diff --git a/Koha/REST/V1/Acquisitions/Orders.pm b/Koha/REST/V1/Acquisitions/Orders.pm
index a9c4f8007c..0155a38922 100644
--- a/Koha/REST/V1/Acquisitions/Orders.pm
+++ b/Koha/REST/V1/Acquisitions/Orders.pm
@@ -95,7 +95,7 @@ Controller function that handles retrieving a single Koha::Acquisition::Order ob
 sub get {
     my $c = shift->openapi->valid_input or return;
 
-    my $order = Koha::Acquisition::Orders->find( $c->validation->param('order_id') );
+    my $order = Koha::Acquisition::Orders->find( $c->param('order_id') );
 
     unless ($order) {
         return $c->render(
@@ -105,11 +105,9 @@ sub get {
     }
 
     return try {
-        my $embed = $c->stash('koha.embed');
-
         return $c->render(
             status  => 200,
-            openapi => $order->to_api({ embed => $embed })
+            openapi => $c->objects->to_api( $order ),
         );
     }
     catch {
@@ -127,7 +125,7 @@ sub add {
     my $c = shift->openapi->valid_input or return;
 
     return try {
-        my $order = Koha::Acquisition::Order->new_from_api( $c->validation->param('body') );
+        my $order = Koha::Acquisition::Order->new_from_api( $c->req->json );
         $order->store->discard_changes;
 
         $c->res->headers->location(
@@ -136,7 +134,7 @@ sub add {
 
         return $c->render(
             status  => 201,
-            openapi => $order->to_api
+            openapi => $c->objects->to_api( $order ),
         );
     }
     catch {
@@ -160,7 +158,7 @@ Controller function that handles updating a Koha::Acquisition::Order object
 sub update {
     my $c = shift->openapi->valid_input or return;
 
-    my $order = Koha::Acquisition::Orders->find( $c->validation->param('order_id') );
+    my $order = Koha::Acquisition::Orders->find( $c->param('order_id') );
 
     unless ($order) {
         return $c->render(
@@ -170,12 +168,12 @@ sub update {
     }
 
     return try {
-        $order->set_from_api( $c->validation->param('body') );
+        $order->set_from_api( $c->req->json );
         $order->store()->discard_changes;
 
         return $c->render(
             status  => 200,
-            openapi => $order->to_api
+            openapi => $c->objects->to_api( $order ),
         );
     }
     catch {
@@ -192,7 +190,7 @@ Controller function that handles deleting a Koha::Patron object
 sub delete {
     my $c = shift->openapi->valid_input or return;
 
-    my $order = Koha::Acquisition::Orders->find( $c->validation->param('order_id') );
+    my $order = Koha::Acquisition::Orders->find( $c->param('order_id') );
 
     unless ($order) {
         return $c->render(
@@ -215,23 +213,4 @@ sub delete {
     };
 }
 
-=head2 Internal methods
-
-=head3 table_name_fixer
-
-    $q = $c->table_name_fixer( $q );
-
-The Koha::Biblio representation includes the biblioitem.* attributes. This is handy
-for API consumers but as they are different tables, converting the queries that mention
-biblioitem columns can be tricky. This method renames known column names as used on Koha's
-UI.
-
-=cut
-
-sub table_name_fixer {
-    my ( $self, $q ) = @_;
-    $q =~ s/biblio\.(?=isbn|ean|publisher)/biblio.biblioitem./g;
-    return $q;
-}
-
 1;
diff --git a/Koha/REST/V1/Acquisitions/Vendors.pm b/Koha/REST/V1/Acquisitions/Vendors.pm
index eb0d4112e2..5ac4833931 100644
--- a/Koha/REST/V1/Acquisitions/Vendors.pm
+++ b/Koha/REST/V1/Acquisitions/Vendors.pm
@@ -62,10 +62,12 @@ Controller function that handles retrieving a single Koha::Acquisition::Booksell
 sub get {
     my $c = shift->openapi->valid_input or return;
 
-    my $vendor = Koha::Acquisition::Booksellers->find( $c->validation->param('vendor_id') );
+    my $vendor = Koha::Acquisition::Booksellers->find( $c->param('vendor_id') );
     unless ($vendor) {
-        return $c->render( status  => 404,
-                           openapi => { error => "Vendor not found" } );
+        return $c->render(
+            status  => 404,
+            openapi => { error => "Vendor not found" }
+        );
     }
 
     return try {
@@ -88,7 +90,7 @@ Controller function that handles adding a new Koha::Acquisition::Bookseller obje
 sub add {
     my $c = shift->openapi->valid_input or return;
 
-    my $vendor = Koha::Acquisition::Bookseller->new_from_api( $c->validation->param('body') );
+    my $vendor = Koha::Acquisition::Bookseller->new_from_api( $c->req->json );
 
     return try {
         $vendor->store;
@@ -115,8 +117,8 @@ sub update {
     my $vendor;
 
     return try {
-        $vendor = Koha::Acquisition::Booksellers->find( $c->validation->param('vendor_id') );
-        $vendor->set_from_api( $c->validation->param('body') );
+        $vendor = Koha::Acquisition::Booksellers->find( $c->param('vendor_id') );
+        $vendor->set_from_api( $c->req->json );
         $vendor->store();
         return $c->render(
             status  => 200,
@@ -132,7 +134,6 @@ sub update {
         }
 
         $c->unhandled_exception($_);
-
     };
 
 }
@@ -147,7 +148,7 @@ sub delete {
     my $c = shift->openapi->valid_input or return;
 
     return try {
-        my $vendor = Koha::Acquisition::Booksellers->find( $c->validation->param('vendor_id') );
+        my $vendor = Koha::Acquisition::Booksellers->find( $c->param('vendor_id') );
 
         unless ( $vendor ) {
             return $c->render(
diff --git a/Koha/REST/V1/AdvancedEditorMacro.pm b/Koha/REST/V1/AdvancedEditorMacro.pm
index 472d4ce87c..093b078605 100644
--- a/Koha/REST/V1/AdvancedEditorMacro.pm
+++ b/Koha/REST/V1/AdvancedEditorMacro.pm
@@ -66,12 +66,12 @@ Controller function that handles retrieving a single Koha::AdvancedEditorMacro
 sub get {
     my $c = shift->openapi->valid_input or return;
     my $patron = $c->stash('koha.user');
-    my $macro = Koha::AdvancedEditorMacros->find({
-        id => $c->validation->param('advancededitormacro_id'),
-    });
+    my $macro  = Koha::AdvancedEditorMacros->find( $c->param('advancededitormacro_id') );
     unless ($macro) {
-        return $c->render( status  => 404,
-                           openapi => { error => "Macro not found" } );
+        return $c->render(
+            status  => 404,
+            openapi => { error => "Macro not found" }
+        );
     }
     if( $macro->shared ){
         return $c->render( status => 403, openapi => {
@@ -97,7 +97,7 @@ sub get_shared {
     my $c = shift->openapi->valid_input or return;
     my $patron = $c->stash('koha.user');
     my $macro = Koha::AdvancedEditorMacros->find({
-        id => $c->validation->param('advancededitormacro_id'),
+        id => $c->param('advancededitormacro_id'),
     });
     unless ($macro) {
         return $c->render( status  => 404,
@@ -120,13 +120,15 @@ Controller function that handles adding a new Koha::AdvancedEditorMacro object
 sub add {
     my $c = shift->openapi->valid_input or return;
 
-    if( defined $c->validation->param('body')->{shared} && $c->validation->param('body')->{shared} == 1 ){
+    my $body = $c->req->json;
+
+    if( defined $body->{shared} && $body->{shared} == 1 ){
         return $c->render( status  => 403,
                            openapi => { error => "To create shared macros you must use advancededitor/shared" } );
     }
 
     return try {
-        my $macro = Koha::AdvancedEditorMacro->new_from_api( $c->validation->param('body') );
+        my $macro = Koha::AdvancedEditorMacro->new_from_api( $body );
         $macro->store->discard_changes;
         $c->res->headers->location( $c->req->url->to_string . '/' . $macro->id );
         return $c->render(
@@ -148,12 +150,14 @@ Controller function that handles adding a new shared Koha::AdvancedEditorMacro o
 sub add_shared {
     my $c = shift->openapi->valid_input or return;
 
-    unless( defined $c->validation->param('body')->{shared} && $c->validation->param('body')->{shared} == 1 ){
+    my $body = $c->req->json;
+
+    unless( defined $body->{shared} && $body->{shared} == 1 ){
         return $c->render( status  => 403,
                            openapi => { error => "To create private macros you must use advancededitor" } );
     }
     return try {
-        my $macro = Koha::AdvancedEditorMacro->new_from_api( $c->validation->param('body') );
+        my $macro = Koha::AdvancedEditorMacro->new_from_api( $body );
         $macro->store->discard_changes;
         $c->res->headers->location( $c->req->url->to_string . '/' . $macro->id );
         return $c->render(
@@ -175,7 +179,7 @@ Controller function that handles updating a Koha::AdvancedEditorMacro object
 sub update {
     my $c = shift->openapi->valid_input or return;
 
-    my $macro = Koha::AdvancedEditorMacros->find( $c->validation->param('advancededitormacro_id') );
+    my $macro = Koha::AdvancedEditorMacros->find( $c->param('advancededitormacro_id') );
 
     if ( not defined $macro ) {
         return $c->render( status  => 404,
@@ -183,7 +187,9 @@ sub update {
     }
     my $patron = $c->stash('koha.user');
 
-    if( $macro->shared == 1 || defined $c->validation->param('body')->{shared} && $c->validation->param('body')->{shared} == 1 ){
+    my $body = $c->req->json;
+
+    if( $macro->shared == 1 || defined $body->{shared} && $body->{shared} == 1 ){
         return $c->render( status  => 403,
                            openapi => { error => "To update a macro as shared you must use the advanced_editor/macros/shared endpoint" } );
     } else {
@@ -194,8 +200,7 @@ sub update {
     }
 
     return try {
-        my $params = $c->req->json;
-        $macro->set_from_api( $params );
+        $macro->set_from_api( $body );
         $macro->store->discard_changes;
         return $c->render( status => 200, openapi => $macro->to_api );
     }
@@ -213,21 +218,22 @@ Controller function that handles updating a shared Koha::AdvancedEditorMacro obj
 sub update_shared {
     my $c = shift->openapi->valid_input or return;
 
-    my $macro = Koha::AdvancedEditorMacros->find( $c->validation->param('advancededitormacro_id') );
+    my $macro = Koha::AdvancedEditorMacros->find( $c->param('advancededitormacro_id') );
+
+    my $body = $c->req->json;
 
     if ( not defined $macro ) {
         return $c->render( status  => 404,
                            openapi => { error => "Object not found" } );
     }
 
-    unless( $macro->shared == 1 || defined $c->validation->param('body')->{shared} && $c->validation->param('body')->{shared} == 1 ){
+    unless( $macro->shared == 1 || defined $body->{shared} && $body->{shared} == 1 ){
         return $c->render( status  => 403,
                            openapi => { error => "You can only update shared macros using this endpoint" } );
     }
 
     return try {
-        my $params = $c->req->json;
-        $macro->set_from_api( $params );
+        $macro->set_from_api( $body );
         $macro->store->discard_changes;
         return $c->render( status => 200, openapi => $macro->to_api );
     }
@@ -245,7 +251,7 @@ Controller function that handles deleting a Koha::AdvancedEditorMacro object
 sub delete {
     my $c = shift->openapi->valid_input or return;
 
