diff --git a/modules/context/api.go b/modules/context/api.go
index b9d130e2a8ac0..517d0cf1dd64c 100644
--- a/modules/context/api.go
+++ b/modules/context/api.go
@@ -8,6 +8,7 @@ package context
 import (
 	"context"
 	"fmt"
+	"html"
 	"net/http"
 	"net/url"
 	"strings"
@@ -21,6 +22,7 @@ import (
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/web/middleware"
 	auth_service "code.gitea.io/gitea/services/auth"
+	"gitea.com/go-chi/session"
 )
 
 // APIContext is a specific context for API service
@@ -190,6 +192,17 @@ func (ctx *APIContext) SetLinkHeader(total, pageSize int) {
 	}
 }
 
+// RequireCSRF requires a validated a CSRF token
+func (ctx *APIContext) RequireCSRF() {
+	headerToken := ctx.Req.Header.Get(ctx.csrf.GetHeaderName())
+	formValueToken := ctx.Req.FormValue(ctx.csrf.GetFormName())
+	if len(headerToken) > 0 || len(formValueToken) > 0 {
+		ctx.csrf.Validate(ctx.Context)
+	} else {
+		ctx.Context.Error(http.StatusUnauthorized, "Missing CSRF token.")
+	}
+}
+
 // CheckForOTP validates OTP
 func (ctx *APIContext) CheckForOTP() {
 	if skip, ok := ctx.Data["SkipLocalTwoFA"]; ok && skip.(bool) {
@@ -241,15 +254,18 @@ func APIAuth(authMethod auth_service.Method) func(*APIContext) {
 
 // APIContexter returns apicontext as middleware
 func APIContexter() func(http.Handler) http.Handler {
+	csrfOpts := getCsrfOpts()
+
 	return func(next http.Handler) http.Handler {
 		return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
 			locale := middleware.Locale(w, req)
 			ctx := APIContext{
 				Context: &Context{
-					Resp:   NewResponse(w),
-					Data:   map[string]interface{}{},
-					Locale: locale,
-					Cache:  cache.GetCache(),
+					Resp:    NewResponse(w),
+					Data:    map[string]interface{}{},
+					Locale:  locale,
+					Session: session.GetSession(req),
+					Cache:   cache.GetCache(),
 					Repo: &Repository{
 						PullRequest: &PullRequest{},
 					},
@@ -260,6 +276,7 @@ func APIContexter() func(http.Handler) http.Handler {
 			defer ctx.Close()
 
 			ctx.Req = WithAPIContext(WithContext(req, ctx.Context), &ctx)
+			ctx.csrf = PrepareCSRFProtector(csrfOpts, ctx.Context)
 
 			// If request sends files, parse them here otherwise the Query() can't be parsed and the CsrfToken will be invalid.
 			if ctx.Req.Method == "POST" && strings.Contains(ctx.Req.Header.Get("Content-Type"), "multipart/form-data") {
@@ -272,6 +289,7 @@ func APIContexter() func(http.Handler) http.Handler {
 			httpcache.AddCacheControlToHeader(ctx.Resp.Header(), 0, "no-transform")
 			ctx.Resp.Header().Set(`X-Frame-Options`, setting.CORSConfig.XFrameOptions)
 
+			ctx.Data["CsrfToken"] = html.EscapeString(ctx.csrf.GetToken())
 			ctx.Data["Context"] = &ctx
 
 			next.ServeHTTP(ctx.Resp, ctx.Req)
diff --git a/routers/api/v1/api.go b/routers/api/v1/api.go
index e1478fa2aa99a..2b8d1c4b44434 100644
--- a/routers/api/v1/api.go
+++ b/routers/api/v1/api.go
@@ -217,6 +217,7 @@ func reqToken() func(ctx *context.APIContext) {
 			return
 		}
 		if ctx.IsSigned {
+			ctx.RequireCSRF()
 			return
 		}
 		ctx.Error(http.StatusUnauthorized, "reqToken", "token is required")
@@ -595,6 +596,7 @@ func buildAuthGroup() *auth.Group {
 		&auth.OAuth2{},
 		&auth.HTTPSign{},
 		&auth.Basic{}, // FIXME: this should be removed once we don't allow basic auth in API
+		&auth.Session{},
 	)
 	if setting.Service.EnableReverseProxyAuth {
 		group.Add(&auth.ReverseProxy{})
@@ -605,10 +607,12 @@ func buildAuthGroup() *auth.Group {
 }
 
