How Celestia processes transactions
Celestia orders transactions and publishes blob data instead of executing smart contracts; validators vote and light nodes sample the data to check it.
Vahe HakobyanEditor-in-chief
Updated Oct 6, 20263 min readFact-checked
On this page
- Blob data is erasure-coded and named before the vote.
- Light nodes sample pieces instead of whole blocks.
- Validators propose blocks and vote on the order.
- Finality lets a rollup rebuild and execute its data.
This guide follows a transaction from the wallet to a finalized block. You do not need to run a node or hold TIA to follow along.
What does Celestia do with transactions?
Celestia orders transactions and makes blob data available. It does not execute smart contracts, so no application logic runs on the chain itself. A transaction there pays a fee in TIA and may carry blob data with the payment.
How does Celestia process transactions step by step
Once a transaction reaches the network, the validators do the work. One of them proposes a block, the rest vote, and light nodes check that the published data can be retrieved.
- 1Receive transactionsValidators collect the transactions and blobs that users and rollups send to the network.
- 2Build the blockOne chosen validator orders the waiting transactions and lays out the block.
- 3Erasure-code the blob dataEach blob is split into extra pieces, so the data can be rebuilt if pieces go missing.
- 4Sort pieces into namespacesThe pieces are filed under namespace IDs, and a rollup reads the namespace that belongs to it.
- 5Vote on the blockThe other validators check the block and vote, and enough votes fix the order.
- 6Sample the dataLight nodes ask for a few random pieces, not the whole block. If the pieces arrive, the data counts as available.
What happens after Celestia finalizes a block?
A block is final once enough validators have voted, and its order will not change. Its data becomes retrievable by anyone. A rollup that posted a blob can rebuild the data and run its own transactions.
Frequently asked questions
Celestia is a layer 1 blockchain with its own validators and consensus rules. Rollups build on top of it, which is why people call them layer 2s.
TIA pays the fee on Celestia. A rollup that posts data there usually charges you in its own token instead.
A blob is a bundle of data a rollup posts to Celestia, often a batch of its own transactions. Blobs can be large, which is why Celestia erasure-codes them before publishing.
No. Smart contracts and dapps run in rollups, and those rollups use Celestia to get their data ordered and published.
