diff --git a/.github/workflows/tests.yaml b/.github/workflows/tests.yaml
index a3233d97..d791cc32 100644
--- a/.github/workflows/tests.yaml
+++ b/.github/workflows/tests.yaml
@@ -7,7 +7,7 @@ env:
 jobs:
   lint:
     if: github.event.pull_request.draft == false
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     permissions:
       contents: read
       actions: read
@@ -41,7 +41,7 @@ jobs:
       - run: pnpm nx affected -t typecheck
   unit-tests:
     if: github.event.pull_request.draft == false
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     permissions:
       contents: read
       actions: write
@@ -87,7 +87,7 @@ jobs:
       - run: pnpm server-output-test
   integration-tests-ts-server:
     if: github.event.pull_request.draft == false
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     permissions:
       contents: read
       actions: write
@@ -99,7 +99,7 @@ jobs:
       - name: Install Dart
         uses: dart-lang/setup-dart@v1
         with:
-          sdk: 3.5.4
+          sdk: 3.6.0
       - name: Install Rust
         uses: dtolnay/rust-toolchain@stable
       - name: Setup Gradle
@@ -131,7 +131,7 @@ jobs:
       - run: pnpm run integration-tests --server ts --affected
   integration-tests-go-server:
     if: github.event.pull_request.draft == false
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     permissions:
       contents: read
       actions: write
@@ -143,7 +143,7 @@ jobs:
       - name: Install Dart
         uses: dart-lang/setup-dart@v1
         with:
-          sdk: 3.5.4
+          sdk: 3.6.0
       - name: Install Rust
         uses: dtolnay/rust-toolchain@stable
       - name: Setup Gradle
diff --git a/languages/dart/dart-client/pubspec.yaml b/languages/dart/dart-client/pubspec.yaml
index 3ff16268..ead8d073 100644
--- a/languages/dart/dart-client/pubspec.yaml
+++ b/languages/dart/dart-client/pubspec.yaml
@@ -4,7 +4,7 @@ version: "0.69.2"
 repository: https://github.com/modiimedia/arri
 issue_tracker: https://github.com/modiimedia/arri/issues
 environment:
-  sdk: ">=3.0.0 <4.0.0"
+  sdk: ">=3.6.0 <4.0.0"
 dependencies:
   http: ">=1.0.0 <2.0.0"
   web_socket_channel: ">=3.0.0 <4.0.0"
diff --git a/languages/dart/dart-codegen-reference/lib/reference_client.dart b/languages/dart/dart-codegen-reference/lib/reference_client.dart
index 57003e31..415f436b 100644
--- a/languages/dart/dart-codegen-reference/lib/reference_client.dart
+++ b/languages/dart/dart-codegen-reference/lib/reference_client.dart
@@ -1,5 +1,5 @@
 // this file was autogenerated by arri
-// ignore_for_file: type=lint, unused_field, unnecessary_cast
+// ignore_for_file: type=lint
 import 'dart:async';
 import 'dart:convert';
 import 'package:arri_client/arri_client.dart';
@@ -115,13 +115,13 @@ class ExampleClientBooksService {
       onClose: onClose,
       onError: onError != null && _onError != null
           ? (err, es) {
-              _onError?.call(onError);
+              _onError.call(onError);
               return onError(err, es);
             }
           : onError != null
               ? onError
               : _onError != null
-                  ? (err, _) => _onError?.call(err)
+                  ? (err, _) => _onError.call(err)
                   : null,
     );
   }
diff --git a/languages/dart/dart-codegen-reference/pubspec.lock b/languages/dart/dart-codegen-reference/pubspec.lock
index e874d3da..ba5d9f47 100644
--- a/languages/dart/dart-codegen-reference/pubspec.lock
+++ b/languages/dart/dart-codegen-reference/pubspec.lock
@@ -414,4 +414,4 @@ packages:
     source: hosted
     version: "3.1.2"
 sdks:
-  dart: ">=3.6.0-0 <4.0.0"
+  dart: ">=3.6.0 <4.0.0"
diff --git a/languages/dart/dart-codegen-reference/pubspec.yaml b/languages/dart/dart-codegen-reference/pubspec.yaml
index e5b746bc..9100cf36 100644
--- a/languages/dart/dart-codegen-reference/pubspec.yaml
+++ b/languages/dart/dart-codegen-reference/pubspec.yaml
@@ -4,7 +4,7 @@ publish_to: none
 repository: https://github.com/modiimedia/arri/tree/master/packages/arri-client-dart-reference
 issue_tracker: https://github.com/modiimedia/arri/issues
 environment:
-  sdk: ">=3.0.0 <4.0.0"
+  sdk: ">=3.6.0 <4.0.0"
 dependencies:
   arri_client:
     path: "../dart-client"
diff --git a/languages/dart/dart-codegen/src/_index.ts b/languages/dart/dart-codegen/src/_index.ts
index 6e7ff903..e32ecc78 100644
--- a/languages/dart/dart-codegen/src/_index.ts
+++ b/languages/dart/dart-codegen/src/_index.ts
@@ -147,7 +147,7 @@ export function createDartClient(
     }
     if (rpcParts.length === 0 && subServiceParts.length === 0) {
         const heading = `// this file was autogenerated by arri
-// ignore_for_file: type=lint, unused_field, unnecessary_cast
+// ignore_for_file: type=lint
 import 'dart:convert';
 import 'package:arri_client/arri_client.dart';`;
 
@@ -157,7 +157,7 @@ ${typeParts.join("\n\n")}`;
     }
     const clientName = validDartClassName(context.clientName, "");
     return `// this file was autogenerated by arri
-// ignore_for_file: type=lint, unused_field, unnecessary_cast
+// ignore_for_file: type=lint
 import 'dart:async';
 import 'dart:convert';
 import 'package:arri_client/arri_client.dart';
diff --git a/languages/dart/dart-codegen/src/procedures.ts b/languages/dart/dart-codegen/src/procedures.ts
index 27fa8e16..ce770c85 100644
--- a/languages/dart/dart-codegen/src/procedures.ts
+++ b/languages/dart/dart-codegen/src/procedures.ts
@@ -76,13 +76,13 @@ export function dartHttpRpcFromSchema(
                 onClose: onClose,
                 onError: onError != null && _onError != null
                     ? (err, es) {
-                        _onError?.call(onError);
+                        _onError.call(onError);
                         return onError(err, es);
                     }
                     : onError != null
                         ? onError
                         : _onError != null
-                            ? (err, _) => _onError?.call(err)
+                            ? (err, _) => _onError.call(err)
                             : null,
             );
         }`;
diff --git a/languages/go/go-server/app.go b/languages/go/go-server/app.go
index 1ef5c9a2..6cb8384c 100644
--- a/languages/go/go-server/app.go
+++ b/languages/go/go-server/app.go
@@ -7,29 +7,30 @@ import (
 	"os"
 )
 
-type App[TContext Context] struct {
+type App[TEvent Event] struct {
 	Mux                  *http.ServeMux
-	CreateContext        func(w http.ResponseWriter, r *http.Request) (*TContext, RpcError)
-	InitializationErrors []error
-	Options              AppOptions[TContext]
-	Procedures           *OrderedMap[RpcDef]
-	Definitions          *OrderedMap[TypeDef]
+	createEvent          func(w http.ResponseWriter, r *http.Request) (*TEvent, RpcError)
+	initializationErrors []error
+	options              AppOptions[TEvent]
+	middleware           []Middleware[TEvent]
+	procedures           *OrderedMap[RpcDef]
+	definitions          *OrderedMap[TypeDef]
 }
 
-func (app *App[TContext]) GetAppDefinition() AppDef {
+func (app *App[TEvent]) GetAppDefinition() AppDef {
 	info := None[AppDefInfo]()
 	name := None[string]()
 	description := None[string]()
 	version := None[string]()
 
-	if len(app.Options.AppName) > 0 {
-		name = Some(app.Options.AppName)
+	if len(app.options.AppName) > 0 {
+		name = Some(app.options.AppName)
 	}
-	if len(app.Options.AppDescription) > 0 {
-		description = Some(app.Options.AppDescription)
+	if len(app.options.AppDescription) > 0 {
+		description = Some(app.options.AppDescription)
 	}
-	if len(app.Options.AppVersion) > 0 {
-		version = Some(app.Options.AppVersion)
+	if len(app.options.AppVersion) > 0 {
+		version = Some(app.options.AppVersion)
 	}
 
 	if name.IsSome() || description.IsSome() || version.IsSome() {
@@ -43,12 +44,12 @@ func (app *App[TContext]) GetAppDefinition() AppDef {
 	return AppDef{
 		SchemaVersion: "0.0.7",
 		Info:          info,
-		Procedures:    *app.Procedures,
-		Definitions:   *app.Definitions,
+		Procedures:    *app.procedures,
+		Definitions:   *app.definitions,
 	}
 }
 
-func (app *App[TContext]) Run(options RunOptions) error {
+func (app *App[TEvent]) Run(options RunOptions) error {
 	defOutput := flag.String("def-out", "", "definition-out")
 	appDefCmd := flag.NewFlagSet("def", flag.ExitOnError)
 	appDefOutput := appDefCmd.String("output", "__definition.json", "output")
@@ -56,14 +57,14 @@ func (app *App[TContext]) Run(options RunOptions) error {
 		switch os.Args[1] {
 		case "def", "definition":
 			appDefCmd.Parse(os.Args[2:])
-			return appDefToFile(app.GetAppDefinition(), *appDefOutput, app.Options.KeyCasing)
+			return appDefToFile(app.GetAppDefinition(), *appDefOutput, app.options.KeyCasing)
 		}
 	}
 	if len(os.Args) > 1 {
 		flag.Parse()
 	}
 	if len(*defOutput) > 0 {
-		err := appDefToFile(app.GetAppDefinition(), *defOutput, app.Options.KeyCasing)
+		err := appDefToFile(app.GetAppDefinition(), *defOutput, app.options.KeyCasing)
 		if err != nil {
 			return err
 		}
@@ -83,24 +84,24 @@ func appDefToFile(appDef AppDef, output string, keyCasing KeyCasing) error {
 	return nil
 }
 
