From 3177e64693b4fd218831ff05a5be19117f5b1b30 Mon Sep 17 00:00:00 2001
From: Yordis Prieto <yordis.prieto@gmail.com>
Date: Sat, 9 May 2026 17:36:47 -0400
Subject: [PATCH] feat(buffa): add MessageFullName trait

Signed-off-by: Yordis Prieto <yordis.prieto@gmail.com>
---
 buffa-codegen/src/impl_message.rs             |   4 +
 .../google.protobuf.compiler.plugin.rs        |  12 +++
 .../generated/google.protobuf.descriptor.rs   | 102 ++++++++++++++++++
 buffa-test/src/tests/basic.rs                 |   9 +-
 .../src/generated/google.protobuf.any.rs      |   3 +
 .../src/generated/google.protobuf.duration.rs |   3 +
 .../src/generated/google.protobuf.empty.rs    |   3 +
 .../generated/google.protobuf.field_mask.rs   |   3 +
 .../src/generated/google.protobuf.struct.rs   |   9 ++
 .../generated/google.protobuf.timestamp.rs    |   3 +
 .../src/generated/google.protobuf.wrappers.rs |  27 +++++
 buffa-types/src/lib.rs                        |  21 ++++
 buffa/src/extension.rs                        |  12 +++
 buffa/src/lib.rs                              |   3 +-
 buffa/src/message.rs                          |  34 ++++++
 docs/guide.md                                 |   7 ++
 .../src/gen/buffa.examples.context.v1.mod.rs  |   1 +
 .../src/gen/buffa.examples.log.v1.mod.rs      |   1 +
 examples/logging/src/gen/mod.rs               |  14 +--
 19 files changed, 262 insertions(+), 9 deletions(-)

diff --git a/buffa-codegen/src/impl_message.rs b/buffa-codegen/src/impl_message.rs
index 8ce3f50..8f46da7 100644
--- a/buffa-codegen/src/impl_message.rs
+++ b/buffa-codegen/src/impl_message.rs
@@ -552,6 +552,10 @@ pub fn generate_message_impl(
             }
         }
 
+        impl ::buffa::MessageFullName for #name_ident {
+            const FULL_NAME: &'static str = #proto_fqn;
+        }
+
         impl ::buffa::Message for #name_ident {
             /// Returns the total encoded size in bytes.
             ///
diff --git a/buffa-descriptor/src/generated/google.protobuf.compiler.plugin.rs b/buffa-descriptor/src/generated/google.protobuf.compiler.plugin.rs
index 8fc20ca..1d220ee 100644
--- a/buffa-descriptor/src/generated/google.protobuf.compiler.plugin.rs
+++ b/buffa-descriptor/src/generated/google.protobuf.compiler.plugin.rs
@@ -41,6 +41,9 @@ impl ::buffa::DefaultInstance for Version {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for Version {
+    const FULL_NAME: &'static str = "google.protobuf.compiler.Version";
+}
 impl ::buffa::Message for Version {
     /// Returns the total encoded size in bytes.
     ///
@@ -255,6 +258,9 @@ impl ::buffa::DefaultInstance for CodeGeneratorRequest {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for CodeGeneratorRequest {
+    const FULL_NAME: &'static str = "google.protobuf.compiler.CodeGeneratorRequest";
+}
 impl ::buffa::Message for CodeGeneratorRequest {
     /// Returns the total encoded size in bytes.
     ///
@@ -512,6 +518,9 @@ impl ::buffa::DefaultInstance for CodeGeneratorResponse {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for CodeGeneratorResponse {
+    const FULL_NAME: &'static str = "google.protobuf.compiler.CodeGeneratorResponse";
+}
 impl ::buffa::Message for CodeGeneratorResponse {
     /// Returns the total encoded size in bytes.
     ///
@@ -832,6 +841,9 @@ pub mod code_generator_response {
             VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
         }
     }
+    impl ::buffa::MessageFullName for File {
+        const FULL_NAME: &'static str = "google.protobuf.compiler.CodeGeneratorResponse.File";
+    }
     impl ::buffa::Message for File {
         /// Returns the total encoded size in bytes.