-    my $macro = Koha::AdvancedEditorMacros->find( $c->validation->param('advancededitormacro_id') );
+    my $macro = Koha::AdvancedEditorMacros->find( $c->param('advancededitormacro_id') );
     if ( not defined $macro ) {
         return $c->render( status  => 404,
                            openapi => { error => "Object not found" } );
@@ -280,7 +286,7 @@ Controller function that handles deleting a shared Koha::AdvancedEditorMacro obj
 sub delete_shared {
     my $c = shift->openapi->valid_input or return;
 
-    my $macro = Koha::AdvancedEditorMacros->find( $c->validation->param('advancededitormacro_id') );
+    my $macro = Koha::AdvancedEditorMacros->find( $c->param('advancededitormacro_id') );
     if ( not defined $macro ) {
         return $c->render( status  => 404,
                            openapi => { error => "Object not found" } );
diff --git a/Koha/REST/V1/ArticleRequests.pm b/Koha/REST/V1/ArticleRequests.pm
index af6884174e..4419bca673 100644
--- a/Koha/REST/V1/ArticleRequests.pm
+++ b/Koha/REST/V1/ArticleRequests.pm
@@ -42,7 +42,7 @@ Controller function that handles cancelling a Koha::ArticleRequest object
 sub cancel {
     my $c = shift->openapi->valid_input or return;
 
-    my $article_request = Koha::ArticleRequests->find( $c->validation->param('article_request_id') );
+    my $article_request = Koha::ArticleRequests->find( $c->param('article_request_id') );
 
     unless ( $article_request ) {
         return $c->render(
@@ -51,8 +51,8 @@ sub cancel {
         );
     }
 
-    my $reason = $c->validation->param('cancellation_reason');
-    my $notes  = $c->validation->param('notes');
+    my $reason = $c->param('cancellation_reason');
+    my $notes  = $c->param('notes');
 
     return try {
 
@@ -80,7 +80,7 @@ Controller function that handles cancelling a patron's Koha::ArticleRequest obje
 sub patron_cancel {
     my $c = shift->openapi->valid_input or return;
 
-    my $patron = Koha::Patrons->find( $c->validation->param('patron_id') );
+    my $patron = Koha::Patrons->find( $c->param('patron_id') );
 
     unless ( $patron ) {
         return $c->render(
@@ -91,7 +91,7 @@ sub patron_cancel {
 
     # patron_id has been validated by the allow-owner check, so the following call to related
     # article requests covers the case of article requests not belonging to the patron
-    my $article_request = $patron->article_requests->find( $c->validation->param('article_request_id') );
+    my $article_request = $patron->article_requests->find( $c->param('article_request_id') );
 
     unless ( $article_request ) {
         return $c->render(
@@ -100,8 +100,8 @@ sub patron_cancel {
         );
     }
 
-    my $reason = $c->validation->param('cancellation_reason');
-    my $notes  = $c->validation->param('notes');
+    my $reason = $c->param('cancellation_reason');
+    my $notes  = $c->param('notes');
 
     return try {
 
diff --git a/Koha/REST/V1/Auth/Identity/Provider/Domains.pm b/Koha/REST/V1/Auth/Identity/Provider/Domains.pm
index 0cdc7ec140..8ab5304a92 100644
--- a/Koha/REST/V1/Auth/Identity/Provider/Domains.pm
+++ b/Koha/REST/V1/Auth/Identity/Provider/Domains.pm
@@ -44,8 +44,7 @@ sub list {
     my $c = shift->openapi->valid_input or return;
 
     return try {
-        my $identity_provider_id = $c->validation->param('identity_provider_id');
-        my $provider         = Koha::Auth::Identity::Providers->find($identity_provider_id);
+        my $provider = Koha::Auth::Identity::Providers->find( $c->param('identity_provider_id') );
 
         unless ($provider) {
             return $c->render(
@@ -78,8 +77,7 @@ sub get {
 
     return try {
 
-        my $identity_provider_id = $c->validation->param('identity_provider_id');
-        my $provider         = Koha::Auth::Identity::Providers->find($identity_provider_id);
+        my $provider = Koha::Auth::Identity::Providers->find( $c->param('identity_provider_id') );
 
         unless ($provider) {
             return $c->render(
@@ -93,8 +91,7 @@ sub get {
 
         my $domains_rs = $provider->domains;
 
-        my $identity_provider_domain_id = $c->validation->param('identity_provider_domain_id');
-        my $domain                  = $c->objects->find( $domains_rs, $identity_provider_domain_id );
+        my $domain = $c->objects->find( $domains_rs, $c->param('identity_provider_domain_id') );
 
         unless ($domain) {
             return $c->render(
@@ -122,8 +119,8 @@ sub add {
     my $c = shift->openapi->valid_input or return;
 
     return try {
-        my $params = $c->validation->param('body');
-        $params->{identity_provider_id} = $c->validation->param('identity_provider_id');
+        my $params = $c->req->json;
+        $params->{identity_provider_id} = $c->param('identity_provider_id');
         Koha::Database->new->schema->txn_do(
             sub {
                 my $domain = Koha::Auth::Identity::Provider::Domain->new_from_api( $params );
@@ -160,11 +157,12 @@ Controller method for updating an identity provider domain.
 sub update {
     my $c = shift->openapi->valid_input or return;
 
-    my $identity_provider_id        = $c->validation->param('identity_provider_id');
-    my $identity_provider_domain_id = $c->validation->param('identity_provider_domain_id');
-
     my $domain = Koha::Auth::Identity::Provider::Domains->find(
-        { identity_provider_id => $identity_provider_id, identity_provider_domain_id => $identity_provider_domain_id } );
+        {
+            identity_provider_id        => $c->param('identity_provider_id'),
+            identity_provider_domain_id => $c->param('identity_provider_domain_id')
+        }
+    );
 
     unless ($domain) {
         return $c->render(
@@ -181,7 +179,7 @@ sub update {
         Koha::Database->new->schema->txn_do(
             sub {
 
-                $domain->set_from_api( $c->validation->param('body') );
+                $domain->set_from_api( $c->req->json );
                 $domain->store->discard_changes;
 
                 return $c->render(
@@ -204,11 +202,12 @@ Controller method for deleting an identity provider.
 sub delete {
     my $c = shift->openapi->valid_input or return;
 
-    my $identity_provider_id        = $c->validation->param('identity_provider_id');
-    my $identity_provider_domain_id = $c->validation->param('identity_provider_domain_id');
-
     my $domain = Koha::Auth::Identity::Provider::Domains->find(
-        { identity_provider_id => $identity_provider_id, identity_provider_domain_id => $identity_provider_domain_id } );
+        {
+            identity_provider_id        => $c->param('identity_provider_id'),
+            identity_provider_domain_id => $c->param('identity_provider_domain_id')
+        }
+    );
 
     unless ($domain) {
         return $c->render(
diff --git a/Koha/REST/V1/Auth/Identity/Providers.pm b/Koha/REST/V1/Auth/Identity/Providers.pm
index fd8a80fae4..aeefb0320e 100644
--- a/Koha/REST/V1/Auth/Identity/Providers.pm
+++ b/Koha/REST/V1/Auth/Identity/Providers.pm
@@ -66,8 +66,7 @@ sub get {
 
     return try {
 
-        my $identity_provider_id = $c->validation->param('identity_provider_id');
-        my $provider = $c->objects->find( Koha::Auth::Identity::Providers->new, $identity_provider_id );
+        my $provider = $c->objects->find( Koha::Auth::Identity::Providers->new, $c->param('identity_provider_id') );
 
         unless ( $provider ) {
             return $c->render(
@@ -100,7 +99,7 @@ sub add {
         Koha::Database->new->schema->txn_do(
             sub {
 
-                my $body = $c->validation->param('body');
+                my $body = $c->req->json;
 
                 my $config   = delete $body->{config};
                 my $mapping  = delete $body->{mapping};
@@ -147,8 +146,7 @@ Controller method for updating an identity provider.
 sub update {
     my $c = shift->openapi->valid_input or return;
 
-    my $identity_provider_id = $c->validation->param('identity_provider_id');
-    my $provider = Koha::Auth::Identity::Providers->find( $identity_provider_id );
+    my $provider = Koha::Auth::Identity::Providers->find( $c->param('identity_provider_id') );
 
     unless ( $provider ) {
         return $c->render(
@@ -165,7 +163,7 @@ sub update {
         Koha::Database->new->schema->txn_do(
             sub {
 
-                my $body = $c->validation->param('body');
+                my $body = $c->req->json;
 
                 my $config   = delete $body->{config};
                 my $mapping  = delete $body->{mapping};
@@ -211,7 +209,7 @@ Controller method for deleting an identity provider.
 sub delete {
     my $c = shift->openapi->valid_input or return;
 
-    my $provider = Koha::Auth::Identity::Providers->find( $c->validation->param('identity_provider_id') );
+    my $provider = Koha::Auth::Identity::Providers->find( $c->param('identity_provider_id') );
     unless ( $provider ) {
         return $c->render(
             status  => 404,
diff --git a/Koha/REST/V1/Auth/Password.pm b/Koha/REST/V1/Auth/Password.pm
index 9c99fd230c..6ed7073921 100644
--- a/Koha/REST/V1/Auth/Password.pm
+++ b/Koha/REST/V1/Auth/Password.pm
@@ -40,7 +40,7 @@ Controller method that checks a patron's password
 
 sub validate {
     my $c = shift->openapi->valid_input or return;
-    my $body   = $c->validation->param('body');
+    my $body   = $c->req->json;
     my $userid = $body->{userid} // '';
     my $patron = Koha::Patrons->find({ userid => $userid });
 
diff --git a/Koha/REST/V1/AuthorisedValues.pm b/Koha/REST/V1/AuthorisedValues.pm
index 56ce3277e6..3a4706f668 100644
--- a/Koha/REST/V1/AuthorisedValues.pm
+++ b/Koha/REST/V1/AuthorisedValues.pm
@@ -36,9 +36,7 @@ This routine returns the authorised values for a given category
 sub list_av_from_category {
     my $c = shift->openapi->valid_input or return;
 
-    my $category_name = $c->validation->param('authorised_value_category_name');
-
-    my $category = Koha::AuthorisedValueCategories->find($category_name);
+    my $category = Koha::AuthorisedValueCategories->find($c->param('authorised_value_category_name'));
 
     unless ($category) {
         return $c->render(
diff --git a/Koha/REST/V1/Authorities.pm b/Koha/REST/V1/Authorities.pm
index 52244d025d..a671c81d1c 100644
--- a/Koha/REST/V1/Authorities.pm
+++ b/Koha/REST/V1/Authorities.pm
@@ -40,7 +40,7 @@ Controller function that handles retrieving a single authority object
 sub get {
     my $c = shift->openapi->valid_input or return;
 
-    my $authority = Koha::Authorities->find( { authid => $c->validation->param('authority_id') } );
+    my $authority = Koha::Authorities->find( { authid => $c->param('authority_id') } );
     unless ( $authority ) {
         return $c->render(
             status  => 404,
@@ -109,7 +109,7 @@ Controller function that handles deleting an authority object
 sub delete {
     my $c = shift->openapi->valid_input or return;
 
