feat(core): Add enableTruncation option to LangGraph integration

.size-limit.js

@@ -276,7 +276,7 @@ module.exports = [
     path: createCDNPath('bundle.tracing.replay.logs.metrics.min.js'),
     gzip: false,
     brotli: false,
-    limit: '250 KB',
+    limit: '251 KB',
   },
   {
     name: 'CDN Bundle (incl. Tracing, Replay, Feedback) - uncompressed',

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

@@ -0,0 +1,15 @@
+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: true,
+  transport: loggingTransport,
+  integrations: [
+    Sentry.langGraphIntegration({
+      enableTruncation: false,
+    }),
+  ],
+});

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

@@ -0,0 +1,42 @@
+import { END, MessagesAnnotation, START, StateGraph } from '@langchain/langgraph';
+import * as Sentry from '@sentry/node';
+
+async function run() {
+  await Sentry.startSpan({ op: 'function', name: 'langgraph-test' }, async () => {
+    const mockLlm = () => {
+      return {
+        messages: [
+          {
+            role: 'assistant',
+            content: 'Mock LLM response',
+            response_metadata: {
+              model_name: 'mock-model',
+              finish_reason: 'stop',
+              tokenUsage: {
+                promptTokens: 20,
+                completionTokens: 10,
+                totalTokens: 30,
+              },
+            },
+          },
+        ],
+      };
+    };
+
+    const graph = new StateGraph(MessagesAnnotation)
+      .addNode('agent', mockLlm)
+      .addEdge(START, 'agent')
+      .addEdge('agent', END)
+      .compile({ name: 'weather_assistant' });
+
+    // Long content that would normally be truncated
+    const longContent = 'A'.repeat(50_000);
+    await graph.invoke({
+      messages: [{ role: 'user', content: longContent }],
+    });
+  });
+
+  await Sentry.flush(2000);
+}
+
+run();

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

@@ -364,4 +364,32 @@ describe('LangGraph integration', () => {
       await createRunner().ignore('event').expect({ transaction: EXPECTED_TRANSACTION_RESUME }).start().completed();
     });
   });
+
+  const longContent = 'A'.repeat(50_000);
+
+  const EXPECTED_TRANSACTION_NO_TRUNCATION = {
+    transaction: 'langgraph-test',
+    spans: expect.arrayContaining([
+      expect.objectContaining({
+        data: expect.objectContaining({
+          [GEN_AI_INPUT_MESSAGES_ATTRIBUTE]: expect.stringContaining(longContent),
+        }),
+      }),
+    ]),
+  };
+
+  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/langgraph/index.ts

@@ -12,8 +12,12 @@ import {
   GEN_AI_REQUEST_AVAILABLE_TOOLS_ATTRIBUTE,
   GEN_AI_SYSTEM_INSTRUCTIONS_ATTRIBUTE,
 } from '../ai/gen-ai-attributes';
-import { truncateGenAiMessages } from '../ai/messageTruncation';
-import { extractSystemInstructions, resolveAIRecordingOptions } from '../ai/utils';
+import {
+  extractSystemInstructions,
+  getJsonString,
+  getTruncatedJsonString,
+  resolveAIRecordingOptions,
+} from '../ai/utils';
 import type { LangChainMessage } from '../langchain/types';
 import { normalizeLangChainMessages } from '../langchain/utils';
 import { startSpan } from '../trace';
@@ -146,10 +150,12 @@ function instrumentCompiledGraphInvoke(
                 span.setAttribute(GEN_AI_SYSTEM_INSTRUCTIONS_ATTRIBUTE, systemInstructions);
               }
 
-              const truncatedMessages = truncateGenAiMessages(filteredMessages as unknown[]);
+              const enableTruncation = options.enableTruncation ?? true;
               const filteredLength = Array.isArray(filteredMessages) ? filteredMessages.length : 0;
               span.setAttributes({
-                [GEN_AI_INPUT_MESSAGES_ATTRIBUTE]: JSON.stringify(truncatedMessages),
+                [GEN_AI_INPUT_MESSAGES_ATTRIBUTE]: enableTruncation
+                  ? getTruncatedJsonString(filteredMessages)
+                  : getJsonString(filteredMessages),
                 [GEN_AI_INPUT_MESSAGES_ORIGINAL_LENGTH_ATTRIBUTE]: filteredLength,
               });
             }

packages/core/src/tracing/langgraph/types.ts

@@ -7,6 +7,11 @@ export interface LangGraphOptions {
    * Enable or disable output recording.
    */
   recordOutputs?: boolean;
+  /**
+   * Enable or disable truncation of recorded input messages.
+   * Defaults to `true`.
+   */
+  enableTruncation?: boolean;
 }
 
 /**