-func printServerStartMessages[TContext Context](app *App[TContext], port uint32, isHttps bool) {
+func printServerStartMessages[TEvent Event](app *App[TEvent], port uint32, isHttps bool) {
 	protocol := "http"
 	if isHttps {
 		protocol = "https"
 	}
 	baseUrl := fmt.Sprintf("%v://localhost:%v", protocol, port)
 	fmt.Printf("Starting server at %v\n", baseUrl)
-	if len(app.Options.RpcRoutePrefix) > 0 {
-		fmt.Printf("Procedures path: %v%v\n", baseUrl, app.Options.RpcRoutePrefix)
+	if len(app.options.RpcRoutePrefix) > 0 {
+		fmt.Printf("Procedures path: %v%v\n", baseUrl, app.options.RpcRoutePrefix)
 	}
-	defPath := app.Options.RpcDefinitionPath
+	defPath := app.options.RpcDefinitionPath
 	if len(defPath) == 0 {
 		defPath = "/__definition"
 	}
-	fmt.Printf("App Definition Path: %v%v\n\n", baseUrl, app.Options.RpcRoutePrefix+defPath)
+	fmt.Printf("App Definition Path: %v%v\n\n", baseUrl, app.options.RpcRoutePrefix+defPath)
 }
 
-func startServer[TContext Context](app *App[TContext], options RunOptions) error {
+func startServer[TEvent Event](app *App[TEvent], options RunOptions) error {
 	port := options.Port
 	if port == 0 {
 		port = 3000
@@ -121,7 +122,7 @@ type RunOptions struct {
 	KeyFile  string
 }
 
-type AppOptions[TContext Context] struct {
+type AppOptions[TEvent Event] struct {
 	AppName string
 	// The current app version. Generated clients will send this in the "client-version" header
 	AppVersion string
@@ -133,61 +134,62 @@ type AppOptions[TContext Context] struct {
 	RpcRoutePrefix string
 	// if not set it will default to "/{RpcRoutePrefix}/__definition"
 	RpcDefinitionPath string
-	OnRequest         func(*http.Request, *TContext) RpcError
-	OnBeforeResponse  func(*http.Request, *TContext, any) RpcError
-	OnAfterResponse   func(*http.Request, *TContext, any) RpcError
-	OnError           func(*http.Request, *TContext, error)
+	OnRequest         func(*http.Request, *TEvent) RpcError
+	OnBeforeResponse  func(*http.Request, *TEvent, any) RpcError
+	OnAfterResponse   func(*http.Request, *TEvent, any) RpcError
+	OnError           func(*http.Request, *TEvent, error)
 }
 
-func NewApp[TContext Context](mux *http.ServeMux, options AppOptions[TContext], createContext func(w http.ResponseWriter, r *http.Request) (*TContext, RpcError)) App[TContext] {
-	app := App[TContext]{
+func NewApp[TEvent Event](mux *http.ServeMux, options AppOptions[TEvent], createEvent func(w http.ResponseWriter, r *http.Request) (*TEvent, RpcError)) App[TEvent] {
+	app := App[TEvent]{
 		Mux:                  mux,
-		CreateContext:        createContext,
-		Options:              options,
-		InitializationErrors: []error{},
-		Procedures:           &OrderedMap[RpcDef]{},
-		Definitions:          &OrderedMap[TypeDef]{},
+		createEvent:          createEvent,
+		options:              options,
+		initializationErrors: []error{},
+		middleware:           []Middleware[TEvent]{},
+		procedures:           &OrderedMap[RpcDef]{},
+		definitions:          &OrderedMap[TypeDef]{},
 	}
-	defPath := app.Options.RpcRoutePrefix + "/__definition"
-	if len(app.Options.RpcDefinitionPath) > 0 {
-		defPath = app.Options.RpcDefinitionPath
+	defPath := app.options.RpcRoutePrefix + "/__definition"
+	if len(app.options.RpcDefinitionPath) > 0 {
+		defPath = app.options.RpcDefinitionPath
 	}
-	onRequest := app.Options.OnRequest
+	onRequest := app.options.OnRequest
 	if onRequest == nil {
-		onRequest = func(r *http.Request, t *TContext) RpcError {
+		onRequest = func(r *http.Request, t *TEvent) RpcError {
 			return nil
 		}
 	}
-	onBeforeResponse := app.Options.OnBeforeResponse
+	onBeforeResponse := app.options.OnBeforeResponse
 	if onBeforeResponse == nil {
-		onBeforeResponse = func(r *http.Request, t *TContext, a any) RpcError {
+		onBeforeResponse = func(r *http.Request, t *TEvent, a any) RpcError {
 			return nil
 		}
 	}
-	onAfterResponse := app.Options.OnAfterResponse
+	onAfterResponse := app.options.OnAfterResponse
 	if onAfterResponse == nil {
-		onAfterResponse = func(r *http.Request, t *TContext, a any) RpcError {
+		onAfterResponse = func(r *http.Request, t *TEvent, a any) RpcError {
 			return nil
 		}
 	}
-	onError := app.Options.OnError
+	onError := app.options.OnError
 	if onError == nil {
-		onError = func(r *http.Request, t *TContext, err error) {}
+		onError = func(r *http.Request, t *TEvent, err error) {}
 	}
 	mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
 		w.Header().Add("Content-Type", "application/json")
-		ctx, ctxErr := app.CreateContext(w, r)
-		if ctxErr != nil {
-			handleError(false, w, r, ctx, ctxErr, onError)
+		event, err := app.createEvent(w, r)
+		if err != nil {
+			handleError(false, w, r, event, err, onError)
 			return
 		}
-		onRequestErr := onRequest(r, ctx)
-		if onRequestErr != nil {
-			handleError(false, w, r, ctx, onRequestErr, onError)
+		err = onRequest(r, event)
+		if err != nil {
+			handleError(false, w, r, event, err, onError)
 			return
 		}
 		if r.URL.Path != "/" {
-			handleError(false, w, r, ctx, Error(404, ""), onError)
+			handleError(false, w, r, event, Error(404, ""), onError)
 			return
 		}
 		w.WriteHeader(200)
@@ -197,8 +199,8 @@ func NewApp[TContext Context](mux *http.ServeMux, options AppOptions[TContext],
 			Version     Option[string]
 			SchemaPath  string
 		}{
-			Title:       app.Options.AppName,
-			Description: app.Options.AppDescription,
+			Title:       app.options.AppName,
+			Description: app.options.AppDescription,
 			Version:     None[string](),
 			SchemaPath:  defPath,
 		}
@@ -211,57 +213,57 @@ func NewApp[TContext Context](mux *http.ServeMux, options AppOptions[TContext],
 		if len(options.AppVersion) > 0 {
 			response.Version = Some(options.AppVersion)
 		}
-		onBeforeResponseErr := onBeforeResponse(r, ctx, response)
-		if onBeforeResponseErr != nil {
-			handleError(false, w, r, ctx, onBeforeResponseErr, onError)
+		err = onBeforeResponse(r, event, response)
+		if err != nil {
+			handleError(false, w, r, event, err, onError)
 			return
 		}
-		jsonResult, _ := EncodeJSON(response, app.Options.KeyCasing)
+		jsonResult, _ := EncodeJSON(response, app.options.KeyCasing)
 		w.Write(jsonResult)
-		onAfterResponseErr := onAfterResponse(r, ctx, response)
+		onAfterResponseErr := onAfterResponse(r, event, response)
 		if onAfterResponseErr != nil {
-			handleError(true, w, r, ctx, onAfterResponseErr, onError)
+			handleError(true, w, r, event, onAfterResponseErr, onError)
 			return
 		}
 	})
 
 	mux.HandleFunc(defPath, func(w http.ResponseWriter, r *http.Request) {
 		w.Header().Add("Content-Type", "application/json")
-		ctx, ctxErr := app.CreateContext(w, r)
-		if ctxErr != nil {
-			handleError(false, w, r, ctx, ctxErr, onError)
+		event, err := app.createEvent(w, r)
+		if err != nil {
+			handleError(false, w, r, event, err, onError)
 			return
 		}
-		onRequestError := onRequest(r, ctx)
-		if onRequestError != nil {
-			handleError(false, w, r, ctx, onRequestError, onError)
+		err = onRequest(r, event)
+		if err != nil {
+			handleError(false, w, r, event, err, onError)
 		}
-		jsonResult, _ := EncodeJSON(app.GetAppDefinition(), app.Options.KeyCasing)
-		beforeResponseErr := onBeforeResponse(r, ctx, jsonResult)
+		jsonResult, _ := EncodeJSON(app.GetAppDefinition(), app.options.KeyCasing)
+		beforeResponseErr := onBeforeResponse(r, event, jsonResult)
 		if beforeResponseErr != nil {
-			handleError(false, w, r, ctx, beforeResponseErr, onError)
+			handleError(false, w, r, event, beforeResponseErr, onError)
 			return
 		}
 		w.WriteHeader(200)
 		w.Write(jsonResult)
-		afterResponseErr := onAfterResponse(r, ctx, jsonResult)
-		if afterResponseErr != nil {
-			handleError(true, w, r, ctx, afterResponseErr, onError)
+		err = onAfterResponse(r, event, jsonResult)
+		if err != nil {
+			handleError(true, w, r, event, err, onError)
 			return
 		}
 	})
 	return app
 }
 
-func handleError[TContext Context](
+func handleError[TEvent Event](
 	responseSent bool,
 	w http.ResponseWriter,
 	r *http.Request,
-	context *TContext,
+	event *TEvent,
 	err RpcError,
-	onError func(*http.Request, *TContext, error),
+	onError func(*http.Request, *TEvent, error),
 ) {
-	onError(r, context, err)
+	onError(r, event, err)
 	if responseSent {
 		return
 	}
@@ -275,8 +277,8 @@ type DefOptions struct {
 	Description  string
 }
 
