diff --git a/dev-packages/node-integration-tests/suites/tracing/openai/openai-tool-calls/test.ts b/dev-packages/node-integration-tests/suites/tracing/openai/openai-tool-calls/test.ts
index 98dab6e77b86..ac40fbe94249 100644
--- a/dev-packages/node-integration-tests/suites/tracing/openai/openai-tool-calls/test.ts
+++ b/dev-packages/node-integration-tests/suites/tracing/openai/openai-tool-calls/test.ts
@@ -182,6 +182,7 @@ describe('OpenAI Tool Calls integration', () => {
           'sentry.origin': 'auto.ai.openai',
           'gen_ai.system': 'openai',
           'gen_ai.request.model': 'gpt-4',
+          'gen_ai.request.messages.original_length': 1,
           'gen_ai.request.messages': '[{"role":"user","content":"What is the weather like in Paris today?"}]',
           'gen_ai.request.available_tools': WEATHER_TOOL_DEFINITION,
           'gen_ai.response.model': 'gpt-4',
@@ -212,6 +213,7 @@ describe('OpenAI Tool Calls integration', () => {
           'gen_ai.system': 'openai',
           'gen_ai.request.model': 'gpt-4',
           'gen_ai.request.stream': true,
+          'gen_ai.request.messages.original_length': 1,
           'gen_ai.request.messages': '[{"role":"user","content":"What is the weather like in Paris today?"}]',
           'gen_ai.request.available_tools': WEATHER_TOOL_DEFINITION,
           'gen_ai.response.model': 'gpt-4',
@@ -241,6 +243,7 @@ describe('OpenAI Tool Calls integration', () => {
           'sentry.origin': 'auto.ai.openai',
           'gen_ai.system': 'openai',
           'gen_ai.request.model': 'gpt-4',
+          'gen_ai.request.messages.original_length': 1,
           'gen_ai.request.messages': '[{"role":"user","content":"What is the weather like in Paris today?"}]',
           'gen_ai.request.available_tools': WEATHER_TOOL_DEFINITION,
           'gen_ai.response.model': 'gpt-4',
@@ -270,6 +273,7 @@ describe('OpenAI Tool Calls integration', () => {
           'gen_ai.system': 'openai',
           'gen_ai.request.model': 'gpt-4',
           'gen_ai.request.stream': true,
+          'gen_ai.request.messages.original_length': 1,
           'gen_ai.request.messages': '[{"role":"user","content":"What is the weather like in Paris today?"}]',
           'gen_ai.request.available_tools': WEATHER_TOOL_DEFINITION,
           'gen_ai.response.model': 'gpt-4',
diff --git a/dev-packages/node-integration-tests/suites/tracing/openai/test.ts b/dev-packages/node-integration-tests/suites/tracing/openai/test.ts
index d56bb27f6a24..e3973d95195a 100644
--- a/dev-packages/node-integration-tests/suites/tracing/openai/test.ts
+++ b/dev-packages/node-integration-tests/suites/tracing/openai/test.ts
@@ -159,6 +159,7 @@ describe('OpenAI integration', () => {
           'gen_ai.system': 'openai',
           'gen_ai.request.model': 'gpt-3.5-turbo',
           'gen_ai.request.temperature': 0.7,
+          'gen_ai.request.messages.original_length': 2,
           'gen_ai.request.messages':
             '[{"role":"system","content":"You are a helpful assistant."},{"role":"user","content":"What is the capital of France?"}]',
           'gen_ai.response.model': 'gpt-3.5-turbo',
@@ -214,6 +215,7 @@ describe('OpenAI integration', () => {
           'sentry.origin': 'auto.ai.openai',
           'gen_ai.system': 'openai',
           'gen_ai.request.model': 'error-model',
+          'gen_ai.request.messages.original_length': 1,
           'gen_ai.request.messages': '[{"role":"user","content":"This will fail"}]',
         },
         description: 'chat error-model',
@@ -231,6 +233,7 @@ describe('OpenAI integration', () => {
           'gen_ai.request.model': 'gpt-4',
           'gen_ai.request.temperature': 0.8,
           'gen_ai.request.stream': true,
+          'gen_ai.request.messages.original_length': 2,
           'gen_ai.request.messages':
             '[{"role":"system","content":"You are a helpful assistant."},{"role":"user","content":"Tell me about streaming"}]',
           'gen_ai.response.text': 'Hello from OpenAI streaming!',
@@ -287,6 +290,7 @@ describe('OpenAI integration', () => {
           'gen_ai.operation.name': 'chat',
           'gen_ai.request.model': 'error-model',
           'gen_ai.request.stream': true,
+          'gen_ai.request.messages.original_length': 1,
           'gen_ai.request.messages': '[{"role":"user","content":"This will fail"}]',
           'gen_ai.system': 'openai',
           'sentry.op': 'gen_ai.chat',
diff --git a/dev-packages/node-integration-tests/suites/tracing/openai/v6/test.ts b/dev-packages/node-integration-tests/suites/tracing/openai/v6/test.ts
index 23520852f070..3784fb7e4631 100644
--- a/dev-packages/node-integration-tests/suites/tracing/openai/v6/test.ts
+++ b/dev-packages/node-integration-tests/suites/tracing/openai/v6/test.ts
@@ -159,6 +159,7 @@ describe('OpenAI integration (V6)', () => {
           'gen_ai.system': 'openai',
           'gen_ai.request.model': 'gpt-3.5-turbo',
           'gen_ai.request.temperature': 0.7,
+          'gen_ai.request.messages.original_length': 2,
           'gen_ai.request.messages':
             '[{"role":"system","content":"You are a helpful assistant."},{"role":"user","content":"What is the capital of France?"}]',
           'gen_ai.response.model': 'gpt-3.5-turbo',
@@ -214,6 +215,7 @@ describe('OpenAI integration (V6)', () => {
           'sentry.origin': 'auto.ai.openai',
           'gen_ai.system': 'openai',
           'gen_ai.request.model': 'error-model',
