $this->reader()->readCsvData(2);
+        $this->assertCount(2, $data);
+        $this->assertSame('Alice', $data[0]['Name']);
+        $this->assertSame('Bob', $data[1]['Name']);
+    }
+
+    public function testMaxDataRowsZeroMeansAll(): void
+    {
+        $this->write("Name;Age\nAlice;30\nBob;25\nCarol;20\n");
+        $data = $this->reader()->readCsvData(0);
+        $this->assertCount(3, $data);
+    }
+
+    // -------------------------------------------------------------------------
+    // Empty line skipping
+    // -------------------------------------------------------------------------
+
+    public function testEmptyLinesAreSkipped(): void
+    {
+        $this->write("Name;Age\nAlice;30\n\nBob;25\n\n");
+        $data = $this->reader()->readCsvData();
+        $this->assertCount(2, $data);
+    }
+
+    // -------------------------------------------------------------------------
+    // BOM removal
+    // -------------------------------------------------------------------------
+
+    public function testBomIsRemovedFromFirstColumnName(): void
+    {
+        // UTF-8 BOM followed immediately by the header
+        $this->write("\xEF\xBB\xBFName;Age\nAlice;30\n");
+        $data = $this->reader(1, ';', true)->readCsvData();
+        $this->assertCount(1, $data);
+        // The column must be 'Name', not the BOM-prefixed version
+        $this->assertArrayHasKey('Name', $data[0]);
+        $this->assertSame('Alice', $data[0]['Name']);
+    }
+
+    public function testNoBomFlagLeavesHeaderIntact(): void
+    {
+        // If hasBom is false, BOM bytes stay and the key will be mangled — we only
+        // assert that the clean path (hasBom=true) works, tested above.
+        // Here we just verify normal CSV without BOM also works when hasBom=false.
+        $this->write("Name;Age\nAlice;30\n");
+        $data = $this->reader(1, ';', false)->readCsvData();
+        $this->assertArrayHasKey('Name', $data[0]);
+    }
+
+    // -------------------------------------------------------------------------
+    // getHeaders
+    // -------------------------------------------------------------------------
+
+    public function testGetHeaders(): void
+    {
+        $this->write("Col1;Col2;Col3\nA;B;C\n");
+        $headers = $this->reader()->getHeaders();
+        $this->assertSame(['Col1', 'Col2', 'Col3'], $headers);
+    }
+
+    // -------------------------------------------------------------------------
+    // Row with fewer columns than headers
+    // -------------------------------------------------------------------------
+
+    public function testShortRowPaddedWithEmpty(): void
+    {
+        $this->write("A;B;C\n1;2\n");
+        $data = $this->reader()->readCsvData();
+        $this->assertCount(1, $data);
+        $this->assertSame('1', $data[0]['A']);
+        $this->assertSame('2', $data[0]['B']);
+        $this->assertSame('', $data[0]['C']);
+    }
+
+    // -------------------------------------------------------------------------
+    // Error cases
+    // -------------------------------------------------------------------------
+
+    public function testFileNotFoundThrowsRuntimeException(): void
+    {
+        $this->expectException(\RuntimeException::class);
+        $reader = new CsvReader('/nonexistent/path/file.csv', ['inputDelimiter' => ';', 'headerLine' => 1]);
+        $reader->readLines();
+    }
+
+    public function testHeaderLineBeyondFileLengthThrows(): void
+    {
+        $this->write("Name;Age\nAlice;30\n");
+        $this->expectException(\RuntimeException::class);
+        $this->reader(99)->readCsvData();
+    }
+}
diff --git a/tests/MetadataExtractorTest.php b/tests/MetadataExtractorTest.php
new file mode 100644
index 0000000..c3514f7
--- /dev/null
+++ b/tests/MetadataExtractorTest.php
