compaction-protocol

Used by /build to manage context rot. Read on-demand at compaction steps; do not preload.

Tool order

1. Context editing first. Clear stale tool results verbatim. This is rot-immune because nothing is paraphrased.
2. Sub-agent delegation second. If the next bulk read can be delegated, the lead never accumulates the rot in the first place.
3. Summarization-based /compact last. Re-summarization compresses, but it also creates a new lower-fidelity anchor the model will over-attend to. Use only when conversation bulk (not tool output) is the source of pressure.

When to trigger

Trigger on concept shifts, not percentages:

• Next action unrelated to recent tool results. Clear stale results before they distort the next decision.
• Starting a new sub-issue or task-list item. Concept boundary.
• Just spawned a sub-agent. Isolation already in place.
• About to read large files or wide paths. Delegate instead — prevent rot, don't compact.
• Auto-compact warning appears. Stop, run protocol, resume. Never let it run unattended.

Context editing — the default

Use context editing to clear superseded tool outputs (reads after edits, old test runs, stale doc lookups). Reports 84% reduction vs. summarization; no paraphrase artifacts. Default tool — reach for /compact only when context editing can't fix the root pressure.

Summarization-based /compact — last resort

When conversation bulk (not tool output) is the pressure, write the Keep list to .claude/NOTES.md first:

/compact

Keep: <architectural decisions>; <current task and files in scope>;
<unresolved bugs or failing tests>; <open questions from the issue>.

Drop: <rejected alternatives>; <tool outputs already acted on>;
<API docs already internalized>; <exploration that led nowhere>.

Keep what the model can't reconstruct from the issue or .claude/NOTES.md. Drop anything large and replayable.

Verification

After compaction, run: Summarize where we are and what the next step is.

Diff the summary against the Keep list in .claude/NOTES.md. If anything is missing, restate it explicitly before the next tool call. If hollow, abort and re-read the issue + .claude/NOTES.md.

Rules

• Compaction is a build-time responsibility. Do not defer to /wrap-up.
• Each step is more lossy. Context editing → delegation → /compact. Never skip steps.