diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..e6a5c6f
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,8 @@
+# Runtime data files (backed up by rsync, not by git)
+data/heartbeat.jsonl
+data/ledger.jsonl
+data/queue.jsonl
+
+# Build artifacts
+_build/
+deps/