Fiber Web Framework Errors

Fiber is an Express-inspired web framework for Go that's quickly gaining traction among developers who prefer familiar routing and middleware patterns without the overhead of heavier frameworks. If you're building APIs or web services with Fiber, you're probably enjoying its speed and developer experience—but sooner or later, production will throw errors at you, and you'll need visibility into what went wrong. Go Fiber error monitoring gives you that visibility, and setting it up takes just a few minutes.

Unlike older Go frameworks like Gin or Echo, Fiber documentation on error tracking is sparse. That's where this guide comes in: we'll walk through integrating Fiber with Sentry-compatible error tracking, capturing both HTTP errors and panics, and building middleware that works with your app's error flow. By the end, you'll have a reliable error reporting pipeline that tells you about failures before your users file complaints.

Setting Up LightTrace with the Sentry SDK

Fiber doesn't require a special SDK—you use the standard Sentry SDK for Go, just like you would for any other Go application. Start by adding the SDK to your project:

go get github.com/getsentry/sentry-go

Then initialize Sentry early in your app startup, before any requests come in:

package main

import (
	"github.com/getsentry/sentry-go"
	"github.com/gofiber/fiber/v2"
)

func main() {
	err := sentry.Init(sentry.ClientOptions{
		Dsn: "https://<key>@light-trace.robomiri.com/1",
	})
	if err != nil {
		log.Fatalf("sentry.Init failed: %v", err)
	}
	// Flush buffered events before the program exits
	defer sentry.Flush(2 * time.Second)

	app := fiber.New()
	// ... rest of your app
}

Replace <key> with your LightTrace project key (found in your project settings) and light-trace.robomiri.com with your LightTrace instance URL. The Sentry SDK is fully compatible—it speaks the same protocol, so you point it at LightTrace by changing only the DSN.

Building Error Capture Middleware

The real value of error monitoring comes from catching panics and HTTP errors automatically, without having to instrument every handler. Fiber's middleware system makes this straightforward:

app.Use(func(c *fiber.Ctx) error {
	defer func() {
		if r := recover(); r != nil {
			// Capture panic
			sentry.CaptureException(fmt.Errorf("panic: %v", r))
			c.Status(fiber.StatusInternalServerError).JSON(
				fiber.Map{"error": "Internal server error"},
			)
		}
	}()
	return c.Next()
})

This middleware wraps every request and catches panics before Fiber's default panic handler takes over. Now add error recovery at the end of your handler chain:

app.Use(func(c *fiber.Ctx) error {
	err := c.Next()
	if err != nil {
		// Capture HTTP errors
		sentry.CaptureException(err)
		// Let Fiber's error handler format the response
		return err
	}
	return nil
})

This pattern ensures every unhandled error—including panics—gets reported to LightTrace before the response goes out. You're not slowing down error handling; you're just piping errors through Sentry's non-blocking event queue.

Capturing Context and Breadcrumbs

Raw error messages aren't much help without context. LightTrace groups errors by fingerprint and shows you the full picture: request method, URL, headers, query params, and the user who triggered it. Add context to every request:

app.Use(func(c *fiber.Ctx) error {
	sentry.WithScope(func(scope *sentry.Scope) {
		scope.SetTag("route", c.Route().Path)
		scope.SetTag("method", c.Method())
		scope.SetContext("http", map[string]interface{}{
			"url":    c.Request().URI().String(),
			"method": c.Method(),
		})
		if user := c.Get("user_id"); user != "" {
			scope.SetUser(sentry.User{ID: user})
		}
		err := c.Next()
		if err != nil {
			sentry.CaptureException(err)
		}
		return err
	})
	return nil
})

Breadcrumbs are a smaller unit of context—think of them as a request log. When an error happens, LightTrace shows you the breadcrumb trail leading up to it. Fiber's logging works great for this; pipe it through Sentry:

app.Use(func(c *fiber.Ctx) error {
	start := time.Now()
	err := c.Next()
	duration := time.Since(start)
	
	sentry.AddBreadcrumb(&sentry.Breadcrumb{
		Category: "http",
		Message:  fmt.Sprintf("%s %s", c.Method(), c.Path()),
		Level:    "info",
		Data: map[string]interface{}{
			"status":   c.Response().StatusCode(),
			"duration": duration.Milliseconds(),
		},
	})
	return err
})

Now every request that leads to an error is logged with timing and status, helping you see what happened in the moments before failure.

Handling Different Error Types

Not all errors are created equal. Database timeouts, validation failures, and 404s need different treatment than application crashes. Here's how to categorize them:

app.Post("/items", func(c *fiber.Ctx) error {
	var item Item
	if err := c.BodyParser(&item); err != nil {
		// Validation error—not an app fault
		sentry.CaptureException(err)
		sentry.GetHubFromContext(c.Context()).LastEventID()
		return c.Status(fiber.StatusBadRequest).JSON(
			fiber.Map{"error": err.Error()},
		)
	}
	
	if err := database.Create(&item); err != nil {
		// Database error—app fault, needs investigation
		sentry.CaptureException(err)
		return c.Status(fiber.StatusInternalServerError).JSON(
			fiber.Map{"error": "Database error"},
		)
	}
	
	return c.Status(fiber.StatusCreated).JSON(item)
})

Use tags and error messages to differentiate them in LightTrace. You can filter, group, and alert on errors by type, severity, and frequency. This is where error monitoring becomes actionable: you ignore benign 400s but get alerted on every 500.

Best Practices for Production

Set sample rates wisely. If your app is high-traffic, sending every event can add up. Configure a sample rate to keep costs reasonable:

sentry.Init(sentry.ClientOptions{
	Dsn:        "https://<key>@light-trace.robomiri.com/1",
	TracesSampleRate: 0.1, // 10% of requests
})

Scrub sensitive data. PII and secrets can leak into error reports. Configure a before-send hook to filter them:

sentry.Init(sentry.ClientOptions{
	Dsn: "https://<key>@light-trace.robomiri.com/1",
	BeforeSend: func(event *sentry.Event, hint *sentry.EventHint) *sentry.Event {
		// Scrub authorization headers
		if event.Request != nil {
			delete(event.Request.Headers, "Authorization")
		}
		return event
	},
})

Test locally first. Use environment-based DSN configuration so development errors don't flood your production project:

dsn := os.Getenv("SENTRY_DSN")
if dsn == "" {
	dsn = "https://key@light-trace.robomiri.com/1" // fallback for CI/prod
}
sentry.Init(sentry.ClientOptions{Dsn: dsn})

These practices keep your error data clean, actionable, and cost-effective.

Learning More

If you're new to error tracking in general, it's worth understanding what signals matter. For a broader view of Go error tracking patterns, that guide covers multiple frameworks. And if you're evaluating how to debug production errors, error monitoring is just one piece—but a crucial one.

If you're using Fiber alongside frontend JavaScript, don't forget to add error tracking to your app on the client side too. Full-stack observability means catching errors wherever they happen.

Getting started with error monitoring in Fiber is low-friction and pays back immediately. Your future self—the one troubleshooting a 3am production incident—will thank you.