diff --git a/packages/assistant-stream/CHANGELOG.md b/packages/assistant-stream/CHANGELOG.md
index 081476690..de2ef450a 100644
--- a/packages/assistant-stream/CHANGELOG.md
+++ b/packages/assistant-stream/CHANGELOG.md
@@ -1,5 +1,11 @@
 # assistant-stream
 
+## 0.0.12
+
+### Patch Changes
+
+- ignore unsupported data stream parts
+
 ## 0.0.11
 
 ### Patch Changes
diff --git a/packages/assistant-stream/package.json b/packages/assistant-stream/package.json
index a471c865f..161502725 100644
--- a/packages/assistant-stream/package.json
+++ b/packages/assistant-stream/package.json
@@ -1,6 +1,6 @@
 {
   "name": "assistant-stream",
-  "version": "0.0.11",
+  "version": "0.0.12",
   "license": "MIT",
   "exports": {
     ".": {
diff --git a/packages/assistant-stream/src/core/serialization/DataStream.ts b/packages/assistant-stream/src/core/serialization/DataStream.ts
index e279b713e..90122153f 100644
--- a/packages/assistant-stream/src/core/serialization/DataStream.ts
+++ b/packages/assistant-stream/src/core/serialization/DataStream.ts
@@ -151,6 +151,33 @@ export class DataStreamDecoder {
               break;
             }
 
+            case "9": {
+              const { toolCallId, args } = value as {
+                toolCallId: string;
+                toolName: string;
+                args: object;
+              };
+              controller.enqueue({
+                type: "tool-call-begin",
+                toolCallId,
+                toolName: toolCallId,
+              });
+              controller.enqueue({
+                type: "tool-call-delta",
+                toolCallId,
+                argsTextDelta: JSON.stringify(args),
+              });
+              break;
+            }
+
+            case "2":
+            case "3":
+            case "8":
+            case "d":
+            case "e": {
+              break; // ignore
+            }
+
             default:
               const exhaustiveCheck: string = type;
               throw new Error(`unsupported chunk type: ${exhaustiveCheck}`);