-    my $authority = Koha::Authorities->find( { authid => $c->validation->param('authority_id') } );
+    my $authority = Koha::Authorities->find( { authid => $c->param('authority_id') } );
 
     if ( not defined $authority ) {
         return $c->render(
@@ -203,7 +203,7 @@ Controller function that handles modifying an authority object
 sub update {
     my $c = shift->openapi->valid_input or return;
 
-    my $authid = $c->validation->param('authority_id');
+    my $authid = $c->param('authority_id');
     my $authority = Koha::Authorities->find( { authid => $authid } );
 
     if ( not defined $authority ) {
diff --git a/Koha/REST/V1/BackgroundJobs.pm b/Koha/REST/V1/BackgroundJobs.pm
index 4db1ea3f3f..eb672dbc9c 100644
--- a/Koha/REST/V1/BackgroundJobs.pm
+++ b/Koha/REST/V1/BackgroundJobs.pm
@@ -38,7 +38,8 @@ sub list {
 
     return try {
 
-        my $only_current = delete $c->validation->output->{only_current};
+        my $only_current = $c->param('only_current');
+        $c->req->params->remove('only_current');
 
         my $bj_rs = Koha::BackgroundJobs->new;
 
@@ -66,7 +67,7 @@ sub get {
 
     return try {
 
-        my $job_id = $c->validation->param('job_id');
+        my $job_id = $c->param('job_id');
         my $patron = $c->stash('koha.user');
 
         my $can_manage_background_jobs =
diff --git a/Koha/REST/V1/Biblios.pm b/Koha/REST/V1/Biblios.pm
index ca58870e3d..eef084bc2c 100644
--- a/Koha/REST/V1/Biblios.pm
+++ b/Koha/REST/V1/Biblios.pm
@@ -53,7 +53,7 @@ sub get {
     $attributes = { prefetch => [ 'metadata' ] } # don't prefetch metadata if not needed
         unless $c->req->headers->accept =~ m/application\/json/;
 
-    my $biblio = Koha::Biblios->find( { biblionumber => $c->validation->param('biblio_id') }, $attributes );
+    my $biblio = Koha::Biblios->find( { biblionumber => $c->param('biblio_id') }, $attributes );
 
     unless ( $biblio ) {
         return $c->render(
@@ -125,7 +125,7 @@ Controller function that handles deleting a biblio object
 sub delete {
     my $c = shift->openapi->valid_input or return;
 
-    my $biblio = Koha::Biblios->find( $c->validation->param('biblio_id') );
+    my $biblio = Koha::Biblios->find( $c->param('biblio_id') );
 
     if ( not defined $biblio ) {
         return $c->render(
@@ -162,7 +162,7 @@ sub get_public {
     my $c = shift->openapi->valid_input or return;
 
     my $biblio = Koha::Biblios->find(
-        { biblionumber => $c->validation->param('biblio_id') },
+        { biblionumber => $c->param('biblio_id') },
         { prefetch     => ['metadata'] } );
 
     unless ($biblio) {
@@ -255,7 +255,7 @@ Controller function that handles retrieving biblio's items
 sub get_items {
     my $c = shift->openapi->valid_input or return;
 
-    my $biblio = Koha::Biblios->find( { biblionumber => $c->validation->param('biblio_id') }, { prefetch => ['items'] } );
+    my $biblio = Koha::Biblios->find( { biblionumber => $c->param('biblio_id') }, { prefetch => ['items'] } );
 
     unless ( $biblio ) {
         return $c->render(
@@ -268,8 +268,7 @@ sub get_items {
 
     return try {
 
-        my $items_rs = $biblio->items;
-        my $items    = $c->objects->search( $items_rs );
+        my $items = $c->objects->search( $biblio->items );
         return $c->render(
             status  => 200,
             openapi => $items
@@ -290,7 +289,7 @@ sub add_item {
     my $c = shift->openapi->valid_input or return;
 
     try {
-        my $biblio_id = $c->validation->param('biblio_id');
+        my $biblio_id = $c->param('biblio_id');
         my $biblio    = Koha::Biblios->find( $biblio_id );
 
         unless ($biblio) {
@@ -300,7 +299,7 @@ sub add_item {
             );
         }
 
-        my $body = $c->validation->param('body');
+        my $body = $c->req->json;
 
         $body->{biblio_id} = $biblio_id;
 
@@ -403,9 +402,9 @@ sub update_item {
     my $c = shift->openapi->valid_input or return;
 
     try {
-        my $biblio_id = $c->validation->param('biblio_id');
-        my $item_id = $c->validation->param('item_id');
-        my $biblio = Koha::Biblios->find({ biblionumber => $biblio_id });
+        my $biblio_id = $c->param('biblio_id');
+        my $item_id   = $c->param('item_id');
+        my $biblio    = Koha::Biblios->find( { biblionumber => $biblio_id } );
         unless ($biblio) {
             return $c->render(
                 status  => 404,
@@ -422,7 +421,7 @@ sub update_item {
             );
         }
 
-        my $body = $c->validation->param('body');
+        my $body = $c->req->json;
 
         $body->{biblio_id} = $biblio_id;
 
@@ -458,10 +457,11 @@ List Koha::Checkout objects
 sub get_checkouts {
     my $c = shift->openapi->valid_input or return;
 
-    my $checked_in = delete $c->validation->output->{checked_in};
+    my $checked_in = $c->param('checked_in');
+    $c->req->params->remove('checked_in');
 
     try {
-        my $biblio = Koha::Biblios->find( $c->validation->param('biblio_id') );
+        my $biblio = Koha::Biblios->find( $c->param('biblio_id') );
 
         unless ($biblio) {
             return $c->render(
@@ -495,8 +495,7 @@ used for building the dropdown selector
 sub pickup_locations {
     my $c = shift->openapi->valid_input or return;
 
-    my $biblio_id = $c->validation->param('biblio_id');
-    my $biblio = Koha::Biblios->find( $biblio_id );
+    my $biblio = Koha::Biblios->find( $c->param('biblio_id') );
 
     unless ($biblio) {
         return $c->render(
@@ -505,8 +504,8 @@ sub pickup_locations {
         );
     }
 
-    my $patron_id = delete $c->validation->output->{patron_id};
-    my $patron    = Koha::Patrons->find( $patron_id );
+    my $patron = Koha::Patrons->find( $c->param('patron_id') );
+    $c->req->params->remove('patron_id');
 
     unless ($patron) {
         return $c->render(
@@ -562,7 +561,10 @@ access.
 sub get_items_public {
     my $c = shift->openapi->valid_input or return;
 
-    my $biblio = Koha::Biblios->find( { biblionumber => $c->validation->param('biblio_id') }, { prefetch => ['items'] } );
+    my $biblio = Koha::Biblios->find(
+        $c->param('biblio_id'),
+        { prefetch => ['items'] }
+    );
 
     unless ( $biblio ) {
         return $c->render(
@@ -599,7 +601,7 @@ Set rating for the logged in user
 sub set_rating {
     my $c = shift->openapi->valid_input or return;
 
-    my $biblio = Koha::Biblios->find( $c->validation->param('biblio_id') );
+    my $biblio = Koha::Biblios->find( $c->param('biblio_id') );
 
     unless ($biblio) {
         return $c->render(
@@ -619,7 +621,7 @@ sub set_rating {
         );
     }
 
-    my $body   = $c->validation->param('body');
+    my $body         = $c->req->json;
     my $rating_value = $body->{rating};
 
     return try {
@@ -733,8 +735,7 @@ Controller function that handles modifying an biblio object
 sub update {
     my $c = shift->openapi->valid_input or return;
 
-    my $biblio_id = $c->param('biblio_id');
-    my $biblio    = Koha::Biblios->find($biblio_id);
+    my $biblio = Koha::Biblios->find( $c->param('biblio_id') );
 
     if ( ! defined $biblio ) {
         return $c->render(
@@ -776,11 +777,11 @@ sub update {
             );
         }
 
-        ModBiblio( $record, $biblio_id, $frameworkcode );
+        ModBiblio( $record, $biblio->id, $frameworkcode );
 
         $c->render(
             status  => 200,
-            openapi => { id => $biblio_id }
+            openapi => { id => $biblio->id }
         );
     }
     catch {
diff --git a/Koha/REST/V1/Biblios/ItemGroups.pm b/Koha/REST/V1/Biblios/ItemGroups.pm
index b81eee7620..c38de5251e 100644
--- a/Koha/REST/V1/Biblios/ItemGroups.pm
+++ b/Koha/REST/V1/Biblios/ItemGroups.pm
@@ -42,9 +42,8 @@ Controller function that handles listing Koha::Biblio::ItemGroup objects
 
 sub list {
     my $c = shift->openapi->valid_input or return;
-    my $biblio_id = $c->validation->param('biblio_id');
 
-    my $biblio=Koha::Biblios->find( $biblio_id);
+    my $biblio = Koha::Biblios->find( $c->param('biblio_id') );
 
     return try {
 #my $item_groups_set = Koha::Biblio::ItemGroups->new;
@@ -70,8 +69,8 @@ sub get {
     my $c = shift->openapi->valid_input or return;
 
     try {
-        my $item_group_id = $c->validation->param('item_group_id');
-        my $biblio_id = $c->validation->param('biblio_id');
+        my $item_group_id = $c->param('item_group_id');
+        my $biblio_id     = $c->param('biblio_id');
 
         my $item_group = $c->objects->find( Koha::Biblio::ItemGroups->new, $item_group_id );
 
@@ -154,8 +153,8 @@ sub update {
     my $c = shift->openapi->valid_input or return;
 
     return try {
-        my $item_group_id = $c->validation->param('item_group_id');
-        my $biblio_id     = $c->validation->param('biblio_id');
+        my $item_group_id = $c->param('item_group_id');
+        my $biblio_id     = $c->param('biblio_id');
 
         my $item_group = Koha::Biblio::ItemGroups->find( $item_group_id );
 
@@ -168,7 +167,7 @@ sub update {
             );
         }
 
-        my $item_group_data = $c->validation->param('body');
+        my $item_group_data = $c->req->json;
         $item_group->set_from_api( $item_group_data )->store->discard_changes();
 
         return $c->render(
@@ -204,11 +203,12 @@ sub delete {
 
     my $c = shift->openapi->valid_input or return;
 
-    my $item_group_id = $c->validation->param('item_group_id');
-    my $biblio_id     = $c->validation->param('biblio_id');
-
     my $item_group = Koha::Biblio::ItemGroups->find(
-        { item_group_id => $item_group_id, biblio_id => $biblio_id } );
+        {
+            item_group_id => $c->param('item_group_id'),
+            biblio_id     => $c->param('biblio_id')
+        }
+    );
 
     if ( not defined $item_group ) {
         return $c->render(
diff --git a/Koha/REST/V1/Biblios/ItemGroups/Items.pm b/Koha/REST/V1/Biblios/ItemGroups/Items.pm
index a946e5fefc..c241962207 100644
--- a/Koha/REST/V1/Biblios/ItemGroups/Items.pm
+++ b/Koha/REST/V1/Biblios/ItemGroups/Items.pm
@@ -43,9 +43,7 @@ sub add {
 
     return try {
 
-        my $item_group = Koha::Biblio::ItemGroups->find(
-            $c->validation->param('item_group_id')
-        );
+        my $item_group = Koha::Biblio::ItemGroups->find( $c->param('item_group_id') );
 
         unless ( $item_group ) {
             return $c->render(
@@ -56,7 +54,7 @@ sub add {
             );
         }
 
