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

# API Reference

> Complete reference for all Contazen API endpoints

## Overview

The Contazen API provides programmatic access to all features of the Contazen invoicing platform. This reference documents every endpoint, parameter, and response.

## Base URL

All API endpoints are relative to:

```
https://api.contazen.ro/v1
```

## Available Resources

<CardGroup cols={2}>
  <Card title="Clients" icon="users">
    Manage your customers and business partners

    * List, search, and filter clients
    * Create B2B and B2C clients
    * Update client information
    * Track client history
  </Card>

  <Card title="Invoices" icon="file-invoice">
    Create and manage invoices

    * Generate fiscal documents
    * Send invoices via email
    * Track payment status
    * E-Factura integration
  </Card>

  <Card title="Products" icon="box">
    Manage your product catalog

    * Create products and services
    * Set pricing and VAT rates
    * Organize by categories
    * Track inventory
  </Card>

  <Card title="Payments" icon="credit-card">
    Process and track payments

    * Record payments
    * Generate receipts
    * Payment reconciliation
    * Payment reminders
  </Card>
</CardGroup>

## Authentication

<Note>
  To test the API endpoints in this documentation, you need to add your API key in the **Authorization** field of the API playground. Enter it as: `Bearer sk_live_YOUR_API_KEY`
</Note>

## Request Format

### Headers

All requests must include:

```http theme={null}
Authorization: Bearer YOUR_API_KEY
Content-Type: application/json
Accept: application/json
```

### Optional Headers

```http theme={null}
Accept-Language: ro
```

## Response Format

All responses follow this structure:

### Success Response

```json theme={null}
{
  "success": true,
  "data": {
    // Response data
  },
  "meta": {
    "version": "v1",
    "response_time": "12.45ms"
  }
}
```

### Error Response

```json theme={null}
{
  "success": false,
  "error": {
    "message": "Human-readable error message",
    "type": "error_type",
    "code": "error_code",
    "status": 400
  },
  "meta": {
    "version": "v1",
    "response_time": "12.5ms"
  }
}
```

## Common Parameters

### Pagination

Most list endpoints support pagination:

| Parameter  | Type    | Default | Description               |
| ---------- | ------- | ------- | ------------------------- |
| `page`     | integer | 1       | Page number               |
| `per_page` | integer | 50      | Items per page (max: 100) |

### Filtering

List endpoints typically support:

| Parameter    | Type   | Description           |
| ------------ | ------ | --------------------- |
| `search`     | string | Search term           |
| `sort`       | string | Sort field            |
| `order`      | string | Sort order (asc/desc) |
| `start_date` | string | Filter by date range  |
| `end_date`   | string | Filter by date range  |

### Expanding

Some endpoints support expanding nested objects:

```
GET /api/v1/invoices/inv_123?expand[]=lines&expand[]=payments
```

## OpenAPI Specification

Download our complete OpenAPI specification:

<Card title="OpenAPI 3.0 Spec" icon="file-code" href="/contazen-api.openapi.yaml">
  Machine-readable API specification for code generation and testing
</Card>

## Need Help?

<CardGroup cols={2}>
  <Card title="Postman Collection" icon="code" href="/postman-collection">
    Import our Postman collection for easy API testing
  </Card>

  <Card title="Support" icon="headset" href="mailto:contact@contazen.ro">
    Contact our support team for assistance
  </Card>
</CardGroup>