-func RegisterDef[TContext Context](app *App[TContext], input any, options DefOptions) {
-	def, err := ToTypeDef(input, app.Options.KeyCasing)
+func RegisterDef[TEvent Event](app *App[TEvent], input any, options DefOptions) {
+	def, err := ToTypeDef(input, app.options.KeyCasing)
 	if err != nil {
 		panic(err)
 	}
@@ -289,5 +291,5 @@ func RegisterDef[TContext Context](app *App[TContext], input any, options DefOpt
 	if len(options.Description) > 0 {
 		def.Metadata.Value.Description = Some(options.Description)
 	}
-	app.Definitions.Set(def.Metadata.Unwrap().Id.Unwrap(), *def)
+	app.definitions.Set(def.Metadata.Unwrap().Id.Unwrap(), *def)
 }
diff --git a/languages/go/go-server/app_def.go b/languages/go/go-server/app_def.go
index 3a5a71d3..d65a8587 100644
--- a/languages/go/go-server/app_def.go
+++ b/languages/go/go-server/app_def.go
@@ -7,6 +7,7 @@ import (
 	"strings"
 
 	"github.com/iancoleman/strcase"
+	"github.com/modiimedia/arri/languages/go/go-server/utils"
 )
 
 type AppDef struct {
@@ -64,7 +65,7 @@ func ToRpcDef(value interface{}, options ArriHttpRpcOptions) (*RpcDef, error) {
 	}
 	rawParams := valueType.In(0)
 	params := Some(rawParams.Name())
-	hasParam := !isEmptyMessage(rawParams)
+	hasParam := !utils.IsEmptyMessage(rawParams)
 	if !hasParam {
 		params = None[string]()
 	}
@@ -73,7 +74,7 @@ func ToRpcDef(value interface{}, options ArriHttpRpcOptions) (*RpcDef, error) {
 		rawResponse = rawResponse.Elem()
 	}
 	response := Some(rawResponse.Name())
-	hasResponse := !isEmptyMessage(rawResponse)
+	hasResponse := !utils.IsEmptyMessage(rawResponse)
 	if !hasResponse {
 		response = None[string]()
 	}
diff --git a/languages/go/go-server/context.go b/languages/go/go-server/context.go
deleted file mode 100644
index ccf96b5c..00000000
--- a/languages/go/go-server/context.go
+++ /dev/null
@@ -1,31 +0,0 @@
-package arri
-
-import (
-	"net/http"
-)
-
-type Context interface {
-	Request() *http.Request
-	Writer() http.ResponseWriter
-}
-
-type DefaultContext struct {
-	request *http.Request
-	writer  http.ResponseWriter
-}
-
-func (c DefaultContext) Request() *http.Request {
-	return c.request
-}
-
-func (c DefaultContext) Writer() http.ResponseWriter {
-	return c.writer
-}
-
-func CreateDefaultContext(w http.ResponseWriter, r *http.Request) (*DefaultContext, RpcError) {
-	ctx := DefaultContext{
-		request: r,
-		writer:  w,
-	}
-	return &ctx, nil
-}
diff --git a/languages/go/go-server/decode_json.go b/languages/go/go-server/decode_json.go
index ae3209cf..4eeb85eb 100644
--- a/languages/go/go-server/decode_json.go
+++ b/languages/go/go-server/decode_json.go
@@ -9,6 +9,7 @@ import (
 	"time"
 
 	"github.com/iancoleman/strcase"
+	"github.com/modiimedia/arri/languages/go/go-server/utils"
 	"github.com/tidwall/gjson"
 )
 
@@ -97,7 +98,7 @@ func DecodeJSON[T any](data []byte, v *T, keyCasing KeyCasing) *DecoderError {
 	value := reflect.ValueOf(&v)
 	if !parsedResult.Exists() {
 		t := value.Type()
-		if isNullableTypeOrPointer(t) || isOptionalType(t) {
+		if utils.IsNullableTypeOrPointer(t) || utils.IsOptionalType(t) {
 			return nil
 		}
 		err := NewDecoderError([]ValidationError{NewValidationError("expected JSON input but received nothing", "", "")})
@@ -168,10 +169,10 @@ func typeFromJSON(data *gjson.Result, target reflect.Value, context *DecoderCont
 		if t.Name() == "Time" {
 			return timestampFromJSON(data, target, context)
 		}
-		if isOptionalType(t) {
+		if utils.IsOptionalType(t) {
 			return optionFromJson(data, target, context)
 		}
-		if isNullableTypeOrPointer(t) {
+		if utils.IsNullableTypeOrPointer(t) {
 			return nullableFromJson(data, target, context)
 		}
 		if t.Implements(reflect.TypeFor[ArriModel]()) {
@@ -628,7 +629,7 @@ func structFromJSON(data *gjson.Result, target reflect.Value, c *DecoderContext)
 			}
 			enumValues = Some(vals)
 		}
-		isOptional := isOptionalType(fieldType)
+		isOptional := utils.IsOptionalType(fieldType)
 		if isOptional {
 			ctx := c.copyWith(
 				Some(c.CurrentDepth+1),
@@ -648,7 +649,7 @@ func structFromJSON(data *gjson.Result, target reflect.Value, c *DecoderContext)
 			Some(c.InstancePath+"/"+fieldName),
 			Some(c.SchemaPath+"/properties/"+fieldName),
 		)
-		isNullable := isNullableTypeOrPointer(fieldType)
+		isNullable := utils.IsNullableTypeOrPointer(fieldType)
 		if isNullable {
 			success := nullableFromJson(&jsonResult, field, &ctx)
 			if !success {
diff --git a/languages/go/go-server/decode_json_test.go b/languages/go/go-server/decode_json_test.go
index 3be94a18..8143170c 100644
--- a/languages/go/go-server/decode_json_test.go
+++ b/languages/go/go-server/decode_json_test.go
@@ -232,16 +232,10 @@ func TestDecodeStdUser(t *testing.T) {
 	}
 }
 
-func BenchmarkStdDecodeObjectWithEveryType(b *testing.B) {
-	for i := 0; i < b.N; i++ {
-		target := objectWithEveryType{}
-		json.Unmarshal(_objectWithEveryTypeInput, &target)
-	}
-}
-func BenchmarkArriDecodeObjectWithEveryType(b *testing.B) {
+func BenchmarkArriDecodeUser(b *testing.B) {
 	for i := 0; i < b.N; i++ {
-		target := objectWithEveryType{}
-		arri.DecodeJSON(_objectWithEveryTypeInput, &target, arri.KeyCasingCamelCase)
+		user := benchUser{}
+		arri.DecodeJSON(benchUserInput, &user, arri.KeyCasingCamelCase)
 	}
 }
 
@@ -252,10 +246,17 @@ func BenchmarkStdDecodeUser(b *testing.B) {
 	}
 }
 
-func BenchmarkArriDecodeUser(b *testing.B) {
+func BenchmarkArriDecodeObjectWithEveryType(b *testing.B) {
 	for i := 0; i < b.N; i++ {
-		user := benchUser{}
-		arri.DecodeJSON(benchUserInput, &user, arri.KeyCasingCamelCase)
+		target := objectWithEveryType{}
+		arri.DecodeJSON(_objectWithEveryTypeInput, &target, arri.KeyCasingCamelCase)
+	}
+}
+
+func BenchmarkStdDecodeObjectWithEveryType(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		target := objectWithEveryType{}
+		json.Unmarshal(_objectWithEveryTypeInput, &target)
 	}
 }
 
diff --git a/languages/go/go-server/decode_url_query.go b/languages/go/go-server/decode_url_query.go
index 8b86ab33..7bacc57c 100644
--- a/languages/go/go-server/decode_url_query.go
+++ b/languages/go/go-server/decode_url_query.go
@@ -9,6 +9,7 @@ import (
 	"time"
 
 	"github.com/iancoleman/strcase"
+	"github.com/modiimedia/arri/languages/go/go-server/utils"
 )
 
 func FromUrlQuery[T any](values url.Values, target *T, keyCasing KeyCasing) *DecoderError {
@@ -49,7 +50,7 @@ func FromUrlQuery[T any](values url.Values, target *T, keyCasing KeyCasing) *Dec
 
 		}
 		urlValue := values.Get(key)
-		isOptional := isOptionalType(fieldType)
+		isOptional := utils.IsOptionalType(fieldType)
 		if isOptional {
 			ctx := ctx.copyWith(
 				None[uint32](),
@@ -73,7 +74,7 @@ func FromUrlQuery[T any](values url.Values, target *T, keyCasing KeyCasing) *Dec
 			Some(ctx.InstancePath+"/"+key),
 			Some(ctx.SchemaPath+"/optionalProperties"),
 		)
-		isNullable := isNullableTypeOrPointer(fieldType)
+		isNullable := utils.IsNullableTypeOrPointer(fieldType)
 		if isNullable {
 			nullableTypeFromUrlQuery(urlValue, &field, &ctx)
 			continue
diff --git a/languages/go/go-server/encode_json.go b/languages/go/go-server/encode_json.go
index 111ecfe3..377f0668 100644
--- a/languages/go/go-server/encode_json.go
+++ b/languages/go/go-server/encode_json.go
@@ -6,6 +6,8 @@ import (
 	"sort"
 	"strconv"
 	"time"
+
+	"github.com/modiimedia/arri/languages/go/go-server/utils"
 )
 
 type jsonEncodingCtx struct {
@@ -63,7 +65,7 @@ func encodeValueToJSON(v reflect.Value, c *jsonEncodingCtx) error {
 		return encodeUint64ToJSON(v, c)
 	case reflect.Struct:
 		t := v.Type()
-		if isNullableType(t) {
+		if utils.IsNullableType(t) {
 			return encodeNullableToJSON(v, c)
 		}
 		if t.Implements(reflect.TypeFor[ArriModel]()) {
@@ -197,12 +199,12 @@ func encodeStructToJSON(v reflect.Value, c *jsonEncodingCtx) error {
 		if !field.IsExported() {
 			continue
 		}
-		fieldName := getSerialKey(&field, c.keyCasing)
+		fieldName := utils.GetSerialKey(&field, c.keyCasing)
 		fieldValue := v.Field(i)
 		c.instancePath = c.instancePath + "/" + fieldName
-		if isOptionalType(field.Type) {
+		if utils.IsOptionalType(field.Type) {
 			c.schemaPath = "/optionalProperties/" + fieldName
-			if !optionalHasValue(&fieldValue) {
+			if !utils.OptionalHasValue(&fieldValue) {
 				c.instancePath = oldInstancePath
 				c.schemaPath = oldSchemaPath
 				continue
diff --git a/languages/go/go-server/error.go b/languages/go/go-server/error.go
index b4b4e2e1..beb53cd2 100644
--- a/languages/go/go-server/error.go
+++ b/languages/go/go-server/error.go
@@ -85,6 +85,7 @@ var statusMessages = map[uint32]string{
 	511: "Network authentication required",
 }
 