-        unless ( $item_group->biblio_id eq $c->validation->param('biblio_id') ) {
+        unless ( $item_group->biblio_id eq $c->param('biblio_id') ) {
             return $c->render(
                 status  => 409,
                 openapi => {
@@ -66,7 +64,7 @@ sub add {
         }
 
         # All good, add the item
-        my $body    = $c->validation->param('body');
+        my $body    = $c->req->json;
         my $item_id = $body->{item_id};
 
         $item_group->add_item({ item_id => $item_id });
@@ -125,8 +123,8 @@ Controller function that handles unlinking an item from a Koha::Biblio::ItemGrou
 sub delete {
     my $c = shift->openapi->valid_input or return;
 
-    my $item_group_id = $c->validation->param('item_group_id');
-    my $item_id       = $c->validation->param('item_id');
+    my $item_group_id = $c->param('item_group_id');
+    my $item_id       = $c->param('item_id');
 
     my $item_link = Koha::Biblio::ItemGroup::Items->find(
         {
diff --git a/Koha/REST/V1/CashRegisters/Cashups.pm b/Koha/REST/V1/CashRegisters/Cashups.pm
index 12b6f30214..f3cf06dae7 100644
--- a/Koha/REST/V1/CashRegisters/Cashups.pm
+++ b/Koha/REST/V1/CashRegisters/Cashups.pm
@@ -40,11 +40,7 @@ Controller function that handles retrieving a cash registers cashup actions
 sub list {
     my $c = shift->openapi->valid_input or return;
 
-    my $register = Koha::Cash::Registers->find(
-        {
-            id => $c->validation->param('cash_register_id')
-        }
-    );
+    my $register = Koha::Cash::Registers->find( $c->param('cash_register_id') );
 
     unless ($register) {
         return $c->render(
@@ -56,8 +52,7 @@ sub list {
     }
 
     return try {
-        my $cashups_rs = $register->cashups;
-        my $cashups    = $c->objects->search($cashups_rs);
+        my $cashups = $c->objects->search( $register->cashups );
         return $c->render( status => 200, openapi => $cashups );
     }
     catch {
@@ -75,8 +70,7 @@ sub get {
     my $c = shift->openapi->valid_input or return;
 
     return try {
-        my $cashup = Koha::Cash::Register::Cashups->find(
-            $c->validation->param('cashup_id') );
+        my $cashup = Koha::Cash::Register::Cashups->find( $c->param('cashup_id') );
         unless ($cashup) {
             return $c->render(
                 status  => 404,
diff --git a/Koha/REST/V1/Checkouts.pm b/Koha/REST/V1/Checkouts.pm
index bf5b2d5153..e94d027e49 100644
--- a/Koha/REST/V1/Checkouts.pm
+++ b/Koha/REST/V1/Checkouts.pm
@@ -46,7 +46,8 @@ List Koha::Checkout objects
 sub list {
     my $c = shift->openapi->valid_input or return;
 
-    my $checked_in = delete $c->validation->output->{checked_in};
+    my $checked_in = $c->param('checked_in');
+    $c->req->params->remove('checked_in');
 
     try {
         my $checkouts_set;
@@ -77,7 +78,7 @@ get one checkout
 sub get {
     my $c = shift->openapi->valid_input or return;
 
-    my $checkout_id = $c->validation->param('checkout_id');
+    my $checkout_id = $c->param('checkout_id');
     my $checkout = Koha::Checkouts->find( $checkout_id );
     $checkout = Koha::Old::Checkouts->find( $checkout_id )
         unless ($checkout);
@@ -293,7 +294,7 @@ sub get_renewals {
     my $c = shift->openapi->valid_input or return;
 
     try {
-        my $checkout_id = $c->validation->param('checkout_id');
+        my $checkout_id = $c->param('checkout_id');
         my $checkout    = Koha::Checkouts->find($checkout_id);
         $checkout = Koha::Old::Checkouts->find($checkout_id)
           unless ($checkout);
@@ -328,8 +329,8 @@ Renew a checkout
 sub renew {
     my $c = shift->openapi->valid_input or return;
 
-    my $checkout_id = $c->validation->param('checkout_id');
-    my $seen = $c->validation->param('seen') || 1;
+    my $checkout_id = $c->param('checkout_id');
+    my $seen = $c->param('seen') || 1;
     my $checkout = Koha::Checkouts->find( $checkout_id );
 
     unless ($checkout) {
@@ -379,7 +380,7 @@ Checks if the checkout could be renewed and return the related information.
 sub allows_renewal {
     my $c = shift->openapi->valid_input or return;
 
-    my $checkout_id = $c->validation->param('checkout_id');
+    my $checkout_id = $c->param('checkout_id');
     my $checkout = Koha::Checkouts->find( $checkout_id );
 
     unless ($checkout) {
diff --git a/Koha/REST/V1/Cities.pm b/Koha/REST/V1/Cities.pm
index 3dfc91d56f..fccb013b24 100644
--- a/Koha/REST/V1/Cities.pm
+++ b/Koha/REST/V1/Cities.pm
@@ -35,8 +35,7 @@ sub list {
     my $c = shift->openapi->valid_input or return;
 
     return try {
-        my $cities_set = Koha::Cities->new;
-        my $cities = $c->objects->search( $cities_set );
+        my $cities = $c->objects->search( Koha::Cities->new );
         return $c->render( status => 200, openapi => $cities );
     }
     catch {
@@ -53,7 +52,7 @@ sub get {
     my $c = shift->openapi->valid_input or return;
 
     return try {
-        my $city = Koha::Cities->find( $c->validation->param('city_id') );
+        my $city = Koha::Cities->find( $c->param('city_id') );
         unless ($city) {
             return $c->render( status  => 404,
                             openapi => { error => "City not found" } );
@@ -74,7 +73,7 @@ sub add {
     my $c = shift->openapi->valid_input or return;
 
     return try {
-        my $city = Koha::City->new_from_api( $c->validation->param('body') );
+        my $city = Koha::City->new_from_api( $c->req->json );
         $city->store;
         $c->res->headers->location( $c->req->url->to_string . '/' . $city->cityid );
         return $c->render(
@@ -94,7 +93,7 @@ sub add {
 sub update {
     my $c = shift->openapi->valid_input or return;
 
-    my $city = Koha::Cities->find( $c->validation->param('city_id') );
+    my $city = Koha::Cities->find( $c->param('city_id') );
 
     if ( not defined $city ) {
         return $c->render( status  => 404,
@@ -102,7 +101,7 @@ sub update {
     }
 
     return try {
-        $city->set_from_api( $c->validation->param('body') );
+        $city->set_from_api( $c->req->json );
         $city->store();
         return $c->render( status => 200, openapi => $city->to_api );
     }
@@ -118,7 +117,7 @@ sub update {
 sub delete {
     my $c = shift->openapi->valid_input or return;
 
-    my $city = Koha::Cities->find( $c->validation->param('city_id') );
+    my $city = Koha::Cities->find( $c->param('city_id') );
     if ( not defined $city ) {
         return $c->render( status  => 404,
                            openapi => { error => "Object not found" } );
diff --git a/Koha/REST/V1/Clubs/Holds.pm b/Koha/REST/V1/Clubs/Holds.pm
index 7af5602a81..d2111f9cee 100644
--- a/Koha/REST/V1/Clubs/Holds.pm
+++ b/Koha/REST/V1/Clubs/Holds.pm
@@ -44,8 +44,8 @@ sub add {
     my $c = shift->openapi->valid_input or return;
 
     return try {
-        my $body    = $c->validation->param('body');
-        my $club_id = $c->validation->param('club_id');
+        my $body    = $c->req->json;
+        my $club_id = $c->param('club_id');
 
         my $biblio;
 
diff --git a/Koha/REST/V1/Config/SMTP/Servers.pm b/Koha/REST/V1/Config/SMTP/Servers.pm
index 5949c535f4..c5974e929a 100644
--- a/Koha/REST/V1/Config/SMTP/Servers.pm
+++ b/Koha/REST/V1/Config/SMTP/Servers.pm
@@ -59,7 +59,7 @@ sub get {
     my $c = shift->openapi->valid_input or return;
 
     return try {
-        my $smtp_server = Koha::SMTP::Servers->find( $c->validation->param('smtp_server_id') );
+        my $smtp_server = Koha::SMTP::Servers->find( $c->param('smtp_server_id') );
 
         unless ($smtp_server) {
             return $c->render(
@@ -93,7 +93,7 @@ sub add {
 
     return try {
 
-        my $smtp_server = Koha::SMTP::Server->new_from_api( $c->validation->param('body') );
+        my $smtp_server = Koha::SMTP::Server->new_from_api( $c->req->json );
         $smtp_server->store->discard_changes;
 
         $c->res->headers->location( $c->req->url->to_string . '/' . $smtp_server->id );
@@ -127,7 +127,7 @@ Controller method that handles updating a Koha::SMTP::Server object
 sub update {
     my $c = shift->openapi->valid_input or return;
 
-    my $smtp_server = Koha::SMTP::Servers->find( $c->validation->param('smtp_server_id') );
+    my $smtp_server = Koha::SMTP::Servers->find( $c->param('smtp_server_id') );
 
     if ( not defined $smtp_server ) {
         return $c->render(
@@ -139,7 +139,7 @@ sub update {
     }
 
     return try {
-        $smtp_server->set_from_api( $c->validation->param('body') );
+        $smtp_server->set_from_api( $c->req->json );
         $smtp_server->store->discard_changes;
 
         return $c->render(
@@ -171,7 +171,7 @@ Controller method that handles deleting a Koha::SMTP::Server object
 sub delete {
     my $c = shift->openapi->valid_input or return;
 
-    my $smtp_server = Koha::SMTP::Servers->find( $c->validation->param('smtp_server_id') );
+    my $smtp_server = Koha::SMTP::Servers->find( $c->param('smtp_server_id') );
 
     if ( not defined $smtp_server ) {
         return $c->render( status  => 404,
diff --git a/Koha/REST/V1/Holds.pm b/Koha/REST/V1/Holds.pm
index a8a998ef12..00f761511d 100644
--- a/Koha/REST/V1/Holds.pm
+++ b/Koha/REST/V1/Holds.pm
@@ -45,8 +45,7 @@ sub list {
     my $c = shift->openapi->valid_input or return;
 
     return try {
-        my $holds_set = Koha::Holds->new;
-        my $holds     = $c->objects->search( $holds_set );
+        my $holds = $c->objects->search( Koha::Holds->new );
         return $c->render( status => 200, openapi => $holds );
     }
     catch {
@@ -64,7 +63,7 @@ sub add {
     my $c = shift->openapi->valid_input or return;
 
     return try {
-        my $body = $c->validation->param('body');
+        my $body = $c->req->json;
 
         my $biblio;
         my $item;
@@ -247,8 +246,7 @@ sub edit {
     my $c = shift->openapi->valid_input or return;
 
     return try {
-        my $hold_id = $c->validation->param('hold_id');
-        my $hold = Koha::Holds->find( $hold_id );
+        my $hold = Koha::Holds->find( $c->param('hold_id') );
 
         unless ($hold) {
             return $c->render(
@@ -260,7 +258,7 @@ sub edit {
         my $overrides = $c->stash('koha.overrides');
         my $can_override = $overrides->{any} && C4::Context->preference('AllowHoldPolicyOverride');
 
