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

# Bulk API

> The Bulk API provides high-performance access to download large historical datasets in CSV or JSONL format. Designed for data scientists, analysts, and researchers who need to download comprehensive timeseries data at scale.

## Overview

The Bulk API is optimized for downloading large amounts of historical data efficiently. Unlike standard API endpoints that return paginated JSON responses, the Bulk API streams data directly to files in formats optimized for data analysis and processing.

## Available Endpoints

The Bulk API consists of two main endpoints:

* [**Get Available Datasets**](/api-reference/endpoints/bulk/get-v1-datasets) - Returns a catalog of all bulk datasets available based on your subscription tier, including available columns and supported granularities.
* [**Download Dataset**](/api-reference/endpoints/bulk/get-v1-datasets-datasetSlug-granularity-data) - Downloads bulk timeseries data for a specific dataset at a given granularity in CSV or JSONL format.

## Key Features

### Multiple Output Formats

* **CSV**: Comma-separated values, ideal for Excel, pandas, and other data analysis tools
* **JSONL**: JSON Lines format, perfect for streaming data processing and loading into databases

### Flexible Granularities

Download data at different time intervals based on your needs:

* **1d**: Daily intervals
* **1w**: Weekly intervals

### Large Time Ranges

Download months or years of historical data in a single request, with appropriate limits to prevent excessive downloads.

## Use Cases

The Bulk API is ideal for:

* **Data Science & Machine Learning**: Download training datasets for ML models and backtesting algorithms
* **Historical Analysis**: Analyze long-term trends and patterns across multiple assets
* **Data Warehousing**: Populate your data warehouse with comprehensive crypto market data
* **Research**: Academic research requiring large historical datasets
* **Backtesting**: Test trading strategies against extensive historical data

## Getting Started

1. **Get your API key**: Visit [messari.io/account/api](https://messari.io/account/api) to obtain your API key
2. **Check available datasets**: Call the `/bulk/v1/datasets` endpoint to see which datasets you have access to
3. **Download data**: Use the dataset download endpoint with your desired parameters

## Rate Limits & Best Practices

* The Bulk API has concurrency limits to ensure system stability
* Downloads are limited by time range based on granularity to prevent excessive data transfer
* For very large datasets, consider breaking requests into smaller time ranges
* Downloaded files are gzip-compressed when supported by your client to reduce transfer time

## Authentication

All Bulk API requests require authentication via the `x-messari-api-key` header. Access to specific datasets depends on your subscription tier (FREE, PROFESSIONAL, or ENTERPRISE).