From 59c834885369b150ff8356313c521eb0f722ab10 Mon Sep 17 00:00:00 2001
From: Robbert van Ginkel <570934+robbertvanginkel@users.noreply.github.com>
Date: Tue, 23 Dec 2025 11:34:01 +0100
Subject: [PATCH] Fix InlineWebSocketAdapter message delivery

When attempting to reproduce https://www.rivet.dev/docs/actors/websocket-handler/ with createFileSystemDriver, messages sent from the actor to the client are never delivered. The connection appears to work (open/close events fire), but message routing fails silently. When using handleRawWebSocket with an InlineWebSocketAdapter, messages sent from the actor to the client are never delivered.

https://github.com/rivet-dev/rivet/blob/c9cfd90d5fb152fd47fc93acfadb1dec7f18e6bf/rivetkit-typescript/packages/rivetkit/src/actor/router-websocket-endpoints.ts#L319-L325 Looks up an adaptor, but this is never set for InlineWebSocketAdapter.
---
 .../rivetkit/src/common/inline-websocket-adapter.ts      | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/rivetkit-typescript/packages/rivetkit/src/common/inline-websocket-adapter.ts b/rivetkit-typescript/packages/rivetkit/src/common/inline-websocket-adapter.ts
index 921eb42041..028cb7e927 100644
--- a/rivetkit-typescript/packages/rivetkit/src/common/inline-websocket-adapter.ts
+++ b/rivetkit-typescript/packages/rivetkit/src/common/inline-websocket-adapter.ts
@@ -50,6 +50,9 @@ export class InlineWebSocketAdapter implements UniversalWebSocket {
 			readyState: 1,
 		});
 
+		// Set __adapter on WSContext so handleRawWebSocket.onMessage can route messages back
+		(this.#wsContext as any).__adapter = this;
+
 		// Initialize the connection
 		//
 		// Defer initialization to allow event listeners to be attached first
@@ -207,6 +210,12 @@ export class InlineWebSocketAdapter implements UniversalWebSocket {
 			this.close(1011, "Internal error during initialization");
 		}
 	}
+	/**
+	 * Handle message from actor (called via __adapter from handleRawWebSocket.onMessage)
+	 */
+	_handleMessage(event: MessageEvent) {
+	  this.#handleMessage(event.data);
+	}
 
 	/**
 	 * Handle messages received from the server via the WSContext