+          'gen_ai.request.messages.original_length': 1,
           'gen_ai.request.messages': '[{"role":"user","content":"This will fail"}]',
         },
         description: 'chat error-model',
@@ -231,6 +233,7 @@ describe('OpenAI integration (V6)', () => {
           'gen_ai.request.model': 'gpt-4',
           'gen_ai.request.temperature': 0.8,
           'gen_ai.request.stream': true,
+          'gen_ai.request.messages.original_length': 2,
           'gen_ai.request.messages':
             '[{"role":"system","content":"You are a helpful assistant."},{"role":"user","content":"Tell me about streaming"}]',
           'gen_ai.response.text': 'Hello from OpenAI streaming!',
@@ -287,6 +290,7 @@ describe('OpenAI integration (V6)', () => {
           'gen_ai.operation.name': 'chat',
           'gen_ai.request.model': 'error-model',
           'gen_ai.request.stream': true,
+          'gen_ai.request.messages.original_length': 1,
           'gen_ai.request.messages': '[{"role":"user","content":"This will fail"}]',
           'gen_ai.system': 'openai',
           'sentry.op': 'gen_ai.chat',
@@ -306,6 +310,7 @@ describe('OpenAI integration (V6)', () => {
       // Check that custom options are respected
       expect.objectContaining({
         data: expect.objectContaining({
+          'gen_ai.request.messages.original_length': expect.any(Number),
           'gen_ai.request.messages': expect.any(String), // Should include messages when recordInputs: true
           'gen_ai.response.text': expect.any(String), // Should include response text when recordOutputs: true
         }),
@@ -313,6 +318,7 @@ describe('OpenAI integration (V6)', () => {
       // Check that custom options are respected for streaming
       expect.objectContaining({
         data: expect.objectContaining({
+          'gen_ai.request.messages.original_length': expect.any(Number),
           'gen_ai.request.messages': expect.any(String), // Should include messages when recordInputs: true
           'gen_ai.response.text': expect.any(String), // Should include response text when recordOutputs: true
           'gen_ai.request.stream': true, // Should be marked as stream
diff --git a/dev-packages/node-integration-tests/suites/tracing/vercelai/test.ts b/dev-packages/node-integration-tests/suites/tracing/vercelai/test.ts
index 2ccf8a1dc212..8112bcadd5f5 100644
--- a/dev-packages/node-integration-tests/suites/tracing/vercelai/test.ts
+++ b/dev-packages/node-integration-tests/suites/tracing/vercelai/test.ts
@@ -67,6 +67,7 @@ describe('Vercel AI integration', () => {
       expect.objectContaining({
         data: {
           'gen_ai.prompt': '{"prompt":"Where is the second span?"}',
+          'gen_ai.request.messages.original_length': 1,
           'gen_ai.request.messages': '[{"role":"user","content":"Where is the second span?"}]',
           'gen_ai.request.model': 'mock-model-id',
           'gen_ai.response.model': 'mock-model-id',
@@ -95,6 +96,7 @@ describe('Vercel AI integration', () => {
       expect.objectContaining({
         data: {
           'gen_ai.request.messages': expect.any(String),
+          'gen_ai.request.messages.original_length': expect.any(Number),
           'gen_ai.request.model': 'mock-model-id',
           'gen_ai.response.finish_reasons': ['stop'],
           'gen_ai.response.id': expect.any(String),
@@ -205,6 +207,7 @@ describe('Vercel AI integration', () => {
       expect.objectContaining({
         data: {
           'gen_ai.prompt': '{"prompt":"Where is the first span?"}',
+          'gen_ai.request.messages.original_length': 1,
           'gen_ai.request.messages': '[{"role":"user","content":"Where is the first span?"}]',
           'gen_ai.request.model': 'mock-model-id',
           'gen_ai.response.model': 'mock-model-id',
@@ -237,6 +240,7 @@ describe('Vercel AI integration', () => {
       // Second span - doGenerate for first call, should also include input/output fields when sendDefaultPii: true
       expect.objectContaining({
         data: {
+          'gen_ai.request.messages.original_length': 1,
           'gen_ai.request.messages': '[{"role":"user","content":[{"type":"text","text":"Where is the first span?"}]}]',
           'gen_ai.request.model': 'mock-model-id',
           'gen_ai.response.finish_reasons': ['stop'],
@@ -275,6 +279,7 @@ describe('Vercel AI integration', () => {
       expect.objectContaining({
         data: {
           'gen_ai.prompt': '{"prompt":"Where is the second span?"}',
+          'gen_ai.request.messages.original_length': 1,
           'gen_ai.request.messages': '[{"role":"user","content":"Where is the second span?"}]',
           'gen_ai.request.model': 'mock-model-id',
           'gen_ai.response.model': 'mock-model-id',
@@ -308,6 +313,7 @@ describe('Vercel AI integration', () => {
       expect.objectContaining({
         data: {
           'gen_ai.request.messages': expect.any(String),
+          'gen_ai.request.messages.original_length': expect.any(Number),
           'gen_ai.request.model': 'mock-model-id',
           'gen_ai.response.finish_reasons': ['stop'],
           'gen_ai.response.id': expect.any(String),
@@ -345,6 +351,7 @@ describe('Vercel AI integration', () => {
       expect.objectContaining({
         data: {
           'gen_ai.prompt': '{"prompt":"What is the weather in San Francisco?"}',
+          'gen_ai.request.messages.original_length': 1,
           'gen_ai.request.messages': '[{"role":"user","content":"What is the weather in San Francisco?"}]',