         ///
diff --git a/buffa-descriptor/src/generated/google.protobuf.descriptor.rs b/buffa-descriptor/src/generated/google.protobuf.descriptor.rs
index b86be0d..d1f800f 100644
--- a/buffa-descriptor/src/generated/google.protobuf.descriptor.rs
+++ b/buffa-descriptor/src/generated/google.protobuf.descriptor.rs
@@ -200,6 +200,9 @@ impl ::buffa::DefaultInstance for FileDescriptorSet {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for FileDescriptorSet {
+    const FULL_NAME: &'static str = "google.protobuf.FileDescriptorSet";
+}
 impl ::buffa::Message for FileDescriptorSet {
     /// Returns the total encoded size in bytes.
     ///
@@ -385,6 +388,9 @@ impl ::buffa::DefaultInstance for FileDescriptorProto {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for FileDescriptorProto {
+    const FULL_NAME: &'static str = "google.protobuf.FileDescriptorProto";
+}
 impl ::buffa::Message for FileDescriptorProto {
     /// Returns the total encoded size in bytes.
     ///
@@ -913,6 +919,9 @@ impl ::buffa::DefaultInstance for DescriptorProto {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for DescriptorProto {
+    const FULL_NAME: &'static str = "google.protobuf.DescriptorProto";
+}
 impl ::buffa::Message for DescriptorProto {
     /// Returns the total encoded size in bytes.
     ///
@@ -1326,6 +1335,9 @@ pub mod descriptor_proto {
             VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
         }
     }
+    impl ::buffa::MessageFullName for ExtensionRange {
+        const FULL_NAME: &'static str = "google.protobuf.DescriptorProto.ExtensionRange";
+    }
     impl ::buffa::Message for ExtensionRange {
         /// Returns the total encoded size in bytes.
         ///
@@ -1491,6 +1503,9 @@ pub mod descriptor_proto {
             VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
         }
     }
+    impl ::buffa::MessageFullName for ReservedRange {
+        const FULL_NAME: &'static str = "google.protobuf.DescriptorProto.ReservedRange";
+    }
     impl ::buffa::Message for ReservedRange {
         /// Returns the total encoded size in bytes.
         ///
@@ -1636,6 +1651,9 @@ impl ::buffa::DefaultInstance for ExtensionRangeOptions {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for ExtensionRangeOptions {
+    const FULL_NAME: &'static str = "google.protobuf.ExtensionRangeOptions";
+}
 impl ::buffa::Message for ExtensionRangeOptions {
     /// Returns the total encoded size in bytes.
     ///
@@ -1911,6 +1929,9 @@ pub mod extension_range_options {
             VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
         }
     }
+    impl ::buffa::MessageFullName for Declaration {
+        const FULL_NAME: &'static str = "google.protobuf.ExtensionRangeOptions.Declaration";
+    }
     impl ::buffa::Message for Declaration {
         /// Returns the total encoded size in bytes.
         ///
@@ -2188,6 +2209,9 @@ impl ::buffa::DefaultInstance for FieldDescriptorProto {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for FieldDescriptorProto {
+    const FULL_NAME: &'static str = "google.protobuf.FieldDescriptorProto";
+}
 impl ::buffa::Message for FieldDescriptorProto {
     /// Returns the total encoded size in bytes.
     ///
@@ -2749,6 +2773,9 @@ impl ::buffa::DefaultInstance for OneofDescriptorProto {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for OneofDescriptorProto {
+    const FULL_NAME: &'static str = "google.protobuf.OneofDescriptorProto";
+}
 impl ::buffa::Message for OneofDescriptorProto {
     /// Returns the total encoded size in bytes.
     ///
@@ -2914,6 +2941,9 @@ impl ::buffa::DefaultInstance for EnumDescriptorProto {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for EnumDescriptorProto {
+    const FULL_NAME: &'static str = "google.protobuf.EnumDescriptorProto";
+}
 impl ::buffa::Message for EnumDescriptorProto {
     /// Returns the total encoded size in bytes.
     ///
@@ -3180,6 +3210,9 @@ pub mod enum_descriptor_proto {
             VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
         }
     }
+    impl ::buffa::MessageFullName for EnumReservedRange {
+        const FULL_NAME: &'static str = "google.protobuf.EnumDescriptorProto.EnumReservedRange";
+    }
     impl ::buffa::Message for EnumReservedRange {
         /// Returns the total encoded size in bytes.
