Context Management

Claude has a context window limit. Learning to manage it is essential for working with large codebases.

Understanding Context

Claude's context window is like its "working memory":

• Claude 3.5 Sonnet: 200K tokens (~150K words)
• Everything counts: Your messages, Claude's responses, file contents

When context fills up, you need to manage it.

Context Commands

/clear

Clears all context and starts fresh:

> /clear
Starting new session...

Use when:

• Switching to unrelated tasks
• Context is cluttered with old info
• Claude seems confused

/compact

Summarizes current context to free space:

> /compact
Compacting context...
Retained: Key files, recent changes
Freed: 45K tokens

Use when:

• Getting "context limit" warnings
• Mid-session and need more space
• Want to continue current work

/resume

Continues from a previous session:

claude --resume

Use when:

• Continuing yesterday's work
• Picking up after a break
• Need previous context

Strategies for Large Projects

1. Scope Your Requests

# Too broad
> Review the codebase

# Better
> Review the authentication module in src/auth/

2. Use Directory CLAUDE.md

Create CLAUDE.md files in subdirectories:

/src/auth/CLAUDE.md
/src/payments/CLAUDE.md
/src/notifications/CLAUDE.md

3. Reference Don't Include

# Instead of pasting code
> The function in src/utils/validation.ts has a bug

# Claude will read just that file

4. Summarize Before Clearing

> Summarize what we've done so far before I clear context

Then after clearing:

> We just completed: [paste summary]
> Now let's continue with...

Context Usage Patterns

Monitoring Context

Ask Claude about usage:

> How much context have we used?

Or check the status indicator in your terminal.

Next Steps

In the next module, you'll learn advanced techniques: sub-agents, MCPs, and hooks.