/cost-tracker

name: cost-tracker
description: Track session costs, set budget alerts, and optimize token spend. Use to check costs mid-session or set spending limits.
user-invocable: true

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

# 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

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