-        my $body = $c->validation->output->{body};
+        my $body = $c->req->json;
 
         my $pickup_library_id = $body->{pickup_library_id};
 
@@ -283,7 +281,7 @@ sub edit {
         my $suspended_until = $body->{suspended_until} || $hold->suspend_until;
 
         my $params = {
-            reserve_id    => $hold_id,
+            reserve_id    => $hold->id,
             branchcode    => $pickup_library_id,
             rank          => $priority,
             suspend_until => $suspended_until,
@@ -312,8 +310,7 @@ Method that handles deleting a Koha::Hold object
 sub delete {
     my $c = shift->openapi->valid_input or return;
 
-    my $hold_id = $c->validation->param('hold_id');
-    my $hold    = Koha::Holds->find($hold_id);
+    my $hold = Koha::Holds->find($c->param('hold_id'));
 
     unless ($hold) {
         return $c->render( status => 404, openapi => { error => "Hold not found." } );
@@ -341,9 +338,9 @@ Method that handles suspending a hold
 sub suspend {
     my $c = shift->openapi->valid_input or return;
 
-    my $hold_id  = $c->validation->param('hold_id');
-    my $hold     = Koha::Holds->find($hold_id);
-    my $body     = $c->req->json;
+    my $hold = Koha::Holds->find( $c->param('hold_id') );
+    my $body = $c->req->json;
+
     my $end_date = ($body) ? $body->{end_date} : undef;
 
     unless ($hold) {
@@ -381,9 +378,8 @@ Method that handles resuming a hold
 sub resume {
     my $c = shift->openapi->valid_input or return;
 
-    my $hold_id = $c->validation->param('hold_id');
-    my $hold    = Koha::Holds->find($hold_id);
-    my $body    = $c->req->json;
+    my $hold = Koha::Holds->find($c->param('hold_id'));
+    my $body = $c->req->json;
 
     unless ($hold) {
         return $c->render( status => 404, openapi => { error => 'Hold not found.' } );
@@ -407,8 +403,7 @@ Method that handles modifying a Koha::Hold object
 sub update_priority {
     my $c = shift->openapi->valid_input or return;
 
-    my $hold_id = $c->validation->param('hold_id');
-    my $hold = Koha::Holds->find($hold_id);
+    my $hold = Koha::Holds->find($c->param('hold_id'));
 
     unless ($hold) {
         return $c->render(
@@ -421,7 +416,7 @@ sub update_priority {
         my $priority = $c->req->json;
         C4::Reserves::_FixPriority(
             {
-                reserve_id => $hold_id,
+                reserve_id => $hold->id,
                 rank       => $priority
             }
         );
@@ -443,8 +438,7 @@ used for building the dropdown selector
 sub pickup_locations {
     my $c = shift->openapi->valid_input or return;
 
-    my $hold_id = $c->validation->param('hold_id');
-    my $hold = Koha::Holds->find( $hold_id, { prefetch => [ 'patron' ] } );
+    my $hold = Koha::Holds->find( $c->param('hold_id'), { prefetch => [ 'patron' ] } );
 
     unless ($hold) {
         return $c->render(
@@ -509,11 +503,7 @@ Method that handles modifying the pickup location of a Koha::Hold object
 sub update_pickup_location {
     my $c = shift->openapi->valid_input or return;
 
-    my $hold_id = $c->validation->param('hold_id');
-    my $body    = $c->validation->param('body');
-    my $pickup_library_id = $body->{pickup_library_id};
-
-    my $hold = Koha::Holds->find($hold_id);
+    my $hold = Koha::Holds->find($c->param('hold_id'));
 
     unless ($hold) {
         return $c->render(
@@ -522,8 +512,13 @@ sub update_pickup_location {
         );
     }
 
+
     return try {
 
+        my $body = $c->req->json;
+
+        my $pickup_library_id = $body->{pickup_library_id};
+
         my $overrides    = $c->stash('koha.overrides');
         my $can_override = $overrides->{any} && C4::Context->preference('AllowHoldPolicyOverride');
 
@@ -556,5 +551,4 @@ sub update_pickup_location {
     };
 }
 
-
 1;
diff --git a/Koha/REST/V1/Illbackends.pm b/Koha/REST/V1/Illbackends.pm
index 02096db565..8b70d9368e 100644
--- a/Koha/REST/V1/Illbackends.pm
+++ b/Koha/REST/V1/Illbackends.pm
@@ -62,7 +62,7 @@ Get one backend
 sub get {
     my $c = shift->openapi->valid_input;
 
-    my $backend_id = $c->validation->param('ill_backend_id');
+    my $backend_id = $c->param('ill_backend_id');
 
     return try {
 
diff --git a/Koha/REST/V1/ImportBatchProfiles.pm b/Koha/REST/V1/ImportBatchProfiles.pm
index 2da99c6c17..9d951ea399 100644
--- a/Koha/REST/V1/ImportBatchProfiles.pm
+++ b/Koha/REST/V1/ImportBatchProfiles.pm
@@ -44,10 +44,9 @@ sub list {
     my $c = shift->openapi->valid_input or return;
 
     return try {
-        my $profiles_set = Koha::ImportBatchProfiles->new;
-        my $profiles = $c->objects->search( $profiles_set );
+        my $profiles = $c->objects->search( Koha::ImportBatchProfiles->new );
         return $c->render(
-            status => 200,
+            status  => 200,
             openapi => $profiles
         );
     }
@@ -65,7 +64,7 @@ Method that handles adding a new Koha::ImportBatchProfile object
 sub add {
     my $c = shift->openapi->valid_input or return;
 
-    my $body = $c->validation->param('body');
+    my $body = $c->req->json;
 
     return try {
         my $profile = Koha::ImportBatchProfile->new_from_api( $body )->store;
@@ -89,19 +88,18 @@ sub edit {
     my $c = shift->openapi->valid_input or return;
 
     return try {
-        my $profile_id = $c->validation->param('import_batch_profile_id');
-        my $profile = Koha::ImportBatchProfiles->find( $profile_id );
+        my $profile = Koha::ImportBatchProfiles->find( $c->param('import_batch_profile_id') );
         unless ($profile) {
-            return $c->render( status  => 404,
-                            openapi => {error => "Import batch profile not found"} );
+            return $c->render(
+                status  => 404,
+                openapi => {error => "Import batch profile not found"}
+            );
         }
 
-        my $body = $c->req->json;
-
-        $profile->set_from_api($body)->store;
+        $profile->set_from_api($c->req->json)->store;
 
         return $c->render(
-            status => 200,
+            status  => 200,
             openapi => $profile->to_api
         );
     }
@@ -119,8 +117,7 @@ Method that handles deleting a Koha::ImportBatchProfile object
 sub delete {
     my $c = shift->openapi->valid_input or return;
 
-    my $profile_id = $c->validation->param('import_batch_profile_id');
-    my $profile = Koha::ImportBatchProfiles->find( $profile_id );
+    my $profile = Koha::ImportBatchProfiles->find( $c->param('import_batch_profile_id') );
 
     unless ($profile) {
         return $c->render( status  => 404,
diff --git a/Koha/REST/V1/ImportRecordMatches.pm b/Koha/REST/V1/ImportRecordMatches.pm
index b414a091ef..64ffd1f8dd 100644
--- a/Koha/REST/V1/ImportRecordMatches.pm
+++ b/Koha/REST/V1/ImportRecordMatches.pm
@@ -40,9 +40,8 @@ DELETE /api/v1/import_batches/{import_batch_id}/records/{import_record_id}/match
 sub unset_chosen {
     my $c = shift->openapi->valid_input or return;
 
-    my $import_record_id = $c->validation->param('import_record_id');
     my $matches = Koha::Import::Record::Matches->search({
-        import_record_id => $import_record_id,
+        import_record_id => $c->param('import_record_id'),
     });
     unless ($matches) {
         return $c->render(
@@ -72,8 +71,8 @@ Body should contain the condidate_match_id to chose
 sub set_chosen {
     my $c = shift->openapi->valid_input or return;
 
-    my $import_record_id = $c->validation->param('import_record_id');
-    my $body    = $c->validation->param('body');
+    my $import_record_id = $c->param('import_record_id');
+    my $body = $c->req->json;
     my $candidate_match_id = $body->{'candidate_match_id'};
 
     my $match = Koha::Import::Record::Matches->find({
diff --git a/Koha/REST/V1/Items.pm b/Koha/REST/V1/Items.pm
index 52c95f59f5..3079135286 100644
--- a/Koha/REST/V1/Items.pm
+++ b/Koha/REST/V1/Items.pm
@@ -95,7 +95,7 @@ sub get {
 
     try {
         my $items_rs = Koha::Items->new;
-        my $item = $c->objects->find($items_rs, $c->validation->param('item_id'));
+        my $item = $c->objects->find($items_rs, $c->param('item_id'));
         unless ( $item ) {
             return $c->render(
                 status => 404,
@@ -119,7 +119,7 @@ sub delete {
     my $c = shift->openapi->valid_input or return;
 
     return try {
-        my $item = Koha::Items->find($c->validation->param('item_id'));
+        my $item = Koha::Items->find($c->param('item_id'));
         unless ( $item ) {
             return $c->render(
                 status => 404,
@@ -184,7 +184,7 @@ used for building the dropdown selector
 sub pickup_locations {
     my $c = shift->openapi->valid_input or return;
 
-    my $item_id = $c->validation->param('item_id');
+    my $item_id = $c->param('item_id');
     my $item = Koha::Items->find( $item_id );
 
     unless ($item) {
@@ -194,9 +194,11 @@ sub pickup_locations {
         );
     }
 
-    my $patron_id = delete $c->validation->output->{patron_id};
+    my $patron_id = $c->param('patron_id');
     my $patron    = Koha::Patrons->find( $patron_id );
 
+    $c->req->params->remove('patron_id');
+
     unless ($patron) {
         return $c->render(
             status  => 400,
@@ -250,7 +252,7 @@ Controller function that handles bundled_items Koha::Item objects
 sub bundled_items {
     my $c = shift->openapi->valid_input or return;
 
-    my $item_id = $c->validation->param('item_id');
+    my $item_id = $c->param('item_id');
     my $item = Koha::Items->find( $item_id );
 
     unless ($item) {
@@ -282,7 +284,7 @@ Controller function that handles adding items to this bundle
 sub add_to_bundle {
     my $c = shift->openapi->valid_input or return;
 
-    my $item_id = $c->validation->param('item_id');
+    my $item_id = $c->param('item_id');
     my $item = Koha::Items->find( $item_id );
 
     unless ($item) {
@@ -292,7 +294,9 @@ sub add_to_bundle {
         );
     }
 
-    my $bundle_item_id = $c->validation->param('body')->{'external_id'};
+    my $body = $c->req->json;
+
+    my $bundle_item_id = $body->{'external_id'};
     $bundle_item_id = barcodedecode($bundle_item_id);
     my $bundle_item = Koha::Items->find( { barcode => $bundle_item_id } );
 
