What is Chia?

Chia is a public blockchain that launched in 2021. Its native coin is XCH. Like Bitcoin it has no company deciding who may transact, and every full node keeps a copy of the whole history. Unlike Bitcoin it is not secured by burning electricity: the network is secured by disk space (see proof of space and time). Anyone with spare storage can take part in producing blocks, which Chia calls farming.

Coins, not accounts

Chia does not keep balances in accounts. Value lives in coins, each with an amount in mojos (one XCH is a trillion mojos) and a puzzle hash, the hash of the small program that decides how the coin may be spent. Spending a coin destroys it and creates new coins; an address is simply a puzzle hash written in a friendlier form. When this site shows an “address balance” it is adding up the unspent coins that share one puzzle hash.

Coins are programs

The program behind a coin is written in Chialisp and runs on the CLVM, a tiny virtual machine every node executes. That is what makes tokens (CATs), NFTs, decentralised identities and offers possible without special-casing them in the protocol: they are just coins with particular puzzles. It also explains the word cost you will see everywhere here: every spend has a CLVM cost, and a block can carry at most 11 billion of it.

A block every 18.75 seconds, transactions in a third of them

A new block arrives on average every 18.75 seconds, but only about one in three is a transaction block that actually includes spends; the others only carry the proofs that keep the chain moving. The dashboard shows both kinds and counts down to the next transaction block.

Where the coins came from

Every block pays a reward of 1 XCH, 1/8 to the farmer and 7/8 to the pool of the winning plot. It halves every three years (it was 2 XCH at launch) until it stays at 0.125 XCH from 2033, so new coins enter circulation at a known rate. Before the first block, Chia Network created a 21 million XCH prefarm held in publicly auditable custody wallets.