diff --git a/.size-limit.js b/.size-limit.js
index cad516a0a49a..043b1d8555bf 100644
--- a/.size-limit.js
+++ b/.size-limit.js
@@ -8,7 +8,7 @@ module.exports = [
     path: 'packages/browser/build/npm/esm/prod/index.js',
     import: createImport('init'),
     gzip: true,
-    limit: '26 KB',
+    limit: '27 KB',
   },
   {
     name: '@sentry/browser - with treeshaking flags',
@@ -59,7 +59,7 @@ module.exports = [
     path: 'packages/browser/build/npm/esm/prod/index.js',
     import: createImport('init', 'browserTracingIntegration', 'replayIntegration'),
     gzip: true,
-    limit: '83 KB',
+    limit: '84 KB',
   },
   {
     name: '@sentry/browser (incl. Tracing, Replay) - with treeshaking flags',
@@ -96,7 +96,7 @@ module.exports = [
     path: 'packages/browser/build/npm/esm/prod/index.js',
     import: createImport('init', 'browserTracingIntegration', 'replayIntegration', 'feedbackIntegration'),
     gzip: true,
-    limit: '100 KB',
+    limit: '101 KB',
   },
   {
     name: '@sentry/browser (incl. Feedback)',
@@ -138,7 +138,7 @@ module.exports = [
     path: 'packages/browser/build/npm/esm/prod/index.js',
     import: createImport('init', 'metrics', 'logger'),
     gzip: true,
-    limit: '28 KB',
+    limit: '29 KB',
   },
   // React SDK (ESM)
   {
@@ -178,7 +178,7 @@ module.exports = [
     path: 'packages/svelte/build/esm/index.js',
     import: createImport('init'),
     gzip: true,
-    limit: '26 KB',
+    limit: '27 KB',
   },
   // Browser CDN bundles
   {
@@ -197,7 +197,7 @@ module.exports = [
     name: 'CDN Bundle (incl. Logs, Metrics)',
     path: createCDNPath('bundle.logs.metrics.min.js'),
     gzip: true,
-    limit: '30 KB',
+    limit: '31 KB',
   },
   {
     name: 'CDN Bundle (incl. Tracing, Logs, Metrics)',
@@ -283,14 +283,14 @@ module.exports = [
     path: createCDNPath('bundle.tracing.replay.logs.metrics.min.js'),
     gzip: false,
     brotli: false,
-    limit: '258.5 KB',
+    limit: '259 KB',
   },
   {
     name: 'CDN Bundle (incl. Tracing, Replay, Feedback) - uncompressed',
     path: createCDNPath('bundle.tracing.replay.feedback.min.js'),
     gzip: false,
     brotli: false,
-    limit: '268 KB',
+    limit: '269 KB',
   },
   {
     name: 'CDN Bundle (incl. Tracing, Replay, Feedback, Logs, Metrics) - uncompressed',
diff --git a/dev-packages/browser-integration-tests/suites/public-api/metrics/simple/test.ts b/dev-packages/browser-integration-tests/suites/public-api/metrics/simple/test.ts
index 66f44878ac86..a50d6c8b2b78 100644
--- a/dev-packages/browser-integration-tests/suites/public-api/metrics/simple/test.ts
+++ b/dev-packages/browser-integration-tests/suites/public-api/metrics/simple/test.ts
@@ -27,6 +27,8 @@ sentryTest('should capture all metric types', async ({ getLocalTestUrl, page })
       content_type: 'application/vnd.sentry.items.trace-metric+json',
     },
     {
+      version: 2,
+      ingest_settings: { infer_ip: 'never', infer_user_agent: 'never' },
       items: [
         {
           timestamp: expect.any(Number),
diff --git a/dev-packages/node-core-integration-tests/suites/light-mode/metrics/test.ts b/dev-packages/node-core-integration-tests/suites/light-mode/metrics/test.ts
index c0c9d291de78..d2a67f8df890 100644
--- a/dev-packages/node-core-integration-tests/suites/light-mode/metrics/test.ts
+++ b/dev-packages/node-core-integration-tests/suites/light-mode/metrics/test.ts
@@ -11,6 +11,7 @@ describe('light mode metrics', () => {
       .unignore('trace_metric')
       .expect({
         trace_metric: {
+          version: 2,
           items: [
             {
               timestamp: expect.any(Number),
diff --git a/dev-packages/node-core-integration-tests/suites/public-api/metrics/test.ts b/dev-packages/node-core-integration-tests/suites/public-api/metrics/test.ts
index 9494ce2a99ca..303eb22f3285 100644
--- a/dev-packages/node-core-integration-tests/suites/public-api/metrics/test.ts
+++ b/dev-packages/node-core-integration-tests/suites/public-api/metrics/test.ts
@@ -11,6 +11,7 @@ describe('metrics', () => {
       .unignore('trace_metric')
       .expect({
         trace_metric: {
+          version: 2,
           items: [
             {
               timestamp: expect.any(Number),
diff --git a/dev-packages/node-integration-tests/suites/public-api/metrics/server-address-option/test.ts b/dev-packages/node-integration-tests/suites/public-api/metrics/server-address-option/test.ts
index 825d94f41624..dfb3094f1bb9 100644
--- a/dev-packages/node-integration-tests/suites/public-api/metrics/server-address-option/test.ts
+++ b/dev-packages/node-integration-tests/suites/public-api/metrics/server-address-option/test.ts
@@ -10,6 +10,7 @@ describe('metrics server.address', () => {
     const runner = createRunner(__dirname, 'scenario.ts')
       .expect({
         trace_metric: {
+          version: 2,
           items: [
             {
               timestamp: expect.any(Number),
diff --git a/dev-packages/node-integration-tests/suites/public-api/metrics/server-address/test.ts b/dev-packages/node-integration-tests/suites/public-api/metrics/server-address/test.ts
index 048513da3c19..86eb295e0c5d 100644
--- a/dev-packages/node-integration-tests/suites/public-api/metrics/server-address/test.ts
+++ b/dev-packages/node-integration-tests/suites/public-api/metrics/server-address/test.ts
@@ -10,6 +10,7 @@ describe('metrics server.address', () => {
     const runner = createRunner(__dirname, 'scenario.ts')
       .expect({
         trace_metric: {
+          version: 2,
           items: [
             {
               timestamp: expect.any(Number),
diff --git a/dev-packages/node-integration-tests/suites/public-api/metrics/test.ts b/dev-packages/node-integration-tests/suites/public-api/metrics/test.ts
index ff67b73e9ad3..9b266552b052 100644
--- a/dev-packages/node-integration-tests/suites/public-api/metrics/test.ts
+++ b/dev-packages/node-integration-tests/suites/public-api/metrics/test.ts
@@ -10,6 +10,7 @@ describe('metrics', () => {
     const runner = createRunner(__dirname, 'scenario.ts')
       .expect({
         trace_metric: {
+          version: 2,
           items: [
             {
               timestamp: expect.any(Number),
diff --git a/packages/core/src/metrics/envelope.ts b/packages/core/src/metrics/envelope.ts
index 71ef0832667b..565b957c4f6d 100644
--- a/packages/core/src/metrics/envelope.ts
+++ b/packages/core/src/metrics/envelope.ts
@@ -4,14 +4,21 @@ import type { SerializedMetric } from '../types-hoist/metric';
 import type { SdkMetadata } from '../types-hoist/sdkmetadata';
 import { dsnToString } from '../utils/dsn';
 import { createEnvelope } from '../utils/envelope';
+import { isBrowser } from '../utils/isBrowser';
 