           'gen_ai.request.model': 'mock-model-id',
           'gen_ai.response.model': 'mock-model-id',
@@ -380,6 +387,7 @@ describe('Vercel AI integration', () => {
         data: {
           'gen_ai.request.available_tools': EXPECTED_AVAILABLE_TOOLS_JSON,
           'gen_ai.request.messages': expect.any(String),
+          'gen_ai.request.messages.original_length': expect.any(Number),
           'gen_ai.request.model': 'mock-model-id',
           'gen_ai.response.finish_reasons': ['tool-calls'],
           'gen_ai.response.id': expect.any(String),
diff --git a/dev-packages/node-integration-tests/suites/tracing/vercelai/v5/test.ts b/dev-packages/node-integration-tests/suites/tracing/vercelai/v5/test.ts
index 01aa715bdc77..179644bbcd73 100644
--- a/dev-packages/node-integration-tests/suites/tracing/vercelai/v5/test.ts
+++ b/dev-packages/node-integration-tests/suites/tracing/vercelai/v5/test.ts
@@ -75,6 +75,7 @@ describe('Vercel AI integration (V5)', () => {
           'vercel.ai.settings.maxRetries': 2,
           'vercel.ai.streaming': false,
           'gen_ai.prompt': '{"prompt":"Where is the second span?"}',
+          'gen_ai.request.messages.original_length': 1,
           'gen_ai.request.messages': '[{"role":"user","content":"Where is the second span?"}]',
           'gen_ai.response.model': 'mock-model-id',
           'gen_ai.usage.input_tokens': 10,
@@ -107,6 +108,7 @@ describe('Vercel AI integration (V5)', () => {
           'vercel.ai.response.id': expect.any(String),
           'gen_ai.response.text': expect.any(String),
           'vercel.ai.response.timestamp': expect.any(String),
+          'gen_ai.request.messages.original_length': expect.any(Number),
           'gen_ai.request.messages': expect.any(String),
           'gen_ai.response.finish_reasons': ['stop'],
           'gen_ai.usage.input_tokens': 10,
@@ -205,6 +207,7 @@ describe('Vercel AI integration (V5)', () => {
           'vercel.ai.operationId': 'ai.generateText',
           'vercel.ai.pipeline.name': 'generateText',
           'vercel.ai.prompt': '{"prompt":"Where is the first span?"}',
+          'gen_ai.request.messages.original_length': 1,
           'gen_ai.request.messages': '[{"role":"user","content":"Where is the first span?"}]',
           'vercel.ai.response.finishReason': 'stop',
           'gen_ai.response.text': 'First span here!',
@@ -231,6 +234,7 @@ describe('Vercel AI integration (V5)', () => {
           'vercel.ai.model.provider': 'mock-provider',
           'vercel.ai.operationId': 'ai.generateText.doGenerate',
           'vercel.ai.pipeline.name': 'generateText.doGenerate',
+          'gen_ai.request.messages.original_length': 1,
           'gen_ai.request.messages': '[{"role":"user","content":[{"type":"text","text":"Where is the first span?"}]}]',
           'vercel.ai.response.finishReason': 'stop',
           'vercel.ai.response.id': expect.any(String),
@@ -263,6 +267,7 @@ describe('Vercel AI integration (V5)', () => {
           'vercel.ai.operationId': 'ai.generateText',
           'vercel.ai.pipeline.name': 'generateText',
           'vercel.ai.prompt': '{"prompt":"Where is the second span?"}',
+          'gen_ai.request.messages.original_length': 1,
           'gen_ai.request.messages': '[{"role":"user","content":"Where is the second span?"}]',
           'vercel.ai.response.finishReason': 'stop',
           'gen_ai.response.text': expect.any(String),
@@ -300,6 +305,7 @@ describe('Vercel AI integration (V5)', () => {
           'vercel.ai.response.id': expect.any(String),
           'gen_ai.response.text': expect.any(String),
           'vercel.ai.response.timestamp': expect.any(String),
+          'gen_ai.request.messages.original_length': expect.any(Number),
           'gen_ai.request.messages': expect.any(String),
           'gen_ai.response.finish_reasons': ['stop'],
           'gen_ai.usage.input_tokens': 10,
@@ -321,6 +327,7 @@ describe('Vercel AI integration (V5)', () => {
           'vercel.ai.operationId': 'ai.generateText',
           'vercel.ai.pipeline.name': 'generateText',
           'vercel.ai.prompt': '{"prompt":"What is the weather in San Francisco?"}',
+          'gen_ai.request.messages.original_length': 1,
           'gen_ai.request.messages': '[{"role":"user","content":"What is the weather in San Francisco?"}]',
           'vercel.ai.response.finishReason': 'tool-calls',
           'gen_ai.response.tool_calls': expect.any(String),
@@ -347,6 +354,7 @@ describe('Vercel AI integration (V5)', () => {
           'vercel.ai.model.provider': 'mock-provider',
           'vercel.ai.operationId': 'ai.generateText.doGenerate',
           'vercel.ai.pipeline.name': 'generateText.doGenerate',
+          'gen_ai.request.messages.original_length': expect.any(Number),
           'gen_ai.request.messages': expect.any(String),
           'vercel.ai.prompt.toolChoice': expect.any(String),
           'gen_ai.request.available_tools': EXPECTED_AVAILABLE_TOOLS_JSON,
diff --git a/packages/core/src/tracing/ai/gen-ai-attributes.ts b/packages/core/src/tracing/ai/gen-ai-attributes.ts
index e76b2945b497..6803810f97b4 100644
--- a/packages/core/src/tracing/ai/gen-ai-attributes.ts
+++ b/packages/core/src/tracing/ai/gen-ai-attributes.ts
@@ -115,6 +115,11 @@ export const GEN_AI_USAGE_TOTAL_TOKENS_ATTRIBUTE = 'gen_ai.usage.total_tokens';
  */
 export const GEN_AI_OPERATION_NAME_ATTRIBUTE = 'gen_ai.operation.name';
 
