This guide covers Fibre clients on celestia-app
v10.4.0 (Mocha: v10.4.0-mocha)
and celestia-node v0.34.3. Fibre requires an
active app version 10 network and registered Fibre servers with enough voting
power to reach quorum. App version 10 is active on
Mainnet Beta and
Mocha. Network activation alone
does not establish that enough Fibre servers are ready to accept uploads.
How Fibre works
You deposit funds into an escrow account.
Your client encodes the blob and signs a payment promise for it.
Your client uploads pieces of the blob (shards) directly to validators'
Fibre servers.
Each server checks its shard and the promise, stores the shard, and returns
a signature.
When validators holding at least 2/3 of total voting power (rounded
down) have signed, your client submits MsgPayForFibre. The chain charges
your escrow and records a small on-chain blob with the commitment.
Anyone with the blob ID can download the blob from the Fibre servers
until retention ends.
Key terms
Term
Meaning
Fibre server
A server run by a validator. It stores and serves blob shards. Also called a Fibre provider.
Escrow account
Prepaid funds that pay for Fibre storage. Separate from your wallet balance.
Payment promise
A message your key signs for each blob. It promises payment from your escrow.
MsgPayForFibre (PFF)
The transaction that settles a payment promise on chain.
Quorum
Signatures from validators holding at least 2/3 of total voting power (rounded down). Needed to settle a blob.
Blob ID
33 bytes: blob version plus commitment. You use it to download the blob.
Retention
How long Fibre servers must keep your shards, counted from promise creation. Set by the shard_retention parameter.
Fibre compared with regular blobs
Fibre
Regular blobs (PayForBlob)
Where the data lives
On validators' Fibre servers, for a limited time
In the block's data square
What goes on chain
MsgPayForFibre and a small blob with the commitment
The full blob data
Maximum size per blob
128 MiB minus 5 bytes
Bounded by the 8 MiB maximum transaction size
How you pay
Prepaid escrow, plus gas for the settlement transaction
Gas fee for the transaction
How you read it back
fibre.Download with the blob ID
blob.Get with height, namespace and commitment
Fibre is a good fit when
Your blobs are large: from several MiB up to 128 MiB.
You need high data throughput and don't need the bytes stored in blocks.
You can keep your own copy of the data, or only need it to be available
for a short window.
Fibre is not a good fit when
You need the data to stay retrievable for days or longer. Fibre is not
archival storage.
Your blobs are tiny. Every Fibre blob is charged for at least 256 KiB.
See pricing.
What Fibre guarantees
Upload: a settled blob carries signed storage attestations from
validators holding at least 2/3 of total voting power (rounded down).
Download: shards from validators holding about 1/3 of voting power
are enough to rebuild the blob.
Integrity: every honest downloader of the same blob ID gets
byte-identical data.
Retention: servers keep shards until the later of two times: the
promise's creation time plus shard_retention (default 4 hours), or the
promise's expiry. The window is counted from promise creation, not upload.
What Fibre does not guarantee
Permanent storage. After retention, servers may delete shards. Keep
your own copy.
That the content is "right". The blob ID binds the bytes, not their
meaning. Check the content in your application.
