Celestia Activates Fibre, Opening Direct Validator Uploads for Rollups

Celestia activated Fibre on mainnet on Oct. 20, giving rollups a separate route to publish large packages of transaction data directly to validators. The project's network status record confirms that app version 10, which introduces Fibre, is live.

The change separates data transport from consensus: validators store pieces of a blob, while Celestia records its commitment and validator signatures onchain. For rollups using Fibre, the chain therefore processes the record of an upload rather than its full payload. Fibre runs alongside existing Celestia blockspace, giving developers a choice rather than automatically moving their data to the new service.

The initial software permits blobs of up to 128 MiB, including headers, and 200 PayForFibre messages per block. Mainnet's documented block cadence is approximately three seconds. Those limits define the submission envelope, not a measured sustained mainnet data rate.

The upgrade uses celestia-app v10.4.0, whose instructions required consensus node operators to install the new binary before activation. A mainnet block returned through QuickNode's public endpoint, dated Oct. 20, records app version 10. Validators run Fibre as a separate service and register their public upload addresses after activation.

“Fibre is now live on Celestia mainnet,” the project said in its announcement.

Mainnet Starts Below the Benchmark Settings

Celestia's Oct. 1 benchmark reported average throughput of 3.07 terabits per second across 120 validators over a 143-second load window. The team described that as enough data for nearly two billion transactions per second. That is a target="__blank" rel="noopener noreferrer ">The Defiant reported last week that daily blob data had fallen during TIA's rally. Celenium's daily series puts the latest complete UTC day, Oct. 19, at about 1.87 billion bytes, compared with 2.05 billion on Oct. 15 and 2.77 billion on Sept. 18. Those are usage figures before the launch, not tests of Fibre's capacity.

Developers also need to account for retrieval. Fibre's current specification sets default shard retention at four hours and says applications needing long-term access must keep a copy elsewhere.