@@ -304,7 +308,6 @@ sub add_to_bundle {
     }
 
     return try {
-        my $body = $c->validation->param('body');
         my $options = {
             force_checkin => $body->{force_checkin},
             ignore_holds => $body->{ignore_holds},
@@ -386,7 +389,7 @@ Controller function that handles removing items from this bundle
 sub remove_from_bundle {
     my $c = shift->openapi->valid_input or return;
 
-    my $item_id = $c->validation->param('item_id');
+    my $item_id = $c->param('item_id');
     my $item = Koha::Items->find( $item_id );
 
     unless ($item) {
@@ -396,7 +399,7 @@ sub remove_from_bundle {
         );
     }
 
-    my $bundle_item_id = $c->validation->param('bundled_item_id');
+    my $bundle_item_id = $c->param('bundled_item_id');
     $bundle_item_id = barcodedecode($bundle_item_id);
     my $bundle_item = Koha::Items->find( { itemnumber => $bundle_item_id } );
 
diff --git a/Koha/REST/V1/Libraries.pm b/Koha/REST/V1/Libraries.pm
index b6ec20e69d..55aa426974 100644
--- a/Koha/REST/V1/Libraries.pm
+++ b/Koha/REST/V1/Libraries.pm
@@ -44,8 +44,7 @@ sub list {
     my $c = shift->openapi->valid_input or return;
 
     return try {
-        my $libraries_set = Koha::Libraries->new;
-        my $libraries     = $c->objects->search( $libraries_set );
+        my $libraries = $c->objects->search( Koha::Libraries->new );
         return $c->render( status => 200, openapi => $libraries );
     }
     catch {
@@ -63,12 +62,13 @@ sub get {
     my $c = shift->openapi->valid_input or return;
 
     return try {
-        my $library_id = $c->validation->param('library_id');
-        my $library = Koha::Libraries->find( $library_id );
+        my $library = Koha::Libraries->find( $c->param('library_id') );
 
         unless ($library) {
-            return $c->render( status  => 404,
-                            openapi => { error => "Library not found" } );
+            return $c->render(
+                status  => 404,
+                openapi => { error => "Library not found" }
+            );
         }
 
         return $c->render(
@@ -91,7 +91,7 @@ sub add {
     my $c = shift->openapi->valid_input or return;
 
     return try {
-        my $library = Koha::Library->new_from_api( $c->validation->param('body') );
+        my $library = Koha::Library->new_from_api( $c->req->json );
         $library->store;
         $c->res->headers->location( $c->req->url->to_string . '/' . $library->branchcode );
 
@@ -121,7 +121,7 @@ Controller function that handles updating a Koha::Library object
 sub update {
     my $c = shift->openapi->valid_input or return;
 
-    my $library = Koha::Libraries->find( $c->validation->param('library_id') );
+    my $library = Koha::Libraries->find( $c->param('library_id') );
 
     if ( not defined $library ) {
         return $c->render(
@@ -154,7 +154,7 @@ sub delete {
 
     my $c = shift->openapi->valid_input or return;
 
-    my $library = Koha::Libraries->find( $c->validation->param( 'library_id' ) );
+    my $library = Koha::Libraries->find( $c->param( 'library_id' ) );
 
     if ( not defined $library ) {
         return $c->render( status => 404, openapi => { error => "Library not found" } );
diff --git a/Koha/REST/V1/OAuth.pm b/Koha/REST/V1/OAuth.pm
index 922134ddc7..f11e065e60 100644
--- a/Koha/REST/V1/OAuth.pm
+++ b/Koha/REST/V1/OAuth.pm
@@ -49,7 +49,7 @@ sub token {
         return $c->render( status => 400, openapi => { error => 'Unimplemented grant type' } );
     }
 
-    my $grant_type = $c->validation->param('grant_type');
+    my $grant_type = $c->param('grant_type');
     unless ( $grant_type eq 'client_credentials' and C4::Context->preference('RESTOAuth2ClientCredentials') ) {
         return $c->render(status => 400, openapi => {error => 'Unimplemented grant type'});
     }
@@ -70,8 +70,8 @@ sub token {
         ( $client_id, $client_secret ) = split( /:/, $decoded_credentials, 2 );
     }
     else {
-        $client_id = $c->validation->param('client_id');
-        $client_secret = $c->validation->param('client_secret');
+        $client_id = $c->param('client_id');
+        $client_secret = $c->param('client_secret');
     }
 
     my $cb = "${grant_type}_grant";
diff --git a/Koha/REST/V1/Patrons.pm b/Koha/REST/V1/Patrons.pm
index 1852d7ccd2..0e04199b55 100644
--- a/Koha/REST/V1/Patrons.pm
+++ b/Koha/REST/V1/Patrons.pm
@@ -47,7 +47,8 @@ sub list {
     return try {
 
         my $query = {};
-        my $restricted = delete $c->validation->output->{restricted};
+        my $restricted = $c->param('restricted');
+        $c->req->params->remove('restricted');
         $query->{debarred} = { '!=' => undef }
             if $restricted;
 
@@ -74,7 +75,7 @@ sub get {
     my $c = shift->openapi->valid_input or return;
 
     return try {
-        my $patron_id = $c->validation->param('patron_id');
+        my $patron_id = $c->param('patron_id');
         my $patron    = $c->objects->find( Koha::Patrons->search_limited, $patron_id );
 
         unless ($patron) {
@@ -108,7 +109,7 @@ sub add {
         Koha::Database->new->schema->txn_do(
             sub {
 
-                my $body = $c->validation->param('body');
+                my $body = $c->req->json;
 
                 my $extended_attributes = delete $body->{extended_attributes} // [];
 
@@ -225,8 +226,7 @@ Controller function that handles updating a Koha::Patron object
 sub update {
     my $c = shift->openapi->valid_input or return;
 
-    my $patron_id = $c->validation->param('patron_id');
-    my $patron    = Koha::Patrons->find( $patron_id );
+    my $patron = Koha::Patrons->find( $c->param('patron_id') );
 
     unless ($patron) {
          return $c->render(
@@ -236,7 +236,7 @@ sub update {
      }
 
     return try {
-        my $body = $c->validation->param('body');
+        my $body = $c->req->json;
         my $user = $c->stash('koha.user');
 
         if (
@@ -269,7 +269,7 @@ sub update {
             }
         }
 
-        $patron->set_from_api($c->validation->param('body'))->store;
+        $patron->set_from_api($body)->store;
         $patron->discard_changes;
         return $c->render( status => 200, openapi => $patron->to_api );
     }
@@ -341,7 +341,7 @@ Controller function that handles deleting a Koha::Patron object
 sub delete {
     my $c = shift->openapi->valid_input or return;
 
-    my $patron = Koha::Patrons->find( $c->validation->param('patron_id') );
+    my $patron = Koha::Patrons->find( $c->param('patron_id') );
 
     unless ( $patron ) {
         return $c->render(
diff --git a/Koha/REST/V1/Patrons/Account.pm b/Koha/REST/V1/Patrons/Account.pm
index 95c998ad56..2cf643029c 100644
--- a/Koha/REST/V1/Patrons/Account.pm
+++ b/Koha/REST/V1/Patrons/Account.pm
@@ -40,8 +40,7 @@ Controller function that handles retrieving a patron's account balance
 sub get {
     my $c = shift->openapi->valid_input or return;
 
-    my $patron_id = $c->validation->param('patron_id');
-    my $patron    = Koha::Patrons->find($patron_id);
+    my $patron = Koha::Patrons->find( $c->param('patron_id') );
 
     unless ($patron) {
         return $c->render(
@@ -84,8 +83,7 @@ sub get {
 sub list_credits {
     my $c = shift->openapi->valid_input or return;
 
-    my $patron_id = $c->validation->param('patron_id');
-    my $patron    = Koha::Patrons->find($patron_id);
+    my $patron = Koha::Patrons->find( $c->param('patron_id') );
 
     unless ($patron) {
         return $c->render(
@@ -95,10 +93,7 @@ sub list_credits {
     }
 
     return try {
-        my $account = $patron->account;
-
-        my $credits_set = $account->credits;
-        my $credits     = $c->objects->search($credits_set);
+        my $credits = $c->objects->search( $patron->account->credits );
         return $c->render( status => 200, openapi => $credits );
     }
     catch {
@@ -115,9 +110,8 @@ Controller function that handles adding a credit to a patron's account
 sub add_credit {
     my $c = shift->openapi->valid_input or return;
 
-    my $patron_id = $c->validation->param('patron_id');
-    my $patron    = Koha::Patrons->find($patron_id);
-    my $user      = $c->stash('koha.user');
+    my $patron = Koha::Patrons->find( $c->param('patron_id') );
+    my $user   = $c->stash('koha.user');
 
     unless ($patron) {
         return $c->render(
@@ -127,7 +121,7 @@ sub add_credit {
     }
 
     my $account = $patron->account;
-    my $body    = $c->validation->param('body');
+    my $body    = $c->req->json;
 
     return try {
         my $credit_type =
@@ -203,8 +197,7 @@ sub add_credit {
 sub list_debits {
     my $c = shift->openapi->valid_input or return;
 
-    my $patron_id = $c->validation->param('patron_id');
-    my $patron    = Koha::Patrons->find($patron_id);
+    my $patron = Koha::Patrons->find( $c->param('patron_id') );
 
     unless ($patron) {
         return $c->render(
@@ -214,10 +207,7 @@ sub list_debits {
     }
 
     return try {
-        my $account = $patron->account;
-
-        my $debits_set = $account->debits;
-        my $debits     = $c->objects->search($debits_set);
+        my $debits = $c->objects->search( $patron->account->debits );
         return $c->render( status => 200, openapi => $debits );
     }
     catch {
@@ -232,8 +222,7 @@ sub list_debits {
 sub add_debit {
     my $c = shift->openapi->valid_input or return;
 
-    my $patron_id = $c->validation->param('patron_id');
-    my $patron    = Koha::Patrons->find($patron_id);
+    my $patron = Koha::Patrons->find( $c->param('patron_id') );
 
     unless ($patron) {
         return $c->render(
@@ -244,7 +233,7 @@ sub add_debit {
 
     return try {
         my $data =
-          Koha::Account::Debit->new_from_api( $c->validation->param('body') )
+          Koha::Account::Debit->new_from_api( $c->req->json )
           ->unblessed;
 
         $data->{library_id}       = delete $data->{branchcode};
diff --git a/Koha/REST/V1/Patrons/Attributes.pm b/Koha/REST/V1/Patrons/Attributes.pm
index 4095a9220a..3d1e347073 100644
--- a/Koha/REST/V1/Patrons/Attributes.pm
+++ b/Koha/REST/V1/Patrons/Attributes.pm
@@ -43,7 +43,7 @@ to a given patron.
 sub list_patron_attributes {
     my $c = shift->openapi->valid_input or return;
 
