Invoicerr nails the exact billing sequence freelancers actually use: draft a quote, send it to the client, collect a legally-binding electronic signature via a secure browser link, convert the approved quote into an invoice, and generate a branded PDF — no DocuSign account, no external signing service, no enterprise complexity. The React frontend with NestJS backend uses Prisma ORM with your choice of SQLite for instant local setup or PostgreSQL for production workloads. Quotes and invoices are first-class objects with independent status tracking — unread, sent, viewed, signed for quotes; paid for invoices — not a single form with a label swap. The e-signature system generates secure-token signing links that clients open in their browser to review and sign documents without needing any account or external service. PDF generation renders quotes, invoices, and receipts with your company logo, name, VAT number, colors, and custom email templates so documents reflect your brand identity rather than the software's defaults. Authentication supports JWT tokens or OIDC providers stored in cookies. The REST API backend enables future integrations with mobile and desktop clients. A plugin system with community-made features and outgoing webhooks extends functionality without forking core code. International-friendly with customizable currencies. Deploy with Docker Compose using the prebuilt image from GitHub Container Registry. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. AGPL-3.0 licensed.