diff --git a/spring-grpc-core/src/main/java/org/springframework/grpc/client/aot/package-info.java b/spring-grpc-core/src/main/java/org/springframework/grpc/client/aot/package-info.java
new file mode 100644
index 00000000..702d6cc2
--- /dev/null
+++ b/spring-grpc-core/src/main/java/org/springframework/grpc/client/aot/package-info.java
@@ -0,0 +1,23 @@
+/*
+ * Copyright 2025-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * AOT (Ahead-Of-Time) processing for gRPC clients.
+ */
+@NullMarked
+package org.springframework.grpc.client.aot;
+
+import org.jspecify.annotations.NullMarked;
diff --git a/spring-grpc-core/src/main/java/org/springframework/grpc/client/interceptor/package-info.java b/spring-grpc-core/src/main/java/org/springframework/grpc/client/interceptor/package-info.java
new file mode 100644
index 00000000..2120528b
--- /dev/null
+++ b/spring-grpc-core/src/main/java/org/springframework/grpc/client/interceptor/package-info.java
@@ -0,0 +1,23 @@
+/*
+ * Copyright 2025-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * gRPC client interceptors.
+ */
+@NullMarked
+package org.springframework.grpc.client.interceptor;
+
+import org.jspecify.annotations.NullMarked;
diff --git a/spring-grpc-core/src/main/java/org/springframework/grpc/client/interceptor/security/package-info.java b/spring-grpc-core/src/main/java/org/springframework/grpc/client/interceptor/security/package-info.java
new file mode 100644
index 00000000..3bd97585
--- /dev/null
+++ b/spring-grpc-core/src/main/java/org/springframework/grpc/client/interceptor/security/package-info.java
@@ -0,0 +1,23 @@
+/*
+ * Copyright 2025-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * Security-related gRPC client interceptors.
+ */
+@NullMarked
+package org.springframework.grpc.client.interceptor.security;
+
+import org.jspecify.annotations.NullMarked;
diff --git a/spring-grpc-core/src/main/java/org/springframework/grpc/client/package-info.java b/spring-grpc-core/src/main/java/org/springframework/grpc/client/package-info.java
new file mode 100644
index 00000000..18787032
--- /dev/null
+++ b/spring-grpc-core/src/main/java/org/springframework/grpc/client/package-info.java
@@ -0,0 +1,23 @@
+/*
+ * Copyright 2025-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * gRPC client infrastructure.
+ */
+@NullMarked
+package org.springframework.grpc.client;
+
+import org.jspecify.annotations.NullMarked;
diff --git a/spring-grpc-core/src/main/java/org/springframework/grpc/internal/package-info.java b/spring-grpc-core/src/main/java/org/springframework/grpc/internal/package-info.java
new file mode 100644
index 00000000..9bc2d030
--- /dev/null
+++ b/spring-grpc-core/src/main/java/org/springframework/grpc/internal/package-info.java
@@ -0,0 +1,23 @@
+/*
+ * Copyright 2025-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * Internal utilities and helpers.
+ */
+@NullMarked
+package org.springframework.grpc.internal;
+
+import org.jspecify.annotations.NullMarked;
diff --git a/spring-grpc-core/src/main/java/org/springframework/grpc/server/exception/package-info.java b/spring-grpc-core/src/main/java/org/springframework/grpc/server/exception/package-info.java
new file mode 100644
index 00000000..4d9c3a5b
--- /dev/null
+++ b/spring-grpc-core/src/main/java/org/springframework/grpc/server/exception/package-info.java
@@ -0,0 +1,23 @@
+/*
+ * Copyright 2025-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * Exception handling for gRPC servers.
+ */
+@NullMarked
+package org.springframework.grpc.server.exception;
+
+import org.jspecify.annotations.NullMarked;
diff --git a/spring-grpc-core/src/main/java/org/springframework/grpc/server/lifecycle/package-info.java b/spring-grpc-core/src/main/java/org/springframework/grpc/server/lifecycle/package-info.java
index 4e8d3ec8..c0d1b557 100644
--- a/spring-grpc-core/src/main/java/org/springframework/grpc/server/lifecycle/package-info.java
+++ b/spring-grpc-core/src/main/java/org/springframework/grpc/server/lifecycle/package-info.java
@@ -1,5 +1,23 @@
+/*
+ * Copyright 2025-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 /**
  * gRPC server events.
  */
-
+@NullMarked
 package org.springframework.grpc.server.lifecycle;
+
+import org.jspecify.annotations.NullMarked;
\ No newline at end of file
diff --git a/spring-grpc-core/src/main/java/org/springframework/grpc/server/package-info.java b/spring-grpc-core/src/main/java/org/springframework/grpc/server/package-info.java
new file mode 100644
index 00000000..96ada6b2
--- /dev/null
+++ b/spring-grpc-core/src/main/java/org/springframework/grpc/server/package-info.java
@@ -0,0 +1,23 @@
+/*
+ * Copyright 2025-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * gRPC server infrastructure.
+ */
+@NullMarked
+package org.springframework.grpc.server;
+
+import org.jspecify.annotations.NullMarked;
diff --git a/spring-grpc-core/src/main/java/org/springframework/grpc/server/security/package-info.java b/spring-grpc-core/src/main/java/org/springframework/grpc/server/security/package-info.java
new file mode 100644
index 00000000..5537ff4f
--- /dev/null
+++ b/spring-grpc-core/src/main/java/org/springframework/grpc/server/security/package-info.java
@@ -0,0 +1,23 @@
+/*
+ * Copyright 2025-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * Security infrastructure for gRPC servers.
+ */
+@NullMarked
+package org.springframework.grpc.server.security;
+
+import org.jspecify.annotations.NullMarked;
diff --git a/spring-grpc-core/src/main/java/org/springframework/grpc/server/service/package-info.java b/spring-grpc-core/src/main/java/org/springframework/grpc/server/service/package-info.java
new file mode 100644
index 00000000..7f2eba68
--- /dev/null
+++ b/spring-grpc-core/src/main/java/org/springframework/grpc/server/service/package-info.java
@@ -0,0 +1,23 @@
+/*
+ * Copyright 2025-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * gRPC service discovery and configuration.
+ */
+@NullMarked
+package org.springframework.grpc.server.service;
+
+import org.jspecify.annotations.NullMarked;