diff --git a/dev-packages/node-integration-tests/suites/tracing/anthropic/test.ts b/dev-packages/node-integration-tests/suites/tracing/anthropic/test.ts
index 3fc3b544b843..ebebf60db042 100644
--- a/dev-packages/node-integration-tests/suites/tracing/anthropic/test.ts
+++ b/dev-packages/node-integration-tests/suites/tracing/anthropic/test.ts
@@ -11,7 +11,7 @@ describe('Anthropic integration', () => {
     spans: expect.arrayContaining([
       // First span - basic message completion without PII
       expect.objectContaining({
-        data: {
+        data: expect.objectContaining({
           'gen_ai.operation.name': 'messages',
           'sentry.op': 'gen_ai.messages',
           'sentry.origin': 'auto.ai.anthropic',
@@ -24,7 +24,7 @@ describe('Anthropic integration', () => {
           'gen_ai.usage.input_tokens': 10,
           'gen_ai.usage.output_tokens': 15,
           'gen_ai.usage.total_tokens': 25,
-        },
+        }),
         description: 'messages claude-3-haiku-20240307',
         op: 'gen_ai.messages',
         origin: 'auto.ai.anthropic',
@@ -32,13 +32,13 @@ describe('Anthropic integration', () => {
       }),
       // Second span - error handling
       expect.objectContaining({
-        data: {
+        data: expect.objectContaining({
           'gen_ai.operation.name': 'messages',
           'sentry.op': 'gen_ai.messages',
           'sentry.origin': 'auto.ai.anthropic',
           'gen_ai.system': 'anthropic',
           'gen_ai.request.model': 'error-model',
-        },
+        }),
         description: 'messages error-model',
         op: 'gen_ai.messages',
         origin: 'auto.ai.anthropic',
@@ -46,13 +46,13 @@ describe('Anthropic integration', () => {
       }),
       // Third span - token counting (no response.text because recordOutputs=false by default)
       expect.objectContaining({
-        data: {
+        data: expect.objectContaining({
           'gen_ai.operation.name': 'messages',
           'sentry.op': 'gen_ai.messages',
           'sentry.origin': 'auto.ai.anthropic',
           'gen_ai.system': 'anthropic',
           'gen_ai.request.model': 'claude-3-haiku-20240307',
-        },
+        }),
         description: 'messages claude-3-haiku-20240307',
         op: 'gen_ai.messages',
         origin: 'auto.ai.anthropic',
@@ -60,7 +60,7 @@ describe('Anthropic integration', () => {
       }),
       // Fourth span - models.retrieve
       expect.objectContaining({
-        data: {
+        data: expect.objectContaining({
           'anthropic.response.timestamp': '2024-05-08T05:20:00.000Z',
           'gen_ai.operation.name': 'models',
           'sentry.op': 'gen_ai.models',
@@ -69,7 +69,7 @@ describe('Anthropic integration', () => {
           'gen_ai.request.model': 'claude-3-haiku-20240307',
           'gen_ai.response.id': 'claude-3-haiku-20240307',
           'gen_ai.response.model': 'claude-3-haiku-20240307',
-        },
+        }),
         description: 'models claude-3-haiku-20240307',
         op: 'gen_ai.models',
         origin: 'auto.ai.anthropic',
@@ -83,88 +83,191 @@ describe('Anthropic integration', () => {
     spans: expect.arrayContaining([
       // First span - basic message completion with PII
       expect.objectContaining({
-        data: {
+        data: expect.objectContaining({
           'gen_ai.operation.name': 'messages',
-          'sentry.op': 'gen_ai.messages',
-          'sentry.origin': 'auto.ai.anthropic',
-          'gen_ai.system': 'anthropic',
+          'gen_ai.request.max_tokens': 100,
+          'gen_ai.request.messages':
+            '[{"role":"system","content":"You are a helpful assistant."},{"role":"user","content":"What is the capital of France?"}]',
           'gen_ai.request.model': 'claude-3-haiku-20240307',
           'gen_ai.request.temperature': 0.7,
-          'gen_ai.request.max_tokens': 100,
-          'gen_ai.request.messages': '[{"role":"user","content":"What is the capital of France?"}]',
-          'gen_ai.response.model': 'claude-3-haiku-20240307',
           'gen_ai.response.id': 'msg_mock123',
+          'gen_ai.response.model': 'claude-3-haiku-20240307',
           'gen_ai.response.text': 'Hello from Anthropic mock!',
+          'gen_ai.system': 'anthropic',
           'gen_ai.usage.input_tokens': 10,
           'gen_ai.usage.output_tokens': 15,
