diff --git a/problems/miniconverter/SPEC-v0.txt b/problems/miniconverter/SPEC-v0.txt
new file mode 100644
index 0000000..769f2b7
--- /dev/null
+++ b/problems/miniconverter/SPEC-v0.txt
@@ -0,0 +1,48 @@
+PROJECT: miniconverter
+AUTHOR: HASAN YILMAZ (250708022)
+VERSION: v0
+DATE: 2026-03-15
+
+========================================
+OVERVIEW
+========================================
+mini-converter is a CLI tool for length unit conversions.
+Supported units: meters (m), kilometers (km), centimeters (cm), millimeters (mm).
+All data is stored in a directory called .miniconv/ in the current directory.
+
+========================================
+COMMANDS
+========================================
+
+--- init ---
+Usage: python miniconverter.py init
+Behavior: Creates .miniconv/ directory and history.dat file.
+Output: "Conversion storage initialized." or "Already initialized."
+
+--- convert ---
+Usage: python miniconverter.py convert <value> <from_unit> <to_unit>
+Behavior: Converts the value and logs it to .miniconv/history.dat.
+Output: "<value> <from_unit> is <result> <to_unit>"
+
+--- history ---
+Usage: python miniconverter.py history
+Output: "Command 'history' will be implemented in future weeks."
+
+--- stats ---
+Usage: python miniconverter.py stats
+Output: "Command 'stats' will be implemented in future weeks."
+
+========================================
+DATA FORMAT
+========================================
+File: .miniconv/history.dat
+Format: value|from_unit|to_unit|result|date
+Example: 10.0|m|cm|1000.0|2026-03-13
+
+========================================
+ERROR HANDLING
+========================================
+- Run before init: "Error: Not initialized. Run: python miniconverter.py init"
+- Unsupported unit: "Error: Unsupported unit <unit>. Use m, km, cm, or mm."
+- Missing arguments: "Usage: python miniconverter.py <command> [args]"
+- Unknown command: "Unknown command: <command>"
diff --git a/problems/miniconverter/SPEC-v1.txt b/problems/miniconverter/SPEC-v1.txt
new file mode 100644
index 0000000..38774da
--- /dev/null
+++ b/problems/miniconverter/SPEC-v1.txt
@@ -0,0 +1,66 @@
+PROJECT: miniconverter
+AUTHOR: HASAN YILMAZ (250708022)
+VERSION: V1
+DATE: 2026-03-27
+
+
+========================================
+OVERVIEW
+========================================
+mini-converter is a CLI tool for length unit conversions.
+Supported units: meters (m), kilometers (km), centimeters (cm), millimeters (mm).
+All data is stored in a directory called .miniconv/ in the current directory.
+
+
+========================================
+COMMANDS
+========================================
+
+--- init ---
+Usage: python miniconverter.py init
+Behavior: Creates .miniconv/ directory and history.dat file.
+Output: "Conversion storage initialized." or "Already initialized."
+
+--- convert ---
+Usage: python miniconverter.py convert <value> <from_unit> <to_unit>
+Behavior: Converts the value and logs it to .miniconv/history.dat.
+
+[V2 ENHANCEMENTS]:
+- Case Insensitivity: Unit inputs (m, km, cm, mm) are accepted regardless of case (e.g., KM, m, Cm are all valid).
+- Decimal Precision: Input values and results support decimal numbers and are processed with 2-decimal precision (e.g., 1.234 m is calculated as 123.40 cm).
+
+Output: "<value> <from_unit> is <result> <to_unit>"
+
+--- history ---
+Usage: python miniconverter.py history
+Output: "Command 'history' will be implemented in future weeks."
+
+--- stats ---
+Usage: python miniconverter.py stats
+Output: "Command 'stats' will be implemented in future weeks."
+
+
+========================================
+V1 CHANGE LOG
+========================================
+1. Added full support for mixed-case unit strings (Case Insensitivity).
+2. Implemented 2-decimal place precision for all numeric calculations.
+3. Maintained backward compatibility with v0 file structures and commands.
+4. Updated error messages to provide better guidance for input units.