 /**
  * Creates a metric container envelope item for a list of metrics.
  *
  * @param items - The metrics to include in the envelope.
+ * @param inferUserData - If true, tells Relay to infer the end-user IP and User-Agent from the incoming request.
+ *                        Only emitted as `ingest_settings` in browser environments.
  * @returns The created metric container envelope item.
  */
-export function createMetricContainerEnvelopeItem(items: Array<SerializedMetric>): MetricContainerItem {
+export function createMetricContainerEnvelopeItem(
+  items: Array<SerializedMetric>,
+  inferUserData?: boolean,
+): MetricContainerItem {
+  const inferSetting = inferUserData ? 'auto' : 'never';
   return [
     {
       type: 'trace_metric',
@@ -19,6 +26,10 @@ export function createMetricContainerEnvelopeItem(items: Array<SerializedMetric>
       content_type: 'application/vnd.sentry.items.trace-metric+json',
     } as MetricContainerItem[0],
     {
+      version: 2,
+      ...(isBrowser() && {
+        ingest_settings: { infer_ip: inferSetting, infer_user_agent: inferSetting },
+      }),
       items,
     },
   ];
@@ -33,6 +44,7 @@ export function createMetricContainerEnvelopeItem(items: Array<SerializedMetric>
  * @param metadata - The metadata to include in the envelope.
  * @param tunnel - The tunnel to include in the envelope.
  * @param dsn - The DSN to include in the envelope.
+ * @param inferUserData - If true, tells Relay to infer the end-user IP and User-Agent from the incoming request.
  * @returns The created envelope.
  */
 export function createMetricEnvelope(
@@ -40,6 +52,7 @@ export function createMetricEnvelope(
   metadata?: SdkMetadata,
   tunnel?: string,
   dsn?: DsnComponents,
+  inferUserData?: boolean,
 ): MetricEnvelope {
   const headers: MetricEnvelope[0] = {};
 
