From 0de9bd6b671d5a98d3710bb340eb9bbb4d5756cf Mon Sep 17 00:00:00 2001
From: Alex Castillo <alex.castillog33@gmail.com>
Date: Wed, 11 Nov 2026 10:11:37 -0400
Subject: [PATCH 1/2] fix(aiclient): propagate messages streaming provider
 errors

---
 .../src/wireApiProvider/messages.types.ts     |  9 ++++++
 .../messagesWireApiProvider.ts                |  5 ++++
 .../aiclient/test/providerAdapter.spec.ts     | 30 +++++++++++++++++++
 3 files changed, 44 insertions(+)

diff --git a/ts/packages/aiclient/src/wireApiProvider/messages.types.ts b/ts/packages/aiclient/src/wireApiProvider/messages.types.ts
index 02c294ee70..16db7f84d8 100644
--- a/ts/packages/aiclient/src/wireApiProvider/messages.types.ts
+++ b/ts/packages/aiclient/src/wireApiProvider/messages.types.ts
@@ -198,7 +198,16 @@ export interface RawContentBlockStopEvent {
     type: "content_block_stop";
 }
 
+export interface RawMessageErrorEvent {
+    type: "error";
+    error: {
+        type: string;
+        message: string;
+    };
+}
+
 export type RawMessageStreamEvent =
+    | RawMessageErrorEvent
     | RawMessageStartEvent
     | RawMessageDeltaEvent
     | RawMessageStopEvent
diff --git a/ts/packages/aiclient/src/wireApiProvider/messagesWireApiProvider.ts b/ts/packages/aiclient/src/wireApiProvider/messagesWireApiProvider.ts
index e0247298e1..11db3c5576 100644
--- a/ts/packages/aiclient/src/wireApiProvider/messagesWireApiProvider.ts
+++ b/ts/packages/aiclient/src/wireApiProvider/messagesWireApiProvider.ts
@@ -205,6 +205,11 @@ export class MessagesWireApiProvider implements ProviderAdapter {
                 const evt = JSON.parse(raw) as RawMessageStreamEvent;
                 const piece: StreamPiece = {};
 
+                if (evt.type === "error") {
+                    piece.error = new Error(evt.error.message);
+                    return piece;
+                }
+
                 if (
                     evt.type === "content_block_delta" &&
                     evt.delta.type === "text_delta"
diff --git a/ts/packages/aiclient/test/providerAdapter.spec.ts b/ts/packages/aiclient/test/providerAdapter.spec.ts
index f22686cb5d..4111489e90 100644
--- a/ts/packages/aiclient/test/providerAdapter.spec.ts
+++ b/ts/packages/aiclient/test/providerAdapter.spec.ts
@@ -294,6 +294,36 @@ describe("ChatCompletionsWireApiProvider (default path is byte-identical)", () =
 describe("MessagesWireApiProvider", () => {
     const adapter = adapterFor("messages");
 
+    test.each([false, true])(
+        "stream reports provider errors (partial text: %s)",
+        (partialText) => {
+            const decoder = adapter.createStreamDecoder!(
+                makeRequest({ stream: true }),
+            );
+            if (partialText) {
+                expect(
+                    decoder.push(
+                        JSON.stringify({
+                            type: "content_block_delta",
+                            index: 0,
+                            delta: { type: "text_delta", text: "Partial answer" },
+                        }),
+                    ).text,
+                ).toBe("Partial answer");
+            }
+            const piece = decoder.push(
+                JSON.stringify({
+                    type: "error",
+                    error: { type: "overloaded_error", message: "Overloaded" },
+                }),
+            );
+            expect(piece.error).toBeInstanceOf(Error);
+            expect(piece.error?.message).toBe("Overloaded");
+            expect(piece.text).toBeUndefined();
+            expect(piece.usage).toBeUndefined();
+        },
+    );
+
     test("buildRequestBody splits system prompt, requires max_tokens", () => {
         const req = makeRequest({
             modelName: "claude-3-5-sonnet",

From 8b5cb613cf6aa43d3c32d84efea58d67b9670347 Mon Sep 17 00:00:00 2001
From: Alex Castillo <alex.castillog33@gmail.com>
Date: Wed, 11 Nov 2026 10:16:57 -0400
Subject: [PATCH 2/2] style(aiclient): format streaming error regression test

---
 ts/packages/aiclient/test/providerAdapter.spec.ts | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/ts/packages/aiclient/test/providerAdapter.spec.ts b/ts/packages/aiclient/test/providerAdapter.spec.ts
index 4111489e90..4afc132c89 100644
--- a/ts/packages/aiclient/test/providerAdapter.spec.ts
+++ b/ts/packages/aiclient/test/providerAdapter.spec.ts
@@ -306,7 +306,10 @@ describe("MessagesWireApiProvider", () => {
                         JSON.stringify({
                             type: "content_block_delta",
                             index: 0,
-                            delta: { type: "text_delta", text: "Partial answer" },
+                            delta: {
+                                type: "text_delta",
+                                text: "Partial answer",
+                            },
                         }),
                     ).text,
                 ).toBe("Partial answer");