anthropics · afmuhaidib · Jun 10, 2026
diff --git a/plugins/this-session/README.md b/plugins/this-session/README.md
@@ -0,0 +1,85 @@
+# this-session
+
+A `/this-session` command that prints a live dashboard of the current Claude Code session — tokens consumed, actual cost, cache savings, models used, and tool call breakdown.
+
+## Overview
+
+Ever wonder how many tokens a long conversation has burned, or how much the cache is actually saving you? `/this-session` reads the live session transcript from `~/.claude/projects/` and renders a formatted monitor right in the chat.
+
+## Example output
+
+```
+╔════════════════════════════════════════════════════════════╗
+║  SESSION MONITOR                                           ║
+╚════════════════════════════════════════════════════════════╝
+
+  SESSION ID   7003719e-9333-448c-b8a5-dae15f4f5823
+  STARTED      6/10/2026, 2:41:25 PM
+  DURATION     18m 42s
+  USER TURNS   12
+  API CALLS    31
+
+  ┌────────────────────────────────────────────────────────────┐
+  │ TOKENS                                                     │
+  ├────────────────────────────────────────────────────────────┤
+  │  Input (direct)               34  ░░░░░░░░░░░░░░░░░░░░    │
+  │  Output                   10,006  ░░░░░░░░░░░░░░░░░░░░    │
+  │  Cache write              37,182  █░░░░░░░░░░░░░░░░░░░    │
+  │  Cache read            1,119,335  ███████████████████░    │
+  │  TOTAL                 1,166,557                          │
+  │  Cache hit rate             96.8%                         │
+  └────────────────────────────────────────────────────────────┘
+
+  ┌────────────────────────────────────────────────────────────┐
+  │ COST                                                       │
+  ├────────────────────────────────────────────────────────────┤
+  │  Actual cost               $0.6254                        │
+  │  Without cache             $3.6197                        │
+  │  Cache savings             $2.9943                        │
+  └────────────────────────────────────────────────────────────┘
+
+  ┌────────────────────────────────────────────────────────────┐
+  │ MODELS                                                     │
+  ├────────────────────────────────────────────────────────────┤
+  │  claude-sonnet-4-6         32 calls    $0.6254            │
+  │    in 34                  out  10,006  ████████████       │
+  └────────────────────────────────────────────────────────────┘
+
+  ┌────────────────────────────────────────────────────────────┐
+  │ TOOLS (top 3)                                              │
+  ├────────────────────────────────────────────────────────────┤
+  │  Bash                          18×  ██████████████████    │
+  │  Edit                           2×  ██░░░░░░░░░░░░░░░░    │
+  │  Write                          1×  █░░░░░░░░░░░░░░░░░    │
+  └────────────────────────────────────────────────────────────┘
+```
+
+## Commands
+
+### `/this-session`
+
+Prints the session dashboard immediately. No arguments needed.
+
+## How it works
+
+- Reads `~/.claude/projects/<cwd-slug>/*.jsonl` (the live session transcript)
+- De-duplicates repeated assistant entries to avoid inflated counts
+- Computes per-model token usage, cost, and cache hit rate
+- Works with mixed-model sessions (e.g. Sonnet + Opus subagents)
+
+## Installation
+
+```sh
+# Copy command definition
+cp plugins/this-session/commands/this-session.md ~/.claude/commands/this-session.md
+
+# Copy the analyzer script
+cp plugins/this-session/this-session.mjs ~/.claude/commands/this-session.mjs
+```
+
+Then type `/this-session` in any Claude Code chat.
+
+## Requirements
+
+- Node.js (any version ≥ 18) — no npm install needed, zero dependencies
+- Claude Code with a live session in `~/.claude/projects/`
diff --git a/plugins/this-session/commands/this-session.md b/plugins/this-session/commands/this-session.md
@@ -0,0 +1,52 @@
+---
+description: Show a live dashboard of the current session — tokens, cost, cache efficiency, models used, and tool call counts.
+allowed-tools: Bash(node:*), Bash(ls:*), Bash(find:*)
+---
+
+Show a real-time overview of this conversation session.
+
+## Steps
+
+1. Find the analyzer script. It is bundled alongside this command inside the plugin directory. Locate it with:
+   ```sh
+   find ~/.claude -name "this-session.mjs" 2>/dev/null | head -1
+   ```
+
+2. Run the script (no arguments — it auto-detects the current session):
+   ```sh
+   node <path-to-script>
+   ```
+
+3. Print the full output verbatim inside a code block so the box-drawing layout renders correctly.
+
+4. After the code block, add a single sentence highlighting the most notable fact (e.g. cache hit rate, dominant cost driver, most-used tool).
