From 5da78291cfbf5b34ce774983fc2a1fa47e632c6d Mon Sep 17 00:00:00 2001
From: Aly Raffauf <aly@aly.codes>
Date: Wed, 16 Sep 2026 02:17:22 -0400
Subject: [PATCH] firehose: handle sync events

---
 internal/firehose/stream.go |  3 +++
 internal/firehose/sync.go   | 33 +++++++++++++++++++++++++++++++++
 2 files changed, 36 insertions(+)
 create mode 100644 internal/firehose/sync.go

diff --git a/internal/firehose/stream.go b/internal/firehose/stream.go
index 1e4f8b2..6beb982 100644
--- a/internal/firehose/stream.go
+++ b/internal/firehose/stream.go
@@ -60,6 +60,9 @@ func (c *Consumer) stream(ctx context.Context, conn *websocket.Conn) {
 		RepoIdentity: func(event *atproto.SyncSubscribeRepos_Identity) error {
 			return c.HandleIdentity(ctx, event)
 		},
+		RepoSync: func(event *atproto.SyncSubscribeRepos_Sync) error {
+			return c.HandleSync(ctx, event)
+		},
 	}
 
 	scheduler := sequential.NewScheduler("asterism", callbacks.EventHandler)
diff --git a/internal/firehose/sync.go b/internal/firehose/sync.go
new file mode 100644
index 0000000..243c838
--- /dev/null
+++ b/internal/firehose/sync.go
@@ -0,0 +1,33 @@
+package firehose
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/bluesky-social/indigo/api/atproto"
+	"github.com/bluesky-social/indigo/atproto/syntax"
+)
+
+func (c *Consumer) HandleSync(ctx context.Context, event *atproto.SyncSubscribeRepos_Sync) error {
+	if err := c.Store.SaveCursor(ctx, event.Seq); err != nil {
+		c.Logger.Error("could not save cursor", "err", err)
+	}
+
+	did, err := syntax.ParseDID(event.Did)
+	if err != nil {
+		return fmt.Errorf("parse sync DID: %w", err)
+	}
+
+	go func() {
+		if err := c.Store.DeleteAllLinks(ctx, did.String()); err != nil {
+			c.Logger.Error("could not clear synced repo links", "did", did, "err", err)
+			return
+		}
+
+		if err := c.Backfill.Repo(ctx, did.String(), c.WantedCollections); err != nil {
+			c.Logger.Error("could not backfill synced repo", "did", did, "err", err)
+		}
+	}()
+
+	return nil
+}
-- 
2.51.2