add stream heartbeat

1 files changed, 3 insertions, 0 deletions

diff --git a/docs/api.md b/docs/api.md
index e813845..cdc722e 100644
--- a/docs/api.md
+++ b/docs/api.md
@@ -194,6 +194,9 @@ node or by sync:
 {"key":"settings/theme","deleted":true}
 ```
 
+While nothing changes, a blank line every 30 s (`--stream-heartbeat`) keeps proxies in
+front from taking the stream for dead; skip blank lines.
+
 An event carries the value as a read would return it then. Changes in quick succession
 may come as one event with the latest value: a stream tells the value, not every write.
 A change that leaves the value as it was sends nothing. The connection stays open; after