+
+## What the dashboard shows
+
+| Section | Details |
+|---|---|
+| Overview | Session ID, start time, duration, user turns, total API calls |
+| Tokens | Input, output, cache-write, cache-read, total, cache hit % |
+| Cost | Actual cost, cost without caching, money saved by caching |
+| Models | Per-model breakdown: calls, tokens in/out, cost |
+| Tools | Top tool calls ranked by frequency |
+
+## Pricing reference (baked into the script)
+
+| Model | Input | Output | Cache write | Cache read |
+|---|---|---|---|---|
+| claude-opus-4-7 / 4-6 | $15/MTok | $75/MTok | $18.75/MTok | $1.50/MTok |
+| claude-sonnet-4-6 | $3/MTok | $15/MTok | $3.75/MTok | $0.30/MTok |
+| claude-haiku-4-5 | $0.80/MTok | $4/MTok | $1.00/MTok | $0.08/MTok |
+
+## Installation
+
+Copy the plugin directory into your Claude commands folder:
+
+```sh
+cp -r plugins/this-session ~/.claude/plugins/this-session
+cp plugins/this-session/commands/this-session.md ~/.claude/commands/this-session.md
+cp plugins/this-session/this-session.mjs ~/.claude/commands/this-session.mjs
+```
+
+Then type `/this-session` in any Claude Code session.
diff --git a/plugins/this-session/this-session.mjs b/plugins/this-session/this-session.mjs
@@ -0,0 +1,257 @@
+#!/usr/bin/env node
+/**
+ * this-session.mjs — analyze the current Claude Code session and print a dashboard.
+ * Usage: node this-session.mjs [<session-jsonl-path>]
+ *
+ * If no path is given it auto-detects the most recently modified .jsonl in
+ * ~/.claude/projects/<cwd-slug>/.
+ */
+
+import fs from "fs";
+import path from "path";
+import os from "os";
+
+// ── Pricing (USD per token) ────────────────────────────────────────────────
+const PRICING = {
+  "claude-opus-4-7":    { in: 15/1e6, out: 75/1e6, cw: 18.75/1e6, cr: 1.50/1e6 },
+  "claude-opus-4-6":    { in: 15/1e6, out: 75/1e6, cw: 18.75/1e6, cr: 1.50/1e6 },
+  "claude-sonnet-4-6":  { in: 3/1e6,  out: 15/1e6, cw: 3.75/1e6,  cr: 0.30/1e6 },
+  "claude-haiku-4-5":   { in: 0.8/1e6,out: 4/1e6,  cw: 1.0/1e6,   cr: 0.08/1e6 },
+  // legacy / fallbacks
+  "claude-opus-4-5":    { in: 15/1e6, out: 75/1e6, cw: 18.75/1e6, cr: 1.50/1e6 },
+  "claude-sonnet-4-5":  { in: 3/1e6,  out: 15/1e6, cw: 3.75/1e6,  cr: 0.30/1e6 },
+};
+function price(model, input, output, cacheWrite, cacheRead) {
+  const p = PRICING[model] || PRICING["claude-sonnet-4-6"];
+  return (input * p.in) + (output * p.out) + (cacheWrite * p.cw) + (cacheRead * p.cr);
+}
+
+// ── Find session file ──────────────────────────────────────────────────────
+function findSessionFile() {
+  const cwd = process.cwd();
+  const projectsDir = path.join(os.homedir(), ".claude", "projects");
+
+  // Build candidate slugs: exact cwd, realpath (resolves symlinks / case), and
+  // a case-insensitive scan of the projects directory as final fallback.