@@ -54,5 +67,5 @@ export function createMetricEnvelope(
     headers.dsn = dsnToString(dsn);
   }
 
-  return createEnvelope<MetricEnvelope>(headers, [createMetricContainerEnvelopeItem(metrics)]);
+  return createEnvelope<MetricEnvelope>(headers, [createMetricContainerEnvelopeItem(metrics, inferUserData)]);
 }
diff --git a/packages/core/src/metrics/internal.ts b/packages/core/src/metrics/internal.ts
index 0545414654ef..26cc11fc0422 100644
--- a/packages/core/src/metrics/internal.ts
+++ b/packages/core/src/metrics/internal.ts
@@ -225,7 +225,13 @@ export function _INTERNAL_flushMetricsBuffer(client: Client, maybeMetricBuffer?:
   }
 
   const clientOptions = client.getOptions();
-  const envelope = createMetricEnvelope(metricBuffer, clientOptions._metadata, clientOptions.tunnel, client.getDsn());
+  const envelope = createMetricEnvelope(
+    metricBuffer,
+    clientOptions._metadata,
+    clientOptions.tunnel,
+    client.getDsn(),
+    clientOptions.sendDefaultPii,
+  );
 
   // Clear the metric buffer after envelopes have been constructed.
   _getBufferMap().set(client, []);
diff --git a/packages/core/src/types-hoist/metric.ts b/packages/core/src/types-hoist/metric.ts
index 976fc9fe863f..1b6380cbc471 100644
--- a/packages/core/src/types-hoist/metric.ts
+++ b/packages/core/src/types-hoist/metric.ts
@@ -77,5 +77,10 @@ export interface SerializedMetric {
 }
 
 export type SerializedMetricContainer = {
+  version?: number;
+  ingest_settings?: {
+    infer_ip?: 'auto' | 'never';
+    infer_user_agent?: 'auto' | 'never';
+  };
   items: Array<SerializedMetric>;
 };
diff --git a/packages/core/test/lib/metrics/envelope.test.ts b/packages/core/test/lib/metrics/envelope.test.ts
index 87132e4bcaa0..25bf5e61923b 100644
--- a/packages/core/test/lib/metrics/envelope.test.ts
+++ b/packages/core/test/lib/metrics/envelope.test.ts
@@ -5,6 +5,7 @@ import type { SerializedMetric } from '../../../src/types-hoist/metric';
 import type { SdkMetadata } from '../../../src/types-hoist/sdkmetadata';
 import * as utilsDsn from '../../../src/utils/dsn';
 import * as utilsEnvelope from '../../../src/utils/envelope';
+import { isBrowser } from '../../../src/utils/isBrowser';
 