+
+
+========================================
+DATA FORMAT
+========================================
+File: .miniconv/history.dat
+Format: value|from_unit|to_unit|result|date
+Example: 10.0|m|cm|1000.00|2026-03-27
+
+
+========================================
+ERROR HANDLING
+========================================
+- Run before init: "Error: Not initialized. Run: python miniconverter.py init"
+- Unsupported unit: "Error: Unsupported unit <unit>. Use m, km, cm, or mm."
+- Missing arguments: "Usage: python miniconverter.py <command> [args]"
+- Unknown command: "Unknown command: <command>"
\ No newline at end of file
diff --git a/problems/miniconverter/SPEC-v2.txt b/problems/miniconverter/SPEC-v2.txt
new file mode 100644
index 0000000..4ae9bf5
--- /dev/null
+++ b/problems/miniconverter/SPEC-v2.txt
@@ -0,0 +1,68 @@
+PROJECT: miniconverter
+AUTHOR: HASAN YILMAZ (250708022)
+VERSION: V2
+DATE: 2026-04-16
+
+========================================
+OVERVIEW
+========================================
+miniconverter is a CLI tool for length unit conversions.
+Supported units: meters (m), kilometers (km), centimeters (cm), millimeters (mm).
+All data is stored in a directory called .miniconv/ in the current directory.
+
+========================================
+COMMANDS
+========================================
+
+--- init ---
+Usage: python miniconverter.py init
+Behavior: Creates .miniconv/ directory and history.dat file.
+Output: "Conversion storage initialized." or "Already initialized."
+
+--- convert ---
+Usage: python miniconverter.py convert <value> <from_unit> <to_unit>
+Behavior: Converts the value and logs it to .miniconv/history.dat.
+
+[V1 ENHANCEMENTS]:
+- Case Insensitivity: Unit inputs (m, km, cm, mm) are accepted regardless of case.
+- Decimal Precision: Input values and results support decimal numbers.
+
+[V2 ENHANCEMENTS]:
+- Value Validation: The system checks if the input <value> is a valid number before processing to prevent crashes.
+- Command Handling: The program identifies and reports unknown commands instead of failing silently.
+- Output & Log Consistency: Standardizes 2-decimal format across all terminal outputs and history.dat entries.
+
+Output: "<value> <from_unit> is <result> <to_unit>"
+
+--- history ---
+Usage: python miniconverter.py history
+Output: "Command 'history' will be implemented in future weeks."
+
+--- stats ---
+Usage: python miniconverter.py stats
+Output: "Command 'stats' will be implemented in future weeks."
+
+========================================
+V2 CHANGE LOG
+========================================
+1. Added full support for mixed-case unit strings (Inherited from V1).
+2. Implemented 2-decimal place precision for all numeric calculations (Inherited from V1).
+3. Added strict validation to catch non-numeric inputs for the <value> argument.
+4. Implemented explicit error messages for unknown CLI commands (e.g., Unknown command: <command>).
+5. Standardized output and log file formatting for better data consistency.
+
+========================================
+DATA FORMAT
+========================================
+File: .miniconv/history.dat
+Format: value|from_unit|to_unit|result|date
+Example: 10.0|m|cm|1000.00|2026-04-16
+
+========================================
+ERROR HANDLING
+========================================
+- Run before init: "Error: Not initialized. Run: python miniconverter.py init"
+- Unsupported unit: "Error: Unsupported unit <unit>. Use m, km, cm, or mm."
+- Invalid Value: "Error: <value> is not a valid number."
