feat: add /cfo skill — session cost + AI spend dashboard

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## 0.0.3 — 2026-03-12
+
+- Add `/cfo` skill — session cost banner + 30-day AI spend dashboard. Reads token usage directly from `~/.claude/projects/` transcripts. Breaks spend down by day, project/branch, detects repeated prompts, and gives personalized cost-saving tips. Includes `ai_spend.py`, a standalone Python dashboard that also supports team/org views and manual logging of Cursor, Lovable, ChatGPT, and other AI tool spend.
+
 ## 0.0.2 — 2026-03-12
 
 - Fix project-local `/browse` installs — compiled binary now resolves `server.ts` from its own directory instead of assuming a global install exists

CLAUDE.md

@@ -21,6 +21,7 @@ gstack/
 ├── review/          # PR review skill
 ├── plan-ceo-review/ # /plan-ceo-review skill
 ├── plan-eng-review/ # /plan-eng-review skill
+├── cfo/             # /cfo skill — session cost + project spend dashboard
 ├── retro/           # Retrospective skill
 ├── setup            # One-time setup: build binary + symlink skills
 ├── SKILL.md         # Browse skill (Claude discovers this)

README.md

@@ -23,6 +23,7 @@ Six opinionated workflow skills for [Claude Code](https://docs.anthropic.com/en/
 | `/ship` | Release engineer | Sync main, run tests, push, open PR. For a ready branch, not for deciding what to build. |
 | `/browse` | QA engineer | Give the agent eyes. It logs in, clicks through your app, takes screenshots, catches breakage. Full QA pass in 60 seconds. |
 | `/retro` | Engineering manager | Analyze commit history, work patterns, and shipping velocity for the week. |
+| `/cfo` | CFO | Show current session cost and elapsed time, then run the full AI spend dashboard for the project. |
 
 ## Demo: one feature, five modes
 
@@ -76,17 +77,17 @@ This is not a prompt pack for beginners. It is an operating system for people wh
 
 ## Install
 
-**Requirements:** [Claude Code](https://docs.anthropic.com/en/docs/claude-code), [Git](https://git-scm.com/), [Bun](https://bun.sh/) v1.0+. `/browse` compiles a native binary — works on macOS and Linux (x64 and arm64).
+**Requirements:** [Claude Code](https://docs.anthropic.com/en/docs/claude-code), [Git](https://git-scm.com/), [Bun](https://bun.sh/) v1.0+, `jq` (`brew install jq`), Python 3.10+. `/browse` compiles a native binary — works on macOS and Linux (x64 and arm64).
 
 ### Step 1: Install on your machine
 
 Open Claude Code and paste this. Claude will do the rest.
 
-> Install gstack: run `git clone https://github.com/garrytan/gstack.git ~/.claude/skills/gstack && cd ~/.claude/skills/gstack && ./setup` then add a "gstack" section to CLAUDE.md that says to use the /browse skill from gstack for all web browsing, never use mcp\_\_claude-in-chrome\_\_\* tools, and lists the available skills: /plan-ceo-review, /plan-eng-review, /review, /ship, /browse, /retro. Then ask the user if they also want to add gstack to the current project so teammates get it.
+> Install gstack: run `git clone https://github.com/garrytan/gstack.git ~/.claude/skills/gstack && cd ~/.claude/skills/gstack && ./setup` then add a "gstack" section to CLAUDE.md that says to use the /browse skill from gstack for all web browsing, never use mcp\_\_claude-in-chrome\_\_\* tools, and lists the available skills: /plan-ceo-review, /plan-eng-review, /review, /ship, /browse, /retro, /cfo. Then ask the user if they also want to add gstack to the current project so teammates get it.
 
