To eliminate YAML indentation errors and cryptic container misconfigurations before running docker compose up, ComposeToolbox pairs a full-featured code editor with a live configuration analyzer in a single self-hostable web workspace. Paste or write any docker-compose.yml file in the left pane to see immediate syntax validation alongside actionable best-practice warnings, such as unpinned latest image tags, missing healthchecks, or deprecated version declarations. On the right side, an interactive Configuration Overview breaks down every defined service, exposed port mapping, persistent volume mount, environment variable, and custom network into structured tabs. Built-in Quick Insert buttons let operators drop new service blocks, volume definitions, or network stanzas into the editor with one click. By mounting the persistent /app/data directory, administrators can define custom quick-insert YAML snippets with selectable hardware and networking icons in custom-templates.yml. Teams can also customize startup-template.yml so the editor opens with their organization's standard homelab or production boilerplate every time the page loads. Keyboard shortcuts, light and dark themes, and one-click YAML formatting or file export streamline daily container authoring. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.