Go slog Handler

Use the Go handler when your application already logs through log/slog and you want the same records to flow into Squasher.

Installation

go get github.com/squasher-ai/squasher-go

Configuration

Create one handler with your Squasher credentials, then build a slog.Logger from it.

main.go

package main

import (
	"log/slog"

	squasher "github.com/squasher-ai/squasher-go"
)

func main() {
	handler := squasher.NewHandler(
		"sq_pk_your_key",
		"your-project-id",
		squasher.WithLevel(slog.LevelInfo),
	)
	defer handler.Close()

	logger := slog.New(handler)
	logger.Info("service started")
}

Option	Type	Default	Description
`WithEndpoint(...)`	`Option`	`https://ingest.squasher.ai`	Override the ingest base URL
`WithHTTPClient(...)`	`Option`	Default `http.Client`	Provide a custom client or timeout policy
`WithBufferSize(...)`	`Option`	`100`	Control the async queue size
`WithLevel(...)`	`Option`	`slog.LevelDebug`	Filter records before they are queued
`WithSampling(...)`	`Option`	Keep all outcomes	Set deterministic outcome sampling

Usage Example

main.go

package main

import (
	"context"
	"log/slog"

	squasher "github.com/squasher-ai/squasher-go"
)

func main() {
	handler := squasher.NewHandler("sq_pk_your_key", "your-project-id")
	defer handler.Close()

	logger := slog.New(handler)
	logger.Error(
		"checkout failed",
		slog.String("service", "api"),
		slog.Int("attempt", 2),
		slog.String("request_id", "req_123"),
	)

	_ = handler.Flush(context.Background())
}

The handler sends records asynchronously, so a final Flush() call is useful during shutdown paths, CLI commands, and tests.

Custom Attributes

Use WithAttrs() for shared fields and WithGroup() for nested attributes that should stay together.

main.go

package main

import (
	"log/slog"

	squasher "github.com/squasher-ai/squasher-go"
)

func main() {
	handler := squasher.NewHandler("sq_pk_your_key", "your-project-id")
	defer handler.Close()

	grouped := handler.WithAttrs([]slog.Attr{
		slog.String("service", "payments"),
	}).WithGroup("http")

	logger := slog.New(grouped)
	logger.Error(
		"request failed",
		slog.String("method", "POST"),
		slog.Int("status", 500),
	)
}

Those attributes are preserved in the structured payload that Squasher receives, which makes them available for filtering and debugging. Use standard attribute names such as event.name, service.version, trace_id, and span_id. The handler keeps numbers and booleans typed and uses trace identifiers for log correlation.

Outcome sampling

Start with the default policy, then change only the rate you need:

sampling := squasher.DefaultSamplingConfig()
sampling.SuccessRate = 0.1

handler := squasher.NewHandler(
    "sq_pk_your_key",
    "your-project-id",
    squasher.WithSampling(sampling),
)

Errors and slow records stay at full fidelity by default. Records with the same trace_id get the same sampling decision.

Agent handoff

Install the Squasher Go SDK, add a slog handler with SQUASHER_API_KEY and SQUASHER_PROJECT_ID from env, preserve existing handlers if present, call Flush or Close during shutdown, and verify with one error-level log.

Get Started

SDKs

Integrations

Migrations

Cloud Log Drains

Features

API Reference

Installation

Configuration

Usage Example

Custom Attributes

Outcome sampling

Agent handoff

​Installation

​Configuration

​Usage Example

​Custom Attributes

​Outcome sampling

​Agent handoff

Installation

Configuration

Usage Example

Custom Attributes

Outcome sampling

Agent handoff