+/**
+ * Original length of messages array, used to indicate truncations had occured
+ */
+export const GEN_AI_REQUEST_MESSAGES_ORIGINAL_LENGTH_ATTRIBUTE = 'gen_ai.request.messages.original_length';
+
 /**
  * The prompt messages
  * Only recorded when recordInputs is enabled
diff --git a/packages/core/src/tracing/anthropic-ai/index.ts b/packages/core/src/tracing/anthropic-ai/index.ts
index d8d06efdc9e5..49ed1c3b3354 100644
--- a/packages/core/src/tracing/anthropic-ai/index.ts
+++ b/packages/core/src/tracing/anthropic-ai/index.ts
@@ -12,7 +12,6 @@ import {
   GEN_AI_REQUEST_AVAILABLE_TOOLS_ATTRIBUTE,
   GEN_AI_REQUEST_FREQUENCY_PENALTY_ATTRIBUTE,
   GEN_AI_REQUEST_MAX_TOKENS_ATTRIBUTE,
-  GEN_AI_REQUEST_MESSAGES_ATTRIBUTE,
   GEN_AI_REQUEST_MODEL_ATTRIBUTE,
   GEN_AI_REQUEST_STREAM_ATTRIBUTE,
   GEN_AI_REQUEST_TEMPERATURE_ATTRIBUTE,
@@ -24,13 +23,7 @@ import {
   GEN_AI_RESPONSE_TOOL_CALLS_ATTRIBUTE,
   GEN_AI_SYSTEM_ATTRIBUTE,
 } from '../ai/gen-ai-attributes';
-import {
-  buildMethodPath,
-  getFinalOperationName,
-  getSpanOperation,
-  getTruncatedJsonString,
-  setTokenUsageAttributes,
-} from '../ai/utils';
+import { buildMethodPath, getFinalOperationName, getSpanOperation, setTokenUsageAttributes } from '../ai/utils';
 import { instrumentAsyncIterableStream, instrumentMessageStream } from './streaming';
 import type {
   AnthropicAiInstrumentedMethod,
@@ -39,7 +32,7 @@ import type {
   AnthropicAiStreamingEvent,
   ContentBlock,
 } from './types';
-import { handleResponseError, messagesFromParams, shouldInstrument } from './utils';
+import { handleResponseError, messagesFromParams, setMessagesAttribute, shouldInstrument } from './utils';
 
