Go 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

go get go.opentelemetry.io/otel/sdk/log
go get go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploghttp

2
Get your project API key
Required
You'll need your PostHog project API key to authenticate log requests. This is the same key you use for capturing events and exceptions with the PostHog SDK.
Important: Use your project API key which starts with phc_. Do not use a personal API key (which starts with phx_).
You can find your project API key in Project Settings under "Project Variables" → "Project API key".

Configure the SDK

Required

Set up the OpenTelemetry SDK to send logs to PostHog.

Go
package main

import (
    "os"
    "context"
    "log"
    "log/slog"

    "go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploghttp"
    "go.opentelemetry.io/otel/exporters/stdout/stdoutlog"
    "go.opentelemetry.io/contrib/bridges/otelslog"
    otellog "go.opentelemetry.io/otel/sdk/log"
    "go.opentelemetry.io/otel/log/global"
)

func main() {
    ctx := context.Background()

    // Create OTLP HTTP exporter
    exporter, err := otlploghttp.New(ctx,
        otlploghttp.WithEndpoint("us.i.posthog.com"),
        otlploghttp.WithURLPath("/i/v1/logs"),
        otlploghttp.WithHeaders(map[string]string{
            "Authorization": "Bearer <ph_project_api_key>",
        }),
    )
    if err != nil {
        panic(err)
    }

    // you could also set this outside your application
    os.Setenv("OTEL_SERVICE_NAME", "my-service")

    stdoutExporter, _ := stdoutlog.New()

    // Create logger provider
    loggerProvider := otellog.NewLoggerProvider(
        otellog.WithProcessor(otellog.NewBatchProcessor(exporter)),
        // optional, also log to stdout
        otellog.WithProcessor(otellog.NewSimpleProcessor(stdoutExporter)),
    )
    defer func() {
        loggerProvider.Shutdown(context.Background())
    }()

    global.SetLoggerProvider(loggerProvider)
    slog.SetDefault(otelslog.NewLogger(""))

    log.Println("this is a log line")
}

Alternatively, you can pass the API key as a query parameter by modifying the URL path:

Go
otlploghttp.WithURLPath("/i/v1/logs?token=<ph_project_api_key>")

Use OpenTelemetry logging

Required

Now you can start logging with OpenTelemetry:

Go
import (
    "go.opentelemetry.io/otel/log"
)

logger := otel.GetLoggerProvider().Logger("my-app")

logger.Info(ctx, "User action",
    log.String("userId", "123"),
    log.String("action", "login"),
)

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
Link session replay	Connect logs to users and session replays by passing `posthogDistinctId` and `sessionId`

Troubleshoot common issues

Go 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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