-    my $patron = Koha::Patrons->find( $c->validation->param('patron_id') );
+    my $patron = Koha::Patrons->find( $c->param('patron_id') );
 
     unless ($patron) {
         return $c->render(
@@ -56,8 +56,7 @@ sub list_patron_attributes {
 
     return try {
 
-        my $attributes_rs = $patron->extended_attributes;
-        my $attributes    = $c->objects->search($attributes_rs);
+        my $attributes = $c->objects->search( $patron->extended_attributes );
 
         return $c->render(
             status  => 200,
@@ -78,7 +77,7 @@ Controller method that handles adding a Koha::Patron::Attribute to a given patro
 sub add {
     my $c = shift->openapi->valid_input or return;
 
-    my $patron = Koha::Patrons->find( $c->validation->param('patron_id') );
+    my $patron = Koha::Patrons->find( $c->param('patron_id') );
 
     unless ($patron) {
         return $c->render(
@@ -93,7 +92,7 @@ sub add {
 
         my $attribute = $patron->add_extended_attribute(
             Koha::Patron::Attribute->new_from_api( # new_from_api takes care of mapping attributes
-                $c->validation->param('body')
+                $c->req->json
             )->unblessed
         );
 
@@ -150,7 +149,7 @@ Controller method that handles overwriting extended attributes for a given patro
 sub overwrite {
     my $c = shift->openapi->valid_input or return;
 
-    my $patron = Koha::Patrons->find( $c->validation->param('patron_id') );
+    my $patron = Koha::Patrons->find( $c->param('patron_id') );
 
     unless ($patron) {
         return $c->render(
@@ -163,7 +162,7 @@ sub overwrite {
 
     return try {
 
-        my $body = $c->validation->every_param('body');
+        my $body = $c->req->json;
 
         my @attrs;
 
@@ -228,7 +227,7 @@ Controller method that handles updating a single extended patron attribute.
 sub update {
     my $c = shift->openapi->valid_input or return;
 
-    my $patron = Koha::Patrons->find( $c->validation->param('patron_id') );
+    my $patron = Koha::Patrons->find( $c->param('patron_id') );
 
     unless ($patron) {
         return $c->render(
@@ -241,7 +240,7 @@ sub update {
 
     return try {
         my $attribute = $patron->extended_attributes->find(
-            $c->validation->param('extended_attribute_id') );
+            $c->param('extended_attribute_id') );
 
         unless ($attribute) {
             return $c->render(
@@ -252,7 +251,7 @@ sub update {
             );
         }
 
-        $attribute->set_from_api( $c->validation->param('body') )->store;
+        $attribute->set_from_api( $c->req->json )->store;
         $attribute->discard_changes;
 
         return $c->render(
@@ -302,7 +301,7 @@ Controller method that handles removing an extended patron attribute.
 sub delete {
     my $c = shift->openapi->valid_input or return;
 
-    my $patron = Koha::Patrons->find( $c->validation->param('patron_id') );
+    my $patron = Koha::Patrons->find( $c->param('patron_id') );
 
     unless ($patron) {
         return $c->render(
@@ -316,7 +315,7 @@ sub delete {
     return try {
 
         my $attribute = $patron->extended_attributes->find(
-            $c->validation->param('extended_attribute_id') );
+            $c->param('extended_attribute_id') );
 
         unless ($attribute) {
             return $c->render(
diff --git a/Koha/REST/V1/Patrons/Holds.pm b/Koha/REST/V1/Patrons/Holds.pm
index e4c2547ccb..88eea15b53 100644
--- a/Koha/REST/V1/Patrons/Holds.pm
+++ b/Koha/REST/V1/Patrons/Holds.pm
@@ -38,7 +38,7 @@ Controller function that handles listing Koha::Hold objects for the requested pa
 sub list {
     my $c = shift->openapi->valid_input or return;
 
-    my $patron = Koha::Patrons->find( $c->validation->param('patron_id') );
+    my $patron = Koha::Patrons->find( $c->param('patron_id') );
 
     unless ( $patron ) {
         return $c->render(
@@ -51,8 +51,7 @@ sub list {
 
     return try {
 
-        my $holds_rs = $patron->holds;
-        my $holds    = $c->objects->search( $holds_rs );
+        my $holds = $c->objects->search( $patron->holds );
 
         return $c->render(
             status  => 200,
diff --git a/Koha/REST/V1/Patrons/Password.pm b/Koha/REST/V1/Patrons/Password.pm
index 96f259c381..4b4b89dea9 100644
--- a/Koha/REST/V1/Patrons/Password.pm
+++ b/Koha/REST/V1/Patrons/Password.pm
@@ -44,8 +44,8 @@ sub set {
 
     my $c = shift->openapi->valid_input or return;
 
-    my $patron = Koha::Patrons->find( $c->validation->param('patron_id') );
-    my $body   = $c->validation->param('body');
+    my $patron = Koha::Patrons->find( $c->param('patron_id') );
+    my $body   = $c->req->json;
 
     unless ($patron) {
         return $c->render( status => 404, openapi => { error => "Patron not found." } );
@@ -87,8 +87,8 @@ sub set_public {
 
     my $c = shift->openapi->valid_input or return;
 
-    my $body      = $c->validation->param('body');
-    my $patron_id = $c->validation->param('patron_id');
+    my $body      = $c->req->json;
+    my $patron_id = $c->param('patron_id');
 
     my $user = $c->stash('koha.user');
 
diff --git a/Koha/REST/V1/Patrons/Password/Expiration.pm b/Koha/REST/V1/Patrons/Password/Expiration.pm
index de0abb748f..a038071ab0 100644
--- a/Koha/REST/V1/Patrons/Password/Expiration.pm
+++ b/Koha/REST/V1/Patrons/Password/Expiration.pm
@@ -43,13 +43,14 @@ sub set {
 
     my $c = shift->openapi->valid_input or return;
 
-    my $patron = Koha::Patrons->find( $c->validation->param('patron_id') );
-    my $body   = $c->validation->param('body');
+    my $patron = Koha::Patrons->find( $c->param('patron_id') );
 
     unless ($patron) {
         return $c->render( status => 404, openapi => { error => "Patron not found." } );
     }
 
+    my $body = $c->req->json;
+
     my $password_expiration_date   = $body->{expiration_date} // "";
 
     return try {
diff --git a/Koha/REST/V1/Quotes.pm b/Koha/REST/V1/Quotes.pm
index 53475ec9c2..51a35c9602 100644
--- a/Koha/REST/V1/Quotes.pm
+++ b/Koha/REST/V1/Quotes.pm
@@ -35,8 +35,7 @@ sub list {
     my $c = shift->openapi->valid_input or return;
 
     return try {
-        my $quotes_set = Koha::Quotes->new;
-        my $quotes = $c->objects->search( $quotes_set );
+        my $quotes = $c->objects->search( Koha::Quotes->new );
         return $c->render( status => 200, openapi => $quotes );
     }
     catch {
@@ -53,10 +52,12 @@ sub get {
     my $c = shift->openapi->valid_input or return;
 
     return try {
-        my $quote = Koha::Quotes->find( $c->validation->param('quote_id') );
+        my $quote = Koha::Quotes->find( $c->param('quote_id') );
         unless ($quote) {
-            return $c->render( status  => 404,
-                            openapi => { error => "quote not found" } );
+            return $c->render(
+                status  => 404,
+                openapi => { error => "quote not found" }
+            );
         }
 
         return $c->render( status => 200, openapi => $quote->to_api );
@@ -74,7 +75,7 @@ sub add {
     my $c = shift->openapi->valid_input or return;
 
     return try {
-        my $quote = Koha::Quote->new_from_api( $c->validation->param('body') );
+        my $quote = Koha::Quote->new_from_api( $c->req->json );
         $quote->store;
         $c->res->headers->location( $c->req->url->to_string . '/' . $quote->id );
         return $c->render(
@@ -94,7 +95,7 @@ sub add {
 sub update {
     my $c = shift->openapi->valid_input or return;
 
-    my $quote = Koha::Quotes->find( $c->validation->param('quote_id') );
+    my $quote = Koha::Quotes->find( $c->param('quote_id') );
 
     if ( not defined $quote ) {
         return $c->render( status  => 404,
@@ -102,7 +103,7 @@ sub update {
     }
 
     return try {
-        $quote->set_from_api( $c->validation->param('body') );
+        $quote->set_from_api( $c->req->json );
         $quote->store();
         return $c->render( status => 200, openapi => $quote->to_api );
     }
@@ -118,7 +119,7 @@ sub update {
 sub delete {
     my $c = shift->openapi->valid_input or return;
 
-    my $quote = Koha::Quotes->find( $c->validation->param('quote_id') );
+    my $quote = Koha::Quotes->find( $c->param('quote_id') );
     if ( not defined $quote ) {
         return $c->render( status  => 404,
                            openapi => { error => "Object not found" } );
diff --git a/Koha/REST/V1/ReturnClaims.pm b/Koha/REST/V1/ReturnClaims.pm
index 850b0f76c2..ad9a61acf1 100644
--- a/Koha/REST/V1/ReturnClaims.pm
+++ b/Koha/REST/V1/ReturnClaims.pm
@@ -40,7 +40,7 @@ Claim that a checked out item was returned.
 
 sub claim_returned {
     my $c    = shift->openapi->valid_input or return;
-    my $body = $c->validation->param('body');
+    my $body = $c->req->json;
 
     return try {
         my $itemnumber      = $body->{item_id};
@@ -99,8 +99,8 @@ Update the notes of an existing claim
 sub update_notes {
     my $c = shift->openapi->valid_input or return;
 
-    my $claim_id = $c->validation->param('claim_id');
-    my $body     = $c->validation->param('body');
+    my $claim_id = $c->param('claim_id');
+    my $body     = $c->req->json;
 
     my $claim = Koha::Checkouts::ReturnClaims->find( $claim_id );
 
@@ -143,10 +143,10 @@ Marks a claim as resolved
 =cut
 
 sub resolve_claim {
-    my $c     = shift->openapi->valid_input or return;
+    my $c = shift->openapi->valid_input or return;
 
-    my $claim_id = $c->validation->param('claim_id');
-    my $body     = $c->validation->param('body');
+    my $claim_id = $c->param('claim_id');
+    my $body     = $c->req->json;
 
     my $claim = Koha::Checkouts::ReturnClaims->find($claim_id);
 
@@ -193,7 +193,7 @@ sub delete_claim {
 
     return try {
 
-        my $claim = Koha::Checkouts::ReturnClaims->find( $c->validation->param('claim_id') );
+        my $claim = Koha::Checkouts::ReturnClaims->find( $c->param('claim_id') );
 
         return $c->render(
             status  => 404,
diff --git a/Koha/REST/V1/SearchFilter.pm b/Koha/REST/V1/SearchFilter.pm
index cf796a263f..ce912b82a3 100644
--- a/Koha/REST/V1/SearchFilter.pm
+++ b/Koha/REST/V1/SearchFilter.pm
@@ -38,8 +38,7 @@ Controller function that handles listing Koha::SearchFilter objects
 sub list {
     my $c = shift->openapi->valid_input or return;
     return try {
-        my $filters_set = Koha::SearchFilters->search({});
-        my $filters = $c->objects->search( $filters_set );
+        my $filters = $c->objects->search( Koha::SearchFilters->new );
         return $c->render(
             status  => 200,
             openapi => $filters
@@ -59,7 +58,7 @@ Controller function that handles retrieving a single Koha::AdvancedEditorMacro
 
 sub get {
     my $c = shift->openapi->valid_input or return;
-    my $filter = Koha::SearchFilters->find( $c->validation->param('search_filter_id') );
+    my $filter = Koha::SearchFilters->find( $c->param('search_filter_id') );
     unless ($filter) {
         return $c->render( status  => 404,
                            openapi => { error => "Search filter not found" } );
@@ -78,7 +77,7 @@ sub add {
     my $c = shift->openapi->valid_input or return;
 
     return try {
-        my $filter = Koha::SearchFilter->new_from_api( $c->validation->param('body') );
+        my $filter = Koha::SearchFilter->new_from_api( $c->req->json );
         $filter->store->discard_changes;
         $c->res->headers->location( $c->req->url->to_string . '/' . $filter->id );
         return $c->render(
@@ -106,7 +105,7 @@ Controller function that handles updating a Koha::SearchFilter object
 sub update {
     my $c = shift->openapi->valid_input or return;
 