 // Routes registers all v1 APIs routes to web application.
-func Routes() *web.Route {
+func Routes(sessioner func(http.Handler) http.Handler) *web.Route {
 	m := web.NewRoute()
 
 	m.Use(securityHeaders())
+	m.Use(sessioner)
+
 	if setting.CORSConfig.Enabled {
 		m.Use(cors.Handler(cors.Options{
 			// Scheme:           setting.CORSConfig.Scheme, // FIXME: the cors middleware needs scheme option
diff --git a/routers/init.go b/routers/init.go
index e640ca48453bc..082ccb1841b2d 100644
--- a/routers/init.go
+++ b/routers/init.go
@@ -47,6 +47,7 @@ import (
 	"code.gitea.io/gitea/services/repository/archiver"
 	"code.gitea.io/gitea/services/task"
 	"code.gitea.io/gitea/services/webhook"
+	"gitea.com/go-chi/session"
 )
 
 func mustInit(fn func() error) {
@@ -171,8 +172,20 @@ func NormalRoutes() *web.Route {
 		r.Use(middle)
 	}
 
-	r.Mount("/", web_routers.Routes())
-	r.Mount("/api/v1", apiv1.Routes())
+	sessioner := session.Sessioner(session.Options{
+		Provider:       setting.SessionConfig.Provider,
+		ProviderConfig: setting.SessionConfig.ProviderConfig,
+		CookieName:     setting.SessionConfig.CookieName,
+		CookiePath:     setting.SessionConfig.CookiePath,
+		Gclifetime:     setting.SessionConfig.Gclifetime,
+		Maxlifetime:    setting.SessionConfig.Maxlifetime,
+		Secure:         setting.SessionConfig.Secure,
+		SameSite:       setting.SessionConfig.SameSite,
+		Domain:         setting.SessionConfig.Domain,
+	})
+
+	r.Mount("/", web_routers.Routes(sessioner))
+	r.Mount("/api/v1", apiv1.Routes(sessioner))
 	r.Mount("/api/internal", private.Routes())
 	if setting.Packages.Enabled {
 		r.Mount("/api/packages", packages_router.Routes())
diff --git a/routers/web/web.go b/routers/web/web.go
index a9f43fb2c4feb..18871fd994714 100644
--- a/routers/web/web.go
+++ b/routers/web/web.go
@@ -48,7 +48,6 @@ import (
 	_ "code.gitea.io/gitea/modules/session" // to registers all internal adapters
 
 	"gitea.com/go-chi/captcha"
-	"gitea.com/go-chi/session"
 	"github.com/NYTimes/gziphandler"
 	"github.com/go-chi/chi/v5/middleware"
 	"github.com/go-chi/cors"
@@ -99,7 +98,7 @@ func buildAuthGroup() *auth_service.Group {
 }
 
 // Routes returns all web routes
-func Routes() *web.Route {
+func Routes(sessioner func(http.Handler) http.Handler) *web.Route {
 	routes := web.NewRoute()
 
 	routes.Use(web.WrapWithPrefix(public.AssetsURLPathPrefix, public.AssetsHandlerFunc(&public.Options{
@@ -108,17 +107,6 @@ func Routes() *web.Route {
 		CorsHandler: CorsHandler(),
 	}), "AssetsHandler"))
 
-	sessioner := session.Sessioner(session.Options{
-		Provider:       setting.SessionConfig.Provider,
-		ProviderConfig: setting.SessionConfig.ProviderConfig,
-		CookieName:     setting.SessionConfig.CookieName,
-		CookiePath:     setting.SessionConfig.CookiePath,
-		Gclifetime:     setting.SessionConfig.Gclifetime,
-		Maxlifetime:    setting.SessionConfig.Maxlifetime,
-		Secure:         setting.SessionConfig.Secure,
-		SameSite:       setting.SessionConfig.SameSite,
-		Domain:         setting.SessionConfig.Domain,
-	})
 	routes.Use(sessioner)
 
 	routes.Use(Recovery())