ClientFlow — White-Label Client Portal & Invoicing for Agencies

ClientFlow is a self-hosted client portal for agencies, software studios, consultancies and other B2B service companies. It replaces the mix of email threads, shared folders, spreadsheet invoices and a separate help desk: your team works in one workspace, and every client gets a branded portal showing only their own projects, files, quotes, invoices and support requests.

This is complete application source code — Next.js 16, React 19, TypeScript and PostgreSQL — not a UI kit. It is multi-tenant, so one installation can serve a single company or host many workspaces, each with its own branding, team and clients.

Problems it solves

• Clients ask for status updates by email — they now follow milestones and tasks in the portal.
• Quotes and deliverables get approved "somewhere in the inbox" — approvals are recorded with who and when.
• Invoices are chased manually — overdue reminders go out automatically and clients pay by card.
• Support requests lose context — every ticket sits next to the client's projects and invoices.

Key features

• Projects with milestones, kanban and list views, comments and client sign-off
• Quotes and invoices with per-line tax, discounts, branded PDFs and gap-free numbering
• Stripe Checkout payments confirmed by signed webhooks; bank-transfer and partial payments
• Automatic overdue reminders with the invoice PDF attached
• Support inbox with internal notes, knowledge base and public help centre
• Private file sharing on S3-compatible storage with expiring download links
• Admin dashboard and reports: revenue, receivables aging, projects, tasks, support, CSV export
• Roles and permissions, custom roles, audit log, strict workspace isolation
• White-label branding per workspace: logo, colour, favicon, emails, PDFs, custom domain
• REST API with scoped keys, OpenAPI description and signed webhooks
• Responsive design with light and dark theme; documentation included

Technical details

Next.js App Router with server actions, TypeScript in strict mode, Tailwind CSS 4, Prisma 7 on PostgreSQL, Better Auth, BullMQ with Redis for background jobs, Nodemailer or Resend for email and any S3-compatible storage (AWS S3, Cloudflare R2, MinIO). Money is stored in integer minor units, invoice numbers are allocated in a locked transaction, and every database query is scoped to one workspace. The package ships with a Dockerfile, a Docker Compose stack, a demo data seed, unit, integration and end-to-end tests.

Requirements

• Node.js 22.12+ (24 LTS recommended)
• PostgreSQL 15+
• S3-compatible object storage
• SMTP server or Resend account
• Redis 6+ (recommended, for background jobs)
• Stripe account (optional, for card payments)
• Linux VPS or container hosting — not shared PHP hosting

Who is it for?

Agencies, development studios, consultancies, accounting firms, IT and managed service providers and B2B freelancers who want to own their client portal instead of paying per seat for a hosted one — and developers who build client portals for customers.

What is included?

Full source code, database migrations, demo data seed, Dockerfile and Docker Compose configuration, HTML installation guide (documentation/), detailed Markdown documentation (docs/), screenshots, changelog and automated tests.

Live demo

Try ClientFlow at clientflow.esde.site with one of these accounts:

• Agency owner: full workspace, including billing, reports and settings
  Email: demo@clientflow.test · Password: ClientFlow-demo-2026
• Team member: assigned projects and tasks
  Email: lena@northstar-digital.test · Password: ClientFlow-demo-2026
• Client: client portal of Acme Industries
  Email: client@clientflow.test · Password: ClientFlow-demo-2026

The sign-in page lists these accounts with a one-click fill button. Demo data resets every night. Emails are not sent in the demo, and account, payment and integration settings are read-only.