Optimistic Rollup Lab

backend offline

Chain activity

click a batch to inspect · hover a legend chip to see what each color means

Verified
Suspicious
Dispute live
Finalized
Fraud proven
Pending

OP batches group L2 blocks under one posted output root. Suspicious roots wait for local verification and a user challenge.

L1 Mainnet#0
0
OP L2#0
0

Scoreboard

Watcher flagged 0%Fraud resolved on L1 0%

OP: Optimistic

Trust first, prove fraud after

Batches posted

0

Honest

0

Fraudulent

0

Flagged

0

Verified mismatch

0

In dispute

0

Resolved fraud

0

Fault rate ~1 in 8. Suspicious roots wait for you to verify and challenge during the 120s window.

Optimistic rollup lifecycle

Start a simulation to track every OP batch here - including batches that scroll off the canvas. Swaps, L1 bonds, rollbacks, and balance changes stay visible for the whole session.

Event log

optimistic lane · click any event for details

0 events

Recent

No events yet - start a demo.

Proof lab

Open a proof when you want to study it. Overlays never auto-popup.

Start a demo and wait for batches to resolve. Proof artifacts appear here for you to explore on your schedule.

What happens when an optimistic root is challenged?

  1. The challenge targets a claimed L2 output root or assertion, not usually one transaction directly.
  2. The challenger verifies locally first by deriving the expected state from posted L1 data.
  3. The challenger posts a bond so invalid challenges are costly.
  4. The dispute game narrows the disagreement from a batch to a trace segment to one execution step.
  5. Ethereum verifies the small disputed step or records the final dispute result, not the whole L2 by default.
  6. A successful challenge rejects the bad root and prevents withdrawals that rely on it.
  7. Legitimate transactions in available batch data are not thrown away just because the claimed root was wrong.
  8. Honest nodes re-derive the correct chain and state from available L1 data.
  9. Forced inclusion is separate from fraud proving. It addresses sequencer censorship, not wrong execution.