Claude Code Token Optimization Guide

Cut your token consumption in half. Based on 800 hours of real operation data.

1. Where Your Tokens Actually Go

After 800 hours of autonomous Claude Code operation, here's the measured breakdown of where tokens are consumed:

2. CLAUDE.md Optimization (Highest Impact)

Your CLAUDE.md is the single biggest lever for token savings. It's included in every API call, so every line costs you tokens on every turn.

5 Optimization Patterns

1. Allowlist pattern — Instead of listing 10 things to avoid, state what is allowed. "Only modify files in /src/" is cheaper than listing 10 forbidden directories.
2. One example per rule — Three examples don't help more than one precise example. Cut the extras.
3. One-line reasons — Write "why" in one line. Move detailed explanations to Skills files.
4. Table format — Tables are more token-efficient than bullet lists for structured data like architecture or conventions.
5. Delegate to hooks — Rules you want strictly enforced belong in hooks, not CLAUDE.md. Hooks are free (they run locally), CLAUDE.md costs tokens every turn.

Before & After

# BEFORE: 200+ lines (costs ~5,000 tokens/turn)
## Project Rules
- Do not modify files in /config/
- Do not modify files in /migrations/
- Do not modify files in /.github/
- Do not delete any files without asking
- Do not use rm -rf
- Do not force-push
- Do not commit directly to main
- Always run tests before committing
- Use TypeScript strict mode
... (190 more lines of rules, examples, and explanations)

# AFTER: 35 lines (costs ~800 tokens/turn)
# my-app

## Rules
- Only modify files in /src/ and /tests/ (hook enforced)
- Test before commit (hook enforced)
- TypeScript strict mode

## Architecture
| Layer | Tech | Path |
|-------|------|------|
| API | Express + Zod | /src/api/ |
| DB | Prisma + Postgres | /prisma/ |
| Auth | JWT + bcrypt | /src/auth/ |

## Conventions
- Files: kebab-case
- Functions: camelCase
- One export per file

Result: Same behavior enforcement, 84% fewer tokens per turn. Over a 30-turn session, this saves ~126,000 tokens.

Analyze your current CLAUDE.md: CLAUDE.md Analyzer (free tool)

3. Hook-Based Token Guards

Hooks are shell scripts that run before or after Claude Code's tool calls. They execute locally (zero token cost) and can prevent token waste automatically.

# Install 691+ safety and optimization hooks in 10 seconds
npx cc-safe-setup

Token-Saving Hooks

Quick Setup

# Option 1: Full safety + token optimization suite
npx cc-safe-setup

# Option 2: Token guards only
npx cc-safe-setup
# Then use the Hook Selector to pick only token-related hooks

Choose exactly which hooks you need: Hook Selector (interactive)

4. Model Selection Strategy

Not every task needs Opus. Using the right model per task can cut costs by 60–80%.

Switch models mid-session with /model. No need to restart.

5. Context Management

Context is the most expensive resource in Claude Code. Every message accumulates in the context window, and you pay for all of it on every turn.

Key Practices

• /clear between tasks — When you switch from one feature to another, clear the context. Old context is dead weight that costs tokens on every subsequent turn.
• /compact for long sessions — Compresses conversation history. You can add custom instructions: /compact keep only code changes and test results
• Split sessions every 2–3 hours — After 2–3 hours, compaction quality degrades. Start a fresh session.
• Disable unused MCP servers — Each MCP server adds its tool schemas to every turn. Check with /mcp and disable what you don't need.
• Use targeted file reads — Read file.py lines 50-80 instead of reading entire files. The large-read-guard hook enforces this.

6. Opus 4.7 Survival Tips

Opus 4.7 (released April 16, 2026) changed the token economics significantly:

• 4x faster quota burn — The new tokenizer uses more tokens for the same text. Thinking tokens also increased.
• Safety classifier issues — The April 16 launch introduced auto-mode safety classifier bugs, leading to 20+ data loss incidents in 3 days. (#49302, #50027)
• cache_read billing anomaly — cache_read_input_tokens appearing with no prior cache_creation, inflating costs (#49302)

Immediate Actions for Opus 4.7

1. Lower your token-budget-guard threshold to 70% of your previous setting
2. Use /model sonnet for routine tasks — Opus 4.7 is expensive for simple work
3. Enable pre-compact-checkpoint — Critical with Opus 4.7's increased hallucination rate under pressure
4. Monitor with /cost — Check your actual spending per session

Full Opus 4.7 issue tracker: Opus 4.7 Survival Guide (17 sections, 28 tracked issues)

7. FAQ

Q: My Max Plan ($200/month) runs out in 15 minutes. What's wrong?

Usually caused by a bloated CLAUDE.md (200+ lines), multiple MCP servers running simultaneously, or subagents spawning in loops. Start with Step 2 (CLAUDE.md optimization) — it's the single highest-impact fix. Issue #42796 (1,700+ reactions) tracks this problem.

Q: Pro Plan ($20/month) — can I only use Claude Code 12 out of 30 days?

That matches community reports. With optimization, you can extend usable days to 20–25 by reducing per-session token consumption. The techniques in Step 2–5 above apply to Pro plan users as well.

Q: Do hooks slow down my sessions?

No. Hooks execute locally in 10–50ms. The token savings (thousands to tens of thousands per session) far outweigh the negligible execution time.

Q: I upgraded to Opus 4.7 and my costs doubled. Is this expected?

Yes. Opus 4.7's new tokenizer uses more tokens for the same input. Combined with increased thinking tokens and output length, costs can increase 2–4x. See Section 6 for mitigation steps.

Q: Can I use these techniques with the API (not Claude Code)?

The CLAUDE.md optimization and context management principles apply to any Claude usage. The hooks are specific to Claude Code CLI/desktop.