[tuler]

Why

With a Cartesi sequencer, the payloads the batch submitter posts to the InputBox are SSZ batches of signed user operations. Through a payload decoder they can only appear as one summary line plus a JSON blob, whether the batch carries 2 operations or 200. The batch envelope is protocol-defined, like portal deposits, so the explorer now decodes it itself. The application's decoder only sees each operation's data.

What

Classification and settings

• A per-application batch submitter address, set on the Overview page. It can be shared as a ?submitter= link param, but a banner asks before a link's suggestion is adopted.
• An input is a batch only when its sender is that address, which is how the scheduler classifies inputs. The explorer never guesses by trying to decode the bytes.

UI

• Inputs list: a batch row reads like "Batch #0 · 3 frames · 5 user ops". Its caret unfolds the operations, showing signer, nonce, max fee and the decoded payload. A malformed batch is flagged and does not unfold.
• Input page: a "Sequencer batch" section shows the batch nonce and submitter, then each frame with its safe block, fee price and operations.
• User-op page: each operation has its own linkable page at inputs/:i/ops/:frame/:op.
• User ops tab: lists operations by scanning the submitter's batches, 25 at a time, with a signer filter. The page states how many batches it has scanned so far.

Decoding (apps/explorer/src/sequencer)

• Mirrors the scheduler: decodeBatch follows ethereum_ssz's rules, recoverUserOpSigner follows alloy's signature rules, and feeToLinear follows fee_to_linear.
• Signers are recovered under the EIP-712 domain carried by each input (its chain id and application contract), not under the explorer's settings.
• Pinned by 334 tests against vectors generated from cartesi/sequencer@8a7c914 by scripts/fixturegen. generate-fixtures.sh first checks that the generator uses the same crate versions as the sequencer.

Decoder contract (@deroll/decoder, minor)

• New UserOp record and optional userOp method. input is no longer called for batches. Existing decoders are unaffected.
• The kit README and the explorer docs page describe both.

Mock server

• Adds signed batches to the perp-dex app: two batches with five and one operations, an empty frame, a forged signature, and a malformed submitter payload.

Not included, on purpose

Operations are labelled submitted. The explorer flags only the outcomes that follow from the bytes: a batch that fails to decode, and an operation whose signature recovers no signer. Other outcomes need more than one batch's bytes: stale or out-of-sequence batches, fee and application validation. Copying those scheduler rules into a UI risks misleading users if the copy drifts, so they are left out.

Testing

• bunx tsc -b, bun run lint and the explorer's vitest suite (334 tests) pass.
• Checked in a browser against the mock server with a test userOp decoder:
  • batch rows unfold
  • signers recover to the test keys
  • the forged op shows as unrecoverable
  • the malformed batch is flagged
  • the user-op page and the User ops tab with the signer filter work
  • no console errors

Follow-ups

• The import map pins the kit at 6fa614d. The kit is types-only, so this needs no bump to work, but the pin can move once this lands.
• Move the batch decoding code to @cartesi/codec once Add sequencer wallet extension cartesi/rollups-ts#141 settles.

🤖 Generated with Claude Code

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Project	Deployment	Actions	Updated
deroll	Ready	Preview	Oct 15, 2026 3:19pm UTC
deroll-explorer	Ready	Preview	Oct 15, 2026 3:19pm UTC

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