+// An Arri RPC error. If message is empty arri will replace it with a default message based on the status code.
 func Error(statusCode uint32, message string) errorResponse {
 	msg := message
 	if len(message) == 0 {
@@ -101,6 +102,7 @@ func Error(statusCode uint32, message string) errorResponse {
 	}
 }
 
+// An Arri RPC error with arbitrary data. If message is empty arri will replace it with a default message based on the status code.
 func ErrorWithData(statusCode uint32, message string, data Option[any]) errorResponse {
 	msg := message
 	if len(message) == 0 {
diff --git a/languages/go/go-server/event.go b/languages/go/go-server/event.go
new file mode 100644
index 00000000..d560d5d7
--- /dev/null
+++ b/languages/go/go-server/event.go
@@ -0,0 +1,37 @@
+package arri
+
+import (
+	"net/http"
+)
+
+// Event interface that is available in every RPC call
+type Event interface {
+	Request() *http.Request
+	Writer() http.ResponseWriter
+}
+
+// type helper function to help you know if you've fulfilled the IsEvent interface
+func IsEvent(input Event) bool {
+	return true
+}
+
+type DefaultEvent struct {
+	request *http.Request
+	writer  http.ResponseWriter
+}
+
+func (c DefaultEvent) Request() *http.Request {
+	return c.request
+}
+
+func (c DefaultEvent) Writer() http.ResponseWriter {
+	return c.writer
+}
+
+func CreateDefaultEvent(w http.ResponseWriter, r *http.Request) (*DefaultEvent, RpcError) {
+	event := DefaultEvent{
+		request: r,
+		writer:  w,
+	}
+	return &event, nil
+}
diff --git a/languages/go/go-server/event_test.go b/languages/go/go-server/event_test.go
new file mode 100644
index 00000000..3a894ee0
--- /dev/null
+++ b/languages/go/go-server/event_test.go
@@ -0,0 +1,30 @@
+package arri_test
+
+import (
+	"net/http"
+	"testing"
+
+	arri "github.com/modiimedia/arri/languages/go/go-server"
+)
+
+type CustomEvent struct {
+	req *http.Request
+	res http.ResponseWriter
+}
+
+func (e CustomEvent) Request() *http.Request {
+	return e.req
+}
+
+func (e CustomEvent) Writer() http.ResponseWriter {
+	return e.res
+}
+
+func TestIsEvent(t *testing.T) {
+	if !arri.IsEvent(arri.DefaultEvent{}) {
+		t.Fatal()
+	}
+	if !arri.IsEvent(CustomEvent{}) {
+		t.Fatal()
+	}
+}
diff --git a/languages/go/go-server/middleware.go b/languages/go/go-server/middleware.go
new file mode 100644
index 00000000..21781e24
--- /dev/null
+++ b/languages/go/go-server/middleware.go
@@ -0,0 +1,9 @@
+package arri
+
+import "net/http"
+
+type Middleware[TEvent Event] func(r *http.Request, event TEvent, rpcName string) RpcError
+
+func Use[TEvent Event](app *App[TEvent], middleware Middleware[TEvent]) {
+	app.middleware = append(app.middleware, middleware)
+}
diff --git a/languages/go/go-server/procedures.go b/languages/go/go-server/procedures.go
index 13533664..c7107d13 100644
--- a/languages/go/go-server/procedures.go
+++ b/languages/go/go-server/procedures.go
@@ -7,6 +7,7 @@ import (
 	"strings"
 
 	"github.com/iancoleman/strcase"
+	"github.com/modiimedia/arri/languages/go/go-server/utils"
 )
 
 type RpcOptions struct {
@@ -17,7 +18,7 @@ type RpcOptions struct {
 	IsDeprecated bool
 }
 
-func rpc[TParams, TResponse any, TContext Context](app *App[TContext], serviceName string, options RpcOptions, handler func(TParams, TContext) (TResponse, RpcError)) {
+func rpc[TParams, TResponse any, TEvent Event](app *App[TEvent], serviceName string, options RpcOptions, handler func(TParams, TEvent) (TResponse, RpcError)) {
 	handlerType := reflect.TypeOf(handler)
 	rpcSchema, rpcError := ToRpcDef(handler, ArriHttpRpcOptions{})
 	rpcName := rpcNameFromFunctionName(GetFunctionName(handler))
@@ -25,9 +26,9 @@ func rpc[TParams, TResponse any, TContext Context](app *App[TContext], serviceNa
 		rpcName = serviceName + "." + rpcName
 	}
 	if len(serviceName) > 0 {
-		rpcSchema.Http.Path = app.Options.RpcRoutePrefix + "/" + strcase.ToKebab(serviceName) + rpcSchema.Http.Path
+		rpcSchema.Http.Path = app.options.RpcRoutePrefix + "/" + strcase.ToKebab(serviceName) + rpcSchema.Http.Path
 	} else {
-		rpcSchema.Http.Path = app.Options.RpcRoutePrefix + rpcSchema.Http.Path
+		rpcSchema.Http.Path = app.options.RpcRoutePrefix + rpcSchema.Http.Path
 	}
 	if rpcError != nil {
 		panic(rpcError)
@@ -36,7 +37,7 @@ func rpc[TParams, TResponse any, TContext Context](app *App[TContext], serviceNa
 		rpcSchema.Http.Method = strings.ToLower(options.Method)
 	}
 	if len(options.Path) > 0 {
-		rpcSchema.Http.Path = app.Options.RpcRoutePrefix + options.Path
+		rpcSchema.Http.Path = app.options.RpcRoutePrefix + options.Path
 	}
 	if len(options.Description) > 0 {
 		rpcSchema.Http.Description.Set(options.Description)
@@ -49,9 +50,9 @@ func rpc[TParams, TResponse any, TContext Context](app *App[TContext], serviceNa
 		panic("rpc params must be a struct. pointers and other types are not allowed.")
 	}
 	paramsName := getModelName(rpcName, params.Name(), "Params")
-	hasParams := !isEmptyMessage(params)
+	hasParams := !utils.IsEmptyMessage(params)
 	if hasParams {
-		paramsDefContext := _NewTypeDefContext(app.Options.KeyCasing)
+		paramsDefContext := _NewTypeDefContext(app.options.KeyCasing)
 		paramsSchema, paramsSchemaErr := typeToTypeDef(params, paramsDefContext)
 		if paramsSchemaErr != nil {
 			panic(paramsSchemaErr)
@@ -60,7 +61,7 @@ func rpc[TParams, TResponse any, TContext Context](app *App[TContext], serviceNa
 			panic("Procedures cannot accept anonymous structs")
 		}
 		rpcSchema.Http.Params.Set(paramsName)
-		app.Definitions.Set(paramsName, *paramsSchema)
+		app.definitions.Set(paramsName, *paramsSchema)
 	} else {
 		rpcSchema.Http.Params.Unset()
 	}
@@ -69,9 +70,9 @@ func rpc[TParams, TResponse any, TContext Context](app *App[TContext], serviceNa
 		response = response.Elem()
 	}
 	responseName := getModelName(rpcName, response.Name(), "Response")
-	hasResponse := !isEmptyMessage(response)
+	hasResponse := !utils.IsEmptyMessage(response)
 	if hasResponse {
-		responseDefContext := _NewTypeDefContext(app.Options.KeyCasing)
+		responseDefContext := _NewTypeDefContext(app.options.KeyCasing)
 		responseSchema, responseSchemaErr := typeToTypeDef(response, responseDefContext)
 		if responseSchemaErr != nil {
 			panic(responseSchemaErr)
@@ -80,94 +81,110 @@ func rpc[TParams, TResponse any, TContext Context](app *App[TContext], serviceNa
 			panic("Procedures cannot return anonymous structs")
 		}
 		rpcSchema.Http.Response.Set(responseName)
-		app.Definitions.Set(responseName, *responseSchema)
+		app.definitions.Set(responseName, *responseSchema)
 	} else {
 		rpcSchema.Http.Response.Unset()
 	}
-	app.Procedures.Set(rpcName, *rpcSchema)
-	onRequest := app.Options.OnRequest
+	app.procedures.Set(rpcName, *rpcSchema)
+	onRequest := app.options.OnRequest
 	if onRequest == nil {
-		onRequest = func(r *http.Request, t *TContext) RpcError {
+		onRequest = func(r *http.Request, t *TEvent) RpcError {
 			return nil
 		}
 	}
-	onBeforeResponse := app.Options.OnBeforeResponse
+	onBeforeResponse := app.options.OnBeforeResponse
 	if onBeforeResponse == nil {
-		onBeforeResponse = func(r *http.Request, t *TContext, a any) RpcError {
+		onBeforeResponse = func(r *http.Request, t *TEvent, a any) RpcError {
 			return nil
 		}
 	}
-	onAfterResponse := app.Options.OnAfterResponse
+	onAfterResponse := app.options.OnAfterResponse
 	if onAfterResponse == nil {
-		onAfterResponse = func(r *http.Request, t *TContext, a any) RpcError {
+		onAfterResponse = func(r *http.Request, t *TEvent, a any) RpcError {
 			return nil
 		}
 	}
-	onError := app.Options.OnError
+	onError := app.options.OnError
 	if onError == nil {
-		onError = func(r *http.Request, t *TContext, err error) {}
+		onError = func(r *http.Request, t *TEvent, err error) {}
 	}
 	paramsZero := reflect.Zero(reflect.TypeFor[TParams]())
 	app.Mux.HandleFunc(rpcSchema.Http.Path, func(w http.ResponseWriter, r *http.Request) {
 		w.Header().Add("Content-Type", "application/json")
-		ctx, ctxErr := app.CreateContext(w, r)
-		if ctxErr != nil {
-			handleError(false, w, r, nil, ctxErr, onError)
+		event, err := app.createEvent(w, r)
+		if err != nil {
+			handleError(false, w, r, nil, err, onError)
 			return
 		}
 		if strings.ToLower(r.Method) != rpcSchema.Http.Method {
-			handleError(false, w, r, ctx, Error(404, "Not found"), onError)
+			handleError(false, w, r, event, Error(404, "Not found"), onError)
 			return
 		}
-		onRequestErr := onRequest(r, ctx)
-		if onRequestErr != nil {
-			handleError(false, w, r, ctx, onRequestErr, onError)
+
+		err = onRequest(r, event)
+		if err != nil {
+			handleError(false, w, r, event, err, onError)
 			return
 		}
+
+		if len(app.middleware) > 0 {
+			for i := 0; i < len(app.middleware); i++ {
+				fn := app.middleware[i]
+				err := fn(r, *event, rpcName)
+				if err != nil {
+					handleError(false, w, r, event, err, onError)
+					return
+				}
+			}
+		}
+
 		params, paramsOk := paramsZero.Interface().(TParams)
 		if !paramsOk {
-			handleError(false, w, r, ctx, Error(500, "Error initializing empty params"), onError)
+			handleError(false, w, r, event, Error(500, "Error initializing empty params"), onError)
 			return
 		}
 		if hasParams {
 			switch rpcSchema.Http.Method {
 			case HttpMethodGet:
 				urlValues := r.URL.Query()
-				fromUrlQueryErr := FromUrlQuery(urlValues, &params, app.Options.KeyCasing)
+				fromUrlQueryErr := FromUrlQuery(urlValues, &params, app.options.KeyCasing)
 				if fromUrlQueryErr != nil {
-					handleError(false, w, r, ctx, fromUrlQueryErr, onError)
+					handleError(false, w, r, event, fromUrlQueryErr, onError)
 					return
 				}
 			default:
-				b, bErr := io.ReadAll(r.Body)
-				if bErr != nil {
-					handleError(false, w, r, ctx, Error(400, bErr.Error()), onError)
+				b, err := io.ReadAll(r.Body)
+				if err != nil {
+					handleError(false, w, r, event, Error(400, err.Error()), onError)
 					return
 				}
-				fromJsonErr := DecodeJSON(b, &params, app.Options.KeyCasing)
+				fromJsonErr := DecodeJSON(b, &params, app.options.KeyCasing)
 				if fromJsonErr != nil {
-					handleError(false, w, r, ctx, fromJsonErr, onError)
+					handleError(false, w, r, event, fromJsonErr, onError)
 					return
 				}
 			}
 		}
-		response, responseErr := handler(params, *ctx)
-		if responseErr != nil {
-			payload := responseErr
-			handleError(false, w, r, ctx, payload, onError)
+
+		response, err := handler(params, *event)
+		if err != nil {
+			payload := err
+			handleError(false, w, r, event, payload, onError)
 			return
 		}
-		onBeforeResponseErr := onBeforeResponse(r, ctx, "")
-		if onBeforeResponseErr != nil {
-			handleError(false, w, r, ctx, onBeforeResponseErr, onError)
+
+		err = onBeforeResponse(r, event, "")
+		if err != nil {
+			handleError(false, w, r, event, err, onError)
 			return
 		}
+
 		w.WriteHeader(200)
 		var body []byte
 		if hasResponse {
-			json, jsonErr := EncodeJSON(response, app.Options.KeyCasing)
-			if jsonErr != nil {
-				handleError(false, w, r, ctx, ErrorWithData(500, jsonErr.Error(), Some[any](jsonErr)), onError)
+			json, err := EncodeJSON(response, app.options.KeyCasing)
+			if err != nil {
+				handleError(false, w, r, event, ErrorWithData(500, err.Error(), Some[any](err)), onError)
 				return
 			}
 			body = json
@@ -175,9 +192,10 @@ func rpc[TParams, TResponse any, TContext Context](app *App[TContext], serviceNa
 			body = []byte{}
 		}
 		w.Write([]byte(body))
-		onAfterResponseErr := onAfterResponse(r, ctx, "")
-		if onAfterResponseErr != nil {
-			handleError(false, w, r, ctx, onAfterResponseErr, onError)
+
+		err = onAfterResponse(r, event, "")
+		if err != nil {
+			handleError(true, w, r, event, err, onError)
 		}
 	})
 }
@@ -189,10 +207,10 @@ func getModelName(rpcName string, modelName string, fallbackSuffix string) strin
 	return modelName
 }
 