+- Unknown command: "Unknown command: <command>"
+- Missing arguments: "Usage: python miniconverter.py <command> [args]"
\ No newline at end of file
diff --git a/problems/miniconverter/problem.json b/problems/miniconverter/problem.json
new file mode 100644
index 0000000..dc718e5
--- /dev/null
+++ b/problems/miniconverter/problem.json
@@ -0,0 +1,16 @@
+{
+  "name": "miniconverter",
+  "type": "cli",
+  "language": "python",
+  "adapter": "cli",
+  "binary_name": "solution_v2.py",
+  "v0_spec": "SPEC-v0.txt",
+  "v0_test": "test-v0.sh",
+  "v0_prompt": "Implement {{binary_name}} as described in SPEC-v0.txt using Python. The program must support 'init' and 'convert' commands. Verify your implementation passes all tests by running: bash test-v0.sh",
+  "v1_spec": "SPEC-v1.txt",
+  "v1_test": "test-v1.sh",
+  "v1_prompt": "Read SPEC-v1.txt and extend the existing {{binary_name}} implementation with case-insensitivity and decimal precision as described in SPEC-v1.txt. Verify your implementation passes all tests by running: bash test-v1.sh",
+  "v2_spec": "SPEC-v2.txt",
+  "v2_test": "test-v2.sh",
+  "v2_prompt": "Read SPEC-v2.txt and extend the existing {{binary_name}} implementation with non-numeric value validation as described in SPEC-v2.txt. Verify your implementation passes all tests by running: bash test-v2.sh"
+}
diff --git a/problems/miniconverter/test-v0.sh b/problems/miniconverter/test-v0.sh
new file mode 100644
index 0000000..e3609e0
--- /dev/null
+++ b/problems/miniconverter/test-v0.sh
@@ -0,0 +1,131 @@
+#!/usr/bin/env bash
+# mini-converter v0 Bash Test Script
+# Ogrenci: HASAN YILMAZ 250708022
+set -e
+
+PASS_COUNT=0
+FAIL_COUNT=0
+
+#
+fail() {
+  echo "FAIL: $1"
+  FAIL_COUNT=$((FAIL_COUNT+1))
+}
+
+pass() {
+  echo "PASS: $1"
+  PASS_COUNT=$((PASS_COUNT+1))
+}
+
+cleanup() {
+  # Her testten once klasoru temizle
+  rm -rf .miniconv
+}
+
+# Calistirilacak ana komut
+BIN="python3 solution_v0.py"
+
+######################################
+# Setup
+######################################
+cleanup
+
+######################################
+# Test 1: init creates directory
+######################################
+if $BIN init > /dev/null && [ -d .miniconv ]; then
+  pass "init creates .miniconv directory"
+else
+  fail "init creates .miniconv directory"
+fi
+
+######################################
+# Test 2: init already exists
+######################################
+if $BIN init | grep -q "Already initialized"; then
+  pass "init already exists prints correct message"
+else
+  fail "init already exists prints correct message"
+fi
+
+######################################
+# Test 3: convert m to cm
+######################################
+if $BIN convert 1 m cm | grep -q "1.0 m is 100.0 cm"; then
+  pass "convert 1 m to cm works"
+else
+  fail "convert 1 m to cm works"
+fi
+
+######################################
+# Test 4: convert km to m
+######################################
+if $BIN convert 2 km m | grep -q "2000.0 m"; then
+  pass "convert 2 km to m works"
+else
+  fail "convert 2 km to m works"
+fi
+
+######################################
+# Test 5: unsupported unit
+######################################
+if $BIN convert 5 m mile | grep -q "Error"; then
+  pass "unsupported unit returns Error"
+else
+  fail "unsupported unit returns Error"
+fi
+
+######################################
+# Test 6: future weeks commands (history/stats)
+######################################
+if $BIN history | grep -q "future weeks" && $BIN stats | grep -q "future weeks"; then
+  pass "history/stats show future weeks message"
+else
+  fail "history/stats show future weeks message"
+fi
+
+######################################
+# Test 7: error no init
+######################################
+cleanup
+if $BIN convert 1 m cm | grep -q "Not initialized"; then
+  pass "error when running convert without init"
+else
+  fail "error when running convert without init"
+fi
+
+######################################
+# Test 8: unknown command
+######################################
+$BIN init > /dev/null
+if $BIN reset | grep -q "Unknown command"; then
