feat(core): Add enableTruncation option to Anthropic AI integration (#20181)

This PR adds an `enableTruncation` option to the Anthropic AI
integration that allows users to disable input message truncation. It
defaults to `true` to preserve existing behavior.

Closes: #20136

---------

Co-authored-by: Nicolas Hrubec <nico.hrubec@sentry.io>
Co-authored-by: Nicolas Hrubec <nicolas.hrubec@outlook.com>

Author: andreiborza

dev-packages/node-integration-tests/suites/tracing/anthropic/instrument-no-truncation.mjs

@@ -0,0 +1,24 @@
+import * as Sentry from '@sentry/node';
+import { loggingTransport } from '@sentry-internal/node-integration-tests';
+
+Sentry.init({
+  dsn: 'https://public@dsn.ingest.sentry.io/1337',
+  release: '1.0',
+  tracesSampleRate: 1.0,
+  sendDefaultPii: false,
+  transport: loggingTransport,
+  integrations: [
+    Sentry.anthropicAIIntegration({
+      recordInputs: true,
+      recordOutputs: true,
+      enableTruncation: false,
+    }),
+  ],
+  beforeSendTransaction: event => {
+    // Filter out mock express server transactions
+    if (event.transaction.includes('/anthropic/v1/')) {
+      return null;
+    }
+    return event;
+  },
+});

dev-packages/node-integration-tests/suites/tracing/anthropic/scenario-no-truncation.mjs

@@ -0,0 +1,54 @@
+import { instrumentAnthropicAiClient } from '@sentry/core';
+import * as Sentry from '@sentry/node';
+
+class MockAnthropic {
+  constructor(config) {
+    this.apiKey = config.apiKey;
+    this.messages = {
+      create: this._messagesCreate.bind(this),
+    };
+  }
+
+  async _messagesCreate(params) {
+    await new Promise(resolve => setTimeout(resolve, 10));
+    return {
+      id: 'msg-no-truncation-test',
+      type: 'message',
+      role: 'assistant',
+      content: [{ type: 'text', text: 'Response' }],
+      model: params.model,
+      stop_reason: 'end_turn',
+      stop_sequence: null,
+      usage: { input_tokens: 10, output_tokens: 5 },
+    };
+  }
+}
+
+async function run() {
+  await Sentry.startSpan({ op: 'function', name: 'main' }, async () => {
+    const mockClient = new MockAnthropic({ apiKey: 'mock-api-key' });
+    const client = instrumentAnthropicAiClient(mockClient, { enableTruncation: false, recordInputs: true });
+
+    // Multiple messages with long content (would normally be truncated and popped to last message only)
+    const longContent = 'A'.repeat(50_000);
+    await client.messages.create({
+      model: 'claude-3-haiku-20240307',
+      max_tokens: 100,
+      messages: [
+        { role: 'user', content: longContent },
+        { role: 'assistant', content: 'Some reply' },
+        { role: 'user', content: 'Follow-up question' },
+      ],
+    });
+
+    // Long string input (messagesFromParams wraps it in an array)
+    const longStringInput = 'B'.repeat(50_000);
+    await client.messages.create({
+      model: 'claude-3-haiku-20240307',
+      max_tokens: 100,
+      input: longStringInput,
+    });
+  });
+}
+
+run();

dev-packages/node-integration-tests/suites/tracing/anthropic/test.ts

@@ -802,4 +802,46 @@ describe('Anthropic integration', () => {
       });
     },
   );
+
+  const longContent = 'A'.repeat(50_000);
+  const longStringInput = 'B'.repeat(50_000);
+
+  const EXPECTED_TRANSACTION_NO_TRUNCATION = {
+    transaction: 'main',
+    spans: expect.arrayContaining([
+      // Multiple messages should all be preserved (no popping to last message only)
+      expect.objectContaining({
+        data: expect.objectContaining({
+          [GEN_AI_INPUT_MESSAGES_ATTRIBUTE]: JSON.stringify([
+            { role: 'user', content: longContent },
+            { role: 'assistant', content: 'Some reply' },
+            { role: 'user', content: 'Follow-up question' },
+          ]),
+          [GEN_AI_INPUT_MESSAGES_ORIGINAL_LENGTH_ATTRIBUTE]: 3,
+        }),
+      }),
+      // Long string input should not be truncated (messagesFromParams wraps it in an array)
+      expect.objectContaining({
+        data: expect.objectContaining({
+          [GEN_AI_INPUT_MESSAGES_ATTRIBUTE]: JSON.stringify([longStringInput]),
+          [GEN_AI_INPUT_MESSAGES_ORIGINAL_LENGTH_ATTRIBUTE]: 1,
+        }),
+      }),
+    ]),
+  };
+
+  createEsmAndCjsTests(
+    __dirname,
+    'scenario-no-truncation.mjs',
+    'instrument-no-truncation.mjs',
+    (createRunner, test) => {
+      test('does not truncate input messages when enableTruncation is false', async () => {
+        await createRunner()
+          .ignore('event')
+          .expect({ transaction: EXPECTED_TRANSACTION_NO_TRUNCATION })
+          .start()
+          .completed();
+      });
+    },
+  );
 });