-func Rpc[TParams, TResponse any, TContext Context](app *App[TContext], handler func(TParams, TContext) (TResponse, RpcError), options RpcOptions) {
+func Rpc[TParams, TResponse any, TEvent Event](app *App[TEvent], handler func(TParams, TEvent) (TResponse, RpcError), options RpcOptions) {
 	rpc(app, "", options, handler)
 }
 
-func ScopedRpc[TParams, TResponse any, TContext Context](app *App[TContext], serviceName string, handler func(TParams, TContext) (TResponse, RpcError), options RpcOptions) {
+func ScopedRpc[TParams, TResponse any, TEvent Event](app *App[TEvent], serviceName string, handler func(TParams, TEvent) (TResponse, RpcError), options RpcOptions) {
 	rpc(app, serviceName, options, handler)
 }
diff --git a/languages/go/go-server/procedures_sse.go b/languages/go/go-server/procedures_sse.go
index d5ee2abf..3fb86507 100644
--- a/languages/go/go-server/procedures_sse.go
+++ b/languages/go/go-server/procedures_sse.go
@@ -10,6 +10,7 @@ import (
 	"time"
 
 	"github.com/iancoleman/strcase"
+	"github.com/modiimedia/arri/languages/go/go-server/utils"
 )
 
 type SseController[T any] interface {
@@ -113,7 +114,7 @@ func (controller *defaultSseController[T]) SetPingInterval(duration time.Duratio
 	controller.pingDuration = duration
 }
 
-func eventStreamRpc[TParams, TResponse any, TContext Context](app *App[TContext], serviceName string, options RpcOptions, handler func(TParams, SseController[TResponse], TContext) RpcError) {
+func eventStreamRpc[TParams, TResponse any, TEvent Event](app *App[TEvent], serviceName string, options RpcOptions, handler func(TParams, SseController[TResponse], TEvent) RpcError) {
 	handlerType := reflect.TypeOf(handler)
 	rpcSchema, rpcError := ToRpcDef(
 		handler,
@@ -132,21 +133,21 @@ func eventStreamRpc[TParams, TResponse any, TContext Context](app *App[TContext]
 		panic(rpcError)
 	}
 	if len(serviceName) > 0 {
-		rpcSchema.Http.Path = app.Options.RpcRoutePrefix + "/" + strcase.ToKebab(serviceName) + rpcSchema.Http.Path
+		rpcSchema.Http.Path = app.options.RpcRoutePrefix + "/" + strcase.ToKebab(serviceName) + rpcSchema.Http.Path
 	} else {
-		rpcSchema.Http.Path = app.Options.RpcRoutePrefix + rpcSchema.Http.Path
+		rpcSchema.Http.Path = app.options.RpcRoutePrefix + rpcSchema.Http.Path
 	}
 	if len(options.Path) > 0 {
-		rpcSchema.Http.Path = app.Options.RpcRoutePrefix + options.Path
+		rpcSchema.Http.Path = app.options.RpcRoutePrefix + options.Path
 	}
 	params := handlerType.In(0)
 	if params.Kind() != reflect.Struct {
 		panic("rpc params must be a struct. pointers and other types are not allowed.")
 	}
 	paramName := getModelName(rpcName, params.Name(), "Params")
-	hasParams := !isEmptyMessage(params)
+	hasParams := !utils.IsEmptyMessage(params)
 	if hasParams {
-		paramsDefContext := _NewTypeDefContext(app.Options.KeyCasing)
+		paramsDefContext := _NewTypeDefContext(app.options.KeyCasing)
 		paramsSchema, paramsSchemaErr := typeToTypeDef(params, paramsDefContext)
 		if paramsSchemaErr != nil {
 			panic(paramsSchemaErr)
@@ -155,7 +156,7 @@ func eventStreamRpc[TParams, TResponse any, TContext Context](app *App[TContext]
 			panic("Procedures cannot accept anonymous structs")
 		}
 		rpcSchema.Http.Params.Set(paramName)
-		app.Definitions.Set(paramName, *paramsSchema)
+		app.definitions.Set(paramName, *paramsSchema)
 	} else {
 		rpcSchema.Http.Params.Unset()
 	}
@@ -164,9 +165,9 @@ func eventStreamRpc[TParams, TResponse any, TContext Context](app *App[TContext]
 		response = response.Elem()
 	}
 	responseName := getModelName(rpcName, response.Name(), "Response")
-	hasResponse := !isEmptyMessage(response)
+	hasResponse := !utils.IsEmptyMessage(response)
 	if hasResponse {
-		responseDefContext := _NewTypeDefContext(app.Options.KeyCasing)
+		responseDefContext := _NewTypeDefContext(app.options.KeyCasing)
 		responseSchema, responseSchemaErr := typeToTypeDef(response, responseDefContext)
 		if responseSchemaErr != nil {
 			panic(responseSchemaErr)
@@ -175,98 +176,111 @@ func eventStreamRpc[TParams, TResponse any, TContext Context](app *App[TContext]
 			panic("Procedures cannot return anonymous structs")
 		}
 		rpcSchema.Http.Response.Set(responseName)
-		app.Definitions.Set(responseName, *responseSchema)
+		app.definitions.Set(responseName, *responseSchema)
 	} else {
 		rpcSchema.Http.Response.Unset()
 	}
-	app.Procedures.Set(rpcName, *rpcSchema)
+	app.procedures.Set(rpcName, *rpcSchema)
 	onRequest, _, onAfterResponse, onError := getHooks(app)
 	paramsZero := reflect.Zero(reflect.TypeFor[TParams]())
 	app.Mux.HandleFunc(rpcSchema.Http.Path, func(w http.ResponseWriter, r *http.Request) {
-		ctx, ctxErr := app.CreateContext(w, r)
-		if ctxErr != nil {
-			handleError(false, w, r, nil, ctxErr, onError)
+		event, err := app.createEvent(w, r)
+		if err != nil {
+			handleError(false, w, r, nil, err, onError)
 			return
 		}
 		if strings.ToLower(r.Method) != rpcSchema.Http.Method {
-			handleError(false, w, r, ctx, Error(404, "Not found"), onError)
+			handleError(false, w, r, event, Error(404, "Not found"), onError)
 			return
 		}
-		onRequestErr := onRequest(r, ctx)
-		if onRequestErr != nil {
-			handleError(false, w, r, ctx, onRequestErr, onError)
+		err = onRequest(r, event)
+		if err != nil {
+			handleError(false, w, r, event, err, onError)
 			return
 		}
+
+		if len(app.middleware) > 0 {
+			for i := 0; i < len(app.middleware); i++ {
+				fn := app.middleware[i]
+				err := fn(r, *event, rpcName)
+				if err != nil {
+					handleError(false, w, r, event, err, onError)
+					return
+				}
+			}
+		}
+
 		params, paramsOk := paramsZero.Interface().(TParams)
 		if !paramsOk {
-			handleError(false, w, r, ctx, Error(500, "Error initializing empty params"), onError)
+			handleError(false, w, r, event, Error(500, "Error initializing empty params"), onError)
 			return
 		}
 		if hasParams {
 			switch rpcSchema.Http.Method {
 			case HttpMethodGet:
 				urlValues := r.URL.Query()
-				fromUrlQueryErr := FromUrlQuery(urlValues, &params, app.Options.KeyCasing)
+				fromUrlQueryErr := FromUrlQuery(urlValues, &params, app.options.KeyCasing)
 				if fromUrlQueryErr != nil {
-					handleError(false, w, r, ctx, fromUrlQueryErr, onError)
+					handleError(false, w, r, event, fromUrlQueryErr, onError)
 					return
 				}
 			default:
 				b, bErr := io.ReadAll(r.Body)
 				if bErr != nil {
-					handleError(false, w, r, ctx, Error(400, bErr.Error()), onError)
+					handleError(false, w, r, event, Error(400, bErr.Error()), onError)
 					return
 				}
-				fromJsonErr := DecodeJSON(b, &params, app.Options.KeyCasing)
+				fromJsonErr := DecodeJSON(b, &params, app.options.KeyCasing)
 				if fromJsonErr != nil {
-					handleError(false, w, r, ctx, fromJsonErr, onError)
+					handleError(false, w, r, event, fromJsonErr, onError)
 					return
 				}
 			}
 		}
-		sseController := newDefaultSseController[TResponse](w, r, app.Options.KeyCasing)
-		responseErr := handler(params, sseController, *ctx)
-		if responseErr != nil {
-			handleError(false, w, r, ctx, responseErr, onError)
+
+		sseController := newDefaultSseController[TResponse](w, r, app.options.KeyCasing)
+		err = handler(params, sseController, *event)
+		if err != nil {
+			handleError(false, w, r, event, err, onError)
 			return
 		}
-		onAfterResponseErr := onAfterResponse(r, ctx, "")
-		if onAfterResponseErr != nil {
-			handleError(false, w, r, ctx, onAfterResponseErr, onError)
+		err = onAfterResponse(r, event, "")
+		if err != nil {
+			handleError(false, w, r, event, err, onError)
 		}
 	})
 }
 
