> ## Documentation Index
> Fetch the complete documentation index at: https://docs.appsignal.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Gin-gonic Instrumentation

[Gin-gonic](https://gin-gonic.com) is a full featured web framework for Go.
Data reported from Gin-gonic is supported by AppSignal.

This page will help you get set up to instrument Gin-gonic applications and report request parameters and payloads.

## Setup

To instrument your Go-gin application, you'll need to import the OpenTelemetry official instrumentation package:

<CodeGroup>
  ```go Go theme={null}
  import "go.opentelemetry.io/contrib/instrumentation/github.com/gin-gonic/gin/otelgin"
  ```
</CodeGroup>

The Go-gin instrumentation is packaged as a router middleware, as you can see in the example below, the tracer initialization is called before anything as described in more detail in the [Go installation](/go/installation) page. Adding `otelgin.Middleware()` to your app router is all that you need to get all your requests instrumented.

<CodeGroup>
  ```go Go theme={null}
  func main() {
  	cleanup := initOpenTelemetry()
  	defer cleanup()

  	router := gin.New()
  	// This middleware must be added before any middlewares or routes
  	router.Use(otelgin.Middleware("your-app-name"))
  	// Your routes, app's logic, and server start up
  	// ...
  }
  ```
</CodeGroup>

## Reporting request parameters

By default, the Gin instrumentation does not report any incoming request parameters, like query strings and JSON body contents.

To report these values to AppSignal, add a middleware to your Gin-gonic stack as follows:

<CodeGroup>
  ```go Go theme={null}
  import (
  	"bytes"
  	"encoding/json"
  	"context"
  	"io/ioutil"
  	"net/url"

  	"github.com/gin-gonic/gin"
  	"go.opentelemetry.io/otel/attribute"
  	"go.opentelemetry.io/otel/trace"
  )

  func recordParameters(c *gin.Context) {
  	span := trace.SpanFromContext(c.Request.Context())

  	// Query parameters
  	requestQueryParameters := c.Request.URL.Query()
  	attributeQueryParameters := make(map[string]any)
  	for k, v := range requestQueryParameters {
  		attributeQueryParameters[k] = v
  	}

  	if len(attributeQueryParameters) > 0 {
  		serializedQueryParams, err := json.Marshal(attributeQueryParameters)
  		if err == nil {
  			span.SetAttributes(attribute.String("appsignal.request.query_parameters", string(serializedQueryParams)))
  		}
  	}

  	// Request body payload
  	var serializedBodyPayload string
  	var payload map[string]interface{}
  	requestBodyPayload, err := ioutil.ReadAll(c.Request.Body)
  	if err != nil {
  		c.Next()
  		return
  	}
  	c.Request.Body = ioutil.NopCloser(bytes.NewBuffer(requestBodyPayload))
  	contentType := c.GetHeader("Content-Type")
  	if contentType == "application/json" {
  		serializedBodyPayload = string(requestBodyPayload)
  	} else if contentType == "application/x-www-form-urlencoded" {
  		// Parse form-urlencoded body
  		values, err := url.ParseQuery(string(requestBodyPayload))
  		if err != nil {
  			c.Next()
  			return
  		}

  		// Convert form values to a JSON-compatible map
  		payload = make(map[string]interface{})
  		for key, val := range values {
  			if len(val) == 1 {
  				payload[key] = val[0]
  			} else {
  				payload[key] = val
  			}
  		}
  		json, _ := json.Marshal(payload)
  		serializedBodyPayload = string(json)
  	} else {
  		c.Next()
  		return
  	}
  	if len(serializedBodyPayload) > 0 {
  		span.SetAttributes(attribute.String("appsignal.request.payload", serializedBodyPayload))
  	}
  	c.Next()
  }

  func main() {
  	// Init OpenTelemetry
  	cleanup := initOpenTelemetry()
  	defer cleanup()

  	r := gin.New()
  	r.Use(otelgin.Middleware("opentelemetry-go-gin"))
  	// After the OpenTelemetry middleware, but before your other middlewares:
  	r.Use(recordParameters)
  	// Other middlewares and router handlers go here...
  }
  ```
</CodeGroup>