fix: expose run error in legacy runtime events

Author: ranst91

typescript-sdk/packages/client/src/legacy/convert.ts

@@ -18,6 +18,7 @@ import {
   StateDeltaEvent,
   MessagesSnapshotEvent,
   ToolCall,
+  RunErrorEvent,
 } from "@ag-ui/core";
 import { Observable } from "rxjs";
 import {
@@ -36,6 +37,7 @@ import {
   LegacyActionExecutionMessage,
   LegacyResultMessage,
   LegacyActionExecutionResult,
+  LegacyRunError
 } from "./types";
 import untruncateJson from "untruncate-json";
 
@@ -319,7 +321,14 @@ export const convertToLegacyEvents =
           case EventType.RUN_ERROR: {
             // legacy protocol does not have an event for errors
             console.error("Run error", event);
-            return [];
+            const errorEvent = event as RunErrorEvent;
+            return [
+              {
+                type: LegacyRuntimeEventTypes.enum.RunError,
+                message: errorEvent.message,
+                code: errorEvent.code,
+              } as LegacyRunError,
+            ];
           }
           case EventType.STEP_STARTED: {
             const stepStarted = event as StepStartedEvent;

typescript-sdk/packages/client/src/legacy/types.ts

@@ -84,6 +84,13 @@ export const LegacyMetaEvent = z.object({
   value: z.any(),
 });
 
+
+export const LegacyRunError = z.object({
+  type: z.literal(LegacyRuntimeEventTypes.enum.RunError),
+  message: z.string(),
+  code: z.string().optional(),
+});
+
 export const LegacyRuntimeProtocolEvent = z.discriminatedUnion("type", [
   LegacyTextMessageStart,
   LegacyTextMessageContent,
@@ -94,6 +101,7 @@ export const LegacyRuntimeProtocolEvent = z.discriminatedUnion("type", [
   LegacyActionExecutionResult,
   LegacyAgentStateMessage,
   LegacyMetaEvent,
+  LegacyRunError,
 ]);
 
 // Protocol Event type exports
@@ -109,6 +117,7 @@ export type LegacyActionExecutionResult = z.infer<typeof LegacyActionExecutionRe
 export type LegacyAgentStateMessage = z.infer<typeof LegacyAgentStateMessage>;
 export type LegacyMetaEvent = z.infer<typeof LegacyMetaEvent>;
 export type LegacyRuntimeProtocolEvent = z.infer<typeof LegacyRuntimeProtocolEvent>;
+export type LegacyRunError = z.infer<typeof LegacyRunError>;
 
 // Message schemas (with kind discriminator)
 export const LegacyTextMessageSchema = z.object({