+  const candidates = new Set();
+  const addSlug = p => candidates.add(p.replace(/\//g, "-"));
+  addSlug(cwd);
+  try { addSlug(fs.realpathSync(cwd)); } catch {}
+
+  let dir = null;
+  for (const slug of candidates) {
+    const d = path.join(projectsDir, slug);
+    if (fs.existsSync(d)) { dir = d; break; }
+  }
+
+  // Case-insensitive fallback: scan project dir names
+  if (!dir && fs.existsSync(projectsDir)) {
+    const cwdSlugLower = cwd.replace(/\//g, "-").toLowerCase();
+    for (const entry of fs.readdirSync(projectsDir)) {
+      if (entry.toLowerCase() === cwdSlugLower) {
+        dir = path.join(projectsDir, entry);
+        break;
+      }
+    }
+  }
+
+  if (!dir) return null;
+  const files = fs.readdirSync(dir)
+    .filter(f => f.endsWith(".jsonl"))
+    .map(f => ({ f, mt: fs.statSync(path.join(dir, f)).mtimeMs }))
+    .sort((a, b) => b.mt - a.mt);
+  return files.length ? path.join(dir, files[0].f) : null;
+}
+
+// ── Parse JSONL ────────────────────────────────────────────────────────────
+function parse(filePath) {
+  const raw = fs.readFileSync(filePath, "utf8").split("\n").filter(Boolean);
+  const entries = raw.map(l => { try { return JSON.parse(l); } catch { return null; } }).filter(Boolean);
+
+  let sessionId = null;
+  let startTime = null, endTime = null;
+  const models = new Map(); // model → { calls, input, output, cacheWrite, cacheRead }
+  let tools = new Map();    // toolName → count
+  let userTurns = 0;
+  const seenMsgIds = new Set();
+
+  for (const e of entries) {
+    if (!sessionId && e.sessionId) sessionId = e.sessionId;
+
+    const ts = e.timestamp ? new Date(e.timestamp).getTime() : null;
+    if (ts) {
+      if (!startTime || ts < startTime) startTime = ts;
+      if (!endTime || ts > endTime) endTime = ts;
+    }
+
+    if (e.type === "user") userTurns++;
+
+    const msg = e.message;
+    if (!msg) continue;
+
+    // de-dupe repeated assistant entries (Claude Code sometimes writes the same msg multiple times)
+    const msgId = msg.id;
+    if (msgId && seenMsgIds.has(msgId)) continue;
+    if (msgId) seenMsgIds.add(msgId);
+
+    const usage = msg.usage;
+    if (usage && msg.role === "assistant") {
+      const model = msg.model || "unknown";
+      if (!models.has(model)) models.set(model, { calls: 0, input: 0, output: 0, cacheWrite: 0, cacheRead: 0 });
+      const m = models.get(model);
+      m.calls++;
+      m.input      += usage.input_tokens || 0;
+      m.output     += usage.output_tokens || 0;
+      m.cacheWrite += usage.cache_creation_input_tokens || 0;
+      m.cacheRead  += usage.cache_read_input_tokens || 0;
+    }
+
+    // count tool use calls
+    if (Array.isArray(msg.content)) {
+      for (const block of msg.content) {
+        if (block.type === "tool_use") {
+          tools.set(block.name, (tools.get(block.name) || 0) + 1);
+        }
+      }
+    }
+  }
+
+  return { sessionId, startTime, endTime, models, tools, userTurns };
+}
+
+// ── Formatting helpers ─────────────────────────────────────────────────────
+const fmtN  = n => n.toLocaleString();
+const fmtMs = ms => {
+  const s = Math.round(ms / 1000);
+  if (s < 60) return `${s}s`;
+  const m = Math.floor(s / 60), rem = s % 60;
+  if (m < 60) return `${m}m ${rem}s`;
+  const h = Math.floor(m / 60), rm = m % 60;
+  return `${h}h ${rm}m`;
+};
+const fmtUSD = n => `$${n.toFixed(4)}`;
+const bar = (val, max, width = 20) => {
+  const filled = max > 0 ? Math.round((val / max) * width) : 0;
+  return "█".repeat(filled) + "░".repeat(width - filled);
+};
+const pad = (s, n) => String(s).padEnd(n);
+const lpad = (s, n) => String(s).padStart(n);
+
+// ── Render ─────────────────────────────────────────────────────────────────
+function render(data) {
+  const { sessionId, startTime, endTime, models, tools, userTurns } = data;
+  const duration = startTime && endTime ? endTime - startTime : 0;
+
+  // totals
+  let totalInput = 0, totalOutput = 0, totalCW = 0, totalCR = 0, totalCalls = 0;
+  let totalCost = 0;
+  for (const [model, m] of models) {