 /**
  * Extract request attributes from method arguments
@@ -83,15 +76,7 @@ function extractRequestAttributes(args: unknown[], methodPath: string): Record<s
  */
 function addPrivateRequestAttributes(span: Span, params: Record<string, unknown>): void {
   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 });
-  }
+  setMessagesAttribute(span, messages);
 
   if ('prompt' in params) {
     span.setAttributes({ [GEN_AI_PROMPT_ATTRIBUTE]: JSON.stringify(params.prompt) });
diff --git a/packages/core/src/tracing/anthropic-ai/utils.ts b/packages/core/src/tracing/anthropic-ai/utils.ts
index 01f86b41adfc..f10b3ebe6358 100644
--- a/packages/core/src/tracing/anthropic-ai/utils.ts
+++ b/packages/core/src/tracing/anthropic-ai/utils.ts
@@ -1,6 +1,11 @@
 import { captureException } from '../../exports';
 import { SPAN_STATUS_ERROR } from '../../tracing';
 import type { Span } from '../../types-hoist/span';
+import {
+  GEN_AI_REQUEST_MESSAGES_ATTRIBUTE,
+  GEN_AI_REQUEST_MESSAGES_ORIGINAL_LENGTH_ATTRIBUTE,
+} from '../ai/gen-ai-attributes';
+import { getTruncatedJsonString } from '../ai/utils';
 import { ANTHROPIC_AI_INSTRUMENTED_METHODS } from './constants';
 import type { AnthropicAiInstrumentedMethod, AnthropicAiResponse } from './types';
 
