diff --git a/whatsdirty/test.sh b/whatsdirty/test.sh
new file mode 100755
index 0000000..26dd6a1
--- /dev/null
+++ b/whatsdirty/test.sh
@@ -0,0 +1,141 @@
+#!/bin/bash
+set -euo pipefail
+
+SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )"
+WHATSDIRTY_SCRIPT="$SCRIPT_DIR/whatsdirty.sh"
+CONFIG_FILE="$HOME/.config/whatsdirty.conf"
+BACKUP_FILE=""
+TEST_PASSED=true
+
+# Colors for output
+GREEN='\033[0;32m'
+RED='\033[0;31m'
+NC='\033[0m' # No Color
+
+# Function to print test results
+print_test() {
+    local test_name="$1"
+    local result="$2"
+    if [ "$result" = "PASS" ]; then
+        echo -e "${GREEN}✓${NC} $test_name"
+    else
+        echo -e "${RED}✗${NC} $test_name"
+        TEST_PASSED=false
+    fi
+}
+
+# Function to cleanup and restore
+cleanup() {
+    if [ -n "$BACKUP_FILE" ] && [ -f "$BACKUP_FILE" ]; then
+        cp "$BACKUP_FILE" "$CONFIG_FILE"
+        rm -f "$BACKUP_FILE"
+    elif [ -n "$BACKUP_FILE" ]; then
+        # Original didn't exist, so remove the created one
+        rm -f "$CONFIG_FILE"
+    fi
+}
+
+# Set up trap to restore config on exit
+trap cleanup EXIT
+
+echo "Testing whatsdirty.sh configuration behavior..."
+echo
+
+# Backup existing config if it exists
+if [ -f "$CONFIG_FILE" ]; then
+    BACKUP_FILE=$(mktemp)
+    cp "$CONFIG_FILE" "$BACKUP_FILE"
+else
+    # Mark that we need to remove the config file on cleanup
+    BACKUP_FILE="NONE_EXISTED"
+fi
+
+# Remove config to start fresh
+rm -f "$CONFIG_FILE"
+
+# Test 1: Running without arguments and no config should fail
+echo "Test 1: First run without arguments (should fail)"
+OUTPUT=$("$WHATSDIRTY_SCRIPT" 2>&1 || true)
+if echo "$OUTPUT" | grep -q "No directory specified and no saved directory found"; then
+    print_test "First run without args shows error" "PASS"
+else
+    print_test "First run without args shows error" "FAIL"
+    echo "  Expected: 'No directory specified and no saved directory found'"
+    echo "  Got: $OUTPUT"
+fi
+
+# Test 2: Running with a valid directory should save config
+echo -e "\nTest 2: First run with directory argument"
+TEST_DIR="/home/j/code"
+if [ -d "$TEST_DIR" ]; then
+    "$WHATSDIRTY_SCRIPT" "$TEST_DIR" > /dev/null 2>&1
+    if [ -f "$CONFIG_FILE" ] && [ "$(cat "$CONFIG_FILE")" = "$TEST_DIR" ]; then
+        print_test "Directory saved to config" "PASS"
+    else
+        print_test "Directory saved to config" "FAIL"
+    fi
+else
+    print_test "Directory saved to config" "SKIP (test directory not found)"
+fi
+
+# Test 3: Running without arguments should use saved directory
+echo -e "\nTest 3: Subsequent run without arguments"
+if "$WHATSDIRTY_SCRIPT" > /dev/null 2>&1; then
+    print_test "Uses saved directory from config" "PASS"
+else
+    print_test "Uses saved directory from config" "FAIL"
+fi
+
+# Test 4: Running with new directory should update config
+echo -e "\nTest 4: Run with different directory"
+NEW_TEST_DIR="$SCRIPT_DIR/.."
+if [ -d "$NEW_TEST_DIR" ]; then
+    CANONICAL_DIR=$(cd "$NEW_TEST_DIR" && pwd)
+    "$WHATSDIRTY_SCRIPT" "$NEW_TEST_DIR" > /dev/null 2>&1
+    if [ -f "$CONFIG_FILE" ] && [ "$(cat "$CONFIG_FILE")" = "$CANONICAL_DIR" ]; then
+        print_test "Config updated with new directory" "PASS"
+    else
+        print_test "Config updated with new directory" "FAIL"
+    fi
+else
+    print_test "Config updated with new directory" "SKIP (test directory not found)"
+fi
+
+# Test 5: Invalid directory should fail
+echo -e "\nTest 5: Invalid directory handling"
+OUTPUT=$("$WHATSDIRTY_SCRIPT" "/nonexistent/directory" 2>&1 || true)
+if echo "$OUTPUT" | grep -q "Directory '/nonexistent/directory' not found"; then
+    print_test "Invalid directory shows error" "PASS"
+else
+    print_test "Invalid directory shows error" "FAIL"
+    echo "  Expected: 'Directory '/nonexistent/directory' not found'"
+    echo "  Got: $OUTPUT"
+fi
+
+# Test 6: Saved directory that no longer exists
+echo -e "\nTest 6: Saved directory that no longer exists"
+mkdir -p "$(dirname "$CONFIG_FILE")"
+echo "/nonexistent/saved/directory" > "$CONFIG_FILE"
+OUTPUT=$("$WHATSDIRTY_SCRIPT" 2>&1 || true)
+if echo "$OUTPUT" | grep -q "no longer exists"; then
+    # Check that config was removed
+    if [ ! -f "$CONFIG_FILE" ]; then
+        print_test "Handles deleted saved directory" "PASS"
+    else
+        print_test "Handles deleted saved directory" "FAIL (config not cleaned up)"
+    fi
+else
+    print_test "Handles deleted saved directory" "FAIL"
+    echo "  Expected message about directory no longer existing"
+    echo "  Got: $OUTPUT"
+fi
+
+# Summary
+echo
+if [ "$TEST_PASSED" = true ]; then
+    echo -e "${GREEN}All tests passed!${NC}"
+    exit 0
+else
+    echo -e "${RED}Some tests failed!${NC}"
+    exit 1
+fi
\ No newline at end of file
diff --git a/whatsdirty/whatsdirty.sh b/whatsdirty/whatsdirty.sh
index 1b8bed8..8d59dcd 100755
--- a/whatsdirty/whatsdirty.sh
+++ b/whatsdirty/whatsdirty.sh
@@ -8,11 +8,48 @@
 # for each git repo print the name of the repo, the datestamp of the last commit, 
 # the nubmer of changes since then, and whether it's clean or not.
 