-    my $filter = Koha::SearchFilters->find( $c->validation->param('search_filter_id') );
+    my $filter = Koha::SearchFilters->find( $c->param('search_filter_id') );
 
     if ( not defined $filter ) {
         return $c->render( status  => 404,
@@ -114,8 +113,7 @@ sub update {
     }
 
     return try {
-        my $params = $c->req->json;
-        $filter->set_from_api( $params );
+        $filter->set_from_api( $c->req->json );
         $filter->store->discard_changes;
         return $c->render( status => 200, openapi => $filter->to_api );
     }
@@ -133,7 +131,7 @@ Controller function that handles deleting a Koha::SearchFilter object
 sub delete {
     my $c = shift->openapi->valid_input or return;
 
-    my $filter = Koha::SearchFilters->find( $c->validation->param('search_filter_id') );
+    my $filter = Koha::SearchFilters->find( $c->param('search_filter_id') );
     if ( not defined $filter ) {
         return $c->render( status  => 404,
                            openapi => { error => "Object not found" } );
diff --git a/Koha/REST/V1/Stage.pm b/Koha/REST/V1/Stage.pm
index b72a28e750..8e1c4ce734 100644
--- a/Koha/REST/V1/Stage.pm
+++ b/Koha/REST/V1/Stage.pm
@@ -36,13 +36,12 @@ Move a stage up or down the stockrotation rota.
 
 sub move {
     my $c = shift->openapi->valid_input or return;
-    my $input = $c->validation->output;
 
-    my $rota  = Koha::StockRotationRotas->find( $input->{rota_id} );
-    my $stage = Koha::StockRotationStages->find( $input->{stage_id} );
+    my $rota  = Koha::StockRotationRotas->find( $c->param('rota_id') );
+    my $stage = Koha::StockRotationStages->find( $c->param('stage_id') );
 
     if ( $stage && $rota ) {
-        my $result = $stage->move_to( $input->{position} );
+        my $result = $stage->move_to( $c->req->json );
         return $c->render( openapi => {}, status => 200 ) if $result;
         return $c->render(
             openapi => { error => "Bad request - new position invalid" },
diff --git a/Koha/REST/V1/Suggestions.pm b/Koha/REST/V1/Suggestions.pm
index 4bc27709d1..67bcbe04fd 100644
--- a/Koha/REST/V1/Suggestions.pm
+++ b/Koha/REST/V1/Suggestions.pm
@@ -63,8 +63,7 @@ sub get {
     my $c = shift->openapi->valid_input or return;
 
     return try {
-        my $suggestion_id = $c->validation->param('suggestion_id');
-        my $suggestion = $c->objects->find( Koha::Suggestions->new, $suggestion_id );
+        my $suggestion = $c->objects->find( Koha::Suggestions->new, $c->param('suggestion_id') );
 
         unless ($suggestion) {
             return $c->render(
@@ -92,7 +91,7 @@ Controller method that handles adding a new Koha::Suggestion object
 sub add {
     my $c = shift->openapi->valid_input or return;
 
-    my $body = $c->validation->param('body');
+    my $body = $c->req->json;
 
     # FIXME: This should be handled in Koha::Suggestion->store
     $body->{'status'} = 'ASKED'
@@ -171,8 +170,7 @@ Controller method that handles modifying Koha::Suggestion object
 sub update {
     my $c = shift->openapi->valid_input or return;
 
-    my $suggestion_id = $c->validation->param('suggestion_id');
-    my $suggestion = Koha::Suggestions->find( $suggestion_id );
+    my $suggestion = Koha::Suggestions->find( $c->param('suggestion_id') );
 
     return $c->render(
         status  => 404,
@@ -181,7 +179,7 @@ sub update {
 
     return try {
 
-        my $body = $c->validation->param('body');
+        my $body = $c->req->json;
 
         $suggestion->set_from_api( $body )->store;
         $suggestion->discard_changes;
@@ -206,8 +204,7 @@ Controller method that handles removing a Koha::Suggestion object
 sub delete {
     my $c = shift->openapi->valid_input or return;
 
-    my $suggestion_id = $c->validation->param('suggestion_id');
-    my $suggestion = Koha::Suggestions->find( $suggestion_id );
+    my $suggestion = Koha::Suggestions->find( $c->param('suggestion_id') );
 
     return $c->render(
         status  => 404,
diff --git a/Koha/REST/V1/Tickets.pm b/Koha/REST/V1/Tickets.pm
index b27a56d3da..a63ff3539d 100644
--- a/Koha/REST/V1/Tickets.pm
+++ b/Koha/REST/V1/Tickets.pm
@@ -38,8 +38,7 @@ sub list {
     my $c = shift->openapi->valid_input or return;
 
     return try {
-        my $tickets_set = Koha::Tickets->new;
-        my $tickets     = $c->objects->search($tickets_set);
+        my $tickets = $c->objects->search(Koha::Tickets->new);
         return $c->render( status => 200, openapi => $tickets );
     }
     catch {
@@ -56,7 +55,7 @@ sub get {
     my $c = shift->openapi->valid_input or return;
 
     return try {
-        my $ticket = Koha::Tickets->find( $c->validation->param('ticket_id') );
+        my $ticket = Koha::Tickets->find( $c->param('ticket_id') );
         unless ($ticket) {
             return $c->render(
                 status  => 404,
@@ -80,7 +79,7 @@ sub add {
     my $patron = $c->stash('koha.user');
 
     return try {
-        my $body   = $c->validation->param('body');
+        my $body = $c->req->json;
 
         # Set reporter from session
         $body->{reporter_id} = $patron->id;
@@ -108,7 +107,7 @@ sub add {
 sub update {
     my $c = shift->openapi->valid_input or return;
 
-    my $ticket = Koha::Tickets->find( $c->validation->param('ticket_id') );
+    my $ticket = Koha::Tickets->find( $c->param('ticket_id') );
 
     if ( not defined $ticket ) {
         return $c->render(
@@ -118,7 +117,7 @@ sub update {
     }
 
     return try {
-        $ticket->set_from_api( $c->validation->param('body') );
+        $ticket->set_from_api( $c->req->json );
         $ticket->store();
         return $c->render( status => 200, openapi => $ticket->to_api );
     }
@@ -134,7 +133,7 @@ sub update {
 sub delete {
     my $c = shift->openapi->valid_input or return;
 
-    my $ticket = Koha::Tickets->find( $c->validation->param('ticket_id') );
+    my $ticket = Koha::Tickets->find( $c->param('ticket_id') );
     if ( not defined $ticket ) {
         return $c->render(
             status  => 404,
@@ -162,7 +161,7 @@ sub list_updates {
     my $c = shift->openapi->valid_input or return;
 
     return try {
-        my $ticket = Koha::Tickets->find( $c->validation->param('ticket_id') );
+        my $ticket = Koha::Tickets->find( $c->param('ticket_id') );
         unless ($ticket) {
             return $c->render(
                 status  => 404,
@@ -187,8 +186,8 @@ sub add_update {
     my $c = shift->openapi->valid_input or return;
     my $patron = $c->stash('koha.user');
 
-    my $ticket_id_param = $c->validation->param('ticket_id');
-    my $ticket_update   = $c->validation->param('body');
+    my $ticket_id_param = $c->param('ticket_id');
+    my $ticket_update   = $c->req->json;
     $ticket_update->{ticket_id} //= $ticket_id_param;
 
     if ( $ticket_update->{ticket_id} != $ticket_id_param ) {
diff --git a/Koha/REST/V1/TransferLimits.pm b/Koha/REST/V1/TransferLimits.pm
index c7d056d18d..0d7b0eb472 100644
--- a/Koha/REST/V1/TransferLimits.pm
+++ b/Koha/REST/V1/TransferLimits.pm
@@ -47,8 +47,7 @@ sub list {
     my $c = shift->openapi->valid_input or return;
 
     return try {
-        my $limits_set = Koha::Item::Transfer::Limits->new;
-        my $limits = $c->objects->search( $limits_set );
+        my $limits = $c->objects->search( Koha::Item::Transfer::Limits->new );
         return $c->render( status => 200, openapi => $limits );
     }
     catch {
@@ -66,7 +65,7 @@ sub add {
     my $c = shift->openapi->valid_input or return;
 
     return try {
-        my $params = $c->validation->param( 'body' );
+        my $params = $c->req->json;
         my $transfer_limit = Koha::Item::Transfer::Limit->new_from_api( $params );
 
         if ( Koha::Item::Transfer::Limits->search( $transfer_limit->attributes_from_api($params) )->count == 0 ) {
@@ -102,7 +101,7 @@ sub delete {
 
     my $c = shift->openapi->valid_input or return;
 
-    my $transfer_limit = Koha::Item::Transfer::Limits->find( $c->validation->param( 'limit_id' ) );
+    my $transfer_limit = Koha::Item::Transfer::Limits->find( $c->param( 'limit_id' ) );
 
     if ( not defined $transfer_limit ) {
         return $c->render( status => 404, openapi => { error => "Transfer limit not found" } );
@@ -127,7 +126,7 @@ sub batch_add {
     my $c = shift->openapi->valid_input or return;
 
     return try {
-        my $params = $c->validation->param( 'body' );
+        my $params = $c->req->json;
 
         my @libraries = Koha::Libraries->search->as_list;
 
@@ -175,7 +174,7 @@ sub batch_delete {
     my $c = shift->openapi->valid_input or return;
 
     return try {
-        my $params = $c->validation->param( 'body' );
+        my $params = $c->req->json;
         my $transfer_limit = Koha::Item::Transfer::Limit->new_from_api( $params );
         my $search_params = $transfer_limit->unblessed;
 
diff --git a/Koha/REST/V1/TwoFactorAuth.pm b/Koha/REST/V1/TwoFactorAuth.pm
index 29679a544c..9681fca16d 100644
--- a/Koha/REST/V1/TwoFactorAuth.pm
+++ b/Koha/REST/V1/TwoFactorAuth.pm
@@ -131,8 +131,8 @@ sub verification {
 
     return try {
 
-        my $pin_code = $c->validation->param('pin_code');
-        my $secret32 = $c->validation->param('secret32');
+        my $pin_code = $c->param('pin_code');
+        my $secret32 = $c->param('secret32');
 
         my $auth     = Koha::Auth::TwoFactorAuth->new(
             { patron => $patron, secret32 => $secret32 } );