> ## Documentation Index
> Fetch the complete documentation index at: https://docs.paypulse.cv/llms.txt
> Use this file to discover all available pages before exploring further.

# Introduction

> API documentation for PayPulse — subscription billing and revenue operations.

## Welcome to PayPulse

PayPulse is a subscription billing platform that handles invoicing, dunning, usage-based pricing, and secure payments.

**Base URL:** `https://api.paypulse.cv/api/v1`

<CardGroup>
  <Card title="Quickstart" icon="bolt" href="/quickstart">
    Get your first API call running in 2 minutes.
  </Card>

  <Card title="Authentication" icon="key" href="/authentication">
    Learn how to authenticate with API keys and JWT tokens.
  </Card>

  <Card title="API Reference" icon="code" href="/api-reference/auth">
    Full reference for every endpoint.
  </Card>
</CardGroup>

## Core concepts

| Concept              | Description                                                 |
| -------------------- | ----------------------------------------------------------- |
| **Merchant**         | Your business account. Owns projects and API keys.          |
| **Project**          | A logical grouping for plans, customers, and subscriptions. |
| **Plan**             | A pricing configuration — fixed or metered billing.         |
| **Subscription**     | A customer's active enrollment in a plan.                   |
| **Invoice**          | A billing record generated each period.                     |
| **Checkout Session** | A hosted payment page for customers to subscribe.           |

## Authentication

All API requests require either:

* **API key** — passed as `X-Api-Key` header. Scopes to a project.
* **JWT token** — passed as `Authorization: Bearer <token>`. Used for merchant management routes.

Some endpoints accept both (dual-auth). See [Authentication](/authentication) for details.

## Rate limits

* **100 requests/second** per API key
* **1000 requests/minute** per merchant

Rate limit headers are included in every response:

```
X-RateLimit-Limit: 100
X-RateLimit-Remaining: 97
X-RateLimit-Reset: 1690000000
```