Single Serving Applications - The Clones

About the author: I'm Charles Sieg, a cloud architect and platform engineer who builds apps, services, and infrastructure for Fortune 1000 clients through Vantalect. If your organization is rethinking its software strategy in the age of AI-assisted engineering, let's talk.

I'm systematically replacing my SaaS subscriptions with Single Serving Applications. These are purpose-built, AI-generated apps designed for an audience of one. Each clone is built by Claude Opus 4.6 from a requirements document, runs via Docker Compose, and costs essentially nothing to operate.

This page is a running catalog of every clone I've built. I'll add a new entry each time I replace another subscription.

GitHub Clone, February 12, 2026

Single-user Git hosting platform.

The largest clone by far, nearly three times the combined size of the previous three. A full-featured Git hosting platform called GitPub with repository management, code browsing with syntax highlighting and blame view, commits with diffs, branches with ahead/behind indicators, pull requests with three merge strategies (merge, squash, rebase) and inline comments, issues with labels, releases with assets, global search with qualifier support, activity feeds, insights, notifications, bookmarks, dark/light themes, and 50+ REST API endpoints. Built with isomorphic-git for pure-JavaScript Git operations on bare repositories with no native Git dependency.

The first clone that required multiple build sessions, parallel agent coordination (11 agents), and explicit planning documents (test plan + build plan). Claude also produced a cost and schedule analysis estimating that a human team would need 8 weeks and $127,200 to reproduce the same output.

Confluence Clone, February 11, 2026

Knowledge base and wiki for personal documentation.

A full-featured knowledge base with a WYSIWYG rich text editor powered by TipTap (ProseMirror), hierarchical page tree with arbitrary nesting, breadcrumb navigation, auto-save with status indicator, version history with one-click restore, full-text search, command palette (Cmd+K), sidebar filtering, code blocks with syntax highlighting, tables, task lists, and emoji page icons. The most compact clone yet: SQLite instead of PostgreSQL, single Docker container, 2,100 lines total.

Trello Clone, February 10, 2026

Kanban boards for personal project management.

A full-featured Kanban board with drag-and-drop list and card reordering, markdown descriptions with auto-save, color-coded labels, checklists with progress bars, due dates with overdue indicators, global search, card filtering, a command palette (Cmd+K), keyboard shortcuts, dark mode, and full workspace export/import. Claude wrote the requirements document and the technical design. My total input was two prompts.

Harvest Clone, February 9, 2026

Time tracking and invoicing for consultants.

The Harvest clone covers time entry with an editable week grid, expense tracking with file attachments, project management grouped by client, invoice creation with a multi-step wizard, PDF generation, reports with CSV export, and a full settings page. It reproduces Harvest's orange brand identity and card-based layout. The week view is an actual editable grid (just like the real Harvest) where you can click into cells and enter hours directly.

This clone started it all. I built it as a head-to-head benchmark between Claude Opus 4.6 and GPT-5.3-Codex. Claude's version covered 97% of Harvest's features. Codex's version ran but suffered from architectural shortcuts. I use Claude's version daily.

The Pattern

Every clone follows the same process:

1. Write (or generate) a requirements document. Be specific about the data model, the views, the workflows.
2. Hand it to Claude Opus 4.6 with a prompt to build a Dockerized full-stack application.
3. Walk away. Come back in ~20 minutes to a running app.
4. Validate and iterate. Test it for a few days alongside the SaaS product.
5. Cancel the subscription.

Four clones built. ~32,000 lines of code generated. 263 tests passing. Total cost: under $100 in API tokens. Combined annual savings: growing daily.

The source code for every clone is available on GitHub. Clone the repo, run docker compose up --build, and see for yourself.