Logs Nodejs

Node.js logs installation - Docs

1. 1

   Install OpenTelemetry packages

   Required

   Terminal

   PostHog AI

   Copy

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

2. 2

   Get your project token

   Required

   You'll need your PostHog project token to authenticate log requests. This is the same key you use for capturing events and exceptions with the PostHog SDK.

   Important: Use your project token which starts with phc_. Do not use a personal API key (which starts with phx_).

   You can find your project token in Project Settings.

3. 3

   Configure the SDK

   Required

   Set up the OpenTelemetry SDK to send logs to PostHog.

   JavaScript

   PostHog AI

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   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 <ph_project_token>'
         }
       })
     )
   });
   sdk.start();

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

   JavaScript

   PostHog AI

   Copy

   const sdk = new NodeSDK({
     logRecordProcessor: new BatchLogRecordProcessor(
       new OTLPLogExporter({
         url: 'https://us.i.posthog.com/i/v1/logs?token=<ph_project_token>'
       })
     )
   });

4. 4

   Use OpenTelemetry logging

   Required

   Now you can start logging with OpenTelemetry:

   JavaScript

   PostHog AI

   Copy

   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. 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

6. Next steps

   Checkpoint

   What you can do with your logs

   Action	Description
   Why you need logs	What logs show you that nothing else does
   Search logs	Use the search interface to find specific log entries
   Filter by level	Filter by INFO, WARN, ERROR, etc.
   Link session replay	Connect logs to users and session replays by passing posthogDistinctId and sessionId
   Logging best practices	Learn what to log, how to structure logs, and patterns that make logs useful in production

   Troubleshoot common issues

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