Node.js logs installation

Logs is in beta

Logs is free to use whilst in beta, though we'd love to hear your feedback in app.

Install OpenTelemetry packages

Required

Terminal
npm install @opentelemetry/sdk-node @opentelemetry/exporter-logs-otlp-http @opentelemetry/api-logs @opentelemetry/resources

2
Get your project API key
Required
You'll need your PostHog project API key to authenticate log requests. This is the same API key you use for capturing events and exceptions.
You can find your project API key in Project Settings.

Configure the SDK

Required

Set up the OpenTelemetry SDK to send logs to PostHog.

JavaScript
import { NodeSDK } from '@opentelemetry/sdk-node';
import { OTLPLogExporter } from '@opentelemetry/exporter-logs-otlp-http';
import { BatchLogRecordProcessor } from '@opentelemetry/sdk-logs';
import { resourceFromAttributes } from '@opentelemetry/resources';

const sdk = new NodeSDK({
  resource: resourceFromAttributes({
    'service.name': 'my-node-service',
  }),
  logRecordProcessor: new BatchLogRecordProcessor(
    new OTLPLogExporter({
      url: 'https://us.i.posthog.com/i/v1/logs',
      headers: {
        'Authorization': `Bearer ${YOUR_PROJECT_API_KEY}`
      }
    })
  )
});

sdk.start();

Alternatively, you can pass the API key as a query parameter:

JavaScript
const sdk = new NodeSDK({
  logRecordProcessor: new BatchLogRecordProcessor(
    new OTLPLogExporter({
      url: `https://us.i.posthog.com/i/v1/logs?token=${YOUR_PROJECT_API_KEY}`
    })
  )
});

Use OpenTelemetry logging

Required

Now you can start logging with OpenTelemetry:

JavaScript
import { logs } from '@opentelemetry/api-logs';

const logger = logs.getLogger('my-app');

// Log with different levels and attributes
logger.emit({ severityText: 'trace', body: 'log data', attributes: {'my_attribute': 'stringValue'} });
logger.emit({ severityText: 'warn', body: 'log data', attributes: {'warning_count': 3} });
logger.emit({ severityText: 'error', body: 'log data', attributes: {'json_attribute': [1,2,3]} });

5
Test your setup
Recommended
Once everything is configured, test that logs are flowing into PostHog:
1. Send a test log from your application
2. Check the PostHog logs interface for your log entries
3. Verify the logs appear in your project
View your logs in PostHog

Next steps

Checkpoint

What you can do with your logs

Action	Description
Search logs	Use the search interface to find specific log entries
Filter by level	Filter by `INFO`, `WARN`, `ERROR`, etc.
Set up alerts	Get notified when specific log patterns occur
Correlate with events	Connect log data with your PostHog analytics

Troubleshoot common issues

Node.js logs installation

Install OpenTelemetry packages

Get your project API key

Configure the SDK

Use OpenTelemetry logging

Test your setup

Next steps

Community questions

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