cost-tracker

# Cost Tracker Monitor and optimize Claude Code session costs. ## Trigger Use when: - Checking session costs - Setting budget alerts - Optimizing token spend - Planning multi-session work ## Cost Awareness ### Check Current Costs ```bash # Session cost is shown at the end of each session # Mid-session: check the status bar or run /cost ``` ### Cost Drivers | Operation | Relative Cost | Optimization | |-----------|--------------|-------------| | Large file reads | High | Use offset/limit params | | Broad grep searches | Medium | Scope to specific dirs | | Subagent spawning | High (new context) | Reuse agents via SendMessage | | Repeated tool calls | Cumulative | Batch operations | | MCP tool calls | Variable | Minimize round-trips | | Model selection | 3-10x difference | Use haiku for simple tasks | ### Token Budget by Task Type | Task | Typical Cost | Budget Alert | |------|-------------|-------------| | Bug fix | $0.10-0.50 | $1.00 | | Feature (small) | $0.50-2.00 | $3.00 | | Feature (large) | $2.00-8.00 | $10.00 | | Refactor | $1.00-5.00 | $7.00 | | Code review | $0.20-1.00 | $2.00 | ### Tool-Call Budgets Set explicit budgets by task complexity: | Task Type | Tool-Call Budget | Wrap-Up At | |-----------|-----------------|------------| | Quick fix / lookup | 20 calls | 15 | | Bug fix | 30 calls | 25 | | Feature (small) | 50 calls | 40 | | Feature (large) | 80 calls | 65 | | Refactor | 50 calls | 40 | At the wrap-up threshold: commit progress, assess remaining work, decide whether to continue or start fresh. ### Optimization Strategies 1. **Scope prompts tightly** — "Fix the auth bug in src/auth/login.ts" vs "Fix the auth bug" 2. **Use the right model** — Haiku for simple lookups, Sonnet for features, Opus for architecture 3. **Delegate to subagents** — Search/explore operations in subagents keep main context lean 4. **Compact proactively** — Don't wait for auto-compact; compact at task boundaries 5. **Read selectively** — Use `offset` and `limit` params for large files 6. **Batch operations** — Multiple independent tool calls in one message 7. **One-pass discipline** — Write complete solution, test once, stop if green 8. **No re-reads** — Don't re-read unchanged files; trust cached knowledge 9. **Read before write** — Never write a file without reading it first 10. **Kill output bloat** — No sycophantic openers, no closing fluff, no prompt restatement ## Budget Alerts Set mental checkpoints: - **50% budget** — Are you on track? Should you compact? - **80% budget** — Wrap up current task, avoid new exploration - **100% budget** — Commit what you have, start fresh session ## Output ```text COST TRACKER Session cost: $X.XX Token usage: [input]K in / [output]K out Cache hit rate: ~XX% Top cost drivers: 1. [operation] — $X.XX 2. [operation] — $X.XX Optimization tips: - [specific suggestion] ``` ## Rules - Track costs as awareness, not hard limits - Never sacrifice code quality to save tokens - Compact at task boundaries, not mid-task - Use subagents for exploration-heavy work