           'gen_ai.usage.total_tokens': 25,
-        },
+          'sentry.op': 'gen_ai.messages',
+          'sentry.origin': 'auto.ai.anthropic',
+        }),
         description: 'messages claude-3-haiku-20240307',
         op: 'gen_ai.messages',
         origin: 'auto.ai.anthropic',
         status: 'ok',
       }),
-      // Second span - error handling with PII
       expect.objectContaining({
-        data: {
+        data: expect.objectContaining({
+          'http.request.method': 'POST',
+          'http.request.method_original': 'POST',
+          'http.response.header.content-length': 247,
+          'http.response.status_code': 200,
+          'otel.kind': 'CLIENT',
+          'sentry.op': 'http.client',
+          'sentry.origin': 'auto.http.otel.node_fetch',
+          'url.path': '/anthropic/v1/messages',
+          'url.query': '',
+          'url.scheme': 'http',
+        }),
+        op: 'http.client',
+        origin: 'auto.http.otel.node_fetch',
+        status: 'ok',
+      }),
+
+      // Second - error handling with PII
+      expect.objectContaining({
+        data: expect.objectContaining({
           'gen_ai.operation.name': 'messages',
+          'gen_ai.request.messages': '[{"role":"user","content":"This will fail"}]',
+          'gen_ai.request.model': 'error-model',
+          'gen_ai.system': 'anthropic',
           'sentry.op': 'gen_ai.messages',
           'sentry.origin': 'auto.ai.anthropic',
-          'gen_ai.system': 'anthropic',
-          'gen_ai.request.model': 'error-model',
-          'gen_ai.request.messages': '[{"role":"user","content":"This will fail"}]',
-        },
+        }),
         description: 'messages error-model',
         op: 'gen_ai.messages',
         origin: 'auto.ai.anthropic',
         status: 'internal_error',
       }),
-      // Third span - token counting with PII (response.text is present because sendDefaultPii=true enables recordOutputs)
       expect.objectContaining({
-        data: {
+        data: expect.objectContaining({
+          'http.request.method': 'POST',
+          'http.request.method_original': 'POST',
+          'http.response.header.content-length': 15,
+          'http.response.status_code': 404,
+          'otel.kind': 'CLIENT',
+          'sentry.op': 'http.client',
+          'sentry.origin': 'auto.http.otel.node_fetch',
+          'url.path': '/anthropic/v1/messages',
+          'url.query': '',
+          'url.scheme': 'http',
+        }),
+        op: 'http.client',
+        origin: 'auto.http.otel.node_fetch',
+        status: 'not_found',
+      }),
+
+      // Third - token counting with PII (response.text is present because sendDefaultPii=true enables recordOutputs)
+      expect.objectContaining({
+        data: expect.objectContaining({
           'gen_ai.operation.name': 'messages',
+          'gen_ai.request.messages': '[{"role":"user","content":"What is the capital of France?"}]',
+          'gen_ai.request.model': 'claude-3-haiku-20240307',
+          'gen_ai.response.text': '15',
+          'gen_ai.system': 'anthropic',
           'sentry.op': 'gen_ai.messages',
           'sentry.origin': 'auto.ai.anthropic',
-          'gen_ai.system': 'anthropic',
-          'gen_ai.request.model': 'claude-3-haiku-20240307',
-          'gen_ai.request.messages': '[{"role":"user","content":"What is the capital of France?"}]',
-          'gen_ai.response.text': '15', // Only present because recordOutputs=true when sendDefaultPii=true
-        },
+        }),
         description: 'messages claude-3-haiku-20240307',
         op: 'gen_ai.messages',
         origin: 'auto.ai.anthropic',
         status: 'ok',
       }),
-      // Fourth span - models.retrieve with PII
       expect.objectContaining({
-        data: {
+        data: expect.objectContaining({
+          'http.request.method': 'POST',
+          'http.request.method_original': 'POST',
+          'http.response.header.content-length': 19,
+          'http.response.status_code': 200,
+          'otel.kind': 'CLIENT',
+          'sentry.op': 'http.client',
+          'sentry.origin': 'auto.http.otel.node_fetch',
+          'url.path': '/anthropic/v1/messages/count_tokens',
+          'url.query': '',
+          'url.scheme': 'http',
+        }),
+        op: 'http.client',
