*** Note before README. This is a tool I made with AI help to find and verify various xPub derivation structures in making Cold Wallets. For comparison use Blockpath.com tools. All data is yours. Just download the html and open it with a web browser. Hope it helps. ***

A single‑file, client‑side xPub scanner for Bitcoin SV. Derives addresses from an xPub and queries public explorers for balances. No backend, no keys sent to a server.

• Pure client: one HTML file (xpub-tracker.html). Open in a browser.
• Derivation modes: m/i (root), m/0/i (receiving), m/1/i (change).
• Adjustable gap limit and lookahead.
• Balance totals (sats + BSV) and per‑address detail.
• Local persistence via localStorage (xpubs, settings, view prefs).
• Dark/light themes with accessible link contrast.

1. Download or clone this folder.
2. Open xpub-tracker.html directly in your browser (double‑click or drag into a tab).
   • No dev server required.
3. Add an xPub (or tPub) and choose a derivation mode.
4. Click "Rescan" on an entry to refresh with the current settings.

• Derivation Branch: m/0/i, m/1/i, or m/i.
• Gap Limit: stop after N consecutive unused addresses.
• Max Lookahead: maximum indexes to scan.
• Expand/Collapse all; Compact mode for dense lists.
• Export a single xPub’s addresses or export/import all data (JSON files, client‑side only).

• Client‑only: No seeds, xprivs, or sensitive data are collected or transmitted.
• Network calls go to public explorers:
  • WhatsOnChain: https://api.whatsonchain.com/v1/bsv/{main|test}
  • GorillaPool WoC mirror (fallback only for some paths)
• What gets shared: Derived addresses are requested from explorers to obtain balances (standard for SPV‑style lookups).
• Local data: Stored in localStorage under keys like bsv-xpub-tracker, bsv-xpub-settings, compact-mode, theme. Clear your browser storage to remove.
• No analytics/telemetry.

• If your xPub is already at a deeper path (e.g., change branch), switching between m/0 and m/1 may not be possible from that node. The UI shows the scan mode used and previews the first derived address to make behavior explicit.
• If you encounter rate limiting from explorers, rescans may take longer; the app adds small pacing and retries automatically.
• Google Fonts are referenced for UI. For a zero‑external‑UI build, remove the fonts <link> and rely on system fonts.

• Browser performance warnings about long click handlers are benign; rescans run asynchronously and UI remains interactive.
• Extension noise (e.g., "message channel closed") can appear in the console; try an incognito window if distracting.
• If balances look stale, click Rescan. Ensure the desired branch is selected; the header shows the active mode and first derived address.

• This is intentionally a single HTML file for portability. No build tooling.
• You can edit xpub-tracker.html directly.