@@ -11,6 +16,19 @@ export function shouldInstrument(methodPath: string): methodPath is AnthropicAiI
   return ANTHROPIC_AI_INSTRUMENTED_METHODS.includes(methodPath as AnthropicAiInstrumentedMethod);
 }
 
+/**
+ * Set the messages and messages original length attributes.
+ */
+export function setMessagesAttribute(span: Span, messages: unknown): void {
+  const length = Array.isArray(messages) ? messages.length : undefined;
+  if (length !== 0) {
+    span.setAttributes({
+      [GEN_AI_REQUEST_MESSAGES_ATTRIBUTE]: getTruncatedJsonString(messages),
+      [GEN_AI_REQUEST_MESSAGES_ORIGINAL_LENGTH_ATTRIBUTE]: length,
+    });
+  }
+}
+
 /**
  * Capture error information from the response
  * @see https://docs.anthropic.com/en/api/errors#error-shapes
@@ -32,11 +50,15 @@ 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 { system, messages, input } = params;
 
   const systemMessages = typeof system === 'string' ? [{ role: 'system', content: params.system }] : [];
 
-  const userMessages = Array.isArray(messages) ? messages : messages != null ? [messages] : [];
+  const inputParamMessages = Array.isArray(input) ? input : input != null ? [input] : undefined;
+
+  const messagesParamMessages = Array.isArray(messages) ? messages : messages != null ? [messages] : [];
+
+  const userMessages = inputParamMessages ?? messagesParamMessages;
 
   return [...systemMessages, ...userMessages];
 }
diff --git a/packages/core/src/tracing/google-genai/index.ts b/packages/core/src/tracing/google-genai/index.ts
index 9c53e09fd1ca..53af7a9632cb 100644
--- a/packages/core/src/tracing/google-genai/index.ts
+++ b/packages/core/src/tracing/google-genai/index.ts
@@ -11,6 +11,7 @@ import {
   GEN_AI_REQUEST_FREQUENCY_PENALTY_ATTRIBUTE,
   GEN_AI_REQUEST_MAX_TOKENS_ATTRIBUTE,
   GEN_AI_REQUEST_MESSAGES_ATTRIBUTE,
+  GEN_AI_REQUEST_MESSAGES_ORIGINAL_LENGTH_ATTRIBUTE,
   GEN_AI_REQUEST_MODEL_ATTRIBUTE,
   GEN_AI_REQUEST_PRESENCE_PENALTY_ATTRIBUTE,
   GEN_AI_REQUEST_TEMPERATURE_ATTRIBUTE,
@@ -165,8 +166,9 @@ function addPrivateRequestAttributes(span: Span, params: Record<string, unknown>
     messages.push(...contentUnionToMessages(params.message as PartListUnion, 'user'));
   }
 
-  if (messages.length) {
+  if (Array.isArray(messages) && messages.length) {
     span.setAttributes({
+      [GEN_AI_REQUEST_MESSAGES_ORIGINAL_LENGTH_ATTRIBUTE]: messages.length,
       [GEN_AI_REQUEST_MESSAGES_ATTRIBUTE]: JSON.stringify(truncateGenAiMessages(messages)),
     });
   }
diff --git a/packages/core/src/tracing/langchain/utils.ts b/packages/core/src/tracing/langchain/utils.ts
index 9a8fa9aed26d..0a07ae8df370 100644
--- a/packages/core/src/tracing/langchain/utils.ts
+++ b/packages/core/src/tracing/langchain/utils.ts
@@ -5,6 +5,7 @@ import {
   GEN_AI_REQUEST_FREQUENCY_PENALTY_ATTRIBUTE,
   GEN_AI_REQUEST_MAX_TOKENS_ATTRIBUTE,
   GEN_AI_REQUEST_MESSAGES_ATTRIBUTE,
+  GEN_AI_REQUEST_MESSAGES_ORIGINAL_LENGTH_ATTRIBUTE,
   GEN_AI_REQUEST_MODEL_ATTRIBUTE,
   GEN_AI_REQUEST_PRESENCE_PENALTY_ATTRIBUTE,
   GEN_AI_REQUEST_STREAM_ATTRIBUTE,
@@ -253,6 +254,7 @@ export function extractLLMRequestAttributes(
   const attrs = baseRequestAttributes(system, modelName, 'pipeline', llm, invocationParams, langSmithMetadata);
 
   if (recordInputs && Array.isArray(prompts) && prompts.length > 0) {
+    setIfDefined(attrs, GEN_AI_REQUEST_MESSAGES_ORIGINAL_LENGTH_ATTRIBUTE, prompts.length);
     const messages = prompts.map(p => ({ role: 'user', content: p }));
     setIfDefined(attrs, GEN_AI_REQUEST_MESSAGES_ATTRIBUTE, asString(messages));
   }
@@ -282,6 +284,7 @@ export function extractChatModelRequestAttributes(
 