+        origin: 'auto.http.otel.node_fetch',
+        status: 'ok',
+      }),
+
+      // Fourth - models.retrieve with PII
+      expect.objectContaining({
+        data: expect.objectContaining({
           'anthropic.response.timestamp': '2024-05-08T05:20:00.000Z',
           'gen_ai.operation.name': 'models',
-          'sentry.op': 'gen_ai.models',
-          'sentry.origin': 'auto.ai.anthropic',
-          'gen_ai.system': 'anthropic',
           'gen_ai.request.model': 'claude-3-haiku-20240307',
           'gen_ai.response.id': 'claude-3-haiku-20240307',
           'gen_ai.response.model': 'claude-3-haiku-20240307',
-        },
+          'gen_ai.system': 'anthropic',
+          'sentry.op': 'gen_ai.models',
+          'sentry.origin': 'auto.ai.anthropic',
+        }),
         description: 'models claude-3-haiku-20240307',
         op: 'gen_ai.models',
         origin: 'auto.ai.anthropic',
         status: 'ok',
       }),
-      // Fifth span - messages.create with stream: true
+      expect.objectContaining({
+        data: expect.objectContaining({
+          'http.request.method': 'GET',
+          'http.request.method_original': 'GET',
+          'http.response.header.content-length': 123,
+          'http.response.status_code': 200,
+          'otel.kind': 'CLIENT',
+          'sentry.op': 'http.client',
+          'sentry.origin': 'auto.http.otel.node_fetch',
+          'url.path': '/anthropic/v1/models/claude-3-haiku-20240307',
+          'url.query': '',
+          'url.scheme': 'http',
+          'user_agent.original': 'Anthropic/JS 0.63.0',
+        }),
+        op: 'http.client',
+        origin: 'auto.http.otel.node_fetch',
+        status: 'ok',
+      }),
+
+      // Fifth - messages.create with stream: true
       expect.objectContaining({
         data: expect.objectContaining({
           'gen_ai.operation.name': 'messages',
+          'gen_ai.request.messages': '[{"role":"user","content":"What is the capital of France?"}]',
           'gen_ai.request.model': 'claude-3-haiku-20240307',
           'gen_ai.request.stream': true,
+          'gen_ai.response.id': 'msg_stream123',
+          'gen_ai.response.model': 'claude-3-haiku-20240307',
+          'gen_ai.response.streaming': true,
+          'gen_ai.response.text': 'Hello from stream!',
+          'gen_ai.system': 'anthropic',
+          'gen_ai.usage.input_tokens': 10,
+          'gen_ai.usage.output_tokens': 15,
+          'gen_ai.usage.total_tokens': 25,
+          'sentry.op': 'gen_ai.messages',
+          'sentry.origin': 'auto.ai.anthropic',
         }),
         description: 'messages claude-3-haiku-20240307 stream-response',
         op: 'gen_ai.messages',
         origin: 'auto.ai.anthropic',
         status: 'ok',
       }),
-      // Sixth span - messages.stream
+      expect.objectContaining({
+        data: expect.objectContaining({
+          'http.request.method': 'POST',
+          'http.request.method_original': 'POST',
+          'http.response.status_code': 200,
+          'otel.kind': 'CLIENT',
+          'sentry.op': 'http.client',
+          'sentry.origin': 'auto.http.otel.node_fetch',
+          'url.path': '/anthropic/v1/messages',
+          'url.query': '',
+          'url.scheme': 'http',
+          'user_agent.original': 'Anthropic/JS 0.63.0',
+        }),
+        op: 'http.client',
+        origin: 'auto.http.otel.node_fetch',
+        status: 'ok',
+      }),
+
+      // Sixth - messages.stream
       expect.objectContaining({
         data: expect.objectContaining({
           'gen_ai.operation.name': 'messages',
diff --git a/packages/core/src/tracing/anthropic-ai/index.ts b/packages/core/src/tracing/anthropic-ai/index.ts
index aa48a1e4c21d..d8d06efdc9e5 100644
--- a/packages/core/src/tracing/anthropic-ai/index.ts
+++ b/packages/core/src/tracing/anthropic-ai/index.ts
@@ -39,7 +39,7 @@ import type {
   AnthropicAiStreamingEvent,
   ContentBlock,
 } from './types';
-import { handleResponseError, shouldInstrument } from './utils';
+import { handleResponseError, messagesFromParams, shouldInstrument } from './utils';
 
 /**
  * Extract request attributes from method arguments
@@ -82,10 +82,12 @@ function extractRequestAttributes(args: unknown[], methodPath: string): Record<s
  * This is only recorded if recordInputs is true.
