What is IOST? How It Works & Where to Use It

Overview

IOST at a glance.

IOST, short for Internet of Services Token, is a Layer 1 blockchain whose Olympus mainnet went live in February 2019. It was designed for high transaction throughput and lets developers write smart contracts in JavaScript rather than a specialized language. Here is how it works and what it is used for, not the price.

Total value locked (DeFi)

n/a

Value locked in DeFi protocols on IOST. Updated Jun 8, 2026. Source: DefiLlama.

Native token

IOST

Used for fees and securing the network. See the live IOST price.

How it works

How IOST works.

IOST uses a Proof of Believability consensus, where nodes are scored on a believability factor that combines their IOST balance, their record of past contributions, and their behavior on the network. The protocol rotates block production across qualified nodes rather than concentrating it in a few, and validators are selected through community votes. This is paired with sharding so that work can be split across groups of nodes.

Consensus: Proof of Believability (PoB)

IOST uses a Proof of Believability consensus, where nodes are scored on a believability factor that combines their IOST balance, their record of past contributions, and their behavior on the network. The protocol rotates block production across qualified nodes rather than concentrating it in a few, and validators are selected through community votes. This is paired with sharding so that work can be split across groups of nodes.

Believability scoring

Each node is rated on a believability factor drawn from its token balance, its contributions to the network, and its behavior, which influences its role in producing and verifying blocks.

JavaScript contracts

Smart contracts on IOST are written in JavaScript, a widely used language, which lowers the barrier for developers who already know web programming.

Servi nodes

Servi or Partner nodes produce blocks and are chosen by community votes, with both the voters and the selected nodes earning token rewards.

Sharding

IOST uses a sharding design called Efficient Distributed Sharding that divides nodes into groups so transactions can be processed in parallel.

Ecosystem & usage

What IOST is used for.

IOST is used to run smart contracts, host decentralized applications, and support voting and staking on the network.

Running applications

Developers deploy smart contracts and decentralized applications written in JavaScript on the IOST base layer.

Voting for nodes

IOST holders vote for Servi nodes that produce blocks, and both voters and selected nodes receive token rewards.

Paying fees

IOST is the native token used to pay for transactions and contract execution on the network.

In Zypto App

Hold, swap and spend IOST.

IOST is integrated in Zypto App. Hold IOST in self-custody, swap it to any supported asset, and use it across Zypto’s features.

Hold IOST in Zypto How to buy IOST

Be the reason IOST ships next.

IOST isn’t in Zypto App yet. Post the request to your followers, chains with the most demand get prioritised.

Request on X

FAQ

Common questions.

What is IOST used for?

IOST is the native token of the IOST Layer 1 blockchain. It is used to pay transaction fees, to run smart contracts and applications, and to vote for the nodes that produce blocks.

How does IOST reach consensus?

IOST uses Proof of Believability, which scores nodes on a believability factor built from their token balance, contributions, and behavior, then rotates block production across qualified nodes selected by community votes.

What language are IOST smart contracts written in?

Smart contracts on IOST are written in JavaScript, which lets developers who already know web programming build on the network without learning a specialized contract language.

What is the supply of IOST?

IOST has a total supply of 21 billion tokens set at its token sale, with a small amount of new issuance each year used to reward nodes, voters, and ecosystem development.

Can I hold IOST in Zypto App?

Not yet. IOST isn't in Zypto App at the moment. You can hold it in any self-custodial wallet, and you can ask us to add IOST using the "Request IOST" button above.

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