diff --git a/js/plugins/google-cloud/src/telemetry/action.ts b/js/plugins/google-cloud/src/telemetry/action.ts
index e3630bb1d..241a8f738 100644
--- a/js/plugins/google-cloud/src/telemetry/action.ts
+++ b/js/plugins/google-cloud/src/telemetry/action.ts
@@ -30,6 +30,8 @@ import {
   createCommonLogAttributes,
   extractErrorName,
   extractOuterFeatureNameFromPath,
+  truncate,
+  truncatePath,
 } from '../utils.js';
 
 class ActionTelemetry implements Telemetry {
@@ -79,8 +81,8 @@ class ActionTelemetry implements Telemetry {
     }
 
     if (subtype === 'tool' && logInputAndOutput) {
-      const input = attributes['genkit:input'] as string;
-      const output = attributes['genkit:output'] as string;
+      const input = truncate(attributes['genkit:input'] as string);
+      const output = truncate(attributes['genkit:output'] as string);
       const sessionId = attributes['genkit:sessionId'] as string;
       const threadName = attributes['genkit:threadName'] as string;
 
@@ -159,7 +161,7 @@ class ActionTelemetry implements Telemetry {
     sessionId?: string,
     threadName?: string
   ) {
-    const path = toDisplayPath(qualifiedPath);
+    const path = truncatePath(toDisplayPath(qualifiedPath));
     const sharedMetadata = {
       ...createCommonLogAttributes(span, projectId),
       path,
diff --git a/js/plugins/google-cloud/src/telemetry/engagement.ts b/js/plugins/google-cloud/src/telemetry/engagement.ts
index 77daef21d..cdf8d91cb 100644
--- a/js/plugins/google-cloud/src/telemetry/engagement.ts
+++ b/js/plugins/google-cloud/src/telemetry/engagement.ts
@@ -24,7 +24,7 @@ import {
   Telemetry,
   internalMetricNamespaceWrap,
 } from '../metrics.js';
-import { createCommonLogAttributes } from '../utils.js';
+import { createCommonLogAttributes, truncate } from '../utils.js';
 
 class EngagementTelemetry implements Telemetry {
   /**
@@ -81,7 +81,9 @@ class EngagementTelemetry implements Telemetry {
       feedbackValue: attributes['genkit:metadata:feedbackValue'],
     };
     if (attributes['genkit:metadata:textFeedback']) {
-      metadata['textFeedback'] = attributes['genkit:metadata:textFeedback'];
+      metadata['textFeedback'] = truncate(
+        attributes['genkit:metadata:textFeedback'] as string
+      );
     }
     logger.logStructured(`UserFeedback[${name}]`, metadata);
   }
diff --git a/js/plugins/google-cloud/src/telemetry/feature.ts b/js/plugins/google-cloud/src/telemetry/feature.ts
index 932bd40ae..2c3e3c980 100644
--- a/js/plugins/google-cloud/src/telemetry/feature.ts
+++ b/js/plugins/google-cloud/src/telemetry/feature.ts
@@ -26,7 +26,12 @@ import {
   Telemetry,
   internalMetricNamespaceWrap,
 } from '../metrics.js';
-import { createCommonLogAttributes, extractErrorName } from '../utils.js';
+import {
+  createCommonLogAttributes,
+  extractErrorName,
+  truncate,
+  truncatePath,
+} from '../utils.js';
 
 class FeaturesTelemetry implements Telemetry {
   /**
@@ -77,8 +82,8 @@ class FeaturesTelemetry implements Telemetry {
     }
 
     if (logInputAndOutput) {
-      const input = attributes['genkit:input'] as string;
-      const output = attributes['genkit:output'] as string;
+      const input = truncate(attributes['genkit:input'] as string);
+      const output = truncate(attributes['genkit:output'] as string);
       const sessionId = attributes['genkit:sessionId'] as string;
       const threadName = attributes['genkit:threadName'] as string;
 
