diff --git a/README_SETUP.md b/README_SETUP.md
index 5cbe1d42077b8d6d10473cc294a4fed783b6faee..a537665d85893a13cd5f652cfd23add2759cdbed 100644
--- a/README_SETUP.md
+++ b/README_SETUP.md
@@ -35,7 +35,7 @@ The coverage report can be viewed in a browser by opening
 
 ## Code Formatting
 
-* `clang-format -i --verbose **/*.c **/*.h`
+* `clang-format -i --verbose **/*.cpp **/*.h`
 
 ## Documentation
 
diff --git a/include/authentication.h b/include/authentication.h
index 25f56550e1bb89eaf986d0f115cf2b01e3ec4a12..cf8a7bf86830e682231858a180a8c95ea88287f8 100644
--- a/include/authentication.h
+++ b/include/authentication.h
@@ -36,18 +36,19 @@
 
 namespace caosdb {
 namespace authentication {
-using grpc::MetadataCredentialsPlugin;
-using grpc::string_ref;
+using caosdb::utils::base64_encode;
 using grpc::AuthContext;
+using grpc::MetadataCredentialsPlugin;
 using grpc::Status;
-using caosdb::utils::base64_encode;
+using grpc::string_ref;
 
 /**
  * @brief Abstract base class for authenticators.
  */
 class Authenticator {
 public:
-  virtual auto getCallCredentials() const -> std::shared_ptr<grpc::CallCredentials> = 0;
+  virtual auto getCallCredentials() const
+    -> std::shared_ptr<grpc::CallCredentials> = 0;
 };
 
 /**
@@ -59,23 +60,26 @@ class MetadataCredentialsPluginImpl : public MetadataCredentialsPlugin {
 private:
   std::string key;
   std::string value;
+
 public:
   MetadataCredentialsPluginImpl(std::string key, std::string value);
 
-  Status GetMetadata(
-      string_ref service_url, string_ref method_name,
-      const AuthContext& channel_auth_context,
-      std::multimap<grpc::string, grpc::string>* metadata) override;
+  Status
+  GetMetadata(string_ref service_url, string_ref method_name,
+              const AuthContext &channel_auth_context,
+              std::multimap<grpc::string, grpc::string> *metadata) override;
 };
 
 class PlainPasswordAuthenticator : public Authenticator {
 private:
   std::string basic;
-public:
-  PlainPasswordAuthenticator(const std::string& username, const std::string& password);
 
-  auto getCallCredentials() const -> std::shared_ptr<grpc::CallCredentials> override;
+public:
+  PlainPasswordAuthenticator(const std::string &username,
+                             const std::string &password);
 
+  auto getCallCredentials() const
+    -> std::shared_ptr<grpc::CallCredentials> override;
 };
 } // namespace authentication
 } // namespace caosdb
diff --git a/include/connection.h b/include/connection.h
index abe12af13d6e5f4decadf0b2d8bf81a9022c7c22..0b535fa0642e9f797dac1f6a511506a1a760ca24 100644
--- a/include/connection.h
+++ b/include/connection.h
@@ -49,10 +49,10 @@ class VersionInfo;
 } // namespace caosdb
 
 namespace caosdb {
+using caosdb::authentication::Authenticator;
 using caosdb::info::v1alpha1::GeneralInfoService;
 using caosdb::info::v1alpha1::VersionInfo;
 using grpc::ChannelCredentials;
-using caosdb::authentication::Authenticator;
 
 class CACertificateProvider {
 public:
@@ -118,9 +118,9 @@ public:
     const std::string &host, int port,
     const std::shared_ptr<CACertificateProvider> &cacert);
   SslCaosDBConnectionConfig(
-      const std::string &host, int port,
-      const std::shared_ptr<CACertificateProvider> &cacert,
-      const std::shared_ptr<Authenticator> &authenticator);
+    const std::string &host, int port,
+    const std::shared_ptr<CACertificateProvider> &cacert,
+    const std::shared_ptr<Authenticator> &authenticator);
   [[nodiscard]] auto getChannelCredentials() const
     -> std::shared_ptr<ChannelCredentials> override;
   [[nodiscard]] auto toString() const -> std::string override;
diff --git a/include/utils.h b/include/utils.h
index 4d7e3ea1a60026342ecac9676825ee0711356262..75e04bee03aa2abb435d740d03db5faede3fb569 100644
--- a/include/utils.h
+++ b/include/utils.h
@@ -66,7 +66,7 @@ inline auto get_env_var(const std::string &key, const std::string &fall_back)
  * @brief
  * @todo use boost-beast's implementation
  */
-inline auto base64_encode(const std::string& plain) -> std::string {
+inline auto base64_encode(const std::string &plain) -> std::string {
   return plain;
 }
 
diff --git a/src/authentication.cpp b/src/authentication.cpp
index 0b7f47b755ae592a56b3dbf9b1c7c4068d15e825..9286a857b1a886e8b48f083e2ab169045102d98b 100644
--- a/src/authentication.cpp
+++ b/src/authentication.cpp
@@ -27,31 +27,36 @@
 #include <utility>
 
 namespace caosdb::authentication {
-using grpc::MetadataCredentialsPlugin;
-using grpc::string_ref;
+using caosdb::utils::base64_encode;
 using grpc::AuthContext;
+using grpc::MetadataCredentialsPlugin;
 using grpc::Status;
-using caosdb::utils::base64_encode;
+using grpc::string_ref;
 
