CLAUDE_AUTOCOMPACT_PCT_OVERRIDE cannot raise threshold above default (~83%)

Summary

CLAUDE_AUTOCOMPACT_PCT_OVERRIDE is documented as allowing users to control when auto-compaction triggers, but it can only lower the threshold below the default — never raise it. Setting it to 95 (meaning "compact at 95% usage") has no effect because of a Math.min clamp in the threshold calculation.

Root cause

In the minified source, the threshold function (deobfuscated) does:

function getAutoCompactThreshold(model) {
  let effectiveWindow = getEffectiveWindow(model);
  let defaultThreshold = effectiveWindow - 13000;     // ~83.5% of 200k
  let override = process.env.CLAUDE_AUTOCOMPACT_PCT_OVERRIDE;
  if (override) {
    let pct = parseFloat(override);
    if (!isNaN(pct) && pct > 0 && pct <= 100) {
      let userThreshold = Math.floor(effectiveWindow * (pct / 100));
      return Math.min(userThreshold, defaultThreshold);  // ← override silently capped
    }
  }
  return defaultThreshold;
}

Math.min(userThreshold, defaultThreshold) means any value above ~83% is ignored.

Expected behavior

Setting CLAUDE_AUTOCOMPACT_PCT_OVERRIDE=95 should trigger auto-compaction at 95% context usage, not ~83%. If there's a safety reason for the buffer, it should be documented — and the env var should either work as advertised or not exist.

Reproduction

1. Set "env": { "CLAUDE_AUTOCOMPACT_PCT_OVERRIDE": "95" } in ~/.claude/settings.json
2. Start a long conversation
3. Observe compaction triggers at ~80-85%, not 95%