Product Requirements Document (PRD) Template

# [Product Name] — Product Requirements Document (PRD)

## 1. Executive Summary & Product Vision
- **Product Overview**: What is the application and why does it exist?
- **Vision & Success Metrics**: Measurable business & engineering milestones (e.g. 99.9% uptime, <200ms API response).
- **Primary Platform Target**: Web, Mobile (iOS/Android), Browser Extension, or Microservice.

## 2. Problem Statement & User Personas
- **Target Audience**: Who will rely on this tool daily?
- **Core User Personas**:
  | Persona Name | Role | Primary Objective | Daily Frustration | Technical Level |
  |---|---|---|---|---|
  | [Name] | [Job Title] | [Goal] | [Current Pain Point] | [Low/Mid/High] |

## 3. Scope & Feature Priority Matrix
- **In-Scope (P0 / Critical)**: Must-have capabilities required for production MVP launch.
- **In-Scope (P1 / Important)**: High-value features scheduled for immediate follow-up release.
- **Out-of-Scope (Non-Goals)**: Explicitly excluded features to prevent scope creep.

## 4. Functional Specifications & Acceptance Criteria
For every P0 and P1 feature:
### Feature ID: [FEAT-001] [Feature Name]
- **Description**: What does this feature do?
- **Business Logic Rules**: Explicit operational boundaries, validation limits, and calculations.
- **Acceptance Criteria (GIVEN / WHEN / THEN)**:
  - *Success Case*: GIVEN [valid initial condition] WHEN [user triggers action] THEN [expected system result].
  - *Failure Case*: GIVEN [invalid input or network error] WHEN [user triggers action] THEN [user-friendly error state].
- **Edge Cases**: Handling of network timeout, duplicate submissions, and boundary data.

## 5. Technical Constraints & Architecture Requirements
- **Frontend Stack**: (e.g. Next.js 15, React, Tailwind CSS)
- **Backend & API**: (e.g. Node.js, Next.js Server Actions, REST endpoints)
- **Database**: (e.g. PostgreSQL with Row Level Security)
- **Authentication**: (e.g. Google OAuth 2.0 / JWT session cookies)
- **Third-Party Integrations**: (Payment gateways, transactional email, analytics)

## 6. Non-Functional & Security Requirements
- **Performance**: Page load < 1.5s; API response < 300ms.
- **Security & Authorization**: Role-Based Access Control (RBAC), OWASP Top 10 mitigation, sanitized inputs.
- **Accessibility**: WCAG 2.1 AA compliant color contrast, ARIA labels, keyboard navigability.

# PayTrack — Micro-Merchant Cashless Ledger (Worked Example)

## 1. Executive Summary
PayTrack is a lightweight mobile-first web app for micro-merchants in South Asia to record daily customer credit (bakir khata) and send automated SMS payment reminders via bKash/Nagad.

## 2. Target Persona
- **Name**: Kabir Hossain (Corner Store Owner in Dhaka)
- **Goal**: Track customer balances accurately without paper notebooks.
- **Pain Point**: Customers forget credit balances; losing 15-20% of store revenue to untracked debts.
- **Tech Level**: Uses a low-cost Android smartphone with WhatsApp and bKash.

## 3. P0 Feature: Record Customer Credit Entry (FEAT-01)
- **Description**: Merchant adds a debt or payment record for an existing or new customer.
- **Business Rules**:
  - Customer phone must be a valid 11-digit Bangladeshi number (starts with 01).
  - Amount must be a positive integer between ৳1 and ৳100,000.
- **Acceptance Criteria**:
  - **Success Case**:
    - GIVEN a merchant is logged in and selects customer "Rafiq"
    - WHEN merchant enters amount "৳450", note "Rice & Oil", and taps "Record Credit"
    - THEN the customer's total outstanding balance increases by ৳450 and a confirmation toast appears.
  - **Failure Case**:
    - GIVEN the merchant enters amount "0" or leaves it empty
    - WHEN merchant taps "Record Credit"
    - THEN prevent submission and show inline error "Please enter an amount of at least ৳1".
- **Edge Cases**:
  - Offline handling: If merchant loses mobile data, entry is queued locally via IndexedDB and synced immediately upon network recovery.

## 4. Database Schema Excerpt (PostgreSQL)
```sql
CREATE TABLE public.merchants (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  phone VARCHAR(15) UNIQUE NOT NULL,
  store_name TEXT NOT NULL,
  created_at TIMESTAMPTZ DEFAULT now()
);

CREATE TABLE public.ledger_entries (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  merchant_id UUID NOT NULL REFERENCES public.merchants(id) ON DELETE CASCADE,
  customer_name TEXT NOT NULL,
  customer_phone VARCHAR(15) NOT NULL,
  entry_type VARCHAR(10) CHECK (entry_type IN ('credit', 'payment')),
  amount NUMERIC(10, 2) NOT NULL CHECK (amount > 0),
  note TEXT,
  created_at TIMESTAMPTZ DEFAULT now()
);
```