   if (recordInputs && Array.isArray(langChainMessages) && langChainMessages.length > 0) {
     const normalized = normalizeLangChainMessages(langChainMessages.flat());
+    setIfDefined(attrs, GEN_AI_REQUEST_MESSAGES_ORIGINAL_LENGTH_ATTRIBUTE, normalized.length);
     const truncated = truncateGenAiMessages(normalized);
     setIfDefined(attrs, GEN_AI_REQUEST_MESSAGES_ATTRIBUTE, asString(truncated));
   }
diff --git a/packages/core/src/tracing/langgraph/index.ts b/packages/core/src/tracing/langgraph/index.ts
index 5601cddf458b..e5b8d79f72e3 100644
--- a/packages/core/src/tracing/langgraph/index.ts
+++ b/packages/core/src/tracing/langgraph/index.ts
@@ -8,6 +8,7 @@ import {
   GEN_AI_PIPELINE_NAME_ATTRIBUTE,
   GEN_AI_REQUEST_AVAILABLE_TOOLS_ATTRIBUTE,
   GEN_AI_REQUEST_MESSAGES_ATTRIBUTE,
+  GEN_AI_REQUEST_MESSAGES_ORIGINAL_LENGTH_ATTRIBUTE,
 } from '../ai/gen-ai-attributes';
 import { truncateGenAiMessages } from '../ai/messageTruncation';
 import type { LangChainMessage } from '../langchain/types';
@@ -128,7 +129,10 @@ function instrumentCompiledGraphInvoke(
             if (inputMessages && recordInputs) {
               const normalizedMessages = normalizeLangChainMessages(inputMessages);
               const truncatedMessages = truncateGenAiMessages(normalizedMessages);
-              span.setAttribute(GEN_AI_REQUEST_MESSAGES_ATTRIBUTE, JSON.stringify(truncatedMessages));
+              span.setAttributes({
+                [GEN_AI_REQUEST_MESSAGES_ATTRIBUTE]: JSON.stringify(truncatedMessages),
+                [GEN_AI_REQUEST_MESSAGES_ORIGINAL_LENGTH_ATTRIBUTE]: normalizedMessages.length,
+              });
             }
 
             // Call original invoke
diff --git a/packages/core/src/tracing/openai/index.ts b/packages/core/src/tracing/openai/index.ts
index c68e920daf2b..adc49b2b60bc 100644
--- a/packages/core/src/tracing/openai/index.ts
+++ b/packages/core/src/tracing/openai/index.ts
@@ -11,6 +11,7 @@ import {
   GEN_AI_REQUEST_ENCODING_FORMAT_ATTRIBUTE,
   GEN_AI_REQUEST_FREQUENCY_PENALTY_ATTRIBUTE,
   GEN_AI_REQUEST_MESSAGES_ATTRIBUTE,
+  GEN_AI_REQUEST_MESSAGES_ORIGINAL_LENGTH_ATTRIBUTE,
   GEN_AI_REQUEST_MODEL_ATTRIBUTE,
   GEN_AI_REQUEST_PRESENCE_PENALTY_ATTRIBUTE,
   GEN_AI_REQUEST_STREAM_ATTRIBUTE,
@@ -116,13 +117,15 @@ function addResponseAttributes(span: Span, result: unknown, recordOutputs?: bool
 
 // Extract and record AI request inputs, if present. This is intentionally separate from response attributes.
 function addRequestAttributes(span: Span, params: Record<string, unknown>): void {
-  if ('messages' in params) {
-    const truncatedMessages = getTruncatedJsonString(params.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 });
+  const src = 'input' in params ? params.input : 'messages' in params ? params.messages : undefined;
+  // typically an array, but can be other types. skip if an empty array.
+  const length = Array.isArray(src) ? src.length : undefined;
+  if (src && length !== 0) {
+    const truncatedInput = getTruncatedJsonString(src);
+    span.setAttribute(GEN_AI_REQUEST_MESSAGES_ATTRIBUTE, truncatedInput);
+    if (length) {
+      span.setAttribute(GEN_AI_REQUEST_MESSAGES_ORIGINAL_LENGTH_ATTRIBUTE, length);
+    }
   }
 }
 
