From 2983831de033cbaf0db0d39fe132e6929d077729 Mon Sep 17 00:00:00 2001
From: Roscoe Rubin-Rottenberg <roscoe@knotbin.com>
Date: Sun, 12 Apr 2026 13:35:14 -0400
Subject: [PATCH] feat: reply notification root uris

---
 data-plane/indexing/plugins/reply.ts |  4 ++++
 data-plane/indexing/processor.ts     |  2 ++
 utils/push.ts                        | 26 +++++++++++++++++++++++---
 3 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/data-plane/indexing/plugins/reply.ts b/data-plane/indexing/plugins/reply.ts
index fdac905..70451cc 100644
--- a/data-plane/indexing/plugins/reply.ts
+++ b/data-plane/indexing/plugins/reply.ts
@@ -167,6 +167,7 @@ const notifsForInsert = (obj: IndexedReply) => {
     recordCid: string;
     sortAt: string;
     reasonSubject?: string;
+    threadRootUri?: string;
   }> = [];
   const notified = new Set([obj.reply.authorDid]);
   const maybeNotify = (notif: {
@@ -177,6 +178,7 @@ const notifsForInsert = (obj: IndexedReply) => {
     recordCid: string;
     sortAt: string;
     reasonSubject?: string;
+    threadRootUri?: string;
   }) => {
     if (!notified.has(notif.did)) {
       notified.add(notif.did);
@@ -211,6 +213,7 @@ const notifsForInsert = (obj: IndexedReply) => {
         recordUri: obj.reply.uri,
         recordCid: obj.reply.cid,
         sortAt: obj.reply.createdAt,
+        threadRootUri: obj.reply.reply?.root.uri,
       });
       // found hidden reply, don't notify any higher ancestors
       if (threadgateHiddenReplies.includes(ancestorUri.toString())) break;
@@ -232,6 +235,7 @@ const notifsForInsert = (obj: IndexedReply) => {
           recordUri: descendent.uri,
           recordCid: descendent.cid,
           sortAt: descendent.sortAt,
+          threadRootUri: obj.reply.reply?.root.uri,
         });
       }
     }
diff --git a/data-plane/indexing/processor.ts b/data-plane/indexing/processor.ts
index d0d466e..58eabb0 100644
--- a/data-plane/indexing/processor.ts
+++ b/data-plane/indexing/processor.ts
@@ -41,6 +41,7 @@ type Notif = {
   recordCid: string;
   sortAt: string;
   reasonSubject?: string;
+  threadRootUri?: string;
 };
 
 export class RecordProcessor<T, S> {
@@ -374,6 +375,7 @@ export class RecordProcessor<T, S> {
             author: notif.author,
             recordUri: notif.recordUri,
             reasonSubject: notif.reasonSubject,
+            threadRootUri: notif.threadRootUri,
           });
         });
       }
diff --git a/utils/push.ts b/utils/push.ts
index f9856ea..4020ea3 100644
--- a/utils/push.ts
+++ b/utils/push.ts
@@ -8,6 +8,7 @@ export interface PushPayload {
   author: string;
   recordUri: string;
   reasonSubject?: string;
+  threadRootUri?: string;
 }
 
 export interface PushConfig {
@@ -254,13 +255,15 @@ export class PushService {
           recordUri: payload.recordUri,
           ...(payload.reasonSubject &&
             { reasonSubject: payload.reasonSubject }),
+          ...(payload.threadRootUri &&
+            { threadRootUri: payload.threadRootUri }),
         },
       },
     };
 
     // Add platform-specific options
     if (token.platform === "ios") {
-      const threadId = this.getThreadId(payload);
+      const threadId = this.getIosThreadId(payload);
       message.message.apns = {
         headers: {
           "apns-priority": "10",
@@ -274,7 +277,7 @@ export class PushService {
         },
       };
     } else if (token.platform === "android") {
-      const threadId = this.getThreadId(payload);
+      const threadId = this.getAndroidTag(payload);
       message.message.android = {
         priority: "high",
         notification: {
@@ -510,10 +513,27 @@ export class PushService {
     return base64.replace(/\+/g, "-").replace(/\//g, "_").replace(/=+$/, "");
   }
 
-  private getThreadId(payload: PushPayload): string {
+  private getIosThreadId(payload: PushPayload): string {
     if (payload.reason === "follow") {
       return "follows";
     }
+    if (payload.reason === "reply") {
+      return payload.threadRootUri ?? payload.reasonSubject ??
+        payload.recordUri;
+    }
+    if (payload.reasonSubject) {
+      return payload.reasonSubject;
+    }
+    return payload.recordUri;
+  }
+
+  private getAndroidTag(payload: PushPayload): string {
+    if (payload.reason === "follow") {
+      return "follows";
+    }
+    if (payload.reason === "reply") {
+      return payload.reasonSubject ?? payload.recordUri;
+    }
     if (payload.reasonSubject) {
       return payload.reasonSubject;
     }
-- 
2.51.2