add support for ALLOWED_KINDS environment variable to filter event types

compose.yaml

@@ -12,6 +12,7 @@ services:
       POSTGRES_URL: "postgres://postgres:postgres@postgres/postgres?sslmode=disable"
       # RELAY_PUBKEY: optional, will use default if not set
       # RELAY_ICON: optional, will use default if not set
+      # ALLOWED_KINDS: "0,1,20" # optional, will allow all kinds if not set
     ports:
       - 3334:3334
   postgres:

main.go

@@ -1,14 +1,18 @@
 package main
 
 import (
+	"context"
 	"fmt"
 	"net/http"
 	"os"
+	"strconv"
+	"strings"
 	"time"
 
 	"github.com/fiatjaf/eventstore/postgresql"
 	"github.com/fiatjaf/khatru"
 	"github.com/fiatjaf/khatru/policies"
+	"github.com/nbd-wtf/go-nostr"
 )
 
 func getEnv(key, fallback string) string {
@@ -18,6 +22,23 @@ func getEnv(key, fallback string) string {
 	return fallback
 }
 
+func getAllowedKinds() []int {
+	allowedKindsStr := getEnv("ALLOWED_KINDS", "")
+	if allowedKindsStr == "" {
+		return nil // Allow all kinds
+	}
+
+	kindStrs := strings.Split(allowedKindsStr, ",")
+	kinds := make([]int, 0, len(kindStrs))
+
+	for _, k := range kindStrs {
+		if kind, err := strconv.Atoi(strings.TrimSpace(k)); err == nil {
+			kinds = append(kinds, kind)
+		}
+	}
+	return kinds
+}
+
 func main() {
 	// Print ASCII art banner
 	fmt.Print(`
@@ -47,7 +68,24 @@ func main() {
 		panic(err)
 	}
 
-	relay.StoreEvent = append(relay.StoreEvent, db.SaveEvent)
+	allowedKinds := getAllowedKinds()
+
+	relay.StoreEvent = append(relay.StoreEvent,
+		func(ctx context.Context, evt *nostr.Event) error {
+			if allowedKinds == nil {
+				db.SaveEvent(ctx, evt) // Allow all kinds
+				return nil
+			}
+
+			for _, kind := range allowedKinds {
+				if evt.Kind == kind {
+					db.SaveEvent(ctx, evt)
+					return nil
+				}
+			}
+			return fmt.Errorf("event kind %d is not allowed", evt.Kind)
+		},
+	)
 	relay.QueryEvents = append(relay.QueryEvents, db.QueryEvents)
 	relay.DeleteEvent = append(relay.DeleteEvent, db.DeleteEvent)
 	relay.ReplaceEvent = append(relay.ReplaceEvent, db.ReplaceEvent)