-func EventStreamRpc[TParams, TResponse any, TContext Context](app *App[TContext], handler func(TParams, SseController[TResponse], TContext) RpcError, options RpcOptions) {
+func EventStreamRpc[TParams, TResponse any, TEvent Event](app *App[TEvent], handler func(TParams, SseController[TResponse], TEvent) RpcError, options RpcOptions) {
 	eventStreamRpc(app, "", options, handler)
 }
 
-func ScopedEventStreamRpc[TParams, TResponse any, TContext Context](app *App[TContext], scope string, handler func(TParams, SseController[TResponse], TContext) RpcError, options RpcOptions) {
+func ScopedEventStreamRpc[TParams, TResponse any, TEvent Event](app *App[TEvent], scope string, handler func(TParams, SseController[TResponse], TEvent) RpcError, options RpcOptions) {
 	eventStreamRpc(app, scope, options, handler)
 }
 
-func getHooks[TContext Context](app *App[TContext]) (func(*http.Request, *TContext) RpcError, func(*http.Request, *TContext, any) RpcError, func(*http.Request, *TContext, any) RpcError, func(*http.Request, *TContext, error)) {
-	onRequest := app.Options.OnRequest
+func getHooks[TEvent Event](app *App[TEvent]) (func(*http.Request, *TEvent) RpcError, func(*http.Request, *TEvent, any) RpcError, func(*http.Request, *TEvent, any) RpcError, func(*http.Request, *TEvent, error)) {
+	onRequest := app.options.OnRequest
 	if onRequest == nil {
-		onRequest = func(r *http.Request, t *TContext) RpcError {
+		onRequest = func(r *http.Request, e *TEvent) RpcError {
 			return nil
 		}
 	}
-	onBeforeResponse := app.Options.OnBeforeResponse
+	onBeforeResponse := app.options.OnBeforeResponse
 	if onBeforeResponse == nil {
-		onBeforeResponse = func(r *http.Request, t *TContext, a any) RpcError {
+		onBeforeResponse = func(r *http.Request, e *TEvent, a any) RpcError {
 			return nil
 		}
 	}
-	onAfterResponse := app.Options.OnAfterResponse
+	onAfterResponse := app.options.OnAfterResponse
 	if onAfterResponse == nil {
-		onAfterResponse = func(r *http.Request, t *TContext, a any) RpcError {
+		onAfterResponse = func(r *http.Request, e *TEvent, a any) RpcError {
 			return nil
 		}
 	}
-	onError := app.Options.OnError
+	onError := app.options.OnError
 	if onError == nil {
-		onError = func(r *http.Request, t *TContext, err error) {}
+		onError = func(r *http.Request, e *TEvent, err error) {}
 	}
 	return onRequest, onBeforeResponse, onAfterResponse, onError
 }
diff --git a/languages/go/go-server/type_def.go b/languages/go/go-server/type_def.go
index 2a1a0839..0bf88109 100644
--- a/languages/go/go-server/type_def.go
+++ b/languages/go/go-server/type_def.go
@@ -7,6 +7,7 @@ import (
 	"strings"
 
 	"github.com/iancoleman/strcase"
+	"github.com/modiimedia/arri/languages/go/go-server/utils"
 )
 
 const (
@@ -153,7 +154,7 @@ func typeToTypeDef(input reflect.Type, context TypeDefContext) (*TypeDef, error)
 		if input.Implements(reflect.TypeFor[ArriModel]()) {
 			return reflect.New(input).Interface().(ArriModel).TypeDef(context)
 		}
-		if isNullableTypeOrPointer(input) {
+		if utils.IsNullableTypeOrPointer(input) {
 			subType := extractNullableType(input)
 			return typeToTypeDef(
 				subType,
@@ -332,7 +333,7 @@ func structToTypeDef(input reflect.Type, context TypeDefContext) (*TypeDef, erro
 			s := strings.TrimSpace(field.Tag.Get("enumName"))
 			enumName = Some(Some(s))
 		}
-		isOptional := isOptionalType(fieldType)
+		isOptional := utils.IsOptionalType(fieldType)
 		if isOptional {
 			fieldType = extractOptionalType(fieldType)
 		}
diff --git a/languages/go/go-server/utils/reflect_helper_test.go b/languages/go/go-server/utils/reflect_helper_test.go
new file mode 100644
index 00000000..b2f870c6
--- /dev/null
+++ b/languages/go/go-server/utils/reflect_helper_test.go
@@ -0,0 +1,65 @@
+package utils_test
+
+import (
+	"reflect"
+	"testing"
+
+	arri "github.com/modiimedia/arri/languages/go/go-server"
+	"github.com/modiimedia/arri/languages/go/go-server/utils"
+)
+
+type Foo struct {
+	Foo string
+	Bar int
+	Baz bool
+}
+
+func TestIsOptionType(t *testing.T) {
+	stringInput := arri.None[string]()
+	structInput := arri.Some(Foo{})
+
+	if !utils.IsOptionalType(reflect.TypeOf(stringInput)) {
+		t.Fatal()
+	}
+
+	if !utils.IsOptionalType(reflect.TypeOf(&stringInput)) {
+		t.Fatal()
+	}
+
+	if !utils.IsOptionalType(reflect.TypeOf(structInput)) {
+		t.Fatal()
+	}
+
+	if !utils.IsOptionalType(reflect.TypeOf(&structInput)) {
+		t.Fatal()
+	}
+
+	if utils.IsOptionalType(reflect.TypeOf(Foo{})) {
+		t.Fatalf("foo is not a valid optional")
+	}
+
+	if utils.IsOptionalType(reflect.TypeOf("Hello world")) {
+		t.Fatalf("string is not a valid optional")
+	}
+}
+
+func TestIsNullableType(t *testing.T) {
+	stringInput := arri.Null[string]()
+	structInput := arri.NotNull(Foo{})
+
+	if !utils.IsNullableType(reflect.TypeOf(stringInput)) {
+		t.Fatal()
+	}
+
+	if !utils.IsNullableType(reflect.TypeOf(structInput)) {
+		t.Fatal()
+	}
+
+	if utils.IsNullableType(reflect.TypeOf(Foo{})) {
+		t.Fatal()
+	}
+
+	if utils.IsNullableType(reflect.TypeOf("Hello world")) {
+		t.Fatal()
+	}
+}
diff --git a/languages/go/go-server/reflect_helpers.go b/languages/go/go-server/utils/reflect_helpers.go
similarity index 66%
rename from languages/go/go-server/reflect_helpers.go
rename to languages/go/go-server/utils/reflect_helpers.go
index 7b74b413..fa9a7616 100644
--- a/languages/go/go-server/reflect_helpers.go
+++ b/languages/go/go-server/utils/reflect_helpers.go
@@ -1,4 +1,4 @@
-package arri
+package utils
 
 import (
 	"reflect"
@@ -7,14 +7,20 @@ import (
 	"github.com/iancoleman/strcase"
 )
 
-func isOptionalType(t reflect.Type) bool {
+const (
+	KeyCasingPascalCase = "PASCAL_CASE"
+	KeyCasingCamelCase  = "CAMEL_CASE"
+	KeyCasingSnakeCase  = "SNAKE_CASE"
+)
+
+func IsOptionalType(t reflect.Type) bool {
 	if t.Kind() == reflect.Ptr {
-		return isOptionalType(t.Elem())
+		return IsOptionalType(t.Elem())
 	}
 	return t.Kind() == reflect.Struct && strings.HasPrefix(t.Name(), "Option[")
 }
 