         ///
@@ -3311,6 +3344,9 @@ impl ::buffa::DefaultInstance for EnumValueDescriptorProto {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for EnumValueDescriptorProto {
+    const FULL_NAME: &'static str = "google.protobuf.EnumValueDescriptorProto";
+}
 impl ::buffa::Message for EnumValueDescriptorProto {
     /// Returns the total encoded size in bytes.
     ///
@@ -3477,6 +3513,9 @@ impl ::buffa::DefaultInstance for ServiceDescriptorProto {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for ServiceDescriptorProto {
+    const FULL_NAME: &'static str = "google.protobuf.ServiceDescriptorProto";
+}
 impl ::buffa::Message for ServiceDescriptorProto {
     /// Returns the total encoded size in bytes.
     ///
@@ -3668,6 +3707,9 @@ impl ::buffa::DefaultInstance for MethodDescriptorProto {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for MethodDescriptorProto {
+    const FULL_NAME: &'static str = "google.protobuf.MethodDescriptorProto";
+}
 impl ::buffa::Message for MethodDescriptorProto {
     /// Returns the total encoded size in bytes.
     ///
@@ -4082,6 +4124,9 @@ impl ::buffa::DefaultInstance for FileOptions {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for FileOptions {
+    const FULL_NAME: &'static str = "google.protobuf.FileOptions";
+}
 impl ::buffa::Message for FileOptions {
     /// Returns the total encoded size in bytes.
     ///
@@ -4844,6 +4889,9 @@ impl ::buffa::DefaultInstance for MessageOptions {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for MessageOptions {
+    const FULL_NAME: &'static str = "google.protobuf.MessageOptions";
+}
 impl ::buffa::Message for MessageOptions {
     /// Returns the total encoded size in bytes.
     ///
@@ -5204,6 +5252,9 @@ impl ::buffa::DefaultInstance for FieldOptions {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for FieldOptions {
+    const FULL_NAME: &'static str = "google.protobuf.FieldOptions";
+}
 impl ::buffa::Message for FieldOptions {
     /// Returns the total encoded size in bytes.
     ///
@@ -5944,6 +5995,9 @@ pub mod field_options {
             VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
         }
     }
+    impl ::buffa::MessageFullName for EditionDefault {
+        const FULL_NAME: &'static str = "google.protobuf.FieldOptions.EditionDefault";
+    }
     impl ::buffa::Message for EditionDefault {
         /// Returns the total encoded size in bytes.
         ///
@@ -6106,6 +6160,9 @@ pub mod field_options {
             VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
         }
     }
+    impl ::buffa::MessageFullName for FeatureSupport {
+        const FULL_NAME: &'static str = "google.protobuf.FieldOptions.FeatureSupport";
+    }
     impl ::buffa::Message for FeatureSupport {
         /// Returns the total encoded size in bytes.
         ///
@@ -6315,6 +6372,9 @@ impl ::buffa::DefaultInstance for OneofOptions {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for OneofOptions {
+    const FULL_NAME: &'static str = "google.protobuf.OneofOptions";
+}
 impl ::buffa::Message for OneofOptions {
     /// Returns the total encoded size in bytes.
     ///
@@ -6495,6 +6555,9 @@ impl ::buffa::DefaultInstance for EnumOptions {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for EnumOptions {
+    const FULL_NAME: &'static str = "google.protobuf.EnumOptions";
+}
 impl ::buffa::Message for EnumOptions {
     /// Returns the total encoded size in bytes.
     ///
@@ -6731,6 +6794,9 @@ impl ::buffa::DefaultInstance for EnumValueOptions {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for EnumValueOptions {
+    const FULL_NAME: &'static str = "google.protobuf.EnumValueOptions";
+}
 impl ::buffa::Message for EnumValueOptions {
     /// Returns the total encoded size in bytes.
     ///
@@ -6971,6 +7037,9 @@ impl ::buffa::DefaultInstance for ServiceOptions {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for ServiceOptions {
+    const FULL_NAME: &'static str = "google.protobuf.ServiceOptions";
+}
 impl ::buffa::Message for ServiceOptions {
     /// Returns the total encoded size in bytes.