@@ -146,7 +151,7 @@ class FeaturesTelemetry implements Telemetry {
     sessionId?: string,
     threadName?: string
   ) {
-    const path = toDisplayPath(qualifiedPath);
+    const path = truncatePath(toDisplayPath(qualifiedPath));
     const sharedMetadata = {
       ...createCommonLogAttributes(span, projectId),
       path,
diff --git a/js/plugins/google-cloud/src/telemetry/generate.ts b/js/plugins/google-cloud/src/telemetry/generate.ts
index 484a322f6..ee81594de 100644
--- a/js/plugins/google-cloud/src/telemetry/generate.ts
+++ b/js/plugins/google-cloud/src/telemetry/generate.ts
@@ -39,6 +39,8 @@ import {
   createCommonLogAttributes,
   extractErrorName,
   extractOuterFeatureNameFromPath,
+  truncate,
+  truncatePath,
 } from '../utils.js';
 
 type SharedDimensions = {
@@ -59,9 +61,6 @@ class GenerateTelemetry implements Telemetry {
    */
   private _N = internalMetricNamespaceWrap.bind(null, 'ai');
 
-  /** The maximum length (in characters) of a logged prompt message. */
-  private MAX_LOG_CONTENT_CHARS = 128_000;
-
   private actionCounter = new MetricCounter(this._N('generate/requests'), {
     description: 'Counts calls to genkit generate actions.',
     valueType: ValueType.INT,
@@ -136,7 +135,7 @@ class GenerateTelemetry implements Telemetry {
     projectId?: string
   ): void {
     const attributes = span.attributes;
-    const modelName = attributes['genkit:name'] as string;
+    const modelName = truncate(attributes['genkit:name'] as string, 1024);
     const path = (attributes['genkit:path'] as string) || '';
     const input =
       'genkit:input' in attributes
@@ -152,8 +151,10 @@ class GenerateTelemetry implements Telemetry {
         : undefined;
 
     const errName = extractErrorName(span.events);
-    let featureName = (attributes['genkit:metadata:flow:name'] ||
-      extractOuterFeatureNameFromPath(path)) as string;
+    let featureName = truncate(
+      (attributes['genkit:metadata:flow:name'] ||
+        extractOuterFeatureNameFromPath(path)) as string
+    );
     if (!featureName || featureName === '<unknown>') {
       featureName = 'generate';
     }
@@ -162,7 +163,7 @@ class GenerateTelemetry implements Telemetry {
     const threadName = attributes['genkit:threadName'] as string;
 
     if (input) {
-      this.recordGenerateActionMetrics(modelName, featureName, path, input, {
+      this.recordGenerateActionMetrics(modelName, featureName, path, {
         response: output,
         errName,
       });
@@ -209,7 +210,6 @@ class GenerateTelemetry implements Telemetry {
     modelName: string,
     featureName: string,
     path: string,
-    input: GenerateRequestData,
     opts: {
       response?: GenerateResponseData;
       errName?: string;
@@ -235,7 +235,7 @@ class GenerateTelemetry implements Telemetry {
     sessionId?: string,
     threadName?: string
   ) {
-    const path = toDisplayPath(qualifiedPath);
+    const path = truncatePath(toDisplayPath(qualifiedPath));
     const sharedMetadata = {
       ...createCommonLogAttributes(span, projectId),
       model,
@@ -251,7 +251,7 @@ class GenerateTelemetry implements Telemetry {
       topK: input.config?.topK,
       topP: input.config?.topP,
       maxOutputTokens: input.config?.maxOutputTokens,
-      stopSequences: input.config?.stopSequences,
+      stopSequences: truncate(input.config?.stopSequences, 1024),
       source: 'ts',
       sourceVersion: GENKIT_VERSION,
     });
@@ -267,7 +267,7 @@ class GenerateTelemetry implements Telemetry {
     sessionId?: string,
     threadName?: string
   ) {
-    const path = toDisplayPath(qualifiedPath);
+    const path = truncatePath(toDisplayPath(qualifiedPath));
     const sharedMetadata = {
       ...createCommonLogAttributes(span, projectId),
       model,
@@ -305,7 +305,7 @@ class GenerateTelemetry implements Telemetry {
     sessionId?: string,
     threadName?: string
   ) {
-    const path = toDisplayPath(qualifiedPath);
+    const path = truncatePath(toDisplayPath(qualifiedPath));
     const sharedMetadata = {
       ...createCommonLogAttributes(span, projectId),
       model,
@@ -321,7 +321,7 @@ class GenerateTelemetry implements Telemetry {
     message.content.forEach((part, partIdx) => {
       const partCounts = this.toPartCounts(partIdx, parts, 0, 1);
       const initial = output.finishMessage
-        ? { finishMessage: this.toPartLogText(output.finishMessage) }
+        ? { finishMessage: truncate(output.finishMessage) }
         : {};
       logger.logStructured(`Output[${path}, ${model}] ${partCounts}`, {
         ...initial,
@@ -364,10 +364,10 @@ class GenerateTelemetry implements Telemetry {
 