diff --git a/packages/core/src/tracing/vercel-ai/utils.ts b/packages/core/src/tracing/vercel-ai/utils.ts
index b6c5b0ad5aab..05dcc1f43817 100644
--- a/packages/core/src/tracing/vercel-ai/utils.ts
+++ b/packages/core/src/tracing/vercel-ai/utils.ts
@@ -8,6 +8,7 @@ import {
   GEN_AI_GENERATE_TEXT_DO_GENERATE_OPERATION_ATTRIBUTE,
   GEN_AI_INVOKE_AGENT_OPERATION_ATTRIBUTE,
   GEN_AI_REQUEST_MESSAGES_ATTRIBUTE,
+  GEN_AI_REQUEST_MESSAGES_ORIGINAL_LENGTH_ATTRIBUTE,
   GEN_AI_STREAM_OBJECT_DO_STREAM_OPERATION_ATTRIBUTE,
   GEN_AI_STREAM_TEXT_DO_STREAM_OPERATION_ATTRIBUTE,
   GEN_AI_USAGE_INPUT_TOKENS_ATTRIBUTE,
@@ -142,7 +143,24 @@ export function requestMessagesFromPrompt(span: Span, attributes: SpanAttributes
     !attributes[AI_PROMPT_MESSAGES_ATTRIBUTE]
   ) {
     const messages = convertPromptToMessages(prompt);
-    if (messages.length) span.setAttribute(GEN_AI_REQUEST_MESSAGES_ATTRIBUTE, getTruncatedJsonString(messages));
+    if (messages.length) {
+      span.setAttributes({
+        [GEN_AI_REQUEST_MESSAGES_ATTRIBUTE]: getTruncatedJsonString(messages),
+        [GEN_AI_REQUEST_MESSAGES_ORIGINAL_LENGTH_ATTRIBUTE]: messages.length,
+      });
+    }
+  } else if (typeof attributes[AI_PROMPT_MESSAGES_ATTRIBUTE] === 'string') {
+    try {
+      const messages = JSON.parse(attributes[AI_PROMPT_MESSAGES_ATTRIBUTE]);
+      if (Array.isArray(messages)) {
+        span.setAttributes({
+          [AI_PROMPT_MESSAGES_ATTRIBUTE]: undefined,
+          [GEN_AI_REQUEST_MESSAGES_ATTRIBUTE]: getTruncatedJsonString(messages),
+          [GEN_AI_REQUEST_MESSAGES_ORIGINAL_LENGTH_ATTRIBUTE]: messages.length,
+        });
+      }
+      // eslint-disable-next-line no-empty
+    } catch {}
   }
 }
 
diff --git a/packages/core/test/lib/utils/anthropic-utils.test.ts b/packages/core/test/lib/utils/anthropic-utils.test.ts
index 0be295b85813..74d4e6b85c17 100644
--- a/packages/core/test/lib/utils/anthropic-utils.test.ts
+++ b/packages/core/test/lib/utils/anthropic-utils.test.ts
@@ -1,5 +1,6 @@
 import { describe, expect, it } from 'vitest';
-import { messagesFromParams, shouldInstrument } from '../../../src/tracing/anthropic-ai/utils';
+import { messagesFromParams, setMessagesAttribute, shouldInstrument } from '../../../src/tracing/anthropic-ai/utils';
+import type { Span } from '../../../src/types-hoist/span';
 
 describe('anthropic-ai-utils', () => {
   describe('shouldInstrument', () => {
@@ -25,6 +26,19 @@ describe('anthropic-ai-utils', () => {
       ]);
     });
 
+    it('looks to params.input ahead of params.messages', () => {
+      expect(
+        messagesFromParams({
+          input: [{ role: 'user', content: 'input' }],
+          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: 'input' },
+      ]);
+    });
+
     it('includes system message along with non-array messages', () => {
       expect(
         messagesFromParams({
@@ -53,4 +67,42 @@ describe('anthropic-ai-utils', () => {
       ).toStrictEqual([{ role: 'user', content: 'hello' }]);
     });
   });
+
+  describe('setMessagesAtribute', () => {
+    const mock = {
+      attributes: {} as Record<string, any>,
+      setAttributes(kv: Record<string, any>) {
+        for (const [key, val] of Object.entries(kv)) {
+          // eslint-disable-next-line @typescript-eslint/no-dynamic-delete
+          if (val === undefined) delete this.attributes[key];
+          else this.attributes[key] = val;
+        }
+      },
+    };
+    const span = mock as unknown as Span;
+
+    it('sets length along with truncated value', () => {
+      const content = 'A'.repeat(200_000);
+      setMessagesAttribute(span, [{ role: 'user', content }]);
+      const result = [{ role: 'user', content: 'A'.repeat(19972) }];
+      expect(mock.attributes).toStrictEqual({
+        'gen_ai.request.messages.original_length': 1,
+        'gen_ai.request.messages': JSON.stringify(result),
+      });
+    });
+
+    it('removes length when setting new value ', () => {
+      setMessagesAttribute(span, { content: 'hello, world' });
+      expect(mock.attributes).toStrictEqual({
+        'gen_ai.request.messages': '{"content":"hello, world"}',
+      });
+    });
+
+    it('ignores empty array', () => {
+      setMessagesAttribute(span, []);
+      expect(mock.attributes).toStrictEqual({
+        'gen_ai.request.messages': '{"content":"hello, world"}',
+      });
+    });
+  });
 });