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

# API Reference

> Complete HTTP and WebSocket API reference for QuantCite Data Pipeline

## Overview

The QuantCite Data Pipeline provides real-time cryptocurrency market data through a combination of HTTP endpoints and WebSocket connections. The API offers **WebSocket-based** data streaming, **Unified Transaction APIs** for multi-exchange transaction processing, and HTTP endpoints for health checks and usage monitoring.

## Base URL

```
https://data.quantcite.com
```

## WebSocket URL

```
wss://data.quantcite.com/api/v1/ws
```

## Authentication

Different authentication methods are used based on the API type:

### WebSocket Authentication

WebSocket connections use message-based authentication for enhanced security:

```json theme={null}
{
  "type": "authenticate",
  "api_key": "your_api_key_here"
}
```

### HTTP Authentication

HTTP endpoints use different authentication methods:

* **Public Endpoints**: No authentication required (health, exchanges list)
* **Unified APIs**: Session-based authentication with Bearer tokens
* **Data Usage**: API key in URL path parameter

## API Categories

<CardGroup cols={3}>
  <Card title="Public HTTP Endpoints" icon="globe" href="/api-reference/endpoint/health">
    Health checks, data usage monitoring, and general API information without authentication.
  </Card>

  <Card title="Unified Transaction APIs" icon="database" href="/api-reference/unified/overview">
    Standardized transaction processing across multiple exchanges with session authentication.
  </Card>

  <Card title="WebSocket Streaming" icon="wifi" href="/api-reference/websocket/subscribe">
    Real-time orderbook data streaming and market updates from 50+ active exchanges.
  </Card>
</CardGroup>

## API Features

<CardGroup cols={2}>
  <Card title="Real-time Streaming" icon="wifi">
    WebSocket-based orderbook updates from 52+ active exchanges across 70+ supported platforms with sub-second latency and SSL security.
  </Card>

  <Card title="Transaction Processing" icon="arrows-rotate">
    Unified API for fetching cryptocurrency transactions from multiple exchanges in standardized format.
  </Card>

  <Card title="50GB Data Limit" icon="database">
    Generous monthly data allowance with real-time usage tracking and automatic resets.
  </Card>

  <Card title="Multi-Exchange Support" icon="building-columns">
    Aggregated data from major cryptocurrency exchanges worldwide with unified transaction formats.
  </Card>
</CardGroup>

## Supported Data

### Exchanges

* **Total Supported**: 70+ exchanges
* **Active Exchanges**: 52+ exchanges
* **Major Exchanges**: Binance, OKX, Coinbase, Kraken, Bybit, KuCoin, Gate.io, MEXC, Bitget, Crypto.com

### Trading Pairs

* **Total Pairs**: 50,000+ trading pairs
* **Major Pairs**: BTC/USDT, ETH/USDT, BNB/USDT, ADA/USDT, SOL/USDT
* **Quote Currencies**: USDT, USD, EUR, BTC, ETH

### Data Types

* **Orderbook Data**: Real-time bid/ask levels with depth
* **Market Statistics**: Best bid/ask, spread, mid-price, volume
* **Exchange Information**: Active status, supported pairs
* **Usage Metrics**: Data consumption tracking

## Rate Limits by Tier

| Tier       | Rate Limit     | Monthly Messages | Max Connections | Data Limit |
| ---------- | -------------- | ---------------- | --------------- | ---------- |
| Basic      | 600 req/min    | 10,000           | 5               | 50GB       |
| Premium    | 1,200 req/min  | 100,000          | 20              | 50GB       |
| Developer  | 1,000 req/min  | 50,000           | 15              | 50GB       |
| Enterprise | 10,000 req/min | 1,000,000        | 100             | 50GB       |

## Error Handling

### HTTP Status Codes

* `200` - Success
* `400` - Bad Request (invalid parameters)
* `401` - Unauthorized (invalid API key)
* `404` - Not Found (endpoint/resource not found)
* `429` - Too Many Requests (rate limit exceeded)
* `500` - Internal Server Error

### WebSocket Error Types

* `authentication_error` - Invalid API key or authentication failure
* `subscription_error` - Invalid symbol or exchange
* `rate_limit_exceeded` - Too many requests per minute
* `data_limit_exceeded` - Monthly data limit reached
* `invalid_symbol` - Unsupported trading pair
* `exchange_unavailable` - Exchange not supported or offline

## Getting Started

<CardGroup cols={2}>
  <Card title="Public HTTP Endpoints" icon="terminal" href="/api-reference/endpoint/health">
    Health checks and data usage monitoring via HTTP.
  </Card>

  <Card title="Unified Transaction APIs" icon="database" href="/api-reference/unified/overview">
    Multi-exchange transaction processing with session authentication.
  </Card>

  <Card title="WebSocket Messages" icon="message" href="/api-reference/websocket/subscribe">
    Real-time data subscriptions and orderbook updates.
  </Card>

  <Card title="Quick Start" icon="rocket" href="/quickstart">
    Get connected and receiving data in minutes.
  </Card>
</CardGroup>

## System Statistics

<Info>
  **52+ Active Exchanges** • **70+ Supported Platforms** • **50,000+ Trading Pairs** • **50GB Monthly Limit** • **SSL/WSS Security** • **Sub-second Latency** • **99.9% Uptime**
</Info>