   private toPartLogContent(part: Part): string {
     if (part.text) {
-      return this.toPartLogText(part.text);
+      return truncate(part.text);
     }
     if (part.data) {
-      return this.toPartLogText(JSON.stringify(part.data));
+      return truncate(JSON.stringify(part.data));
     }
     if (part.media) {
       return this.toPartLogMedia(part);
@@ -379,15 +379,11 @@ class GenerateTelemetry implements Telemetry {
       return this.toPartLogToolResponse(part);
     }
     if (part.custom) {
-      return this.toPartLogText(JSON.stringify(part.custom));
+      return truncate(JSON.stringify(part.custom));
     }
     return '<unknown format>';
   }
 
-  private toPartLogText(text: string): string {
-    return text.substring(0, this.MAX_LOG_CONTENT_CHARS);
-  }
-
   private toPartLogMedia(part: MediaPart): string {
     if (part.media.url.startsWith('data:')) {
       const splitIdx = part.media.url.indexOf('base64,');
@@ -400,7 +396,7 @@ class GenerateTelemetry implements Telemetry {
         .digest('hex');
       return `${prefix}<sha256(${hashedContent})>`;
     }
-    return this.toPartLogText(part.media.url);
+    return truncate(part.media.url);
   }
 
   private toPartLogToolRequest(part: ToolRequestPart): string {
@@ -408,7 +404,7 @@ class GenerateTelemetry implements Telemetry {
       typeof part.toolRequest.input === 'string'
         ? part.toolRequest.input
         : JSON.stringify(part.toolRequest.input);
-    return this.toPartLogText(
+    return truncate(
       `Tool request: ${part.toolRequest.name}, ref: ${part.toolRequest.ref}, input: ${inputText}`
     );
   }
@@ -418,7 +414,7 @@ class GenerateTelemetry implements Telemetry {
       typeof part.toolResponse.output === 'string'
         ? part.toolResponse.output
         : JSON.stringify(part.toolResponse.output);
-    return this.toPartLogText(
+    return truncate(
       `Tool response: ${part.toolResponse.name}, ref: ${part.toolResponse.ref}, output: ${outputText}`
     );
   }
diff --git a/js/plugins/google-cloud/src/telemetry/path.ts b/js/plugins/google-cloud/src/telemetry/path.ts
index 79e9fa5b1..495cc2105 100644
--- a/js/plugins/google-cloud/src/telemetry/path.ts
+++ b/js/plugins/google-cloud/src/telemetry/path.ts
@@ -31,6 +31,7 @@ import {
   extractErrorMessage,
   extractErrorName,
   extractErrorStack,
+  truncatePath,
 } from '../utils.js';
 
 class PathsTelemetry implements Telemetry {
@@ -123,7 +124,7 @@ class PathsTelemetry implements Telemetry {
     sessionId?: string,
     threadName?: string
   ) {
-    const displayPath = toDisplayPath(path);
+    const displayPath = truncatePath(toDisplayPath(path));
     logger.logStructuredError(`Error[${displayPath}, ${errorName}]`, {
       ...createCommonLogAttributes(span, projectId),
       path: displayPath,
@@ -207,7 +208,7 @@ class PathsTelemetry implements Telemetry {
         flowName: featureName,
         sessionId,
         threadName,
-        paths: flowPaths.map((p) => toDisplayPath(p.path)),
+        paths: flowPaths.map((p) => truncatePath(toDisplayPath(p.path))),
       });
 
       flowPaths.forEach((p) => this.writePathMetric(featureName, p));
diff --git a/js/plugins/google-cloud/src/utils.ts b/js/plugins/google-cloud/src/utils.ts
index bd3f63983..3235ac898 100644
--- a/js/plugins/google-cloud/src/utils.ts
+++ b/js/plugins/google-cloud/src/utils.ts
@@ -18,6 +18,17 @@ import { TraceFlags } from '@opentelemetry/api';
 import { ReadableSpan, TimedEvent } from '@opentelemetry/sdk-trace-base';
 import { resolveCurrentPrincipal } from './auth.js';
 
