diff --git a/cmd/encrypt.go b/cmd/encrypt.go
index 1b88a4e84d..c4284648ff 100644
--- a/cmd/encrypt.go
+++ b/cmd/encrypt.go
@@ -3,11 +3,15 @@ package cmd
 import (
 	"fmt"
 	"log"
+	"os"
+	"path/filepath"
 
 	"github.com/spf13/cobra"
 	"go.starlark.net/starlark"
 
+	"tidbyt.dev/pixlet/manifest"
 	"tidbyt.dev/pixlet/runtime"
+	"tidbyt.dev/pixlet/tools/repo"
 )
 
 const PublicKeysetJSON = `{
@@ -40,6 +44,10 @@ func encrypt(cmd *cobra.Command, args []string) {
 	}
 
 	appID := args[0]
+	if err := validateAppID(args[0]); err != nil {
+		log.Fatalf("Cannot encrypt with appID '%s': %v", appID, err)
+	}
+
 	encrypted := make([]string, len(args)-1)
 
 	for i, val := range args[1:] {
@@ -54,3 +62,40 @@ func encrypt(cmd *cobra.Command, args []string) {
 		fmt.Println(starlark.String(val).String())
 	}
 }
+
+func validateAppID(appID string) error {
+	cwd, err := os.Getwd()
+	if err != nil {
+		return fmt.Errorf("something went wrong with your local filesystem: %v", err)
+	}
+	if !repo.IsInRepo(cwd, "community") {
+		log.Printf("Skipping validation of appID since command is not being run from inside the community repo.")
+		return nil // Can only apply check if running from the community repo
+	}
+	root, err := repo.RepoRoot(cwd)
+	if err != nil {
+		return fmt.Errorf("something went wrong with your community repo: %v", err)
+	}
+	entries, err := os.ReadDir(filepath.Join(root, "apps"))
+	if err != nil {
+		return fmt.Errorf("something went wrong listing existing apps: %v", err)
+	}
+	for _, e := range entries {
+		if !e.IsDir() {
+			continue
+		}
+		f, err := os.Open(filepath.Join(root, "apps", e.Name(), manifest.ManifestFileName))
+		if err != nil {
+			log.Printf("Skipping %s/%s/%s/%s: %v", root, "apps", e.Name(), manifest.ManifestFileName, err)
+			continue
+		}
+		m, err := manifest.LoadManifest(f)
+		if err != nil {
+			return fmt.Errorf("something went wrong loading manifest for %s: %v", e.Name(), err)
+		}
+		if m.ID == appID {
+			return nil
+		}
+	}
+	return fmt.Errorf("does not match manifest ID for any app in the community repo")
+}