The world’s fairest
live streaming infrastructure
built on P2P nodes

CASTO envisions a world where live streams can be delivered on ultra-low latency, zero server and affordable cost, powered by blockchain. Instead of relying on centralized CDN (Content Delivery Network) or AWS, CASTO will run on CASTO relay nodes worldwide. CASTO will disrupt the existing live streaming industry with its groundbreaking pricing.

Our Mission

With increasing web traffic due to ultra video volume, current CDN system offers unfair cost ecosystem for media startups, which leads to tech giants' monopoly


Currently, most data center and CDNs are concentrated in certain areas - not everywhere. With CASTO, even areas that do not have the best web infrastructure can have access to high-quality video streaming.


As the better quality of videos become available (from HD to 4k and even to 16k), it will require the higher operating cost. CASTO guarantees by using our webRTC agents, and the cost will be up to 80% lower than the current price.


Existing streaming technology such as HLS or RTMP comes with latency of several seconds, at least 3 seconds. CASTO leverages webRTC technology which enables ultra low latency, below 1 second.


This is a real-time visualization map of CASTO nodes location and live streaming status.

Watch now  Start your own

Core Members

CASTO team loves webRTC, peer-to-peer technology, and blockchain.

Jinho Choi

Jinho Choi

CEO, Co-founder

Jaeho Lee

Jaeho Lee

CTO, Co-founder

Hwaeun Shin

Hwaeun Shin


Hyunseop Han

Hyunseop Han

Core Developer

Latest Blog


CASTO and its ultra low latency

Jan 10, 2019 By Cathy Shin

They say show, don’t tell. And that’s what we did

Read More

Hello it's CASTO

Dec 01, 2018 By Cathy Shin

The broadcasting of tomorrow needs CASTO today

Read More

Frequently Asked Questions

For more information, please choose from the below:

CASTO focuses on realizing broadcasting in a decentralized fashion, specializing in live broadcasting. There are many alternatives to deliver files in a decentralized way, yet there isn't a perfect decentralization alternative for live streaming. CASTO aims to solve the technical challenges of the decentralized live streaming.

There are three major costs in the existing live streaming infrastructure. CPU cost for transcoding, network cost for delivering streams, and time cost of handling all of this. So far, we've had so much to consider for when delivering a video from the sender to the viewer. For example, different requirements for image quality and protocol, physical distance, and relative differences in the network made the architecture complex and costly. As the Web becomes popular and WebRTC emerges, some of these are being removed, and CASTO is confident that most of these costs could be reduced in large part due to the decentralization process.

One of CASTO's key features is ultra-low latency, making CASTO perfect match to various media services. For example, e-sports broadcasting (Twitch) or live quiz show (HQ Trivia), or social media broadcasting (Houseparty) are all areas that encourage active participation by users. CASTO and "Interactive Broadcasting," this new trend of broadcasting, are simply a match made in heaven.

Yes, indeed! Live streaming is showing the fastest growth among other video sectors. It is increasing annually by 113% on average. It will grow up to a $70 billion market by 2021. As the younger generations are familiar with watching videos, and even producing them, we believe the market will only get bigger.

Project Overview

RemoteMonster is a company that has long been operating a WebRTC-based broadcasting API business. CASTO is a future-oriented project that is developing in a decentralized fashion based on RemoteMonster's broadcasting technology.

CASTO SDK and most tools will be available as open source. Since it is linked to compensation-related issues, relay nodes will be open to the public after blockchain technology is successfully applied.

CASTO uses blockchain technology to reward network participants and to meter network bandwidth contributions and consumptions reliably.

Over the next year, CASTO team will put more efforts into technical stability and verification than issuing and distributing CASTO Token.

CASTO team cannot guarantee exactly how much you will save at the moment, but we believe CASTO will be at least 50% cheaper than the existing infrastructure.

Understanding the technology

WebRTC: CASTO thoroughly pursues WebRTC based live streaming. Through this, CASTO gains the benefits of ultra-low latency and standardization.

No server: CASTO aims to be perfectly server-less by the end of 2020.

Peer network: The p2p network of CASTO relay nodes replaces the server.

From media transmission to viewing, all network participants deal with media only through the WebRTC API. By treating images just as a stream and skipping file-based processing, CASTO can support ultra-low latency globally.

In principle, everyone will get paid equally based on the same amount of relay they hosted. However, the payment may be made differently depending on the network bandwidth environment in which the relay node operates.

CASTO measures a relay node's contribution strictly according to the stream relay throughput. WebRTC primarily provides real-time statistics related to these transfers. These statistics are then exchanged and verified with each other on a reliable protocol basis.