v0.1.12213 Aug 2026·DevTools, Tabs & interface

Time-travel scrubbing: jump to any pause on the timeline

The last release taught this debugger to step backwards; this one gives it a TIMELINE. Every pause of the current run appears as a row of clickable chips - the breakpoint, each step, where you are now - and clicking any of them jumps execution straight there, however many pauses away, backwards included. One click crosses the whole walk: the engine replays the run deterministically up to exactly that pause and suspends, with every variable at the value it had at that moment. No snapshots are stored and nothing is recorded beyond the walk itself; determinism by construction makes any point of the past directly addressable. Standard time-travel semantics: land in the past and the future is un-walked - stepping re-creates it, byte-identically. Also on the wire for external tools: Debugger.stepTo and Debugger.getTimeline join stepBack on the WebSocket transport. DevTools moves 37 to 38; overall holds at 51.

Parity with the reference browser

74overall, as of v0.1.343

Web APIs / DOM surface42

Security architecture66

GPU / graphics acceleration68

DevTools / extensions72

Networking85

Media85

Accessibility85

Real-world site compatibility99

HTML parsing100

CSS parsing + selectors100

Layout: block / flex / grid / tables / writing-modes100

Paint + visual100

JavaScript language100

JavaScript performance (JIT)100

HTML parsing100

What changed 3 changes

DevTools	The scrubber: a Timeline row in the Debugger panel showing every pause of the current run as a chip (pause number and source line, the current one highlighted); clicking a chip calls the new jump - the recorded command history is cut to the prefix that reaches that pause, queued as the replay plan, and the page re-runs and suspends exactly there. Machine-checked in the gate: from three pauses deep, one jump lands on the FIRST pause byte-identically (reason, function, every scope value), and an out-of-range index is refused without disturbing the parked engine.
DevTools	On the protocol: Debugger.stepTo (index) and Debugger.getTimeline on the WebSocket CDP transport, answered out-of-band like stepBack since the engine thread is parked at the pause being jumped from - an external tool attached over ws:// can read the timeline and jump anywhere in it.
Tabs & interface	Honest scope, as with step-back: a jump replays the run, so side effects re-run and the semantics are exact for deterministic runs (the playground re-runs identical source by construction; a live URL re-fetches). The timeline resets to the replayed prefix after a jump - time-travel without branching timelines. Research note docs/time-travel-debugging.md.