 ### Step 2: Add to your repo so teammates get it (optional)
 
-> Add gstack to this project: run `cp -Rf ~/.claude/skills/gstack .claude/skills/gstack && rm -rf .claude/skills/gstack/.git && cd .claude/skills/gstack && ./setup` then add a "gstack" section to this project's CLAUDE.md that says to use the /browse skill from gstack for all web browsing, never use mcp\_\_claude-in-chrome\_\_\* tools, lists the available skills: /plan-ceo-review, /plan-eng-review, /review, /ship, /browse, /retro, and tells Claude that if gstack skills aren't working, run `cd .claude/skills/gstack && ./setup` to build the binary and register skills.
+> Add gstack to this project: run `cp -Rf ~/.claude/skills/gstack .claude/skills/gstack && rm -rf .claude/skills/gstack/.git && cd .claude/skills/gstack && ./setup` then add a "gstack" section to this project's CLAUDE.md that says to use the /browse skill from gstack for all web browsing, never use mcp\_\_claude-in-chrome\_\_\* tools, lists the available skills: /plan-ceo-review, /plan-eng-review, /review, /ship, /browse, /retro, /cfo, and tells Claude that if gstack skills aren't working, run `cd .claude/skills/gstack && ./setup` to build the binary and register skills.
 
 Real files get committed to your repo (not a submodule), so `git clone` just works. The binary and node\_modules are gitignored — teammates just need to run `cd .claude/skills/gstack && ./setup` once to build (or `/browse` handles it automatically on first use).
 
@@ -383,6 +384,66 @@ It saves a JSON snapshot to `.context/retros/` so the next run can show trends.
 
 ---
 
+## `/cfo`
+
+This is my **CFO mode**.
+
+I want to know what I'm spending before I forget to check. `/cfo` tells me what the current session cost, how long I've been in it, and what the total spend on the project looks like over the last 30 days.
+
+It reads Claude Code's session transcripts directly — no API keys, no third-party tracking. Just token counts from `~/.claude/projects/` turned into dollars.
+
+```
+You:   /cfo
+
+Claude:
+╔══════════════════════════════════════════════════╗
+║  This session                                    ║
+╠══════════════════════════════════════════════════╣
+║  $4.81 · 6h 30m · +122 −14                      ║
+╚══════════════════════════════════════════════════╝
+
+  AI Spend Dashboard  ·  @you  ·  my-project  ·  last 30 days
+
+  Daily Spend
+  ────────────────────────────────────────────────────────────
+  Mar 12  ██████████████████████  $36.23  ✓ 36% of budget
+
+  Spend per Feature / Branch
+  ────────────────────────────────────────────────────────────
+  my-project  /  main           ████████████████████  $36.23
+
+  Prompt Repetition  (potential waste)
+  ────────────────────────────────────────────────────────────
+  Estimated waste from repetition: $1.29
+
+  Cost-Saving Strategies
+  ────────────────────────────────────────────────────────────
+  1.  Excellent cache hit rate (93%). Keep sessions open rather than starting fresh.
+  2.  Average session cost is $18. Scope one feature per session.
+  ...
+```
+
+The dashboard breaks spend down by day, by project/branch, detects repeated prompts that are wasting money, and gives personalized cost-saving tips based on your actual usage patterns.
+
+You can also log spend from other AI tools (Cursor, Lovable, ChatGPT, etc.) and see a unified view:
+
+```bash
+python3 ~/.claude/skills/cfo/ai_spend.py --add
+# Tool name: Cursor
+# Cost in USD: 5.00
+# Date: today
+```
+
+And if your team shares a directory, you can see aggregated spend across everyone:
+
+```bash
+python3 ~/.claude/skills/cfo/ai_spend.py --setup   # configure team_dir
+python3 ~/.claude/skills/cfo/ai_spend.py --export  # share your data
+python3 ~/.claude/skills/cfo/ai_spend.py --team    # see the full team
+```
+
+---
+
 ## Troubleshooting
 
 **Skill not showing up in Claude Code?**
@@ -392,7 +453,7 @@ Run `cd ~/.claude/skills/gstack && ./setup` (or `cd .claude/skills/gstack && ./s
 Run `cd ~/.claude/skills/gstack && bun install && bun run build`. This compiles the browser binary. Requires Bun v1.0+.
 