+/**
+ * The maximum length (in characters) of a logged input or output.
+ * This limit exists to align the logs with GCP logging size limits.
+ * */
+const MAX_LOG_CONTENT_CHARS = 128_000;
+
+/**
+ * The maximum length (in characters) of a flow path.
+ */
+const MAX_PATH_CHARS = 4096;
+
 export function extractOuterFlowNameFromPath(path: string) {
   if (!path || path === '<unknown>') {
     return '<unknown>';
@@ -27,6 +38,17 @@ export function extractOuterFlowNameFromPath(path: string) {
   return flowName ? flowName[1] : '<unknown>';
 }
 
+export function truncate(
+  text: string,
+  limit: number = MAX_LOG_CONTENT_CHARS
+): string {
+  return text ? text.substring(0, limit) : text;
+}
+
+export function truncatePath(path: string) {
+  return truncate(path, MAX_PATH_CHARS);
+}
+
 /**
  * Extract first feature name from a path
  * e.g. for /{myFlow,t:flow}/{myStep,t:flowStep}/{googleai/gemini-pro,t:action,s:model}
@@ -47,7 +69,7 @@ export function extractErrorName(events: TimedEvent[]): string | undefined {
     .map((event) => {
       const attributes = event.attributes;
       return attributes
-        ? (attributes['exception.type'] as string)
+        ? truncate(attributes['exception.type'] as string, 1024)
         : '<unknown>';
     })
     .at(0);
@@ -59,7 +81,7 @@ export function extractErrorMessage(events: TimedEvent[]): string | undefined {
     .map((event) => {
       const attributes = event.attributes;
       return attributes
-        ? (attributes['exception.message'] as string)
+        ? truncate(attributes['exception.message'] as string, 4096)
         : '<unknown>';
     })
     .at(0);
@@ -71,7 +93,7 @@ export function extractErrorStack(events: TimedEvent[]): string | undefined {
     .map((event) => {
       const attributes = event.attributes;
       return attributes
-        ? (attributes['exception.stacktrace'] as string)
+        ? truncate(attributes['exception.stacktrace'] as string, 32_768)
         : '<unknown>';
     })
     .at(0);
diff --git a/js/plugins/google-cloud/tests/logs_test.ts b/js/plugins/google-cloud/tests/logs_test.ts
index e4540c5c1..909740712 100644
--- a/js/plugins/google-cloud/tests/logs_test.ts
+++ b/js/plugins/google-cloud/tests/logs_test.ts
@@ -19,6 +19,7 @@ import {
   beforeAll,
   beforeEach,
   describe,
+  expect,
   it,
   jest,
 } from '@jest/globals';
@@ -31,6 +32,7 @@ import {
   __addTransportStreamForTesting,
   __forceFlushSpansForTesting,
   __getSpanExporterForTesting,
+  __useJsonFormatForTesting,
   enableGoogleCloudTelemetry,
 } from '../src/index.js';
 
@@ -56,6 +58,207 @@ jest.mock('../src/auth.js', () => {
   };
 });
 
