Function Truncate

internal/ctx/ctx.go:85–96

Truncate collapses oversized tool outputs to first 2k + last 2k tokens; inputs at or under 6k pass through unchanged. Head/tail can't overlap: >6k tokens means >24k bytes, well over the 16k kept. Boundaries snap to a valid UTF-8 rune start so non-ASCII output never breaks mid-sequence.

(out string)

// inputs at or under 6k pass through unchanged. Head/tail can't overlap:
// >6k tokens means >24k bytes, well over the 16k kept. Boundaries snap to a
// valid UTF-8 rune start so non-ASCII output never breaks mid-sequence.
func Truncate(out string) string {
	total := Tokens(out)
	if total <= ToolOutputCap {
		return out
	}
	limit := ToolHeadTail * 4
	head := runeBoundaryDown(out, limit)
	tail := runeBoundaryUp(out, len(out)-limit)
	marker := fmt.Sprintf("\n───── truncated: %d tokens total, first %d + last %d shown, the middle is OMITTED. This is a PARTIAL view; you can't review or conclude from code you can't see here, so re-run narrower (grep/sed/head/tail) to read the omitted span. ─────\n",
		total, ToolHeadTail, ToolHeadTail)
	return out[:head] + marker + out[tail:]
}

// runeBoundaryDown walks i left to a rune start so out[:i] never ends