 **Project copy is stale?**
-Re-copy from global: `for s in browse plan-ceo-review plan-eng-review review ship retro; do rm -f .claude/skills/$s; done && rm -rf .claude/skills/gstack && cp -Rf ~/.claude/skills/gstack .claude/skills/gstack && rm -rf .claude/skills/gstack/.git && cd .claude/skills/gstack && ./setup`
+Re-copy from global: `for s in browse plan-ceo-review plan-eng-review review ship retro cfo; do rm -f .claude/skills/$s; done && rm -rf .claude/skills/gstack && cp -Rf ~/.claude/skills/gstack .claude/skills/gstack && rm -rf .claude/skills/gstack/.git && cd .claude/skills/gstack && ./setup`
 
 **`bun` not installed?**
 Install it: `curl -fsSL https://bun.sh/install | bash`
@@ -401,15 +462,15 @@ Install it: `curl -fsSL https://bun.sh/install | bash`
 
 Paste this into Claude Code:
 
-> Update gstack: run `cd ~/.claude/skills/gstack && git fetch origin && git reset --hard origin/main && ./setup`. If this project also has gstack at .claude/skills/gstack, update it too: run `for s in browse plan-ceo-review plan-eng-review review ship retro; do rm -f .claude/skills/$s; done && rm -rf .claude/skills/gstack && cp -Rf ~/.claude/skills/gstack .claude/skills/gstack && rm -rf .claude/skills/gstack/.git && cd .claude/skills/gstack && ./setup`
+> Update gstack: run `cd ~/.claude/skills/gstack && git fetch origin && git reset --hard origin/main && ./setup`. If this project also has gstack at .claude/skills/gstack, update it too: run `for s in browse plan-ceo-review plan-eng-review review ship retro cfo; do rm -f .claude/skills/$s; done && rm -rf .claude/skills/gstack && cp -Rf ~/.claude/skills/gstack .claude/skills/gstack && rm -rf .claude/skills/gstack/.git && cd .claude/skills/gstack && ./setup`
 
 The `setup` script rebuilds the browser binary and re-symlinks skills. It takes a few seconds.
 
 ## Uninstalling
 
 Paste this into Claude Code:
 
-> Uninstall gstack: remove the skill symlinks by running `for s in browse plan-ceo-review plan-eng-review review ship retro; do rm -f ~/.claude/skills/$s; done` then run `rm -rf ~/.claude/skills/gstack` and remove the gstack section from CLAUDE.md. If this project also has gstack at .claude/skills/gstack, remove it by running `for s in browse plan-ceo-review plan-eng-review review ship retro; do rm -f .claude/skills/$s; done && rm -rf .claude/skills/gstack` and remove the gstack section from the project CLAUDE.md too.
+> Uninstall gstack: remove the skill symlinks by running `for s in browse plan-ceo-review plan-eng-review review ship retro cfo; do rm -f ~/.claude/skills/$s; done` then run `rm -rf ~/.claude/skills/gstack` and remove the gstack section from CLAUDE.md. If this project also has gstack at .claude/skills/gstack, remove it by running `for s in browse plan-ceo-review plan-eng-review review ship retro cfo; do rm -f .claude/skills/$s; done && rm -rf .claude/skills/gstack` and remove the gstack section from the project CLAUDE.md too.
 