 vi.mock('../../../src/utils/dsn', () => ({
   dsnToString: vi.fn(dsn => `https://${dsn.publicKey}@${dsn.host}/`),
@@ -12,9 +13,16 @@ vi.mock('../../../src/utils/dsn', () => ({
 vi.mock('../../../src/utils/envelope', () => ({
   createEnvelope: vi.fn((_headers, items) => [_headers, items]),
 }));
+vi.mock('../../../src/utils/isBrowser', () => ({
+  isBrowser: vi.fn(() => false),
+}));
+
+afterEach(() => {
+  vi.mocked(isBrowser).mockReturnValue(false);
+});
 
 describe('createMetricContainerEnvelopeItem', () => {
-  it('creates an envelope item with correct structure', () => {
+  it('emits version: 2 without ingest_settings when not in browser', () => {
     const mockMetric: SerializedMetric = {
       timestamp: 1713859200,
       trace_id: '3d9355f71e9c444b81161599adac6e29',
@@ -26,15 +34,63 @@ describe('createMetricContainerEnvelopeItem', () => {
       attributes: {},
     };
 
-    const result = createMetricContainerEnvelopeItem([mockMetric, mockMetric]);
+    const result = createMetricContainerEnvelopeItem([mockMetric], true);
 
-    expect(result).toHaveLength(2);
     expect(result[0]).toEqual({
       type: 'trace_metric',
-      item_count: 2,
+      item_count: 1,
       content_type: 'application/vnd.sentry.items.trace-metric+json',
     });
-    expect(result[1]).toEqual({ items: [mockMetric, mockMetric] });
+    expect(result[1]).toEqual({
+      version: 2,
+      items: [mockMetric],
+    });
+  });
+
+  it("includes ingest_settings with 'auto' values when in browser and inferUserData is true", () => {
+    vi.mocked(isBrowser).mockReturnValue(true);
+
+    const mockMetric: SerializedMetric = {
+      timestamp: 1713859200,
+      trace_id: '3d9355f71e9c444b81161599adac6e29',
+      span_id: '8b5f5e5e5e5e5e5e',
+      name: 'test.metric',
+      type: 'counter',
+      value: 1,
+      unit: 'count',
+      attributes: {},
+    };
+
+    const result = createMetricContainerEnvelopeItem([mockMetric], true);
+
+    expect(result[1]).toEqual({
+      version: 2,
+      ingest_settings: { infer_ip: 'auto', infer_user_agent: 'auto' },
+      items: [mockMetric],
+    });
+  });
+
+  it("includes ingest_settings with 'never' values when in browser and inferUserData is false", () => {
+    vi.mocked(isBrowser).mockReturnValue(true);
+
+    const mockMetric: SerializedMetric = {
+      timestamp: 1713859200,
+      trace_id: '3d9355f71e9c444b81161599adac6e29',
+      span_id: '8b5f5e5e5e5e5e5e',
+      name: 'test.metric',
+      type: 'counter',
+      value: 1,
+      unit: 'count',
+      attributes: {},
+    };
+
+    const result = createMetricContainerEnvelopeItem([mockMetric], false);
+
+    expect(result[1]).toEqual({
+      version: 2,
+      ingest_settings: { infer_ip: 'never', infer_user_agent: 'never' },
+      items: [mockMetric],
+    });
   });
 });
 
@@ -165,7 +221,7 @@ describe('createMetricEnvelope', () => {
       expect.arrayContaining([
         expect.arrayContaining([
           { type: 'trace_metric', item_count: 2, content_type: 'application/vnd.sentry.items.trace-metric+json' },
-          { items: mockMetrics },
+          { version: 2, items: mockMetrics },
         ]),
       ]),
     );