Thread Navigator for Claude

About

Purpose: Long multi-turn Claude conversations are hard to navigate — earlier exchanges are buried far up the scrollback, and sending a message throws you to the bottom, losing your reading position. Thread Navigator gives the thread a persistent, navigable structure: a native Chrome side panel that acts as a live table of contents and a memory of where you were.

Features as shipped in v1.0.0:
Navigation — the panel lists every user turn with timestamp and turn number, live-updated as the conversation grows. Click any entry to jump straight to it, with a gold flash marking the landing. Jump-to-top and jump-to-latest buttons, keyboard navigation, and a position line (e.g. 07/34) showing where you are. Jumps work even on turns Chrome has unmounted in very long virtualized threads, via scroll-seeking with learned positions.

Reading-position recovery — the differentiator. Your current reading position is tracked continuously (and distinguishes your own scrolling from claude.ai's auto-scrolls). Sending a message records where you were; the ⬑ button returns you there, backed by a history stack so repeated navigation always leaves a trail. The previous position is marked in purple in the index, your current turn in gold.
Bookmarks — star any turn; teal highlights in the index, persisted in Chrome storage across sessions, with a count in the header.

Fidelity — the index comes from claude.ai's own conversation data, so it's complete and correct: it follows message edits and branch switches, resolves duplicate prompts correctly, and shows attachment counts, edit indicators, and a "generating" pulse during streaming. Type sizes track the conversation's text size and zoom. Dense and relaxed layouts switch automatically at five turns.
Footprint — active only on claude.ai, per-tab correct across multiple windows, works immediately on install, minimal permissions, fully local with no network requests of its own.