More info on active projects and modules at dat-ecosystem.org

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Dat

npm install -g dat

Use dat command line to share files with version control, back up data to servers, browse remote files on demand, and automate long-term data preservation.

dat is the first application based upon the Hypercore Protocol, and drove the architectural design through iterative development between 2014 and 2017. There exists a large community around it.

Have questions? Join our chat via IRC or Gitter:

Thanks to our financial supporters!

Table of Contents

• Installation
• Getting Started
• Using Dat
• Troubleshooting
• Javascript API
• For Developers

Installation

Dat can be used as a command line tool or a javascript library:

• Install the $ dat CLI to use in the command line.
• require('dat') - dat-node, a library for downloading and sharing dat archives in javascript apps.

Installing the $ dat command line tool

The recommended way to install dat is through a single file binary distribution version of dat with the one line install command below. The binary includes a copy of node and dat packaged inside a single file, so you just have to download one file in order to start sharing data, with no other dependencies needed on your system:

wget -qO- https://raw.githubusercontent.com/datproject/dat/master/download.sh | bash

Next version

Try the next version of dat! This version (14.0.0) is not compatible with older versions (13.x) and below, and works on node v12.

npm install -g dat@next

Maintainers wanted!

NPM Prerequisites

• Node: You'll need to install Node JS before installing Dat. Dat needs node version 4 or above and npm installed. You can run node -v to check your version.
• npm: npm is installed with node. You can run npm -v to make sure it is installed.

Once you have npm ready, install dat from npm with the --global, -g option, npm install -g dat.

Getting started

What is Dat?

Share, backup, and publish your filesystem. You can turn any folder on your computer into a dat. Dat scans your folder, allowing you to:

• Track your files with automatic version history.
• Share files with others over a secure peer to peer network.
• Automate live backups to external HDs or remote servers.
• Publish and share files with built in HTTP server.

Dat allows you to focus on the fun work without worrying about moving files around. Secure, distributed, fast.

• Documentation: docs.datproject.org
• Dat white paper

Desktop Applications

Rather not use the command line? Check out these options:

• Beaker Browser - An experimental p2p browser with built-in support for the Hypercore Protocol.
• Dat Desktop - A desktop app to manage multiple dats on your desktop machine.

JS Library

Add Dat to your package.json, npm install dat --save. Dat exports the dat-node API via require('dat'). Use it in your javascript applications! Dat Desktop and Dat command line both use dat-node to share and download dats.

Full API documentation is available in the dat-node repository on Github.

We have Dat installed, let's use it!

Dat's unique design works wherever you store your data. You can create a new dat from any folder on your computer.

A dat is some files from your computer and a .dat folder. Each dat has a unique dat:// link. With your dat link, other users can download your files and live sync any updates.

Sharing Data

You can start sharing your files with a single command. Unlike git, you do not have to initialize a repository first, dat share or simply dat will do that for you:

dat <dir>

Use dat to create a dat and sync your files from your computer to other users. Dat scans your files inside <dir>, creating metadata in <dir>/.dat. Dat stores the public link, version history, and file information inside the dat folder.

dat sync and dat share are aliases for the same command.

Downloading Data

dat dat://<link> <download-dir>

Use dat to download files from a remote computer sharing files with Dat. This will download the files from dat://<link> to your <download-dir>. The download exits after it completes but you can continue to update the files later after the clone is done. Use dat pull to update new files or dat sync to live sync changes.

dat clone is an alias for the same command.

Misc Commands

A few other highlights. Run dat help to see the full usage guide.

• dat create or dat init - Create an empty dat and dat.json file.
• dat log ~/data/dat-folder/ or dat log dat://<key> - view the history and metadata information for a dat.

Quick Demos

To get started using Dat, you can try downloading a dat and then sharing a dat of your own.

Download Demo

We made a demo folder just for this exercise. Inside the demo folder is a dat.json file and a gif. We shared these files via Dat and now you can download them with our dat key!

Similar to git, you can download somebody's dat by running dat clone <link>. You can also specify the directory:

❯ dat clone dat://778f8d955175c92e4ced5e4f5563f69bfec0c86cc6f670352c457943666fe639 ~/Downloads/dat-demo
dat v13.5.0
Created new dat in /Users/joe/Downloads/dat-demo/.dat
Cloning: 2 files (1.4 MB)

2 connections | Download 614 KB/s Upload 0 B/s

dat sync complete.
Version 4

This will download our demo files to the ~/Downloads/dat-demo folder. These files are being shared by a server over Dat (to ensure high availability) but you may connect to any number of users also hosting the content.

You can also also view the files online: datbase.org/778f8d955175c92e4ced5e4f5563f69bfec0c86cc6f670352c457943666fe639. datbase.org can download files over Dat and display them on HTTP as long as someone is hosting it. The website temporarily caches data for any visited links (do not view your dat on datbase.org if you do not want us to cache your data).

Sharing Demo

Dat can share files from your computer to anywhere. If you have a friend going through this demo with you, try sharing to them! If not we'll see what we can do.

Find a folder on your computer to share. Inside the folder can be anything, Dat can handle all sorts of files (Dat works with really big folders too!).

First, you can create a new dat inside that folder. Using the dat create command also walks us through making a dat.json file:

❯ dat create
Welcome to dat program!
You can turn any folder on your computer into a Dat.
A dat is a folder with some magic.

This will create a new (empty) dat. Dat will print a link, share this link to give others access to view your files.

Once we have our dat, run dat <dir> to scan your files and sync them to the network. Share the link with your friend to instantly start downloading files.

