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Vantage

Local-first analytics for Claude Code: token, cost, and agent-delegation insight from your own session logs.

thousands of sessions · zero data leaves the machine

role
Architect and sole engineer
stack
Next.js · TypeScript · Tailwind v4 · virtualized lists
status
oss

// 01 - PROBLEM

Heavy Claude Code users accumulate thousands of .jsonl session transcripts and no way to answer: where did the tokens go, what did each session cost, which projects and tools dominate? Existing tools ship your usage data to third parties.

// 02 - APPROACH

  • Reads the session logs Claude Code already writes to ~/.claude/projects - no instrumentation, no telemetry.
  • Insights dashboard: token totals, year heatmap, model mix, per-project and per-branch rollups, tool frequency.
  • Session explorer: server-side search, sort, filter over a virtualized list; per-session agent timeline and delegation tree.
  • Cost view: per-model estimates, 5-hour billing-window tracker, burn-rate meter.

// 03 - ARCHITECTURE

Parse once, cache by mtime
Each file parses a single time into a compact per-session contribution; full message events are dropped after rollup. Memory stays bounded across thousands of sessions.
Local-first, always
Everything computes on the machine that owns the data. Privacy mode anonymizes names for screenshots and demos.

// 04 - PRODUCTION-GRADE

  • Stays fast at thousands-of-sessions scale (windowed virtualization, server-side filtering)
  • Editable per-model pricing so estimates track reality
  • Keyboard-accessible controls, loading skeletons, empty states
  • Nothing leaves the machine - verifiable by reading the code

// 05 - ARTIFACTS