diff --git a/libs/browser/src/lib/services/browser-micro-sentry-client.spec.ts b/libs/browser/src/lib/services/browser-micro-sentry-client.spec.ts
index 6ea2789..24f248b 100644
--- a/libs/browser/src/lib/services/browser-micro-sentry-client.spec.ts
+++ b/libs/browser/src/lib/services/browser-micro-sentry-client.spec.ts
@@ -286,6 +286,7 @@ describe('BrowserMicroSentryClient', () => {
         },
         tags: { tag: 'value' },
         timestamp: expect.any(Number),
+        event_id: expect.any(String),
       });
     });
 
@@ -309,6 +310,7 @@ describe('BrowserMicroSentryClient', () => {
         },
         tags: { tag: 'value' },
         timestamp: expect.any(Number),
+        event_id: expect.any(String),
       });
     });
   });
diff --git a/libs/core/src/lib/helpers/uuid4.spec.ts b/libs/core/src/lib/helpers/uuid4.spec.ts
new file mode 100644
index 0000000..bbc3f18
--- /dev/null
+++ b/libs/core/src/lib/helpers/uuid4.spec.ts
@@ -0,0 +1,16 @@
+import { uuid4 } from './uuid4';
+
+describe('uuid4', () => {
+  it('should be 32 characters long', () => {
+    expect(uuid4().length).toBe(32);
+  });
+
+  it('should be lowercase', () => {
+    const result = uuid4();
+    expect(result).toEqual(result.toLowerCase());
+  });
+
+  it('should not contain dashes', () => {
+    expect(uuid4()).not.toContain('-');
+  });
+});
diff --git a/libs/core/src/lib/helpers/uuid4.ts b/libs/core/src/lib/helpers/uuid4.ts
new file mode 100644
index 0000000..47841c2
--- /dev/null
+++ b/libs/core/src/lib/helpers/uuid4.ts
@@ -0,0 +1,15 @@
+/**
+ * @description Hexadecimal string representing a uuid4 value.
+ * The length is exactly 32 characters.
+ * Dashes are not allowed.
+ * Has to be lowercase.
+ * @see https://develop.sentry.dev/sdk/event-payloads/#required-attributes
+ */
+export function uuid4(): string {
+  return 'xxxxxxxxxxxx4xxxyxxxxxxxxxxxxxxx'.replace(/[xy]/g, (c) => {
+    const r = (Math.random() * 16) | 0;
+    const v = c === 'x' ? r : (r & 0x3) | 0x8;
+
+    return v.toString(16);
+  });
+}
diff --git a/libs/core/src/lib/models/models.ts b/libs/core/src/lib/models/models.ts
index 653054a..563f258 100644
--- a/libs/core/src/lib/models/models.ts
+++ b/libs/core/src/lib/models/models.ts
@@ -37,6 +37,7 @@ export interface SentryRequestBody {
     version: string;
   };
   timestamp: number;
+  event_id: string;
   request?: {
     url?: string;
     headers?: {
diff --git a/libs/core/src/lib/service/micro-sentry-client.spec.ts b/libs/core/src/lib/service/micro-sentry-client.spec.ts
index 5487c61..750ca14 100644
--- a/libs/core/src/lib/service/micro-sentry-client.spec.ts
+++ b/libs/core/src/lib/service/micro-sentry-client.spec.ts
@@ -66,6 +66,7 @@ describe('MiniSentryClient', () => {
         version: expect.any(String),
       },
       timestamp: expect.any(Number),
+      event_id: expect.any(String),
     });
   });
 });
diff --git a/libs/core/src/lib/service/micro-sentry-client.ts b/libs/core/src/lib/service/micro-sentry-client.ts
index e498441..1ad9abd 100644
--- a/libs/core/src/lib/service/micro-sentry-client.ts
+++ b/libs/core/src/lib/service/micro-sentry-client.ts
@@ -2,6 +2,7 @@ import { SentryRequestBody } from '../models/models';
 import { AUTH_HEADER, DSN_REGEXP } from '../consts/consts';
 import { computeStackTrace } from '../helpers/compute-stack-trace';
 import { SentryClientOptions } from '../models/sentry-client-options';
+import { uuid4 } from '../helpers/uuid4';
 
 export class MicroSentryClient {
   readonly authHeader?: string;
@@ -65,6 +66,7 @@ export class MicroSentryClient {
   protected getRequestBlank(): SentryRequestBody {
     return {
       platform: 'javascript',
+      event_id: uuid4(),
       sdk: {
         name: 'micro-sentry.javascript.core',
         version: '0.0.0',