Fiber Middleware

⚠️

The Traceway Go SDK is no longer the recommended way to integrate with Traceway. For new projects, instrument with OpenTelemetry — it works across languages and Traceway natively ingests OTLP. The Go SDK is still supported, but new features land in the OTel path first.

The tracewayfiber package provides middleware for the Fiber (opens in a new tab) web framework. It automatically creates a trace for each request, captures panics and handler errors, and detects client IP addresses.

Installation

go get go.tracewayapp.com
go get go.tracewayapp.com/tracewayfiber

Basic Setup

package main
 
import (
    "github.com/gofiber/fiber/v2"
    tracewayfiber "go.tracewayapp.com/tracewayfiber"
)
 
func main() {
    app := fiber.New()
 
    // Add Traceway middleware (must be before routes)
    app.Use(tracewayfiber.New(
        "your-token@http://localhost:8082/api/report",
    ))
 
    app.Get("/api/users", getUsers)
    app.Post("/api/users", createUser)
 
    app.Listen(":8080")
}

New returns a fiber.Handler and calls traceway.Init internally — do not call Init separately.

What Gets Captured

The middleware automatically captures for every request:

Data	Description
Endpoint	HTTP method + route path (e.g., `GET /api/users/:id`)
Duration	Request processing time
Status Code	HTTP response status
Body Size	Response body size in bytes
Client IP	From Fiber's `c.IP()`
Panics	Recovered and captured with full stack trace
Handler Errors	Errors returned from handlers

Error Detection

A request is considered an error when any of these are true:

A panic occurred during handler execution
A handler returned an error
The response status code is >= 500

Error traces use the error sample rate for sampling decisions.

Panic Recovery

When a panic occurs, the middleware:

Recovers the panic
Captures the full stack trace as an issue
Either re-panics (default, WithRepanic(true)) or returns a 500 error

app.Get("/risky", func(c *fiber.Ctx) error {
    panic("something went wrong")
    // Stack trace is captured, linked to this request's trace
    return nil
})

Handler Errors

Errors returned from Fiber handlers are captured as issues:

app.Get("/api/users/:id", func(c *fiber.Ctx) error {
    user, err := findUser(c.Params("id"))
    if err != nil {
        return err // Captured as an issue
    }
    return c.JSON(user)
})

Context Access

Access Traceway context from within your handlers:

app.Get("/api/users", func(c *fiber.Ctx) error {
    // Get attributes for this request
    attributes := tracewayfiber.GetAttributesFromCtx(c)
    attributes.SetTag("user_id", "123")
 
    // Get trace context
    trace := tracewayfiber.GetTraceFromCtx(c)
 
    return c.SendString("OK")
})

Context is stored in Fiber's Locals store.

Connection package

The connection page in the sidebar will have your projects unique API key and the integration instructions.

Next Steps

Configuration — All options including filtering and passthrough settings
Error Recording — Control what request data is captured on errors

Error Recording Error Recording