diff --git a/client/src/AdriftClient.ts b/client/src/AdriftClient.ts
index ccb418f..16d0dde 100644
--- a/client/src/AdriftClient.ts
+++ b/client/src/AdriftClient.ts
@@ -93,11 +93,13 @@ export class AdriftBareClient extends Client {
             data,
           })
         );
+      },
+      (message: string) => {
+        ws.dispatchEvent(new ErrorEvent("error", { message }));
       }
     );
 
     ws.send = (data: any) => {
-      console.log("Reached AdriftClient.ts send");
       send(data);
     };
 
diff --git a/client/src/Connection.ts b/client/src/Connection.ts
index 876d2b6..1219528 100644
--- a/client/src/Connection.ts
+++ b/client/src/Connection.ts
@@ -8,11 +8,13 @@ import {
   S2CRequestTypes,
   Transport,
   WSClosePayload,
+  WSErrorPayload,
 } from "protocol";
 
 type OpenWSMeta = {
   onclose: (code: number, reason: string, wasClean: boolean) => void;
   onmessage: (data: any) => void;
+  onerror: (message: string) => void;
 };
 
 export class Connection {
@@ -42,10 +44,12 @@ export class Connection {
 
     console.log(requestID, requestType);
 
+    const msgText = () => new TextDecoder().decode(data.slice(cursor));
+    const msgJSON = () => JSON.parse(msgText());
+
     switch (requestType) {
       case S2CRequestTypes.HTTPResponseStart:
-        const decoder = new TextDecoder();
-        const payload = JSON.parse(decoder.decode(data.slice(cursor)));
+        const payload = msgJSON();
         const stream = new ReadableStream({
           start: (controller) => {
             this.openRequestStreams[requestID] = controller;
@@ -82,32 +86,41 @@ export class Connection {
       case S2CRequestTypes.WSDataText: {
         const socketMeta = this.openSockets[requestID];
         if (!socketMeta) return;
-        socketMeta.onmessage(new TextDecoder().decode(data.slice(cursor)));
+        setTimeout(() => socketMeta.onmessage(msgText()));
         break;
       }
 
       case S2CRequestTypes.WSDataBinary: {
         const socketMeta = this.openSockets[requestID];
         if (!socketMeta) return;
-        socketMeta.onmessage(data.slice(cursor));
+        setTimeout(() => socketMeta.onmessage(data.slice(cursor)));
         break;
       }
 
       case S2CRequestTypes.WSClose: {
         const socketMeta = this.openSockets[requestID];
         if (!socketMeta) return;
-        const payload: WSClosePayload = JSON.parse(
-          new TextDecoder().decode(data.slice(cursor))
-        );
-        socketMeta.onclose(
-          payload.code || 1005,
-          payload.reason || "",
-          "wasClean" in payload ? Boolean(payload.wasClean) : false
+        const payload: WSClosePayload = msgJSON();
+        setTimeout(() =>
+          socketMeta.onclose(
+            payload.code || 1005,
+            payload.reason || "",
+            "wasClean" in payload ? Boolean(payload.wasClean) : false
+          )
         );
         delete this.openSockets[requestID];
         break;
       }
 
+      case S2CRequestTypes.WSError: {
+        const socketMeta = this.openSockets[requestID];
+        if (!socketMeta) return;
+        const payload: WSErrorPayload = msgJSON();
+        setTimeout(() => socketMeta.onerror(payload.message));
+        setTimeout(() => socketMeta.onclose(1006, "", false));
+        break;
+      }
+
       default:
         break;
     }
@@ -150,7 +163,8 @@ export class Connection {
     url: URL,
     onopen: () => void,
     onclose: (code: number, reason: string, wasClean: boolean) => void,
-    onmessage: (data: any) => void
+    onmessage: (data: any) => void,
+    onerror: (message: string) => void
   ): {
     send: (data: any) => void;
     close: (code?: number, reason?: string) => void;
@@ -171,7 +185,10 @@ export class Connection {
     });
 
     // this can't be async, just call onopen when opened
-    this.openingSockets[seq] = { onopen, rest: { onmessage, onclose } };
+    this.openingSockets[seq] = {
+      onopen,
+      rest: { onmessage, onclose, onerror },
+    };
 
     return {
       send: (data) => {
diff --git a/protocol/src/index.ts b/protocol/src/index.ts
index 2bd4ac8..805fc8d 100644
--- a/protocol/src/index.ts
+++ b/protocol/src/index.ts
@@ -16,6 +16,7 @@ export const S2CRequestTypes = {
   WSDataText: 4,
   WSDataBinary: 5,
   WSClose: 6,
+  WSError: 7,
 } as const;
 export type S2CRequestType = ObjectValues<typeof S2CRequestTypes>;
 
@@ -44,4 +45,8 @@ export type WSClosePayload = {
   wasClean: boolean;
 };
 
+export type WSErrorPayload = {
+  message: string;
+};
+
 export { Transport } from "./Transport";
diff --git a/server/src/server.ts b/server/src/server.ts
index 68ddc5e..39b74e4 100644
--- a/server/src/server.ts
+++ b/server/src/server.ts
@@ -9,6 +9,7 @@ import {
   S2CRequestType,
   S2CRequestTypes,
   WSClosePayload,
+  WSErrorPayload,
 } from "protocol";
 import { Readable } from "stream";
 import { BareError, bareFetch, options } from "./http";
@@ -164,6 +165,10 @@ export class AdriftServer {
     this._sendJSONRes(seq, S2CRequestTypes.WSClose, payload);
   }
 
+  sendWSError(seq: number, payload: WSErrorPayload) {
+    this._sendJSONRes(seq, S2CRequestTypes.WSError, payload);
+  }
+
   sendWSText(seq: number, textEncoded: ArrayBuffer) {
     const buf = new ArrayBuffer(2 + 1 + textEncoded.byteLength);
     const dataView = new DataView(buf);
@@ -240,10 +245,9 @@ export class AdriftServer {
         const payload = AdriftServer.tryParseJSONPayload(msg.slice(cursor));
         const ws = (this.sockets[seq] = new WebSocket(payload.url));
         ws.binaryType = "arraybuffer";
-        // TODO v important: onerror
         ws.onerror = (e) => {
-          console.log("ws onerror", e);
-          this.sendWSClose(seq, { code: 1006, reason: "", wasClean: false });
+          // WSError implies close with code 1006, reason "" and wasClean false
+          this.sendWSError(seq, { message: e.message });
         };
         ws.onopen = () => {
           this.sendWSOpen(seq);