+  pass "unknown command returns correct message"
+else
+  fail "unknown command returns correct message"
+fi
+
+######################################
+# Test 9: missing arguments
+######################################
+if $BIN convert 10 m | grep -q "Usage"; then
+  pass "missing arguments shows Usage message"
+else
+  fail "missing arguments shows Usage message"
+fi
+
+######################################
+# Summary
+######################################
+echo ""
+echo "========================"
+echo "PASSED: $PASS_COUNT"
+echo "FAILED: $FAIL_COUNT"
+echo "TOTAL:  $((PASS_COUNT + FAIL_COUNT))"
+echo "========================"
+
+if [ "$FAIL_COUNT" -eq 0 ]; then
+  echo "ALL V1 TESTS PASSED"
+  exit 0
+else
+  exit 1
+fi
diff --git a/problems/miniconverter/test-v1.sh b/problems/miniconverter/test-v1.sh
new file mode 100644
index 0000000..b140f1b
--- /dev/null
+++ b/problems/miniconverter/test-v1.sh
@@ -0,0 +1,107 @@
+#!/usr/bin/env bash
+# mini-converter v1 Bash Test Script
+# Ogrenci: HASAN YILMAZ (250708022)
+set -e
+
+PASS_COUNT=0
+FAIL_COUNT=0
+
+#
+fail() {
+  echo "FAIL: $1"
+  FAIL_COUNT=$((FAIL_COUNT+1))
+}
+
+pass() {
+  echo "PASS: $1"
+  PASS_COUNT=$((PASS_COUNT+1))
+}
+
+cleanup() {
+  # Her testten once klasoru temizle [cite: 18]
+  rm -rf .miniconv
+}
+
+# [DIKKAT] Artik solution_v1.py dosyasini test ediyoruz! [cite: 18]
+BIN="python3 solution_v1.py"
+
+######################################
+# Setup
+######################################
+cleanup
+
+######################################
+# Test 1: Case Insensitivity (KM to M) 
+######################################
+$BIN init > /dev/null
+# Kullanici 'KM' ve 'M' yazsa da hata almamali ve dogru sonuc donmeli 
+if $BIN convert 1 KM M | tr '[:upper:]' '[:lower:]' | grep -q "1.0 km is 1000.0 m"; then
+  pass "v2: case insensitivity works (KM -> M)"
+else
+  fail "v2: case insensitivity works (KM -> M)"
+fi
+
+######################################
+# Test 2: Decimal Precision (2 digits) 
+######################################
+# 1.234 metre, 123.4 (veya 123.40) olarak yuvarlanmali 
+if $BIN convert 1.234 m cm | grep -q "123.4"; then
+  pass "v2: decimal precision (2 digits) works"
+else
+  fail "v2: decimal precision (2 digits) works"
+fi
+
+######################################
+# Test 3: init creates folder 
+######################################
+cleanup
+if $BIN init > /dev/null && [ -d .miniconv ]; then
+  pass "init creates .miniconv directory"
+else
+  fail "init creates .miniconv directory"
+fi
+
+######################################
+# Test 4: convert m to cm 
+######################################
+if $BIN convert 1 m cm | grep -q "1.0 m is 100.0 cm"; then
+  pass "convert 1 m to cm works"
+else
+  fail "convert 1 m to cm works"
+fi
+
+######################################
+# Test 5: unsupported unit [cite: 20]
+######################################
+if $BIN convert 5 m mile | grep -q "Error"; then
+  pass "unsupported unit returns Error"
+else
+  fail "unsupported unit returns Error"
+fi
+
+######################################
+# Test 6: error no init [cite: 20]
+######################################
+cleanup
+if $BIN convert 1 m cm | grep -q "Not initialized"; then
+  pass "error when running convert without init"
+else
+  fail "error when running convert without init"
+fi
+
+######################################
+# Summary
+######################################
+echo ""
+echo "========================"
+echo "PASSED: $PASS_COUNT"
+echo "FAILED: $FAIL_COUNT"
+echo "TOTAL:  $((PASS_COUNT + FAIL_COUNT))"
+echo "========================"
+
+if [ "$FAIL_COUNT" -eq 0 ]; then
+  echo "ALL V2 TESTS PASSED"
+  exit 0
+else
+  exit 1
+fi
\ No newline at end of file
diff --git a/problems/miniconverter/test-v2.sh b/problems/miniconverter/test-v2.sh
new file mode 100644
index 0000000..52047d1
--- /dev/null
+++ b/problems/miniconverter/test-v2.sh
@@ -0,0 +1,133 @@
+#!/usr/bin/env bash
+# miniconverter v2 Full Regression Test Script
+# Ogrenci: HASAN YILMAZ (250708022)
+# Guncelleme: V0, V1 ve V2 ozelliklerinin tamamı denetlenmektedir.