-func optionalHasValue(value *reflect.Value) bool {
+func OptionalHasValue(value *reflect.Value) bool {
 	target := value
 	if target.Kind() == reflect.Ptr {
 		if target.IsNil() {
@@ -27,18 +33,18 @@ func optionalHasValue(value *reflect.Value) bool {
 	return isSome.Bool()
 }
 
-func isNullableType(t reflect.Type) bool {
+func IsNullableType(t reflect.Type) bool {
 	return t.Kind() == reflect.Struct && strings.HasPrefix(t.Name(), "Nullable[")
 }
 
-func isNullableTypeOrPointer(t reflect.Type) bool {
+func IsNullableTypeOrPointer(t reflect.Type) bool {
 	if t.Kind() == reflect.Ptr {
-		return isNullableTypeOrPointer(t.Elem())
+		return IsNullableTypeOrPointer(t.Elem())
 	}
 	return t.Kind() == reflect.Struct && strings.HasPrefix(t.Name(), "Nullable[")
 }
 
-func nullableHasValue(val *reflect.Value) bool {
+func NullableHasValue(val *reflect.Value) bool {
 	target := val
 	if target.Kind() == reflect.Ptr {
 		if target.IsNil() {
@@ -51,7 +57,7 @@ func nullableHasValue(val *reflect.Value) bool {
 	return isSet.Bool()
 }
 
-func getSerialKey(field *reflect.StructField, keyCasing KeyCasing) string {
+func GetSerialKey(field *reflect.StructField, keyCasing string) string {
 	keyTag := field.Tag.Get("key")
 	if len(keyTag) > 0 {
 		return keyTag
@@ -67,6 +73,6 @@ func getSerialKey(field *reflect.StructField, keyCasing KeyCasing) string {
 	return strcase.ToLowerCamel(field.Name)
 }
 
-func isEmptyMessage(t reflect.Type) bool {
+func IsEmptyMessage(t reflect.Type) bool {
 	return t.Name() == "EmptyMessage" && strings.Contains(t.PkgPath(), "arri")
 }
diff --git a/playground/go/main.go b/playground/go/main.go
index c0632d76..57a63b94 100644
--- a/playground/go/main.go
+++ b/playground/go/main.go
@@ -8,7 +8,7 @@ import (
 )
 
 func main() {
-	app := arri.NewApp(http.DefaultServeMux, arri.AppOptions[arri.DefaultContext]{}, arri.CreateDefaultContext)
+	app := arri.NewApp(http.DefaultServeMux, arri.AppOptions[arri.DefaultEvent]{}, arri.CreateDefaultEvent)
 	arri.Rpc(&app, SayHello, arri.RpcOptions{})
 	app.Run(arri.RunOptions{})
 }
@@ -21,6 +21,6 @@ type SayHelloResponse struct {
 	Message string `enum:"HELLO,WORLD" enumName:"MESSAGE"`
 }
 
-func SayHello(params SayHelloParams, ctx arri.DefaultContext) (SayHelloResponse, arri.RpcError) {
+func SayHello(params SayHelloParams, event arri.DefaultEvent) (SayHelloResponse, arri.RpcError) {
 	return SayHelloResponse{Message: fmt.Sprintf("Hello %s", params.Name)}, nil
 }
diff --git a/tests/clients/dart/lib/test_client.rpc.dart b/tests/clients/dart/lib/test_client.rpc.dart
index c0d1c8d3..a84fdb0c 100644
--- a/tests/clients/dart/lib/test_client.rpc.dart
+++ b/tests/clients/dart/lib/test_client.rpc.dart
@@ -1,5 +1,5 @@
 // this file was autogenerated by arri
-// ignore_for_file: type=lint, unused_field, unnecessary_cast
+// ignore_for_file: type=lint
 import 'dart:async';
 import 'dart:convert';
 import 'package:arri_client/arri_client.dart';
@@ -257,13 +257,13 @@ class TestClientTestsService {
       onClose: onClose,
       onError: onError != null && _onError != null
           ? (err, es) {
-              _onError?.call(onError);
+              _onError.call(onError);
               return onError(err, es);
             }
           : onError != null
               ? onError
               : _onError != null
-                  ? (err, _) => _onError?.call(err)
+                  ? (err, _) => _onError.call(err)
                   : null,
     );
   }
@@ -302,13 +302,13 @@ class TestClientTestsService {
       onClose: onClose,
       onError: onError != null && _onError != null
           ? (err, es) {
-              _onError?.call(onError);
+              _onError.call(onError);
               return onError(err, es);
             }
           : onError != null
               ? onError
               : _onError != null
-                  ? (err, _) => _onError?.call(err)
+                  ? (err, _) => _onError.call(err)
                   : null,
     );
   }
@@ -344,13 +344,13 @@ class TestClientTestsService {
       onClose: onClose,
       onError: onError != null && _onError != null
           ? (err, es) {
-              _onError?.call(onError);
+              _onError.call(onError);
               return onError(err, es);
             }
           : onError != null
               ? onError
               : _onError != null
-                  ? (err, _) => _onError?.call(err)
+                  ? (err, _) => _onError.call(err)
                   : null,
     );
   }
@@ -385,13 +385,13 @@ class TestClientTestsService {
       onClose: onClose,
       onError: onError != null && _onError != null
           ? (err, es) {
-              _onError?.call(onError);
+              _onError.call(onError);
               return onError(err, es);
             }
           : onError != null
               ? onError
               : _onError != null
-                  ? (err, _) => _onError?.call(err)
+                  ? (err, _) => _onError.call(err)
                   : null,
     );
   }
@@ -430,13 +430,13 @@ class TestClientTestsService {
       onClose: onClose,
       onError: onError != null && _onError != null
           ? (err, es) {
-              _onError?.call(onError);
+              _onError.call(onError);
               return onError(err, es);
             }
           : onError != null
               ? onError
               : _onError != null
-                  ? (err, _) => _onError?.call(err)
+                  ? (err, _) => _onError.call(err)
                   : null,
     );
   }
@@ -470,13 +470,13 @@ class TestClientTestsService {
       onClose: onClose,
       onError: onError != null && _onError != null
           ? (err, es) {
-              _onError?.call(onError);
+              _onError.call(onError);
               return onError(err, es);
             }
           : onError != null
               ? onError
               : _onError != null
-                  ? (err, _) => _onError?.call(err)
+                  ? (err, _) => _onError.call(err)
                   : null,
     );
   }
@@ -530,13 +530,13 @@ class TestClientUsersService {
       onClose: onClose,
       onError: onError != null && _onError != null
           ? (err, es) {
-              _onError?.call(onError);
+              _onError.call(onError);
               return onError(err, es);
             }
           : onError != null
               ? onError
               : _onError != null
-                  ? (err, _) => _onError?.call(err)
+                  ? (err, _) => _onError.call(err)
                   : null,
     );
   }
diff --git a/tests/clients/dart/pubspec.lock b/tests/clients/dart/pubspec.lock
index 26cbdf14..c6df82f2 100644
--- a/tests/clients/dart/pubspec.lock
+++ b/tests/clients/dart/pubspec.lock
@@ -414,4 +414,4 @@ packages:
     source: hosted
     version: "3.1.2"
 sdks:
-  dart: ">=3.6.0-0 <4.0.0"
+  dart: ">=3.6.0 <4.0.0"
diff --git a/tests/clients/dart/pubspec.yaml b/tests/clients/dart/pubspec.yaml
index 5137fbea..f4629443 100644
--- a/tests/clients/dart/pubspec.yaml
+++ b/tests/clients/dart/pubspec.yaml
@@ -3,7 +3,7 @@ description:
 repository: https://github.com/modiimedia/arri
 issue_tracker: https://github.com/modiimedia/arri/issues
 environment:
-  sdk: ">=3.0.0 <4.0.0"
+  sdk: ">=3.6.0 <4.0.0"
 dependencies:
   arri_client:
     path: ../../../languages/dart/dart-client
diff --git a/tests/servers/go/main.go b/tests/servers/go/main.go
index b819248b..e10e17c7 100644
--- a/tests/servers/go/main.go
+++ b/tests/servers/go/main.go
@@ -12,17 +12,17 @@ import (
 	"gopkg.in/loremipsum.v1"
 )
 
-type AppContext struct {
+type RpcEvent struct {
 	XTestHeader string
 	request     *http.Request
 	writer      http.ResponseWriter
 }
 
-func (c AppContext) Request() *http.Request {
+func (c RpcEvent) Request() *http.Request {
 	return c.request
 }
 
-func (c AppContext) Writer() http.ResponseWriter {
+func (c RpcEvent) Writer() http.ResponseWriter {
 	return c.writer
 }
 
@@ -38,30 +38,33 @@ func main() {
 	})
 	app := arri.NewApp(
 		mux,
-		arri.AppOptions[AppContext]{
+		arri.AppOptions[RpcEvent]{
 			AppVersion:     "10",
 			RpcRoutePrefix: "/rpcs",
-			OnRequest: func(r *http.Request, ac *AppContext) arri.RpcError {
-				ac.Writer().Header().Set("Access-Control-Allow-Origin", "*")
-				if len(ac.XTestHeader) == 0 &&
-					r.URL.Path != "/" &&
-					r.URL.Path != "/status" &&
-					r.URL.Path != "/favicon.ico" &&
-					!strings.HasSuffix(r.URL.Path, "__definition") {
-					return arri.Error(401, "Missing test auth header 'x-test-header'")
-				}
+			OnRequest: func(r *http.Request, event *RpcEvent) arri.RpcError {
+				event.Writer().Header().Set("Access-Control-Allow-Origin", "*")
 				return nil
 			},
-			OnError: func(r *http.Request, ac *AppContext, err error) {},
+			OnError: func(r *http.Request, ac *RpcEvent, err error) {},
 		},
-		func(w http.ResponseWriter, r *http.Request) (*AppContext, arri.RpcError) {
-			return &AppContext{
+		func(w http.ResponseWriter, r *http.Request) (*RpcEvent, arri.RpcError) {
+			return &RpcEvent{
 				request:     r,
 				writer:      w,
 				XTestHeader: r.Header.Get("x-test-header"),
 			}, nil
 		},
 	)
+	arri.Use(&app, func(r *http.Request, event RpcEvent, rpcName string) arri.RpcError {
+		if len(event.XTestHeader) == 0 &&
+			r.URL.Path != "/" &&
+			r.URL.Path != "/status" &&
+			r.URL.Path != "/favicon.ico" &&
+			!strings.HasSuffix(r.URL.Path, "__definition") {
+			return arri.Error(401, "Missing test auth header 'x-test-header'")
+		}
+		return nil
+	})
 	arri.RegisterDef(&app, ManuallyAddedModel{}, arri.DefOptions{})
 	arri.ScopedRpc(&app, "tests", EmptyParamsGetRequest, arri.RpcOptions{Method: arri.HttpMethodGet})
 	arri.ScopedRpc(&app, "tests", EmptyParamsPostRequest, arri.RpcOptions{})
@@ -98,7 +101,7 @@ type DeprecatedRpcParams struct {
 	DeprecatedField string `arri:"deprecated"`
 }
 
