Brief Pack Library / Invoicing Software
Invoicing Software Brief Pack for Freelancers
Everything your AI build tool needs to build a invoicing software for freelancers. 14 files. $9.
Built for solo professionals managing clients, projects, and finances.
What this pack defines
Database · 8 tables
- · clients
- · invoices
- · line_items
- · payments
- · expenses
- · tax_rates
- · time_entries
- · projects
52 columns · 7 foreign keys
Roles · 2
- · Owner
- · Client (view-only)
Key sections
- · Invoice builder
- · Payment tracking
- · Expense logging
- · Tax calculation
- · Client portal
Monetization
Freemium
Free / Pro $15/mo
Authentication
Google OAuth + magic link
Integrations
- · Stripe
- · PayPal
- · Wave
Brief pack contents
14 files. 8 tables, 52 columns, 2 roles, 52 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
8 tables, 52 columns, 7 FKs (clients, invoices, line_items…)
05-RLS-POLICIES.sql
Row-level security for 2 roles
06-AUTH-STATE-MACHINE.md
Google OAuth + magic link
07-RBAC-MATRIX.md
Owner · 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
52 test cases, seed data (e.g. owner@test.com)
13-INTEGRATIONS.md
Stripe, PayPal, Wave
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 →