+set -e
+
+PASS_COUNT=0
+FAIL_COUNT=0
+
+# Yardımcı Fonksiyonlar
+fail() {
+  echo "FAIL: $1"
+  FAIL_COUNT=$((FAIL_COUNT+1))
+}
+
+pass() {
+  echo "PASS: $1"
+  PASS_COUNT=$((PASS_COUNT+1))
+}
+
+cleanup() {
+  # Her testten once klasoru temizleyerek izole bir ortam saglıyoruz
+  rm -rf .miniconv
+}
+
+# [KRITIK] problem.json ile uyumlu ikili dosya ismi
+BIN="python3 solution_v2.py"
+
+######################################
+# SETUP & INITIALIZATION
+######################################
+cleanup
+
+######################################
+# TEST 1: V0 - Init Creates Directory
+######################################
+# Program ilk kez calıstıgında dizin olusturmalı
+if $BIN init > /dev/null && [ -d .miniconv ]; then
+  pass "v0: init creates .miniconv directory"
+else
+  fail "v0: init creates .miniconv directory"
+fi
+
+######################################
+# TEST 2: V0 - Basic Conversion (m to cm)
+######################################
+# Temel donusum dogru calısmalı
+if $BIN convert 10 m cm | grep -q "10.0 m is 1000.00 cm"; then
+  pass "v0: basic convert (10m to cm) works"
+else
+  fail "v0: basic convert (10m to cm) works"
+fi
+
+######################################
+# TEST 3: V1 - Case Insensitivity (KM to M)
+######################################
+# Buyuk harf girisleri kucuk harf gibi islenmeli
+if $BIN convert 1 KM M | tr '[:upper:]' '[:lower:]' | grep -q "1.0 km is 1000.00 m"; then
+  pass "v1: case insensitivity works (KM -> M)"
+else
+  fail "v1: case insensitivity works (KM -> M)"
+fi
+
+######################################
+# TEST 4: V1 - Decimal Precision (Float Support)
+######################################
+# Ondalık sayılar 2 basamak hassasiyetle gosterilmeli
+if $BIN convert 1.234 m cm | grep -q "123.40"; then
+  pass "v1: decimal precision (1.234m -> 123.40cm) works"
+else
+  fail "v1: decimal precision (1.234m -> 123.40cm) works"
+fi
+
+######################################
+# TEST 5: V2 - Invalid Value Validation
+######################################
+# Sayı yerine metin girildiginde program cokmemeli
+if $BIN convert elma m cm | grep -q "Error: elma is not a valid number."; then
+  pass "v2: non-numeric value error handling (elma test) works"
+else
+  fail "v2: non-numeric value error handling (elma test) works"
+fi
+
+######################################
+# TEST 6: V2 - Unknown Command Handling
+######################################
+# Bilinmeyen bir komut girildiginde kullanıcı uyarılmalı
+if $BIN reset | grep -q "Unknown command: reset"; then
+  pass "v2: unknown command handling works"
+else
+  fail "v2: unknown command handling works"
+fi
+
+######################################
+# TEST 7: Global - Unsupported Unit Error
+######################################
+# Desteklenmeyen birimler hata dondurmeli
+if $BIN convert 5 m mile | grep -q "Error"; then
+  pass "global: unsupported unit returns Error"
+else
+  fail "global: unsupported unit returns Error"
+fi
+
+######################################
+# TEST 8: Global - Error No Init
+######################################
+cleanup
+# Init yapılmadan islemlere izin verilmemeli
+if $BIN convert 1 m cm | grep -q "Not initialized"; then
+  pass "global: error when running convert without init"
+else
+  fail "global: error when running convert without init"
+fi
+
+######################################
+# SUMMARY REPORT
+######################################
+echo ""
+echo "========================================"
+echo "      MINICONVERTER V2 TEST RESULTS     "
+echo "========================================"
+echo "PASSED: $PASS_COUNT"
+echo "FAILED: $FAIL_COUNT"
+echo "TOTAL TESTS: $((PASS_COUNT + FAIL_COUNT))"
+echo "========================================"
+
+if [ "$FAIL_COUNT" -eq 0 ]; then
+  echo ">>> ALL V0, V1 AND V2 TESTS PASSED <<<"
+  exit 0
+else
+  echo ">>> SOME TESTS FAILED <<<"
+  exit 1
+fi
\ No newline at end of file