-# if no argument is provided, use the current directory
-DIR="${1:-.}"
+# Configuration file path
+CONFIG_FILE="$HOME/.config/whatsdirty.conf"
 
-# make directory canonical
-DIR=$(cd "$DIR" 2>/dev/null && pwd) || { echo "Error: Directory '$1' not found"; exit 1; }
+# Function to save directory to config
+save_directory() {
+    local dir="$1"
+    mkdir -p "$(dirname "$CONFIG_FILE")"
+    echo "$dir" > "$CONFIG_FILE"
+}
+
+# Function to load directory from config
+load_directory() {
+    if [ -f "$CONFIG_FILE" ]; then
+        cat "$CONFIG_FILE"
+    fi
+}
+
+# Determine which directory to use
+if [ $# -eq 0 ]; then
+    # No argument provided - try to load from config
+    SAVED_DIR=$(load_directory)
+    if [ -z "$SAVED_DIR" ]; then
+        echo "Error: No directory specified and no saved directory found."
+        echo "Usage: $0 <directory>"
+        echo "The specified directory will be saved for future use."
+        exit 1
+    fi
+    DIR="$SAVED_DIR"
+else
+    # Argument provided - use it and save to config
+    DIR="$1"
+    # Validate and canonicalize the directory first
+    DIR=$(cd "$DIR" 2>/dev/null && pwd) || { echo "Error: Directory '$1' not found"; exit 1; }
+    save_directory "$DIR"
+fi
+
+# Make sure directory is canonical (in case loaded from config)
+DIR=$(cd "$DIR" 2>/dev/null && pwd) || { 
+    echo "Error: Saved directory '$DIR' no longer exists"; 
+    rm -f "$CONFIG_FILE"
+    exit 1; 
+}
 
 # Color codes
 RED='\033[0;31m'