@@ -0,0 +1,204 @@
+<?php
+
+namespace UbsCsvTransformer\Tests;
+
+use PHPUnit\Framework\TestCase;
+use UbsCsvTransformer\DebugLogger;
+use UbsCsvTransformer\MetadataExtractor;
+
+class MetadataExtractorTest extends TestCase
+{
+    protected function setUp(): void
+    {
+        DebugLogger::reset();
+    }
+
+    // -------------------------------------------------------------------------
+    // Happy path
+    // -------------------------------------------------------------------------
+
+    public function testExtractBasicCapture(): void
+    {
+        $extractor = new MetadataExtractor([[
+            'name'         => 'account_iban',
+            'lineNumber'   => 1,
+            'regex'        => '([A-Z]{2}\d{2}[\w]+)',
+            'captureGroup' => 1,
+        ]]);
+        $result = $extractor->extract(['Account: CH9300762011623852957']);
+        $this->assertSame('CH9300762011623852957', $result['account_iban']);
+    }
+
+    public function testExtractFromSecondLine(): void
+    {
+        $extractor = new MetadataExtractor([[
+            'name'         => 'currency',
+            'lineNumber'   => 2,
+            'regex'        => '(CHF|EUR|USD)',
+            'captureGroup' => 1,
+        ]]);
+        $lines = ['Account info', 'Currency: CHF'];
+        $result = $extractor->extract($lines);
+        $this->assertSame('CHF', $result['currency']);
+    }
+
+    public function testExtractCaptureGroup0ReturnsFullMatch(): void
+    {
+        $extractor = new MetadataExtractor([[
+            'name'         => 'label',
+            'lineNumber'   => 1,
+            'regex'        => 'CHF',
+            'captureGroup' => 0,
+        ]]);
+        $result = $extractor->extract(['Balance: CHF 1000']);
+        $this->assertSame('CHF', $result['label']);
+    }
+
+    public function testExtractMultipleRules(): void
+    {
+        $extractor = new MetadataExtractor([
+            [
+                'name'         => 'iban',
+                'lineNumber'   => 1,
+                'regex'        => '([A-Z]{2}\d{2}\w+)',
+                'captureGroup' => 1,
+            ],
+            [
+                'name'         => 'currency',
+                'lineNumber'   => 2,
+                'regex'        => '(CHF|EUR)',
+                'captureGroup' => 1,
+            ],
+        ]);
+        $result = $extractor->extract(['IBAN: CH9300762011623852957', 'Currency: CHF']);
+        $this->assertSame('CH9300762011623852957', $result['iban']);
+        $this->assertSame('CHF', $result['currency']);
+    }
+
+    // -------------------------------------------------------------------------
+    // Line not available
+    // -------------------------------------------------------------------------
+
+    public function testExtractMissingLineIsSkipped(): void
+    {
+        $extractor = new MetadataExtractor([[
+            'name'         => 'account_iban',
+            'lineNumber'   => 5,
+            'regex'        => '(CH\d+)',
+            'captureGroup' => 1,
+        ]]);
+        $result = $extractor->extract(['Only one line']);
+        $this->assertArrayNotHasKey('account_iban', $result);
+    }
+
+    // -------------------------------------------------------------------------
+    // Invalid regex
+    // -------------------------------------------------------------------------
+
+    public function testExtractInvalidRegexDoesNotCrash(): void
+    {
+        $extractor = new MetadataExtractor([[
+            'name'         => 'bad_rule',
+            'lineNumber'   => 1,
+            'regex'        => '[invalid(regex',
+            'captureGroup' => 1,
+        ]]);
+        $result = $extractor->extract(['some line content']);
+        $this->assertArrayNotHasKey('bad_rule', $result);
