diff --git a/README.md b/README.md
index bd7163e..7f75717 100644
--- a/README.md
+++ b/README.md
@@ -95,6 +95,7 @@ yarn setup:dev
 # - Install all dependencies
 # - Build Docker executor containers
 # - Start development environment with Docker Compose
+# - Auto-shift host ports if default ports are busy (e.g. 27017 -> 27018)
 # - Mount source code for hot-reload (changes auto-reload containers)
 # - Seed database with sample data
 # - Start both API server and worker with live reloading
@@ -255,6 +256,16 @@ yarn docker:clean:all           # Complete Docker cleanup
 yarn build:executors            # Rebuild executor images
 ```
 
+**Port Already In Use (`address already in use`)**:
+
+```bash
+# Retry startup; SafeExec now auto-selects next free host ports
+yarn docker:dev
+
+# Example: if 27017 is busy, MongoDB may use 27018
+# The selected ports are printed in startup logs
+```
+
 ---
 
 ## 🤝 Contributing to SafeExec
diff --git a/package.json b/package.json
index 88a5271..1476d3e 100755
--- a/package.json
+++ b/package.json
@@ -48,18 +48,18 @@
     "fix:docker": "./scripts/fix-docker-permissions.sh",
     "ssl:generate": "./scripts/generate-ssl.sh",
     "docker": "echo 'Use yarn docker:dev, yarn docker:test, or yarn docker:prod'",
-    "docker:dev": "echo '🚀 Starting development environment...' && ENV=development docker compose -f docker-compose.yml up -d",
+    "docker:dev": "echo '🚀 Starting development environment...' && bash ./scripts/docker-up-auto-port.sh development",
     "docker:dev:down": "ENV=development docker compose -f docker-compose.yml down",
     "docker:dev:logs": "ENV=development docker compose -f docker-compose.yml logs -f",
     "docker:dev:shell": "ENV=development docker compose -f docker-compose.yml exec rce-api sh",
     "docker:dev:build": "echo '🏗️ Building development images...' && DOCKER_HOST= ENV=development docker compose -f docker-compose.yml build",
-    "docker:test": "DOCKER_HOST= ENV=test docker compose up -d",
+    "docker:test": "DOCKER_HOST= bash ./scripts/docker-up-auto-port.sh test",
     "docker:test:down": "ENV=test docker compose down",
     "docker:test:run": "ENV=test docker compose run --rm rce-api yarn test",
     "docker:test:coverage": "ENV=test docker compose run --rm rce-api yarn test:coverage",
     "docker:test:integration": "ENV=test docker compose run --rm rce-api yarn test:integration",
     "docker:test:build": "ENV=test docker compose build",
-    "docker:prod": "DOCKER_HOST= ENV=production docker compose up -d",
+    "docker:prod": "DOCKER_HOST= bash ./scripts/docker-up-auto-port.sh production",
     "docker:prod:down": "ENV=production docker compose down",
     "docker:prod:logs": "ENV=production docker compose logs -f",
     "docker:prod:shell": "ENV=production docker compose exec rce-api sh",
@@ -77,7 +77,7 @@
     "docker:seed:dev": "ENV=development docker compose exec rce-api yarn seed",
     "docker:seed:test": "ENV=test docker compose run --rm rce-api yarn seed",
     "docker:seed:prod": "ENV=production docker compose exec rce-api yarn seed",
-    "docker:restart": "echo '🔄 Restarting development environment...' && docker compose -f docker-compose.yml down && ENV=development docker compose -f docker-compose.yml up -d",
+    "docker:restart": "echo '🔄 Restarting development environment...' && docker compose -f docker-compose.yml down && yarn docker:dev",
     "docker:manage": "echo 'Use yarn docker:dev, yarn docker:test, or yarn docker:prod'",
     "setup": "echo '📦 Installing dependencies and building executors...' && yarn install && yarn fix:docker && yarn build:executors",
     "setup:dev": "echo '🚀 Complete development setup...' && yarn setup && yarn docker:setup:dev && yarn docker:seed:dev",
diff --git a/scripts/docker-up-auto-port.sh b/scripts/docker-up-auto-port.sh
new file mode 100644
index 0000000..b5111bb
--- /dev/null
+++ b/scripts/docker-up-auto-port.sh
@@ -0,0 +1,130 @@
+#!/bin/bash
+
+# Start docker compose with automatic host port selection.
+# If a preferred port is busy, the script increments until a free one is found.