-func DeprecatedRpc(_ DeprecatedRpcParams, _ AppContext) (arri.EmptyMessage, arri.RpcError) {
+func DeprecatedRpc(_ DeprecatedRpcParams, _ RpcEvent) (arri.EmptyMessage, arri.RpcError) {
 	return arri.EmptyMessage{}, nil
 }
 
@@ -106,19 +109,19 @@ type DefaultPayload struct {
 	Message string
 }
 
-func EmptyParamsGetRequest(_ arri.EmptyMessage, _ AppContext) (DefaultPayload, arri.RpcError) {
+func EmptyParamsGetRequest(_ arri.EmptyMessage, _ RpcEvent) (DefaultPayload, arri.RpcError) {
 	return DefaultPayload{Message: "ok"}, nil
 }
 
-func EmptyParamsPostRequest(_ arri.EmptyMessage, _ AppContext) (DefaultPayload, arri.RpcError) {
+func EmptyParamsPostRequest(_ arri.EmptyMessage, _ RpcEvent) (DefaultPayload, arri.RpcError) {
 	return DefaultPayload{Message: "ok"}, nil
 }
 
-func EmptyResponseGetRequest(_ DefaultPayload, _ AppContext) (arri.EmptyMessage, arri.RpcError) {
+func EmptyResponseGetRequest(_ DefaultPayload, _ RpcEvent) (arri.EmptyMessage, arri.RpcError) {
 	return arri.EmptyMessage{}, nil
 }
 
-func EmptyResponsePostRequest(_ DefaultPayload, _ AppContext) (arri.EmptyMessage, arri.RpcError) {
+func EmptyResponsePostRequest(_ DefaultPayload, _ RpcEvent) (arri.EmptyMessage, arri.RpcError) {
 	return arri.EmptyMessage{}, nil
 }
 
@@ -127,7 +130,7 @@ type SendErrorParams struct {
 	Message string
 }
 
-func SendError(params SendErrorParams, _ AppContext) (arri.EmptyMessage, arri.RpcError) {
+func SendError(params SendErrorParams, _ RpcEvent) (arri.EmptyMessage, arri.RpcError) {
 	return arri.EmptyMessage{}, arri.Error(uint32(params.Code), params.Message)
 }
 
@@ -181,7 +184,7 @@ type ObjectWithEveryType struct {
 	}
 }
 
-func SendObject(params ObjectWithEveryType, _ AppContext) (ObjectWithEveryType, arri.RpcError) {
+func SendObject(params ObjectWithEveryType, _ RpcEvent) (ObjectWithEveryType, arri.RpcError) {
 	return params, nil
 }
 
@@ -235,7 +238,7 @@ type ObjectWithEveryNullableType struct {
 	}]]]
 }
 
-func SendObjectWithNullableFields(params ObjectWithEveryNullableType, _ AppContext) (ObjectWithEveryNullableType, arri.RpcError) {
+func SendObjectWithNullableFields(params ObjectWithEveryNullableType, _ RpcEvent) (ObjectWithEveryNullableType, arri.RpcError) {
 	return params, nil
 }
 
@@ -247,7 +250,7 @@ type ObjectWithPascalCaseKeys struct {
 	IsAdmin      arri.Option[bool]     `key:"IsAdmin"`
 }
 
-func SendObjectWithPascalCaseKeys(params ObjectWithPascalCaseKeys, _ AppContext) (ObjectWithPascalCaseKeys, arri.RpcError) {
+func SendObjectWithPascalCaseKeys(params ObjectWithPascalCaseKeys, _ RpcEvent) (ObjectWithPascalCaseKeys, arri.RpcError) {
 	return params, nil
 }
 
@@ -259,7 +262,7 @@ type ObjectWithSnakeCaseKeys struct {
 	IsAdmin      arri.Option[bool]     `key:"is_admin"`
 }
 
-func SendObjectWithSnakeCaseKeys(params ObjectWithSnakeCaseKeys, _ AppContext) (ObjectWithSnakeCaseKeys, arri.RpcError) {
+func SendObjectWithSnakeCaseKeys(params ObjectWithSnakeCaseKeys, _ RpcEvent) (ObjectWithSnakeCaseKeys, arri.RpcError) {
 	return params, nil
 }
 
@@ -313,7 +316,7 @@ type ObjectWithEveryOptionalType struct {
 	}]
 }
 
-func SendPartialObject(params ObjectWithEveryOptionalType, _ AppContext) (ObjectWithEveryOptionalType, arri.RpcError) {
+func SendPartialObject(params ObjectWithEveryOptionalType, _ RpcEvent) (ObjectWithEveryOptionalType, arri.RpcError) {
 	return params, nil
 }
 
@@ -323,7 +326,7 @@ type RecursiveObject struct {
 	Value string
 }
 
-func SendRecursiveObject(params RecursiveObject, _ AppContext) (RecursiveObject, arri.RpcError) {
+func SendRecursiveObject(params RecursiveObject, _ RpcEvent) (RecursiveObject, arri.RpcError) {
 	return params, nil
 }
 
@@ -346,7 +349,7 @@ type RecursiveUnion struct {
 	} `discriminator:"SHAPE" description:"Shape node"`
 }
 
-func SendRecursiveUnion(params RecursiveUnion, _ AppContext) (RecursiveUnion, arri.RpcError) {
+func SendRecursiveUnion(params RecursiveUnion, _ RpcEvent) (RecursiveUnion, arri.RpcError) {
 	return params, nil
 }
 
@@ -359,7 +362,7 @@ type AutoReconnectResponse struct {
 	Message string
 }
 
-func StreamAutoReconnect(params AutoReconnectParams, controller arri.SseController[AutoReconnectResponse], ctx AppContext) arri.RpcError {
+func StreamAutoReconnect(params AutoReconnectParams, controller arri.SseController[AutoReconnectResponse], event RpcEvent) arri.RpcError {
 	t := time.NewTicker(time.Millisecond)
 	defer t.Stop()
 	var msgCount uint8 = 0
@@ -393,7 +396,7 @@ type StreamConnectionErrorTestResponse struct {
 func StreamConnectionErrorTest(
 	params StreamConnectionErrorTestParams,
 	controller arri.SseController[StreamConnectionErrorTestResponse],
-	_ AppContext,
+	_ RpcEvent,
 ) arri.RpcError {
 	return arri.Error(uint32(params.StatusCode), params.StatusMessage)
 }
@@ -407,7 +410,7 @@ type StreamLargeObjectsResponse struct {
 	}
 }
 
-func StreamLargeObjects(params arri.EmptyMessage, controller arri.SseController[StreamLargeObjectsResponse], _ AppContext) arri.RpcError {
+func StreamLargeObjects(params arri.EmptyMessage, controller arri.SseController[StreamLargeObjectsResponse], _ RpcEvent) arri.RpcError {
 	t := time.NewTicker(time.Millisecond)
 	defer t.Stop()
 	for {
@@ -480,7 +483,7 @@ type ChatMessageUrl struct {
 	Url       string
 }
 
-func StreamMessages(params ChatMessageParams, controller arri.SseController[ChatMessage], context AppContext) arri.RpcError {
+func StreamMessages(params ChatMessageParams, controller arri.SseController[ChatMessage], event RpcEvent) arri.RpcError {
 	t := time.NewTicker(time.Millisecond)
 	for {
 		select {
@@ -500,8 +503,8 @@ type TestsStreamRetryWithNewCredentialsResponse struct {
 
 var usedTokens map[string]bool = map[string]bool{}
 
-func StreamRetryWithNewCredentials(_ arri.EmptyMessage, controller arri.SseController[TestsStreamRetryWithNewCredentialsResponse], ctx AppContext) arri.RpcError {
-	authToken := ctx.XTestHeader
+func StreamRetryWithNewCredentials(_ arri.EmptyMessage, controller arri.SseController[TestsStreamRetryWithNewCredentialsResponse], event RpcEvent) arri.RpcError {
+	authToken := event.XTestHeader
 	if len(authToken) == 0 {
 		return arri.Error(400, "")
 	}
@@ -528,7 +531,7 @@ func StreamRetryWithNewCredentials(_ arri.EmptyMessage, controller arri.SseContr
 	}
 }
 
-func StreamTenEventsThenEnd(_ arri.EmptyMessage, controller arri.SseController[ChatMessage], ctx AppContext) arri.RpcError {
+func StreamTenEventsThenEnd(_ arri.EmptyMessage, controller arri.SseController[ChatMessage], event RpcEvent) arri.RpcError {
 	t := time.NewTicker(time.Millisecond)
 	defer t.Stop()
 	msgCount := 0
@@ -599,7 +602,7 @@ type UserSettings struct {
 	PreferredTheme       string `enum:"dark-mode,light-mode,system"`
 }
 
-func WatchUser(params UsersWatchUserParams, stream arri.SseController[UsersWatchUserResponse], ctx AppContext) arri.RpcError {
+func WatchUser(params UsersWatchUserParams, stream arri.SseController[UsersWatchUserResponse], event RpcEvent) arri.RpcError {
 	t := time.NewTicker(time.Millisecond)
 	defer t.Stop()
 	msgCount := 0