Walrus & Sui

Podseq pairs Walrus (data availability) with Sui (settlement). Walrus exposes blob availability as Sui objects, so the settlement layer verifies DA on the same chain without an external bridge.

Walrus: data availability#

Blocks are buffered and posted to a Walrus publisher in batches by size: one blob holds many blocks, amortizing the per-blob certification cost. Blobs are stored permanent (not deletable, even by the sequencer) for the configured number of epochs (walrus.epochs, default = max, ≈ 2 years).

Podseq writes through a publisher and reads through an aggregator. Both are HTTP endpoints operated by Walrus storage-node operators.

Sui: settlement#

For each block, podseq submits a Move transaction on Sui recording (settlement is per-block even when DA is batched, so every height maps to its batch's blob id):

• the Walrus BlobId of the block data, and
• the sequencer's commitment (block hash and height).

Because Walrus blobs and storage space are Sui objects, the settlement contract can:

• check that a referenced blob is available and for how long,
• record and verify sequencer commitments,
• extend blob lifetimes,
• mediate storage payments and epoch transitions.

End-to-end trust model#

Block produced
     │
     ▼
Walrus blob  ──► availability attested by the storage committee
     │
     ▼
Sui settlement ──► blob ID + sequencer commitment recorded on L1
     │
     ▼
Full nodes verify: every batch has an available, referenced blob on Suicopy

A full node reconstructing the chain reads the commitments from Sui, fetches each blob (a batch) from Walrus, decodes all blocks in it, picks the block for the current height, verifies the sequencer signature, and re-executes it against Reth. If the blob is missing, the height isn't in the batch, or the signature does not verify, the block is rejected.