  */
 function addPrivateRequestAttributes(span: Span, params: Record<string, unknown>): void {
-  if ('messages' in params) {
-    const truncatedMessages = getTruncatedJsonString(params.messages);
+  const messages = messagesFromParams(params);
+  if (messages.length) {
+    const truncatedMessages = getTruncatedJsonString(messages);
     span.setAttributes({ [GEN_AI_REQUEST_MESSAGES_ATTRIBUTE]: truncatedMessages });
   }
+
   if ('input' in params) {
     const truncatedInput = getTruncatedJsonString(params.input);
     span.setAttributes({ [GEN_AI_REQUEST_MESSAGES_ATTRIBUTE]: truncatedInput });
diff --git a/packages/core/src/tracing/anthropic-ai/utils.ts b/packages/core/src/tracing/anthropic-ai/utils.ts
index 16c85908d4f7..01f86b41adfc 100644
--- a/packages/core/src/tracing/anthropic-ai/utils.ts
+++ b/packages/core/src/tracing/anthropic-ai/utils.ts
@@ -27,3 +27,16 @@ export function handleResponseError(span: Span, response: AnthropicAiResponse):
     });
   }
 }
+
+/**
+ * Include the system prompt in the messages list, if available
+ */
+export function messagesFromParams(params: Record<string, unknown>): unknown[] {
+  const { system, messages } = params;
+
+  const systemMessages = typeof system === 'string' ? [{ role: 'system', content: params.system }] : [];
+
+  const userMessages = Array.isArray(messages) ? messages : messages != null ? [messages] : [];
+
+  return [...systemMessages, ...userMessages];
+}
diff --git a/packages/core/test/lib/utils/anthropic-utils.test.ts b/packages/core/test/lib/utils/anthropic-utils.test.ts
new file mode 100644
index 000000000000..0be295b85813
--- /dev/null
+++ b/packages/core/test/lib/utils/anthropic-utils.test.ts
@@ -0,0 +1,56 @@
+import { describe, expect, it } from 'vitest';
+import { messagesFromParams, shouldInstrument } from '../../../src/tracing/anthropic-ai/utils';
+
+describe('anthropic-ai-utils', () => {
+  describe('shouldInstrument', () => {
+    it('should instrument known methods', () => {
+      expect(shouldInstrument('models.get')).toBe(true);
+    });
+
+    it('should not instrument unknown methods', () => {
+      expect(shouldInstrument('models.unknown.thing')).toBe(false);
+    });
+  });
+
+  describe('messagesFromParams', () => {
+    it('includes system message in messages list', () => {
+      expect(
+        messagesFromParams({
+          messages: [{ role: 'user', content: 'hello' }],
+          system: 'You are a friendly robot awaiting a greeting.',
+        }),
+      ).toStrictEqual([
+        { role: 'system', content: 'You are a friendly robot awaiting a greeting.' },
+        { role: 'user', content: 'hello' },
+      ]);
+    });
+
+    it('includes system message along with non-array messages', () => {
+      expect(
+        messagesFromParams({
+          messages: { role: 'user', content: 'hello' },
+          system: 'You are a friendly robot awaiting a greeting.',
+        }),
+      ).toStrictEqual([
+        { role: 'system', content: 'You are a friendly robot awaiting a greeting.' },
+        { role: 'user', content: 'hello' },
+      ]);
+    });
+
+    it('includes system message if no other messages', () => {
+      expect(
+        messagesFromParams({
+          system: 'You are a friendly robot awaiting a greeting.',
+        }),
+      ).toStrictEqual([{ role: 'system', content: 'You are a friendly robot awaiting a greeting.' }]);
+    });
+
+    it('returns messages if no system message', () => {
+      expect(
+        messagesFromParams({
+          messages: [{ role: 'user', content: 'hello' }],
+        }),
+      ).toStrictEqual([{ role: 'user', content: 'hello' }]);
+    });
+  });
+});