-MetadataCredentialsPluginImpl::MetadataCredentialsPluginImpl(std::string key, std::string value) : key(std::move(key)), value(std::move(value)) {};
+MetadataCredentialsPluginImpl::MetadataCredentialsPluginImpl(std::string key,
+                                                             std::string value)
+  : key(std::move(key)), value(std::move(value)){};
 
 auto MetadataCredentialsPluginImpl::GetMetadata(
-      string_ref /*service_url*/, string_ref /*method_name*/,
-      const AuthContext& /*channel_auth_context*/,
-      std::multimap<grpc::string, grpc::string>* metadata) -> Status {
+  string_ref /*service_url*/, string_ref /*method_name*/,
+  const AuthContext & /*channel_auth_context*/,
+  std::multimap<grpc::string, grpc::string> *metadata) -> Status {
 
-    metadata->insert(std::make_pair(this->key, this->value));
-    return Status::OK;
-  };
+  metadata->insert(std::make_pair(this->key, this->value));
+  return Status::OK;
+};
 
-PlainPasswordAuthenticator::PlainPasswordAuthenticator(const std::string& username, const std::string& password) {
-    this->basic = "Basic " + base64_encode(username + ":" + password);
-  };
+PlainPasswordAuthenticator::PlainPasswordAuthenticator(
+  const std::string &username, const std::string &password) {
+  this->basic = "Basic " + base64_encode(username + ":" + password);
+};
 
-  auto PlainPasswordAuthenticator::getCallCredentials() const -> std::shared_ptr<grpc::CallCredentials> {
-    auto call_creds = grpc::MetadataCredentialsFromPlugin(std::unique_ptr<grpc::MetadataCredentialsPlugin>(
-          new MetadataCredentialsPluginImpl("authentication", this->basic)));
-    return call_creds;
-  };
+auto PlainPasswordAuthenticator::getCallCredentials() const
+  -> std::shared_ptr<grpc::CallCredentials> {
+  auto call_creds = grpc::MetadataCredentialsFromPlugin(
+    std::unique_ptr<grpc::MetadataCredentialsPlugin>(
+      new MetadataCredentialsPluginImpl("authentication", this->basic)));
+  return call_creds;
+};
 
 } // namespace caosdb::authentication
diff --git a/src/caosdbcli.cpp b/src/caosdbcli.cpp
index e2830885418f02938c54f217162507fb1b59bc0a..1d18c07b8036089e2e9a539b1c5a3ca44afdc3b6 100644
--- a/src/caosdbcli.cpp
+++ b/src/caosdbcli.cpp
@@ -37,15 +37,20 @@ auto main() -> int {
             << caosdb::LIBCAOSDB_VERSION_PATCH << ")" << std::endl;
   std::cout << "We don't miss the H of caos." << std::endl;
 
-  const auto pem_file = caosdb::utils::get_env_var("CAOSDB_SERVER_CA_PEM", std::string());
-  const auto host = caosdb::utils::get_env_var("CAOSDB_SERVER_HOST", "localhost");
-  const auto port_str = caosdb::utils::get_env_var("CAOSDB_SERVER_PORT", "8000");
+  const auto pem_file =
+    caosdb::utils::get_env_var("CAOSDB_SERVER_CA_PEM", std::string());
+  const auto host =
+    caosdb::utils::get_env_var("CAOSDB_SERVER_HOST", "localhost");
+  const auto port_str =
+    caosdb::utils::get_env_var("CAOSDB_SERVER_PORT", "8000");
   const auto port = std::stoi(port_str);
 
-  auto auth = std::make_shared<caosdb::authentication::PlainPasswordAuthenticator>("tf", "vuY36moa");
+  auto auth =
+    std::make_shared<caosdb::authentication::PlainPasswordAuthenticator>(
+      "tf", "vuY36moa");
   auto cacert = std::make_shared<caosdb::PemFileCACertProvider>(pem_file);
-  auto config =
-    std::make_shared<caosdb::SslCaosDBConnectionConfig>(host, port, cacert, auth);
+  auto config = std::make_shared<caosdb::SslCaosDBConnectionConfig>(
+    host, port, cacert, auth);
   caosdb::CaosDBConnection connection(config);
   std::cout << std::endl << connection << std::endl;
   const auto &v_info = connection.getVersionInfo();
diff --git a/src/connection.cpp b/src/connection.cpp
index 5505fb85e31fbea95ac4176747a55ff89c9f47c8..5f0d798c0579bc3b3f454293e824a0f0c73727e9 100644
--- a/src/connection.cpp
+++ b/src/connection.cpp
@@ -34,6 +34,7 @@
 #include "caosdb/info/v1alpha1/main.pb.h"
 
 namespace caosdb {
+using caosdb::authentication::Authenticator;
 using caosdb::info::v1alpha1::GeneralInfoService;
 using caosdb::info::v1alpha1::GetVersionInfoRequest;
 using caosdb::info::v1alpha1::GetVersionInfoResponse;
@@ -42,7 +43,6 @@ using caosdb::utils::load_string_file;
 using grpc::InsecureChannelCredentials;
 using grpc::SslCredentials;
 using grpc::SslCredentialsOptions;
-using caosdb::authentication::Authenticator;
 
 PemFileCACertProvider::PemFileCACertProvider(const std::string &path) {
   this->cacert = load_string_file(path);
@@ -111,8 +111,8 @@ SslCaosDBConnectionConfig::SslCaosDBConnectionConfig(
 
   SslCredentialsOptions options;
   options.pem_root_certs = cacert->getCACertPem();
-  this->credentials = grpc::CompositeChannelCredentials(SslCredentials(options), authenticator->getCallCredentials());
-
+  this->credentials = grpc::CompositeChannelCredentials(
+    SslCredentials(options), authenticator->getCallCredentials());
 }
 
 auto SslCaosDBConnectionConfig::getChannelCredentials() const