The Working Set

The working set

Nine commands are worth memorizing; run each one now in a session on your machine:

Command	What it does	Why it matters
/context	Colored-grid visualization of the context window	The tool for understanding what your config costs
/permissions	Allow / ask / deny rules for tools	The guardrail surface; previews Parts 4–5
/mcp	MCP server status + authentication	Part 5 home base
/compact	Summarize the conversation to free space	Use at natural breakpoints; takes optional focus instructions
/clear	Wipe history, start fresh	Cheaper than /compact when you don’t need the thread
/rewind	Roll back conversation and/or code	The undo button most people don’t know exists
/model	Switch model / configure effort	—
/skills	List available skills	Part 3 home base
/doctor	Diagnose installation and settings	First stop when anything misbehaves

…plus /init and /memory from Part 1.

Read your context bill

Run /context immediately after starting a fresh session in your repo. Identify the segments: system prompt, your AGENTS.md, skill descriptions, MCP tools. Everything you add in Parts 3–5 shows up in this view, which makes the rest of the course’s trade-offs concrete.

Tip

/clear vs /compact: clear wipes the conversation entirely; compact summarizes it to free space while keeping the thread. Reach for compact at natural breakpoints in long sessions.