1 files changed, 18 insertions, 0 deletions
diff --git a/packages/cli/src/ndjson.ts b/packages/cli/src/ndjson.ts
new file mode 100644
index 0000000..57093c1
--- /dev/null
+++ b/packages/cli/src/ndjson.ts
@@ -0,0 +1,18 @@
+/**
+ * Pure NDJSON line splitter — zero I/O.
+ *
+ * Splits a buffer on newlines, keeping an incomplete trailing line in `rest`.
+ * Does NOT parse JSON — that is the caller's job.
+ */
+
+export interface SplitResult {
+	readonly lines: readonly string[];
+	readonly rest: string;
+}
+
+export function splitNdjsonLines(buffer: string): SplitResult {
+	const parts = buffer.split("\n");
+	const rest = parts[parts.length - 1] ?? "";
+	const lines = parts.slice(0, -1).filter((l) => l.length > 0);
+	return { lines, rest };
+}