+    totalInput  += m.input;
+    totalOutput += m.output;
+    totalCW     += m.cacheWrite;
+    totalCR     += m.cacheRead;
+    totalCalls  += m.calls;
+    totalCost   += price(model, m.input, m.output, m.cacheWrite, m.cacheRead);
+  }
+  const totalTokens = totalInput + totalOutput + totalCW + totalCR;
+
+  // cache efficiency
+  const cacheHitPct = totalCR + totalCW > 0
+    ? ((totalCR / (totalCR + totalCW)) * 100).toFixed(1)
+    : "0.0";
+
+  // cost without cache
+  const naiveCost = (() => {
+    let c = 0;
+    for (const [model, m] of models) {
+      const p = PRICING[model] || PRICING["claude-sonnet-4-6"];
+      c += (m.input + m.cacheWrite + m.cacheRead) * p.in + m.output * p.out;
+    }
+    return c;
+  })();
+  const savedCost = naiveCost - totalCost;
+
+  const W = 60;
+  const line = "─".repeat(W);
+  const dline = "═".repeat(W);
+
+  const lines = [];
+  const p = s => lines.push(s);
+
+  p(`╔${dline}╗`);
+  p(`║${"  SESSION MONITOR".padEnd(W)}║`);
+  p(`╚${dline}╝`);
+  p("");
+
+  // ── Overview ──
+  p(`  SESSION ID   ${sessionId || "unknown"}`);
+  p(`  STARTED      ${startTime ? new Date(startTime).toLocaleString() : "—"}`);
+  p(`  DURATION     ${fmtMs(duration)}`);
+  p(`  USER TURNS   ${userTurns}`);
+  p(`  API CALLS    ${totalCalls}`);
+  p("");
+
+  // ── Tokens ──
+  p(`  ┌${line}┐`);
+  p(`  │ TOKENS${" ".repeat(W - 7)}│`);
+  p(`  ├${line}┤`);
+  p(`  │  ${pad("Input (direct)",      20)}  ${lpad(fmtN(totalInput), 12)}  ${bar(totalInput, totalTokens)}  │`);
+  p(`  │  ${pad("Output",              20)}  ${lpad(fmtN(totalOutput), 12)}  ${bar(totalOutput, totalTokens)}  │`);
+  p(`  │  ${pad("Cache write",         20)}  ${lpad(fmtN(totalCW), 12)}  ${bar(totalCW, totalTokens)}  │`);
+  p(`  │  ${pad("Cache read",          20)}  ${lpad(fmtN(totalCR), 12)}  ${bar(totalCR, totalTokens)}  │`);
+  p(`  │  ${pad("TOTAL",               20)}  ${lpad(fmtN(totalTokens), 12)}${"".padEnd(22)}  │`);
+  p(`  │  ${pad("Cache hit rate",      20)}  ${lpad(cacheHitPct + "%", 12)}${"".padEnd(22)}  │`);
+  p(`  └${line}┘`);
+  p("");
+
+  // ── Cost ──
+  p(`  ┌${line}┐`);
+  p(`  │ COST${" ".repeat(W - 5)}│`);
+  p(`  ├${line}┤`);
+  p(`  │  ${pad("Actual cost",         20)}  ${lpad(fmtUSD(totalCost), 12)}${"".padEnd(22)}  │`);
+  p(`  │  ${pad("Without cache",       20)}  ${lpad(fmtUSD(naiveCost), 12)}${"".padEnd(22)}  │`);
+  p(`  │  ${pad("Cache savings",       20)}  ${lpad(fmtUSD(savedCost), 12)}${"".padEnd(22)}  │`);
+  p(`  └${line}┘`);
+  p("");
+
+  // ── Models ──
+  if (models.size > 0) {
+    p(`  ┌${line}┐`);
+    p(`  │ MODELS${" ".repeat(W - 7)}│`);
+    p(`  ├${line}┤`);
+    const maxCalls = Math.max(...[...models.values()].map(m => m.calls));
+    for (const [model, m] of [...models.entries()].sort((a, b) => b[1].calls - a[1].calls)) {
+      const c = price(model, m.input, m.output, m.cacheWrite, m.cacheRead);
+      p(`  │  ${pad(model, 24)}  ${lpad(m.calls + " calls", 9)}  ${lpad(fmtUSD(c), 9)}  │`);
+      p(`  │    ${pad("in " + fmtN(m.input), 22)}  out ${lpad(fmtN(m.output), 8)}  ${bar(m.calls, maxCalls, 12)}  │`);
+    }
+    p(`  └${line}┘`);
+    p("");
+  }
+
+  // ── Tools ──
+  if (tools.size > 0) {
+    const sorted = [...tools.entries()].sort((a, b) => b[1] - a[1]).slice(0, 12);
+    const maxCount = sorted[0][1];
+    p(`  ┌${line}┐`);
+    p(`  │ TOOLS (top ${sorted.length})${" ".repeat(W - 13 - String(sorted.length).length)}│`);
+    p(`  ├${line}┤`);
+    for (const [name, cnt] of sorted) {
+      p(`  │  ${pad(name, 26)}  ${lpad(cnt, 5)}×  ${bar(cnt, maxCount, 18)}  │`);
+    }
+    p(`  └${line}┘`);
+    p("");
+  }
+
+  return lines.join("\n");
+}
+
+// ── Main ───────────────────────────────────────────────────────────────────
+const filePath = process.argv[2] || findSessionFile();
+if (!filePath || !fs.existsSync(filePath)) {
+  console.error("No session file found. Pass a path or run from a Claude Code project directory.");
+  process.exit(1);
+}
+
+const data = parse(filePath);
+console.log(render(data));