 ## Development
 

VERSION

@@ -1 +1 @@
-0.0.2
+0.0.3

cfo/SKILL.md

@@ -0,0 +1,103 @@
+---
+name: cfo
+version: 1.0.0
+description: |
+  CFO mode: show current session cost and elapsed time, then run the AI spend
+  dashboard for this project. Tells you exactly what you've spent this session
+  and in total on the project.
+allowed-tools:
+  - Bash
+  - Read
+---
+
+# /cfo — Session Cost + Project Spend Dashboard
+
+You are running the `/cfo` skill. Show what this session cost and what the total project spend looks like.
+
+## Step 1 — Locate the ai_spend.py script
+
+```bash
+if [ -f .claude/skills/cfo/ai_spend.py ]; then
+  echo "SCRIPT=.claude/skills/cfo/ai_spend.py"
+elif [ -f ~/.claude/skills/cfo/ai_spend.py ]; then
+  echo "SCRIPT=$HOME/.claude/skills/cfo/ai_spend.py"
+else
+  echo "SCRIPT=NOT_FOUND"
+fi
+```
+
+If `NOT_FOUND`, tell the user: "ai_spend.py not found. Run `cd ~/.claude/skills/gstack && ./setup` (user install) or `cd .claude/skills/gstack && ./setup` (project install) to reinstall." Then stop.
+
+Set `SCRIPT` to whichever path was found.
+
+## Step 2 — Gather all session metrics in one call
+
+Run this entire block as a single bash command. It finds the transcript, computes cost and elapsed time, and gets git stats — all in one shell so variables don't get lost between calls.
+
+Note: cost is computed using Claude Sonnet pricing (input $3/MTok, cache_write $3.75/MTok, cache_read $0.30/MTok, output $15/MTok). If using Opus or Haiku the estimate will differ; the full dashboard in Step 3 uses per-model pricing.
+
+```bash
+PROJECT_DIR=$(pwd | sed 's|/|-|g')
+TRANSCRIPT=$(ls -t "$HOME/.claude/projects/$PROJECT_DIR"/*.jsonl 2>/dev/null | head -1)
+
+if [ -z "$TRANSCRIPT" ]; then
+  echo "SESSION_COST=unavailable"
+  echo "ELAPSED=unavailable"
+else
+  # Compute cost and timestamps in one awk pass
+  eval $(jq -r 'select(.message.usage) | [
+    (.message.usage.input_tokens // 0),
+    (.message.usage.cache_creation_input_tokens // 0),
+    (.message.usage.cache_read_input_tokens // 0),
+    (.message.usage.output_tokens // 0),
+    (.timestamp // "")
+  ] | @tsv' "$TRANSCRIPT" | awk -F'\t' '
+  NR==1 { first_ts = $5 }
+  { input += $1; cache_write += $2; cache_read += $3; output += $4; last_ts = $5 }
+  END {
+    cost = (input * 3 + cache_write * 3.75 + cache_read * 0.30 + output * 15) / 1000000
+    printf "SESSION_COST=$%.4f\nFIRST_TS=%s\nLAST_TS=%s\n", cost, first_ts, last_ts
+  }')
+
+  # Compute elapsed time
+  ELAPSED=$(python3 -c "
+from datetime import datetime
+def p(s): return datetime.fromisoformat(s.replace('Z','+00:00'))
+diff = p('$LAST_TS') - p('$FIRST_TS')
+m = int(diff.total_seconds() / 60)
+print(f'{m//60}h {m%60}m' if m >= 60 else f'{m}m')
+" 2>/dev/null || echo "unavailable")
+
+  echo "SESSION_COST=$SESSION_COST"
+  echo "ELAPSED=$ELAPSED"
+fi
+
+# Git stats
+GIT_STATS=$(git diff --stat HEAD 2>/dev/null | tail -1)
+echo "GIT_STATS=${GIT_STATS:-none}"
+```
+
+Use the SESSION_COST, ELAPSED, and GIT_STATS values for the banner in Step 4.
+
+## Step 3 — Run the project spend dashboard
+
+```bash
+python3 "$SCRIPT" "$(pwd)" --days 30
+```
+
+## Step 4 — Print the session banner, then the dashboard
+
+Print this banner using the values from Step 2:
+
+```
+╔══════════════════════════════════════════════════╗
+║  This session                                    ║
+╠══════════════════════════════════════════════════╣
+║  $<session_cost> · <elapsed> · <git +N −N>       ║
+╚══════════════════════════════════════════════════╝
+```
+
+Then output the full ai_spend.py dashboard (Step 3 output) below it.
+
+- If SESSION_COST is "unavailable", omit the cost from the banner and note that the transcript was not found.
+- If GIT_STATS is "none", omit the git portion of the banner line.