Status Line — See What the Agent Is Costing You

By default, Claude Code tells you nothing about the two things that matter most while you work: how full the context window is and how much the session has cost. Both are invisible until something goes wrong — the agent starts forgetting earlier instructions, or the bill at the end of the month is a surprise.

A status line fixes that. It is a single line drawn under the prompt, refreshed as you work:

[Opus 5] my-app | 42% ctx | $1.23 | 4m12s | +180/-30

Read left to right: the model answering, the folder you are in, how much of the context window is used, what the session has cost, how long you have been at it, and how many lines of code have changed. When the context number goes amber then red, that is your cue to run /compact — before quality drops.