Context hygiene

Source: home/.claude/rules/context-hygiene.md, home/.claude/rules/thresholds.json, home/.claude/settings.json, home/.claude/statusline.sh, home/.claude/MANUAL.md ch. 2, home/.claude/CLAUDE.md §Status line.

Work between amber and red, in absolute tokens

The working band is defined by two ids in rules/thresholds.json:

• context-amber — currently 150 (thousand tokens, context_k >= 150).
• context-red — currently 300 (thousand tokens, context_k >= 300).

Below amber: keep going. Between amber and red: still fine, but plan a milestone to compact at. At red: propose /handoff first, then /clear. /compact only when the same thread must continue. Neither number is written in statusline.sh or in any hook — both read the JSON by id, so there is exactly one place to change them.

Why percentage of the window is the wrong rule

rules/context-hygiene.md states it directly: “Percentage of the window is NOT the rule: 60% of 1M is twice the red band.” Quality degrades at an absolute context size, not at a proportional one — 300k tokens is a lot of context whether the window is 200k or 1M. statusline.sh’s own header comment makes the same point: “Why absolute tokens and not % of window: quality degrades at an absolute size, not a proportional one. 366k is a lot of context whether the window is 200k or 1M.”

┋ marks the auto-compact ceiling

home/.claude/settings.json sets env.CLAUDE_CODE_AUTO_COMPACT_WINDOW to 400000. The status line marks this point on its bar as ┋. It sits above context-red (300k) on purpose: statusline.sh’s header frames the bar as “a risk gauge, not a fuel gauge” — the ┋ mark shows where auto-compact will fire so the two limits are visible at once, but the red band at 300k is where the user is expected to act first. Compaction is a lossy event meant to be scheduled deliberately after a handoff, not one that should happen to the session because nobody looked at the bar.

At red: /handoff first, then /clear

From home/.claude/CLAUDE.md §Status line:

Signal	Proposed action
context in the red band	/handoff FIRST, then /clear — /compact only if this thread must continue

/clear is reversible and leaves the prior session resumable; /compact is not, so it is reserved for when the thread genuinely has to keep going.

Milestone compaction beats emergency compaction

From rules/context-hygiene.md: compact after plan approval, after tests pass, or before starting a new unrelated task — not only when forced to by the red band. Waiting for the red band or for auto-compact is choosing the worst possible moment to lose context.

Never paste full logs, datasets, or HTML

Summarize to at most 20 lines, keeping the exact lines that matter. This applies to logs, datasets, and raw HTML alike — the rule is about volume pasted into context, not the source’s format.

One task per session

An unrelated question mid-session is a signal to use /btw or /clear, not to keep working across two unrelated goals in the same context.