Bonus HTTP Demo

Dat makes it really easy to share live files on a HTTP server. This is a cool demo because we can also see how version history works! Serve dat files on HTTP with the --http option. For example, dat --http, serves your files to a HTTP website with live reloading and version history! This even works for dats you're downloading (add the --sparse option to only download files you select via HTTP). The default HTTP port is 8080.

Hint: Use localhost:8080/?version=10 to view a specific version.

Get started using Dat today with the share and clone commands or read below for more details.

Usage

The first time you run a command, a .dat folder is created to store the dat metadata. Once a dat is created, you can run all the commands inside that folder, similar to git.

Dat keeps secret keys in the ~/.dat/secret_keys folder. These are required to write to any dats you create.

Creating a dat & dat.json

dat create [<dir>]

The create command prompts you to make a dat.json file and creates a new dat. Import the files with sync or share.

Optionally bypass Title and Description prompt:

dat create --title "MY BITS" --description "are ready to synchronize! 😎"

Optionally bypass dat.json creation:

dat create --yes
dat create -y

Sharing

The quickest way to get started sharing files is to share:

❯ dat 
dat://3e830227b4b2be197679ff1b573cc85e689f202c0884eb8bdb0e1fcecbd93119
Sharing dat: 24 files (383 MB)

0 connections | Download 0 B/s Upload 0 B/s

Importing 528 files to Archive (165 MB/s)
[=-----------------------------------------] 3%
ADD: data/expn_cd.csv (403 MB / 920 MB)

dat [<dir>] [--no-import] [--no-watch]

Start sharing your dat archive over the network. It will import new or updated files since you last ran create or sync. Dat watches files for changes and imports updated files.

• Use --no-import to not import any new or updated files.
• Use --no-watch to not watch directory for changes. --import must be true for --watch to work.

Ignoring Files

By default, Dat will ignore any files in a .datignore file, similar to git. Each file should be separated by a newline. Dat also ignores all hidden folders and files. Supports pattern wildcards (/*.png) and directory-wildcards (/**/cache).

Selecting Files

By default, Dat will download all files. If you want to only download a subset, you can create a .datdownload file which downloads only the files and folders specified. Each should be separated by a newline.

Downloading

Start downloading by running the clone command. This creates a folder, downloads the content and metadata, and a .dat folder inside. Once you started the download, you can resume at any time.

dat <link> [<dir>] [--temp]

Clone a remote dat archive to a local folder. This will create a folder with the key name if no folder is specified.

Downloading via dat.json key

You can use a dat.json file to clone also. This is useful when combining Dat and git, for example. To clone a dat you can specify the path to a folder containing a dat.json:

git git@github.com:joehand/dat-clone-sparse-test.git
dat ./dat-clone-sparse-test

This will download the dat specified in the dat.json file.

Updating Downloaded Archives

Once a dat is clone, you can run either dat pull or dat sync in the folder to update the archive.

dat pull [<dir>]

Download latest files and keep connection open to continue updating as remote source is updated.

Shortcut commands

• dat <link> <dir> will run dat clone for new dats or resume the existing dat in <dir>
• dat <dir> is the same as running dat sync <dir>

Key Management & Moving dats

dat keys provides a few commands to help you move or backup your dats.

Writing to a dat requires the secret key, stored in the ~/.dat folder. You can export and import these keys between dats. First, clone your dat to the new location:

• (original) dat share
• (duplicate) dat clone <link>

Then transfer the secret key:

• (original) dat keys export - copy the secret key printed out.
• (duplicate) dat keys import - this will prompt you for the secret key, paste it in here.

Troubleshooting

We've provided some troubleshooting tips based on issues users have seen. Please open an issue or ask us in our chat room if you need help troubleshooting and it is not covered here.

If you have trouble sharing/downloading in a directory with a .dat folder, try deleting it and running the command again.

Check Your Dat Version

Knowing the version is really helpful if you run into any bugs, and will help us troubleshoot your issue.

Check your Dat version:

dat -v

You should see the Dat semantic version printed, e.g. 14.0.0.

Installation Issues

Node & npm

To use the Dat command line tool you will need to have node and npm installed. Make sure those are installed correctly before installing Dat. You can check the version of each:

node -v
npm -v

Global Install

The -g option installs Dat globally, allowing you to run it as a command. Make sure you installed with that option.

• If you receive an EACCES error, read this guide on fixing npm permissions.
• If you receive an EACCES error, you may also install Dat with sudo: sudo npm install -g dat.
• Have other installation issues? Let us know, you can open an issue or ask us in our chat room.

Debugging Output

If you are having trouble with a specific command, run with the debug environment variable set to dat (and optionally also dat-node). This will help us debug any issues:

DEBUG=dat,dat-node dat dat://<link> dir

Networking Issues

Networking capabilities vary widely with each computer, network, and configuration. Whenever you run Dat there are several steps to share or download files with peers:

1. Discovering Peers
2. Connecting to Peers
3. Sending & Receiving Data

With successful use, Dat will show Connected to 1 peer after connection. If you never see a peer connected, your network may be restricting discovery or connection.

JS API

You can use Dat in your javascript application:

var Dat = require('dat')

Dat('/data', function (err, dat) {
  // use dat
})

Read more about the JS usage provided via dat-node.

For Developers

Please see guidelines on contributing before submitting an issue or PR.

This command line library uses dat-node to create and manage the archives and networking. If you'd like to build your own Dat application that is compatible with this command line tool, we suggest using dat-node.

Installing from source

Clone this repository and in a terminal inside of the folder you cloned run this command:

npm link

This should add a dat command line command to your PATH. Now you can run the dat command to try it out.

The contribution guide also has more tips on our development workflow.

• npm run test to run tests
• npm run auth-server to run a local auth server for testing

License

BSD-3-Clause