+    }
+
+    // -------------------------------------------------------------------------
+    // No match
+    // -------------------------------------------------------------------------
+
+    public function testExtractNoMatchIsSkipped(): void
+    {
+        $extractor = new MetadataExtractor([[
+            'name'         => 'account_iban',
+            'lineNumber'   => 1,
+            'regex'        => '(NOMATCH_\d+)',
+            'captureGroup' => 1,
+        ]]);
+        $result = $extractor->extract(['Account: CH9300762011623852957']);
+        $this->assertArrayNotHasKey('account_iban', $result);
+    }
+
+    // -------------------------------------------------------------------------
+    // Edge cases
+    // -------------------------------------------------------------------------
+
+    public function testExtractEmptyRulesReturnsEmptyArray(): void
+    {
+        $extractor = new MetadataExtractor([]);
+        $result = $extractor->extract(['some line']);
+        $this->assertSame([], $result);
+    }
+
+    public function testExtractEmptyLinesArrayReturnsEmpty(): void
+    {
+        $extractor = new MetadataExtractor([[
+            'name'         => 'iban',
+            'lineNumber'   => 1,
+            'regex'        => '(CH\d+)',
+            'captureGroup' => 1,
+        ]]);
+        $result = $extractor->extract([]);
+        $this->assertSame([], $result);
+    }
+
+    public function testRuleWithMissingNameIsSkipped(): void
+    {
+        $extractor = new MetadataExtractor([[
+            'regex'      => '(\d+)',
+            'lineNumber' => 1,
+        ]]);
+        $result = $extractor->extract(['123']);
+        $this->assertSame([], $result);
+    }
+
+    public function testRuleWithMissingRegexIsSkipped(): void
+    {
+        $extractor = new MetadataExtractor([[
+            'name'       => 'test',
+            'lineNumber' => 1,
+        ]]);
+        $result = $extractor->extract(['some line']);
+        $this->assertSame([], $result);
+    }
+
+    // -------------------------------------------------------------------------
+    // getRuleCount
+    // -------------------------------------------------------------------------
+
+    public function testGetRuleCount(): void
+    {
+        $extractor = new MetadataExtractor([
+            ['name' => 'a', 'regex' => 'x', 'lineNumber' => 1],
+            ['name' => 'b', 'regex' => 'y', 'lineNumber' => 2],
+            ['name' => 'c', 'regex' => 'z', 'lineNumber' => 3],
+        ]);
+        $this->assertSame(3, $extractor->getRuleCount());
+    }
+
+    public function testGetRuleCountEmptyIsZero(): void
+    {
+        $this->assertSame(0, (new MetadataExtractor([]))->getRuleCount());
+    }
+
+    // -------------------------------------------------------------------------
+    // Regex containing '#' delimiter character
+    // -------------------------------------------------------------------------
+
+    public function testRegexContainingHashIsHandled(): void
+    {
+        // Pattern contains '#' which is the internal delimiter — must be escaped
+        $extractor = new MetadataExtractor([[
+            'name'         => 'tag',
+            'lineNumber'   => 1,
+            'regex'        => '(#\d+)',
+            'captureGroup' => 1,
+        ]]);
+        $result = $extractor->extract(['Issue #42 resolved']);
+        $this->assertSame('#42', $result['tag']);
+    }
+}
diff --git a/tests/fixtures/config-ubs-account/expected.csv b/tests/fixtures/config-ubs-account/expected.csv
new file mode 100644
index 0000000..f60b568
--- /dev/null
+++ b/tests/fixtures/config-ubs-account/expected.csv
@@ -0,0 +1,17 @@
+Belastung,Gutschrift,date,process_date,opposing_name,tags,description,opposing_account,notes,account_iban,account_currency
