Key Insight

/compact preserves conversation flow. Fresh context maximizes per-task attention at the cost of continuity.

Sources: Chroma Research - Context Rot | Ralph Loop Origin | METR - Long Task Capability | Anthropic - Context Engineering

What Consumes Context?

Action	Context Cost
Reading a small file	Low (~500 tokens)
Reading a large file	High (~5K+ tokens)
Running commands	Medium (~1K tokens)
Multi-file search	High (~3K+ tokens)
Long conversations	Accumulates

Context Depletion Symptoms

Learn to recognize when context is running out:

Symptom	Severity	Action
Shorter responses than usual	🟡 Warning	Continue with caution
Forgetting CLAUDE.md instructions	🟠 Serious	Document state, prepare checkpoint
Inconsistencies with earlier conversation	🔴 Critical	New session needed
Errors on code already discussed	🔴 Critical	New session needed
"I can't access that file" (when it was read)	🔴 Critical	New session immediately

Context Inspection

Check your context usage in detail:

/context

Example output:

┌─────────────────────────────────────────────────────────────┐
│ CONTEXT USAGE                                    67% used   │
├─────────────────────────────────────────────────────────────┤
│ System Prompt          ████████░░░░░░░░░░░░░░░░  12,450 tk  │
│ System Tools           ██░░░░░░░░░░░░░░░░░░░░░░   3,200 tk  │
│ MCP Tools (5 servers)  ████████████░░░░░░░░░░░░  18,600 tk  │
│ Conversation           ████████████████████░░░░  89,200 tk  │
├─────────────────────────────────────────────────────────────┤
│ TOTAL                                           123,450 tk  │
│ REMAINING                                        76,550 tk  │
└─────────────────────────────────────────────────────────────┘

💡 The Last 20% Rule: Reserve ~20% of context for:

• Multi-file operations at end of session
• Last-minute corrections
• Generating summary/checkpoint

Cost Awareness & Optimization

Note: If you use claude -p, the Agent SDK, GitHub Actions, or any automation harness, a billing model change effective June 15, 2026 introduces a new monthly credit cap on programmatic usage separate from interactive limits. See §9.13: The Interactive/Programmatic Billing Split for the full breakdown, affected tools, and audit steps.

Claude Code isn't free - you're using API credits. Understanding costs helps optimize usage.