Arbitrum Nitro with Celestia DA

Overview

The Arbitrum Nitro integration with Celestia enables Orbit chains to use Celestia for data availability instead of Arbitrum AnyTrust. The implementation uses a sidecar architecture where a separate celestia-server handles Celestia-specific operations via RPC.

How it works

Nitro’s batch poster coordinates with the Celestia DAS server to store batch data:

1. Batch posting: The MaybePostSequencerBatch method checks if a DAS writer is configured and acquires a lock before posting
2. Data storage: The DAS writer calls the Celestia server’s Store method, which:
   • Creates a blob from the batch data
   • Submits it to Celestia with retry logic and gas price adjustment
   • Returns a BlobPointer containing block height, share indices, and data commitments
3. Verification: During disputes, Blobstream (default: SP1 Blobstream) confirms batch availability on Celestia, supporting fraud proofs through the hash oracle trick

Key features

• Sidecar architecture: Processing logic handled by separate celestia-server, keeping Nitro nodes lightweight
• Fallback support: Native fallback mechanism with configurable da-preference parameter (e.g., ["celestia", "anytrust"])
• Preimage oracle: Validators populate preimage mappings with Celestia hashes for fraud proof support
• Robust submission: Automatic retry with gas price adjustment for network congestion

Resources

• Nitro fork repository 
• Celestia DAS server