Claude Code Turn Monitor

Real-time per-turn telemetry for Claude Code in the VS Code status bar. See context fill, cache efficiency, and API-equivalent cost the moment Claude responds — without leaving your editor.

Features

Per-turn metrics in the status bar

After every Claude response, the status bar updates with:

🤖 sonnet-4-6 | Ctx: 31% | Hit: 100% | ~$0.02

Indicator	Description
`Ctx: 31%`	Percentage of the 200K context window consumed this turn
`Hit: 100%`	Cache hit rate — proportion of input served from cache vs billed fresh
`~$0.02`	API-equivalent cost for this turn (subscription users see `~` prefix)

Cache health indicator

The status bar background reflects cache efficiency at a glance:

Blue/Green — hit rate ≥ 70%. Cache is warm; reads cost ~10× less than fresh input.
Orange — hit rate 31–69%. Cache partially stale.
Red — hit rate ≤ 30%. Context is rebuilding every turn at full cost.

Hover tooltip

Hovering the status bar item shows a full token breakdown for the current turn — input, cache write, cache read, output — along with your plan type, rate limit tier, and subscription date read from ~/.claude.json.

Plan awareness

Set claudeWatcher.planType to subscription or api. Subscription users see API-equivalent costs (prefixed ~) rather than actual charges, making the numbers meaningful for understanding value rather than spend.

How It Works

The extension watches ~/.claude/projects/**/*.jsonl — the conversation logs Claude Code writes locally for every session. On each file change, it reads the last assistant entry and computes metrics from the raw token counts.

Per-window isolation: Each VS Code window scopes to its own workspace. Claude Code encodes the workspace path as the project directory name (e.g. /Users/you/project → ~/.claude/projects/-Users-you-project/), so the extension reads only the JSONL files belonging to that window's workspace. Multiple windows running different models — or different projects — display independent metrics.

No Anthropic API calls are made. No extra tokens are consumed. The only network request is a daily fetch of Anthropic's pricing page to calculate cost. If the page cannot be parsed, the extension falls back to hardcoded prices bundled with the release.

Note on usage limits: Session and weekly usage percentages depend on Anthropic's server-side rate limit state, which varies with capacity. Use /usage inside Claude Code for real-time limit data.

Requirements

Claude Code CLI installed and active (creates ~/.claude/projects/ automatically)
VS Code 1.85.0 or later

Configuration

Setting	Default	Description
`claudeWatcher.planType`	`subscription`	`subscription` for Pro/Max/Team flat-fee plans; `api` for pay-as-you-go. Controls cost labelling.

Author

Shivaraj

Claude Code Turn Usage Monitor

shivaraj-arch