+-600.00,,2022-12-30,2022-12-30,"David Peter Reindl",Dauerauftrag,"Steuerrueckstellung
+David Peter Reindl;8906 Bonstetten","CH37 0026 7267 9314 35M2 P","9967864LK2659211
+8906 Bonstetten","CH18 0026 7267 9314 3540 D",CHF
+-46.35,,2022-12-30,2022-12-31,"UBS AG",,"Periode: 2022-10-01 - 2022-12-30
+Zinsabschluss",,9900365AP6356307,"CH18 0026 7267 9314 3540 D",CHF
+-39.90,,2022-12-30,2022-12-30,"Swisscom Grossunternehme",TWINT,"Swisscom Grossunternehme; Zahlung UBS TWINT",,"9967364GK5707142
+8004 Zuerich","CH18 0026 7267 9314 3540 D",CHF
+-8.75,,2022-12-28,2022-12-27,"Coop Pronto Chur",Debitkarte,"18279748-0 08/24
+Coop Pronto Chur;7007 Chur",,"9930862BN7826808
+7007 Chur","CH18 0026 7267 9314 3540 D",CHF
+-1800.00,,2022-12-27,2022-12-27,"Janine Geigele",e-banking,"Skiferien Dolomiten
+Janine Geigele;Am Wasser 36; 8049 Zuerich; CH","CH63 0023 2232 5560 5988 0","9967361TI3188436
+8049 Zuerich","CH18 0026 7267 9314 3540 D",CHF
+,9.00,2022-12-22,2022-12-22,"Friis, Daniela Silvia",TWINT,"Friis, Daniela Silvia",,9930356GK0440989,"CH18 0026 7267 9314 3540 D",CHF
+,19764.80,2022-11-25,2022-11-25,SBB,Gutschrift,"SBB;Corporate Treasury",,9901820E67741531,"CH18 0026 7267 9314 3540 D",CHF
+-14.00,,2022-08-22,2022-08-21,"Friis-Loop, Daniela",TWINT,"Friis-Loop, Daniela; Belastung UBS TWINT",,9967233GK1553933,"CH18 0026 7267 9314 3540 D",CHF
diff --git a/tests/fixtures/config-ubs-account/input.csv b/tests/fixtures/config-ubs-account/input.csv
new file mode 100644
index 0000000..25b7410
--- /dev/null
+++ b/tests/fixtures/config-ubs-account/input.csv
@@ -0,0 +1,18 @@
+Kontonummer:;0267 00931435.40;
+IBAN:;CH18 0026 7267 9314 3540 D;
+Von:;2022-01-03;
+Bis:;2022-12-30;
+Anfangssaldo:;3917.29;
+Schlusssaldo:;-238.80;
+Bewertet in:;CHF;
+Anzahl Transaktionen in diesem Zeitraum:;742;
+
+Abschlussdatum;Abschlusszeit;Buchungsdatum;Valutadatum;Währung;Belastung;Gutschrift;Einzelbetrag;Saldo;Transaktions-Nr.;Beschreibung1;Beschreibung2;Beschreibung3;Fussnoten;
+2022-12-30;;2022-12-30;2022-12-30;CHF;-600.00;;;-238.80;9967864LK2659211;"""David Peter Reindl;8906 Bonstetten""";"""STEUERRUECKSTELLUNG; Dauerauftrag""";"""Konto-Nr. IBAN: CH37 0026 7267 9314 35M2 P; Transaktions-Nr. 9967864LK2659211""";;
+2022-12-30;;2022-12-30;2022-12-31;CHF;-46.35;;;361.20;9900365AP6356307;"Saldo Zinsabschluss";"Periode: 2022-10-01 - 2022-12-30";"Transaktions-Nr. 9900365AP6356307";;
+2022-12-30;;2022-12-30;2022-12-30;CHF;-39.90;;;407.55;9967364GK5707142;"""SWISSCOM GROSSUNTERNEHME; Zahlung UBS TWINT""";;"""Zahlungsgrund: Muellerstrasse 16 na, 8004 Zuerich TWINT-Acc.:+41796305690; Transaktions-Nr. 9967364GK5707142""";;
+2022-12-27;19:57:53;2022-12-28;2022-12-27;CHF;-8.75;;;7592.45;9930862BN7826808;"""Coop Pronto Chur;7007 Chur""";"""18279748-0 08/24; Zahlung Debitkarte""";"Transaktions-Nr. 9930862BN7826808";;
+2022-12-27;;2022-12-27;2022-12-27;CHF;-1800.00;;;7601.20;9967361TI3188436;"""Janine Geigele;Am Wasser 36; 8049 Zuerich; CH""";"""SKIFERIEN DOLOMITEN; e-banking-Vergütungsauftrag""";"""Zahlungsgrund: Wohnung Dolomiten, 2 Personen; Konto-Nr. IBAN: CH63 0023 2232 5560 5988 0; Kosten: E-Banking Inland; Transaktions-Nr. 9967361TI3188436""";;
+2022-12-22;;2022-12-22;2022-12-22;CHF;;9.00;;10436.45;9930356GK0440989;"Friis, Daniela Silvia";"Gutschrift UBS TWINT";"""Zahlungsgrund: +41796741245; TWINT-Acc.:+41796305690; Transaktions-Nr. 9930356GK0440989""";;
+2022-11-25;;2022-11-25;2022-11-25;CHF;;19764.80;;15748.12;9901820E67741531;"""SBB;Corporate Treasury""";"Gutschrift";"""Zahlungsgrund: Lohn/Gehalt 00229537/202211; Transaktions-Nr. 9901820E67741531""";;
+2022-08-21;;2022-08-22;2022-08-21;CHF;-14.00;;;-1544.23;9967233GK1553933;"""FRIIS-LOOP, DANIELA; Belastung UBS TWINT""";;"""Zahlungsgrund: +41796741245; TWINT-Acc.:+41796305690; Transaktions-Nr. 9967233GK1553933""";;