diff --git a/Makefile b/Makefile
index 8cb0738..9a348ac 100644
--- a/Makefile
+++ b/Makefile
@@ -30,4 +30,4 @@ clean:
 .PHONY: generate
 generate:
 	@mkdir -p $(DIST)
-	@./generate.sh
+	@./generate.sh $(handler)
diff --git a/generate.sh b/generate.sh
index cf3e9cb..592f508 100755
--- a/generate.sh
+++ b/generate.sh
@@ -28,8 +28,8 @@ generate_all() {
     gomplate -d source=env:SOURCE -d type=env:TYPE -o "$SOURCE/all-$TYPE.json" -f templates/all.json.tmpl
 }
 
-default_openapi_handler() {
-    printf "Processing %s ...\n" $API
+exec_openapi() {
+    printf "Processing %s ...\n" "$1"
     prepare
     (
         cd "$WORKDIR"
@@ -40,6 +40,11 @@ default_openapi_handler() {
 }
 
 calico_handler() {
+    API=projectcalico.org
+    NAME=calico
+    WORKDIR="${TMP_CRD_DIR}/calico"
+    SOURCE="https://raw.githubusercontent.com/projectcalico/calico/${CALICO_VERSION}/manifests/calico.yaml"
+
     printf "Processing %s ...\n" $API
     prepare
     (
@@ -60,6 +65,10 @@ calico_handler() {
 }
 
 flux_handler() {
+    API=toolkit.fluxcd.io
+    WORKDIR="${TMP_CRD_DIR}/flux"
+    SOURCE="https://github.com/fluxcd/flux2/releases/download/${FLUXCD_VERSION}/crd-schemas.tar.gz"
+
     printf "Processing %s ...\n" $API
     mkdir -p "${WORKDIR}"
     curl -SsfL "${SOURCE}" | tar xz -C "${WORKDIR}"
@@ -82,6 +91,11 @@ flux_handler() {
 }
 
 metallb_handler() {
+    API=metallb.io
+    NAME=metallb
+    WORKDIR="${TMP_CRD_DIR}/$NAME"
+    SOURCE="https://raw.githubusercontent.com/metallb/metallb/${METALLB_VERSION}/charts/metallb/charts/crds/templates/crds.yaml"
+
     printf "Processing %s ...\n" $API
     prepare
     (
@@ -93,50 +107,56 @@ metallb_handler() {
     generate_all "$TARGET_DIR"
 }
 
-## Calico
-API=projectcalico.org
-NAME=calico
-WORKDIR="${TMP_CRD_DIR}/calico"
-SOURCE="https://raw.githubusercontent.com/projectcalico/calico/${CALICO_VERSION}/manifests/calico.yaml"
-calico_handler
+cnpg_handler() {
+    API=postgresql.cnpg.io
+    NAME=cnpg
+    WORKDIR="${TMP_CRD_DIR}/$NAME"
+    SOURCE="https://github.com/cloudnative-pg/cloudnative-pg/releases/download/${CNPG_VERSION}/cnpg-${CNPG_VERSION##v}.yaml"
 
-## Flux2
-API=toolkit.fluxcd.io
-WORKDIR="${TMP_CRD_DIR}/flux"
-SOURCE="https://github.com/fluxcd/flux2/releases/download/${FLUXCD_VERSION}/crd-schemas.tar.gz"
-flux_handler
+    exec_openapi $API
+}
 
-## Metallb
-API=metallb.io
-NAME=metallb
-WORKDIR="${TMP_CRD_DIR}/$NAME"
-SOURCE="https://raw.githubusercontent.com/metallb/metallb/${METALLB_VERSION}/charts/metallb/charts/crds/templates/crds.yaml"
-metallb_handler
+certmanager_handler() {
+    API=cert-manager.io
+    NAME=cert-manager
+    WORKDIR="${TMP_CRD_DIR}/$NAME"
+    SOURCE="https://github.com/cert-manager/cert-manager/releases/download/${CERTMANAGER_VERSION}/cert-manager.crds.yaml"
 
-## Cloudnative-PG
-API=postgresql.cnpg.io
-NAME=cnpg
-WORKDIR="${TMP_CRD_DIR}/$NAME"
-SOURCE="https://github.com/cloudnative-pg/cloudnative-pg/releases/download/${CNPG_VERSION}/cnpg-${CNPG_VERSION##v}.yaml"
-default_openapi_handler
+    exec_openapi $API
+}
 
-## Cert-Manager
-API=cert-manager.io
-NAME=cert-manager
-WORKDIR="${TMP_CRD_DIR}/$NAME"
-SOURCE="https://github.com/cert-manager/cert-manager/releases/download/${CERTMANAGER_VERSION}/cert-manager.crds.yaml"
-default_openapi_handler
+minio_handler() {
+    API=minio.min.io
+    NAME=minio
+    WORKDIR="${TMP_CRD_DIR}/$NAME"
+    SOURCE="https://raw.githubusercontent.com/minio/operator/${MINIO_VERSION}/resources/base/crds/minio.min.io_tenants.yaml"
 
-## Minio
-API=minio.min.io
-NAME=minio
-WORKDIR="${TMP_CRD_DIR}/$NAME"
-SOURCE="https://raw.githubusercontent.com/minio/operator/${MINIO_VERSION}/resources/base/crds/minio.min.io_tenants.yaml"
-default_openapi_handler
+    exec_openapi $API
+}
 
-## K8up
-API=k8up.io
-NAME=k8up
-WORKDIR="${TMP_CRD_DIR}/$NAME"
-SOURCE="https://github.com/k8up-io/k8up/releases/download/k8up-${K8UP_VERSION}/k8up-crd.yaml"
-default_openapi_handler
+k8up_handler() {
+    API=k8up.io
+    NAME=k8up
+    WORKDIR="${TMP_CRD_DIR}/$NAME"
+    SOURCE="https://github.com/k8up-io/k8up/releases/download/k8up-${K8UP_VERSION}/k8up-crd.yaml"
+
+    exec_openapi $API
+}
+
+handlers=(
+    calico_handler
+    flux_handler
+    metallb_handler
+    cnpg_handler
+    certmanager_handler
+    minio_handler
+    k8up_handler
+)
+
+if [ $# -eq 0 ]; then
+    for handler in "${handlers[@]}"; do
+        "$handler"
+    done
+else
+    "$1"_handler
+fi