diff --git a/packages/core/src/v3/apiClient/index.ts b/packages/core/src/v3/apiClient/index.ts
index 7de6e275fc..fbbc209057 100644
--- a/packages/core/src/v3/apiClient/index.ts
+++ b/packages/core/src/v3/apiClient/index.ts
@@ -42,6 +42,7 @@ import {
   RetrieveQueueParam,
   RetrieveRunResponse,
   RetrieveRunTraceResponseBody,
+  RunEvent,
   ScheduleObject,
   SendInputStreamResponseBody,
   StreamBatchItemsResponse,
@@ -700,7 +701,7 @@ export class ApiClient {
 
   listRunEvents(runId: string, requestOptions?: ZodFetchOptions) {
     return zodfetch(
-      z.any(), // TODO: define a proper schema for this
+      RunEvent.array(),
       `${this.baseUrl}/api/v1/runs/${runId}/events`,
       {
         method: "GET",
diff --git a/packages/core/src/v3/schemas/api-type.test.ts b/packages/core/src/v3/schemas/api-type.test.ts
index c936b3c769..47b474aeee 100644
--- a/packages/core/src/v3/schemas/api-type.test.ts
+++ b/packages/core/src/v3/schemas/api-type.test.ts
@@ -1,5 +1,5 @@
 import { describe, it, expect } from "vitest";
-import { InitializeDeploymentRequestBody } from "./api.js";
+import { InitializeDeploymentRequestBody, RunEvent } from "./api.js";
 import type { InitializeDeploymentRequestBody as InitializeDeploymentRequestBodyType } from "./api.js";
 
 describe("InitializeDeploymentRequestBody", () => {
@@ -139,3 +139,60 @@ describe("InitializeDeploymentRequestBody", () => {
     });
   });
 });
+
+describe("RunEvent Schema", () => {
+  const validEvent = {
+    spanId: "span_123",
+    parentId: "span_root",
+    runId: "run_abc",
+    message: "Test event",
+    style: {
+      icon: "task",
+      variant: "primary",
+    },
+    startTime: "2024-03-14T00:00:00Z",
+    duration: 1234,
+    isError: false,
+    isPartial: false,
+    isCancelled: false,
+    level: "INFO",
+    kind: "TASK",
+    attemptNumber: 1,
+  };
+
+  it("parses a valid event correctly", () => {
+    const result = RunEvent.safeParse(validEvent);
+    expect(result.success).toBe(true);
+    if (result.success) {
+      expect(result.data.spanId).toBe("span_123");
+      expect(result.data.startTime).toBeInstanceOf(Date);
+      expect(result.data.level).toBe("INFO");
+    }
+  });
+
+  it("fails on missing required fields", () => {
+    const invalidEvent = { ...validEvent };
+    delete (invalidEvent as any).spanId;
+    const result = RunEvent.safeParse(invalidEvent);
+    expect(result.success).toBe(false);
+  });
+
+  it("fails on invalid level", () => {
+    const invalidEvent = { ...validEvent, level: "INVALID_LEVEL" };
+    const result = RunEvent.safeParse(invalidEvent);
+    expect(result.success).toBe(false);
+  });
+
+  it("coerces startTime to Date", () => {
+    const result = RunEvent.parse(validEvent);
+    expect(result.startTime).toBeInstanceOf(Date);
+    expect(result.startTime.toISOString()).toBe("2024-03-14T00:00:00.000Z");
+  });
+
+  it("allows optional parentId", () => {
+    const eventWithoutParent = { ...validEvent };
+    delete (eventWithoutParent as any).parentId;
+    const result = RunEvent.safeParse(eventWithoutParent);
+    expect(result.success).toBe(true);
+  });
+});
diff --git a/packages/core/src/v3/schemas/api.ts b/packages/core/src/v3/schemas/api.ts
index dc72f155bd..a38b562d4d 100644
--- a/packages/core/src/v3/schemas/api.ts
+++ b/packages/core/src/v3/schemas/api.ts
@@ -9,6 +9,8 @@ import {
 } from "./common.js";
 import { BackgroundWorkerMetadata } from "./resources.js";
 import { DequeuedMessage, MachineResources } from "./runEngine.js";
+import { TaskEventStyle } from "./style.js";
+import { SpanEvents } from "./openTelemetry.js";
 
 export const RunEngineVersion = z.union([z.literal("V1"), z.literal("V2")]);
 
@@ -1639,3 +1641,24 @@ export const SendInputStreamResponseBody = z.object({
   ok: z.boolean(),
 });
 export type SendInputStreamResponseBody = z.infer<typeof SendInputStreamResponseBody>;
+export const TaskEventLevel = z.enum(["TRACE", "DEBUG", "INFO", "LOG", "WARN", "ERROR"]);
+export type TaskEventLevel = z.infer<typeof TaskEventLevel>;
+
+export const RunEvent = z.object({
+  spanId: z.string(),
+  parentId: z.string().optional(),
+  runId: z.string(),
+  message: z.string(),
+  style: TaskEventStyle,
+  startTime: z.coerce.date(),
+  duration: z.number(),
+  isError: z.boolean(),
+  isPartial: z.boolean(),
+  isCancelled: z.boolean(),
+  level: TaskEventLevel,
+  events: SpanEvents.optional(),
+  kind: z.string(),
+  attemptNumber: z.number().optional(),
+});
+
+export type RunEvent = z.infer<typeof RunEvent>;