diff --git a/main.go b/main.go
index e5e9951..f78708b 100644
--- a/main.go
+++ b/main.go
@@ -1,22 +1,127 @@
 package main
 
 import (
+	"encoding/json"
+	"fmt"
 	"net/http"
+	"regexp"
+	"sync/atomic"
 )
 
+type apiConfig struct {
+	fileserverHits atomic.Int32
+}
+
+func (cfg *apiConfig) middlewareMetricsInc(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		cfg.fileserverHits.Add(1)
+		next.ServeHTTP(w, r)
+	})
+}
+
 func readinessHandler(w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("Content-Type", "text/plain; charset=utf-8")
 	w.WriteHeader(http.StatusOK)
 	w.Write([]byte("OK"))
 }
 
+func metricsHandler(cfg *apiConfig) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "text/plain; charset=utf-8")
+		w.WriteHeader(http.StatusOK)
+		hits := cfg.fileserverHits.Load()
+		w.Write([]byte(fmt.Sprintf("Hits: %d", hits)))
+	}
+}
+
+func adminMetricsHandler(cfg *apiConfig) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "text/html; charset=utf-8")
+		w.WriteHeader(http.StatusOK)
+		hits := cfg.fileserverHits.Load()
+		w.Write([]byte(fmt.Sprintf(`<html>
+  <body>
+    <h1>Welcome, Chirpy Admin</h1>
+    <p>Chirpy has been visited %d times!</p>
+  </body>
+</html>`, hits)))
+	}
+}
+func resetMetricsHandler(cfg *apiConfig) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "text/plain; charset=utf-8")
+		cfg.fileserverHits.Store(0)
+		w.WriteHeader(http.StatusOK)
+		w.Write([]byte("Metrics Reset"))
+	}
+}
+func adminResetMetricsHandler(cfg *apiConfig) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "text/html; charset=utf-8")
+		cfg.fileserverHits.Store(0)
+		w.WriteHeader(http.StatusOK)
+		w.Write([]byte("Metrics Reset"))
+	}
+}
+
+func fileServerHandler() http.Handler {
+	fileServer := http.FileServer(http.Dir("./public"))
+	return http.StripPrefix("/app", fileServer)
+}
+
+func validateChirpHandler(w http.ResponseWriter, r *http.Request) {
+	type parameters struct {
+		Body string `json:"body"`
+	}
+
+	profaneWords := []string{"kerfuffle", "sharbert", "fornax"}
+
+	decoder := json.NewDecoder(r.Body)
+	params := parameters{}
+	err := decoder.Decode(&params)
+	if err != nil {
+		w.Header().Set("Content-Type", "application/json; charset=utf-8")
+		w.WriteHeader(http.StatusInternalServerError)
+		w.Write([]byte(`{"error": "Something went wrong"}`))
+		return
+	}
+
+	if len(params.Body) > 140 {
+		w.Header().Set("Content-Type", "application/json; charset=utf-8")
+		w.WriteHeader(http.StatusBadRequest)
+		w.Write([]byte(`{"error": "Chirp is too long"}`))
+		return
+	}
+
+	chirp := params.Body
+
+	for _, word := range profaneWords {
+		// Use word boundaries (\b) to match whole words and ignore punctuation
+		re := regexp.MustCompile(`(?i)\b` + regexp.QuoteMeta(word) + `\b`)
+		chirp = re.ReplaceAllString(chirp, "****")
+	}
+
+	w.Header().Set("Content-Type", "application/json; charset=utf-8")
+	w.WriteHeader(http.StatusOK)
+	w.Write([]byte(fmt.Sprintf(`{"cleaned_body": "%s"}`, chirp)))
+	return
+}
+
 func main() {
+
+	apiCfg := &apiConfig{}
+
 	mux := http.NewServeMux()
 
-	mux.HandleFunc("/healthz", readinessHandler)
+	mux.HandleFunc("GET /api/healthz", readinessHandler)
+	mux.HandleFunc("GET /api/metrics", metricsHandler(apiCfg))
+	mux.HandleFunc("POST /api/reset", resetMetricsHandler(apiCfg))
+	mux.HandleFunc("POST /api/validate_chirp", validateChirpHandler)
 
-	fileServer := http.FileServer(http.Dir("./public"))
-	mux.Handle("/app/", http.StripPrefix("/app", fileServer))
+	mux.HandleFunc("GET /admin/metrics", adminMetricsHandler(apiCfg))
+	mux.HandleFunc("POST /admin/reset", adminResetMetricsHandler(apiCfg))
+
+	mux.Handle("/app/", apiCfg.middlewareMetricsInc(fileServerHandler()))
 
 	server := &http.Server{
 		Addr:    ":8080",
