diff --git a/js/nostr/publishHelpers.js b/js/nostr/publishHelpers.js
index fd9b6749..8b75b61f 100644
--- a/js/nostr/publishHelpers.js
+++ b/js/nostr/publishHelpers.js
@@ -626,6 +626,7 @@ export async function repostEvent({
       : client?.relays,
   );
   const relays = relaysOverride.length ? relaysOverride : Array.from(RELAY_URLS);
+  const chosenPublishRelay = relays.length ? relays[0] : "";
 
   let actorPubkey =
     typeof options.actorPubkey === "string" && options.actorPubkey.trim()
@@ -671,15 +672,23 @@ export async function repostEvent({
     ? options.additionalTags.filter((tag) => Array.isArray(tag) && tag.length >= 2)
     : [];
 
+  const repostKind =
+    Number.isFinite(targetKind) && targetKind !== 1
+      ? 16
+      : 6;
+
   const repostEventPayload = buildRepostEvent({
     pubkey: actorPubkey,
     created_at: createdAt,
     eventId: normalizedId,
     eventRelay,
+    publishRelay: chosenPublishRelay,
     address,
     addressRelay,
     authorPubkey,
     additionalTags,
+    repostKind,
+    targetKind,
   });
 
   try {
diff --git a/js/nostrEventSchemas.js b/js/nostrEventSchemas.js
index d0fed019..3ccfaba9 100644
--- a/js/nostrEventSchemas.js
+++ b/js/nostrEventSchemas.js
@@ -651,22 +651,25 @@ export function buildRepostEvent({
   created_at,
   eventId = "",
   eventRelay = "",
+  publishRelay = "",
   address = "",
   addressRelay = "",
   authorPubkey = "",
   additionalTags = [],
+  repostKind,
+  targetKind,
 }) {
   const schema = getNostrEventSchema(NOTE_TYPES.REPOST);
   const tags = [];
 
   const normalizedEventId = typeof eventId === "string" ? eventId.trim() : "";
-  const normalizedEventRelay = typeof eventRelay === "string" ? eventRelay.trim() : "";
-  if (normalizedEventId) {
-    if (normalizedEventRelay) {
-      tags.push(["e", normalizedEventId, normalizedEventRelay]);
-    } else {
-      tags.push(["e", normalizedEventId]);
-    }
+  const normalizedEventRelay =
+    typeof eventRelay === "string" ? eventRelay.trim() : "";
+  const normalizedPublishRelay =
+    typeof publishRelay === "string" ? publishRelay.trim() : "";
+  const resolvedEventRelay = normalizedEventRelay || normalizedPublishRelay;
+  if (normalizedEventId && resolvedEventRelay) {
+    tags.push(["e", normalizedEventId, resolvedEventRelay]);
   }
 
   const normalizedAddress = typeof address === "string" ? address.trim() : "";
@@ -695,8 +698,26 @@ export function buildRepostEvent({
     });
   }
 
+  const normalizedRepostKind =
+    Number.isFinite(repostKind) && repostKind !== null
+      ? Math.floor(repostKind)
+      : null;
+  const normalizedTargetKind =
+    Number.isFinite(targetKind) && targetKind !== null
+      ? Math.floor(targetKind)
+      : null;
+  const resolvedKind = (() => {
+    if (normalizedRepostKind) {
+      return normalizedRepostKind;
+    }
+    if (normalizedTargetKind !== null) {
+      return normalizedTargetKind === 1 ? schema?.kind ?? 6 : 16;
+    }
+    return schema?.kind ?? 6;
+  })();
+
   return {
-    kind: schema?.kind ?? 6,
+    kind: resolvedKind,
     pubkey,
     created_at,
     tags,
diff --git a/tests/nostr-boost-actions.test.mjs b/tests/nostr-boost-actions.test.mjs
index 714813be..701400a4 100644
--- a/tests/nostr-boost-actions.test.mjs
+++ b/tests/nostr-boost-actions.test.mjs
@@ -84,9 +84,11 @@ function createPublishClient({ actorPubkey = "", sessionPubkey = "", failPublish
     created_at: createdAt,
     eventId: "event123",
     eventRelay: "wss://origin",
+    publishRelay: "wss://relay.example",
     address: "30078:deadbeef:identifier",
     addressRelay: "wss://address",
     authorPubkey: "deadbeef",
+    targetKind: 1,
   });
 
   assert.equal(event.kind, 6);
@@ -98,6 +100,22 @@ function createPublishClient({ actorPubkey = "", sessionPubkey = "", failPublish
   assert.deepEqual(event.tags[2], ["p", "deadbeef"]);
 })();
 
+(function testBuildRepostEventFallsBackToPublishRelay() {
+  const createdAt = 1_700_000_001;
+  const event = buildRepostEvent({
+    pubkey: "actorpubkey",
+    created_at: createdAt,
+    eventId: "event456",
+    publishRelay: "wss://relay.example",
+    authorPubkey: "cafebabe",
+    targetKind: 30078,
+  });
+
+  assert.equal(event.kind, 16);
+  assert.deepEqual(event.tags[0], ["e", "event456", "wss://relay.example"]);
+  assert.deepEqual(event.tags[1], ["p", "cafebabe"]);
+})();
+
 await (async function testRepostEventUsesSessionActorAndDerivesAddress() {
   const eventId = "test-event";
   const authorPubkey = "f".repeat(64);
@@ -117,7 +135,7 @@ await (async function testRepostEventUsesSessionActorAndDerivesAddress() {
     client,
     eventId,
     options: {
-      pointer: ["e", eventId, "wss://origin"],
+      pointer: ["e", eventId],
       authorPubkey,
     },
     resolveActiveSigner: () => null,
@@ -129,9 +147,10 @@ await (async function testRepostEventUsesSessionActorAndDerivesAddress() {
   assert.equal(result.ok, true);
   assert.equal(result.sessionActor, true);
   assert.equal(result.signerPubkey, sessionPubkey);
+  assert.equal(result.event?.kind, 16);
   const tags = result.event?.tags || [];
   assert.ok(Array.isArray(tags), "Repost event should include tags");
-  assert.deepEqual(tags[0], ["e", eventId, "wss://origin"]);
+  assert.deepEqual(tags[0], ["e", eventId, "wss://relay.example"]);
   assert.equal(
     tags.some((tag) => Array.isArray(tag) && tag[0] === "a" && tag[1].startsWith("30078:")),
     true,