The export reflects the final source, uses relative asset URLs, and no source file is newer than the build. The work is complete.

What was built

Gas Time Machine is a single-page Vite + React + TypeScript site under web/, exported to the committed dist/. The user pastes a mainnet transaction hash and the page fetches the transaction, receipt, block and head from a keyless public node. It shows block number, timestamp, gas used, effective gas price, fee in ETH, sender, recipient and status, each hash and address with a copy button. A comparison panel plots the transaction's gas price against the block's base fee, cheapest, median and 90th percentile, gives rank and tier, and draws every transaction in the block as a rank strip with a hover tooltip. A time-travel panel shows days, hours and minutes since mining, ticking every 30 seconds, plus blocks mined since. Loading, invalid-hash, not-found, pending, network and node-error states all exist, and #0x… deep links work.

Checks that ran

• Typecheck passed and 25 unit tests passed across formatting, time, statistics and the RPC client.
• Production build succeeded with relative asset URLs. Deliverables total about 460 KB.
• The built export was inspected in the task browser at 1280, 390 and 320 CSS pixels with no horizontal overflow and no console errors.
• Interactions verified in the browser: examples, Enter submit, inline validation with focus return, loading, not-found and node-rejection errors with retry, copy buttons by keyboard and pointer, chart hover, skip link, and reduced-motion emulation.

Better Interface review

Seven findings were fixed, including two computed contrast failures on chart bars and input borders, a misleading tier badge on single-transaction blocks, and a stale live-region message. Coverage, evidence and measured contrast ratios are in artifacts/validation.md. The implemented tokens, typography, layout and components are documented in DESIGN.md. The README covers install, preview, rebuild and publish.

Limitations to know about

• The task browser has no internet, so real node data was replayed from responses captured with curl. The live endpoints were confirmed reachable from the shell.
• Screenshots were viewed during the session but could not be saved into the repository because the browser cannot write to the workspace and its output folder is not visible from the shell.
• pnpm's store was read-only on this box, so the lockfile is npm's package-lock.json.
• Not verified: clipboard read-back, a real screen reader, native 200% zoom, and rendered contrast over the two alpha backgrounds.