+
+set -euo pipefail
+
+ENVIRONMENT="${1:-development}"
+shift || true
+
+COMPOSE_FILE="docker-compose.yml"
+MAX_SCAN="${MAX_PORT_SCAN_ATTEMPTS:-200}"
+
+# Keep selected ports unique within this run.
+declare -A SELECTED_PORTS
+
+print_info() {
+    echo "[PORT] $1"
+}
+
+print_warn() {
+    echo "[PORT][WARN] $1"
+}
+
+is_numeric_port() {
+    [[ "$1" =~ ^[0-9]+$ ]] && [ "$1" -ge 1 ] && [ "$1" -le 65535 ]
+}
+
+is_port_in_use() {
+    local port="$1"
+
+    if command -v ss >/dev/null 2>&1; then
+        ss -ltnH "( sport = :${port} )" 2>/dev/null | grep -q .
+        return $?
+    fi
+
+    if command -v lsof >/dev/null 2>&1; then
+        lsof -iTCP:"${port}" -sTCP:LISTEN -n -P >/dev/null 2>&1
+        return $?
+    fi
+
+    if command -v netstat >/dev/null 2>&1; then
+        netstat -ltn 2>/dev/null | awk '{print $4}' | grep -E "[:.]${port}$" >/dev/null 2>&1
+        return $?
+    fi
+
+    print_warn "No port-check tool found (ss/lsof/netstat). Assuming port ${port} is free."
+    return 1
+}
+
+is_port_already_selected() {
+    local port="$1"
+    [[ -n "${SELECTED_PORTS[$port]:-}" ]]
+}
+
+find_next_free_port() {
+    local start_port="$1"
+    local label="$2"
+    local attempt=0
+    local port="$start_port"
+
+    while [ "$attempt" -lt "$MAX_SCAN" ]; do
+        if ! is_port_in_use "$port" && ! is_port_already_selected "$port"; then
+            SELECTED_PORTS["$port"]="$label"
+            echo "$port"
+            return 0
+        fi
+
+        port=$((port + 1))
+        if [ "$port" -gt 65535 ]; then
+            break
+        fi
+        attempt=$((attempt + 1))
+    done
+
+    echo ""
+    return 1
+}
+
+resolve_port_var() {
+    local var_name="$1"
+    local default_port="$2"
+    local label="$3"
+
+    local requested_port="${!var_name:-$default_port}"
+
+    if ! is_numeric_port "$requested_port"; then
+        print_warn "${var_name} has invalid value '${requested_port}', using default ${default_port}."
+        requested_port="$default_port"
+    fi
+
+    local resolved_port
+    resolved_port="$(find_next_free_port "$requested_port" "$label")"
+
+    if [ -z "$resolved_port" ]; then
+        echo "[PORT][ERROR] Could not find free port for ${var_name} after ${MAX_SCAN} attempts from ${requested_port}." >&2
+        exit 1
+    fi
+
+    if [ "$resolved_port" != "$requested_port" ]; then
+        print_warn "${label}: ${requested_port} is busy, using ${resolved_port}."
+    else
+        print_info "${label}: using ${resolved_port}."
+    fi
+
+    export "${var_name}=${resolved_port}"
+}
+
+print_info "Resolving host ports for ENV=${ENVIRONMENT}..."
+
+resolve_port_var "MONGO_PORT" "27017" "MongoDB"
+resolve_port_var "REDIS_PORT" "6379" "Redis"
+resolve_port_var "API_PORT" "5000" "API"
+resolve_port_var "DEBUG_PORT" "9229" "Node Debug"
+resolve_port_var "NGINX_HTTP_PORT" "80" "Nginx HTTP"
+resolve_port_var "NGINX_HTTPS_PORT" "443" "Nginx HTTPS"
+
+export ENV="${ENVIRONMENT}"
+
+print_info "Starting docker compose with resolved ports..."
+docker compose -f "${COMPOSE_FILE}" up -d "$@"
+
+print_info "Docker compose started."
+print_info "Resolved host ports:"
+print_info "- MongoDB: ${MONGO_PORT}"
+print_info "- Redis: ${REDIS_PORT}"
+print_info "- API: ${API_PORT}"
+print_info "- Debug: ${DEBUG_PORT}"
+print_info "- Nginx HTTP: ${NGINX_HTTP_PORT}"
+print_info "- Nginx HTTPS: ${NGINX_HTTPS_PORT}"