packages/core/src/tracing/anthropic-ai/index.ts

@@ -72,9 +72,9 @@ function extractRequestAttributes(args: unknown[], methodPath: string, operation
  * Add private request attributes to spans.
  * This is only recorded if recordInputs is true.
  */
-function addPrivateRequestAttributes(span: Span, params: Record<string, unknown>): void {
+function addPrivateRequestAttributes(span: Span, params: Record<string, unknown>, enableTruncation: boolean): void {
   const messages = messagesFromParams(params);
-  setMessagesAttribute(span, messages);
+  setMessagesAttribute(span, messages, enableTruncation);
 
   if ('prompt' in params) {
     span.setAttributes({ [GEN_AI_PROMPT_ATTRIBUTE]: JSON.stringify(params.prompt) });
@@ -206,7 +206,7 @@ function handleStreamingRequest<T extends unknown[], R>(
       originalResult = originalMethod.apply(context, args) as Promise<R>;
 
       if (options.recordInputs && params) {
-        addPrivateRequestAttributes(span, params);
+        addPrivateRequestAttributes(span, params, options.enableTruncation ?? true);
       }
 
       return (async () => {
@@ -228,7 +228,7 @@ function handleStreamingRequest<T extends unknown[], R>(
     return startSpanManual(spanConfig, span => {
       try {
         if (options.recordInputs && params) {
-          addPrivateRequestAttributes(span, params);
+          addPrivateRequestAttributes(span, params, options.enableTruncation ?? true);
         }
         const messageStream = target.apply(context, args);
         return instrumentMessageStream(messageStream, span, options.recordOutputs ?? false);
@@ -289,7 +289,7 @@ function instrumentMethod<T extends unknown[], R>(
           originalResult = target.apply(context, args) as Promise<R>;
 
           if (options.recordInputs && params) {
-            addPrivateRequestAttributes(span, params);
+            addPrivateRequestAttributes(span, params, options.enableTruncation ?? true);
           }
 
           return originalResult.then(

packages/core/src/tracing/anthropic-ai/types.ts

@@ -9,6 +9,11 @@ export interface AnthropicAiOptions {
    * Enable or disable output recording.
    */
   recordOutputs?: boolean;
+  /**
+   * Enable or disable truncation of recorded input messages.
+   * Defaults to `true`.
+   */
+  enableTruncation?: boolean;
 }
 
 export type Message = {

packages/core/src/tracing/anthropic-ai/utils.ts

@@ -7,14 +7,14 @@ import {
   GEN_AI_INPUT_MESSAGES_ORIGINAL_LENGTH_ATTRIBUTE,
   GEN_AI_SYSTEM_INSTRUCTIONS_ATTRIBUTE,
 } from '../ai/gen-ai-attributes';
-import { extractSystemInstructions, getTruncatedJsonString } from '../ai/utils';
+import { extractSystemInstructions, getJsonString, getTruncatedJsonString } from '../ai/utils';
 import type { AnthropicAiResponse } from './types';
 
 /**
  * Set the messages and messages original length attributes.
  * Extracts system instructions before truncation.
  */
-export function setMessagesAttribute(span: Span, messages: unknown): void {
+export function setMessagesAttribute(span: Span, messages: unknown, enableTruncation: boolean): void {
   if (Array.isArray(messages) && messages.length === 0) {
     return;
   }
@@ -29,7 +29,9 @@ export function setMessagesAttribute(span: Span, messages: unknown): void {
 
   const filteredLength = Array.isArray(filteredMessages) ? filteredMessages.length : 1;
   span.setAttributes({
-    [GEN_AI_INPUT_MESSAGES_ATTRIBUTE]: getTruncatedJsonString(filteredMessages),
+    [GEN_AI_INPUT_MESSAGES_ATTRIBUTE]: enableTruncation
+      ? getTruncatedJsonString(filteredMessages)
+      : getJsonString(filteredMessages),
     [GEN_AI_INPUT_MESSAGES_ORIGINAL_LENGTH_ATTRIBUTE]: filteredLength,
   });
 }

packages/core/test/lib/utils/anthropic-utils.test.ts

@@ -98,7 +98,7 @@ describe('anthropic-ai-utils', () => {
 
     it('sets length along with truncated value', () => {
       const content = 'A'.repeat(200_000);
-      setMessagesAttribute(span, [{ role: 'user', content }]);
+      setMessagesAttribute(span, [{ role: 'user', content }], true);
       const result = [{ role: 'user', content: 'A'.repeat(19970) }];
       expect(mock.attributes).toStrictEqual({
         'sentry.sdk_meta.gen_ai.input.messages.original_length': 1,
@@ -107,15 +107,15 @@ describe('anthropic-ai-utils', () => {
     });
 
     it('sets length to 1 for non-array input', () => {
-      setMessagesAttribute(span, { content: 'hello, world' });
+      setMessagesAttribute(span, { content: 'hello, world' }, true);
       expect(mock.attributes).toStrictEqual({
         'sentry.sdk_meta.gen_ai.input.messages.original_length': 1,
         'gen_ai.input.messages': '{"content":"hello, world"}',
       });
     });
 
     it('ignores empty array', () => {
-      setMessagesAttribute(span, []);
+      setMessagesAttribute(span, [], true);
       expect(mock.attributes).toStrictEqual({
         'sentry.sdk_meta.gen_ai.input.messages.original_length': 1,
         'gen_ai.input.messages': '{"content":"hello, world"}',