+describe('GoogleCloudLogs with truncation', () => {
+  let logLines = '';
+  const logStream = new Writable();
+  logStream._write = (chunk, encoding, next) => {
+    logLines = logLines += chunk.toString();
+    next();
+  };
+
+  let ai: Genkit;
+
+  beforeAll(async () => {
+    process.env.GCLOUD_PROJECT = 'test';
+    process.env.GENKIT_ENV = 'dev';
+    __useJsonFormatForTesting();
+    __addTransportStreamForTesting(logStream);
+    await enableGoogleCloudTelemetry({
+      projectId: 'test',
+      forceDevExport: false,
+      metricExportIntervalMillis: 100,
+      metricExportTimeoutMillis: 100,
+    });
+    ai = genkit({
+      // Force GCP Plugin to use in-memory metrics exporter
+      plugins: [],
+    });
+    await waitForLogsInit(ai, logLines);
+  });
+  beforeEach(async () => {
+    logLines = '';
+    __getSpanExporterForTesting().reset();
+  });
+  afterAll(async () => {
+    await ai.stopServers();
+  });
+
+  it('truncates large output logs', async () => {
+    const testModel = createModel(ai, 'testModel', async () => {
+      return {
+        message: {
+          role: 'user',
+          content: [
+            {
+              text: 'r'.repeat(130_000),
+            },
+          ],
+        },
+        finishReason: 'stop',
+        usage: {
+          inputTokens: 10,
+          outputTokens: 14,
+          inputCharacters: 8,
+          outputCharacters: 16,
+          inputImages: 1,
+          outputImages: 3,
+        },
+      };
+    });
+    const testFlow = createFlowWithInput(ai, 'testFlow', async (input) => {
+      return await ai.run('sub1', async () => {
+        return await ai.run('sub2', async () => {
+          return await ai.generate({
+            model: testModel,
+            prompt: `${input} prompt`,
+            config: {
+              temperature: 1.0,
+              topK: 3,
+              topP: 5,
+              maxOutputTokens: 7,
+            },
+          });
+        });
+      });
+    });
+
+    await testFlow('test');
+    await getExportedSpans();
+
+    const logMessages = await getLogs(1, 100, logLines);
+    const logObjects = logMessages.map((l) => JSON.parse(l as string));
+    const logObjectMessages = logObjects.map(
+      (structuredLog) => structuredLog.message
+    );
+
+    expect(logObjectMessages).toContain('Output[testFlow, testFlow]');
+
+    logObjects.map((structuredLog) => {
+      if (structuredLog.message === 'Output[testFlow, testFlow]') {
+        expect(structuredLog.content.length).toBe(128_000);
+      }
+    });
+  });
+
+  it('truncates large input logs', async () => {
+    const testModel = createModel(ai, 'testModel', async () => {
+      return {
+        message: {
+          role: 'user',
+          content: [
+            {
+              text: 'response',
+            },
+          ],
+        },
+        finishReason: 'stop',
+        usage: {
+          inputTokens: 10,
+          outputTokens: 14,
+          inputCharacters: 8,
+          outputCharacters: 16,
+          inputImages: 1,
+          outputImages: 3,
+        },
+      };
+    });
+    const testFlow = createFlowWithInput(ai, 'testFlow', async (input) => {
+      return await ai.run('sub1', async () => {
+        return await ai.run('sub2', async () => {
+          return await ai.generate({
+            model: testModel,
+            prompt: `${input} prompt`,
+            config: {
+              temperature: 1.0,
+              topK: 3,
+              topP: 5,
+              maxOutputTokens: 7,
+            },
+          });
+        });
+      });
+    });
+
+    await testFlow('t'.repeat(130_000));
+    await getExportedSpans();
+
+    const logMessages = await getLogs(1, 100, logLines);
+    const logObjects = logMessages.map((l) => JSON.parse(l as string));
+    const logObjectMessages = logObjects.map(
+      (structuredLog) => structuredLog.message
+    );
+
+    expect(logObjectMessages).toContain('Input[testFlow, testFlow]');
+
+    logObjects.map((structuredLog) => {
+      if (structuredLog.message === 'Input[testFlow, testFlow]') {
+        expect(structuredLog.content.length).toBe(128_000);
+      }
+    });
+  });
+
+  it.only('truncates large model names', async () => {
+    const testModel = createModel(ai, 'm'.repeat(2046), async () => {
+      return {
+        message: {
+          role: 'user',
+          content: [
+            {
+              text: 'response',
+            },
+          ],
+        },
+        finishReason: 'stop',
+        usage: {
+          inputTokens: 10,
+          outputTokens: 14,
+          inputCharacters: 8,
+          outputCharacters: 16,
+          inputImages: 1,
+          outputImages: 3,
+        },
+      };
+    });
+    const testFlow = createFlowWithInput(ai, 'testFlow', async (input) => {
+      return await ai.run('sub1', async () => {
+        return await ai.run('sub2', async () => {
+          return await ai.generate({
+            model: testModel,
+            prompt: `${input} prompt`,
+            config: {
+              temperature: 1.0,
+              topK: 3,
+              topP: 5,
+              maxOutputTokens: 7,
+            },
+          });
+        });
+      });
+    });
+
+    await testFlow('test');
+    await getExportedSpans();
+
+    const logMessages = await getLogs(1, 100, logLines);
+    const logObjects = logMessages.map((l) => JSON.parse(l as string));
+    const logObjectModels = logObjects.map(
+      (structuredLog) => structuredLog.model
+    );
+
+    expect(logObjectModels).toContain('m'.repeat(1024));
+  });
+});
+
 describe('GoogleCloudLogs', () => {
   let logLines = '';
   const logStream = new Writable();