Brief Pack Library / Invoicing Software

Invoicing Software Brief Pack for Agencies

Everything your AI build tool needs to build a invoicing software for agencies. 14 files. $9.

Built for digital, marketing, or creative agencies managing clients and projects.

What this pack defines

Database · 9 tables

  • · clients
  • · invoices
  • · line_items
  • · payments
  • · expenses
  • · tax_rates
  • · projects
  • · time_entries
  • · retainers

62 columns · 8 foreign keys

Roles · 4

  • · Owner
  • · PM
  • · Finance
  • · Client (view-only)

Key sections

  • · Invoice builder
  • · Payment tracking
  • · Expense logging
  • · Tax calculation
  • · Client portal

Monetization

Freemium

Free / Pro $15/mo

Authentication

Team SSO + client portal access

Integrations

  • · Stripe
  • · QuickBooks
  • · Harvest

Brief pack contents

14 files. 9 tables, 62 columns, 4 roles, 60 test cases.

File
Contents tailored for this pack
01-GLOBAL-BRIEF.md
Master spec covering product, monetization, journey
02-DESIGN-SYSTEM.md
Tokens, typography, components
03-CONSTRAINTS.md
What the AI must NOT change
04-DATABASE-SCHEMA.sql
9 tables, 62 columns, 8 FKs (clients, invoices, line_items…)
05-RLS-POLICIES.sql
Row-level security for 4 roles
06-AUTH-STATE-MACHINE.md
Team SSO + client portal access
07-RBAC-MATRIX.md
Owner · PM · Finance · Client (view-only)
08-API-CONTRACTS.md
Endpoint shapes, request/response schemas
09-BILLING-LOGIC.md
Freemium — Free / Pro $15/mo
10-WEBHOOK-HANDLING.md
Idempotency, retry, failure logging
11-AUDIT-LOG.md
What's tracked, retention, who can see it
12-TEST-USERS-SEED.md
60 test cases, seed data (e.g. owner@test.com)
13-INTEGRATIONS.md
Stripe, QuickBooks, Harvest
14-LEGAL-PAGES.md
Privacy, Terms, Refund, Shipping templates

Without BriefKit

200+ iterations

$100+ in build-tool credits, 4–8 weeks, design drift between screens.

With BriefKit

~19 prompts

$9 + one month of your build tool. Spec-locked from prompt 1.

Generate your invoicing software brief pack

Start from this preset. Customize in the builder. Export when your strength score hits 8+.

Generate your invoicing software brief pack →

FAQ