Add ephemeral event support (kinds 20000-29999)

Per NIP-01, ephemeral events are broadcast to subscribers but not
persisted to storage. This enables real-time features like typing
indicators without bloating the database.

Also adds typing-indicators.md spec for kind 20001.

1 files changed, 15 insertions, 0 deletions

diff --git a/internal/handler/websocket/handler.go b/internal/handler/websocket/handler.go
index c64f3f9..b591f61 100644
--- a/internal/handler/websocket/handler.go
+++ b/internal/handler/websocket/handler.go
@@ -359,6 +359,14 @@ func (h *Handler) handleEvent(ctx context.Context, conn *websocket.Conn, raw []j
                 return nil
         }
 
+        // Handle ephemeral events (kinds 20000-29999) - broadcast but don't store
+        if isEphemeralKind(pbEvent.Kind) {
+                h.subs.MatchAndFan(pbEvent)
+                status = "ok"
+                h.sendOK(ctx, conn, event.ID, true, "")
+                return nil
+        }
+
         eventData := &storage.EventData{
                 Event:         pbEvent,
                 CanonicalJSON: canonicalJSON,
@@ -643,3 +651,10 @@ func (h *Handler) isAllowedKind(kind int32) bool {
         }
         return h.allowedKinds[kind]
 }
+
+// isEphemeralKind returns true if the event kind is ephemeral (20000-29999).
+// Ephemeral events are broadcast to subscribers but not stored.
+// See NIP-01: https://github.com/nostr-protocol/nips/blob/master/01.md
+func isEphemeralKind(kind int32) bool {
+        return kind >= 20000 && kind < 30000
+}