     ///
@@ -7161,6 +7230,9 @@ impl ::buffa::DefaultInstance for MethodOptions {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for MethodOptions {
+    const FULL_NAME: &'static str = "google.protobuf.MethodOptions";
+}
 impl ::buffa::Message for MethodOptions {
     /// Returns the total encoded size in bytes.
     ///
@@ -7436,6 +7508,9 @@ impl ::buffa::DefaultInstance for UninterpretedOption {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for UninterpretedOption {
+    const FULL_NAME: &'static str = "google.protobuf.UninterpretedOption";
+}
 impl ::buffa::Message for UninterpretedOption {
     /// Returns the total encoded size in bytes.
     ///
@@ -7700,6 +7775,9 @@ pub mod uninterpreted_option {
             VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
         }
     }
+    impl ::buffa::MessageFullName for NamePart {
+        const FULL_NAME: &'static str = "google.protobuf.UninterpretedOption.NamePart";
+    }
     impl ::buffa::Message for NamePart {
         /// Returns the total encoded size in bytes.
         ///
@@ -7849,6 +7927,9 @@ impl ::buffa::DefaultInstance for FeatureSet {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for FeatureSet {
+    const FULL_NAME: &'static str = "google.protobuf.FeatureSet";
+}
 impl ::buffa::Message for FeatureSet {
     /// Returns the total encoded size in bytes.
     ///
@@ -8499,6 +8580,9 @@ pub mod feature_set {
             VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
         }
     }
+    impl ::buffa::MessageFullName for VisibilityFeature {
+        const FULL_NAME: &'static str = "google.protobuf.FeatureSet.VisibilityFeature";
+    }
     impl ::buffa::Message for VisibilityFeature {
         /// Returns the total encoded size in bytes.
         ///
@@ -8678,6 +8762,9 @@ impl ::buffa::DefaultInstance for FeatureSetDefaults {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for FeatureSetDefaults {
+    const FULL_NAME: &'static str = "google.protobuf.FeatureSetDefaults";
+}
 impl ::buffa::Message for FeatureSetDefaults {
     /// Returns the total encoded size in bytes.
     ///
@@ -8866,6 +8953,9 @@ pub mod feature_set_defaults {
             VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
         }
     }
+    impl ::buffa::MessageFullName for FeatureSetEditionDefault {
+        const FULL_NAME: &'static str = "google.protobuf.FeatureSetDefaults.FeatureSetEditionDefault";
+    }
     impl ::buffa::Message for FeatureSetEditionDefault {
         /// Returns the total encoded size in bytes.
         ///
@@ -9091,6 +9181,9 @@ impl ::buffa::DefaultInstance for SourceCodeInfo {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for SourceCodeInfo {
+    const FULL_NAME: &'static str = "google.protobuf.SourceCodeInfo";
+}
 impl ::buffa::Message for SourceCodeInfo {
     /// Returns the total encoded size in bytes.
     ///
@@ -9303,6 +9396,9 @@ pub mod source_code_info {
             VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
         }
     }
+    impl ::buffa::MessageFullName for Location {
+        const FULL_NAME: &'static str = "google.protobuf.SourceCodeInfo.Location";
+    }
     impl ::buffa::Message for Location {
         /// Returns the total encoded size in bytes.
         ///
@@ -9580,6 +9676,9 @@ impl ::buffa::DefaultInstance for GeneratedCodeInfo {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for GeneratedCodeInfo {
+    const FULL_NAME: &'static str = "google.protobuf.GeneratedCodeInfo";
+}
 impl ::buffa::Message for GeneratedCodeInfo {
     /// Returns the total encoded size in bytes.
     ///
@@ -9720,6 +9819,9 @@ pub mod generated_code_info {
             VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
         }
     }
+    impl ::buffa::MessageFullName for Annotation {
+        const FULL_NAME: &'static str = "google.protobuf.GeneratedCodeInfo.Annotation";
+    }
     impl ::buffa::Message for Annotation {
         /// Returns the total encoded size in bytes.
         ///
diff --git a/buffa-test/src/tests/basic.rs b/buffa-test/src/tests/basic.rs
index 9c91fdf..f0d97ac 100644
--- a/buffa-test/src/tests/basic.rs
+++ b/buffa-test/src/tests/basic.rs
@@ -3,7 +3,14 @@
 use super::round_trip;
 use crate::basic::__buffa::oneof;
 use crate::basic::*;
-use buffa::Message;
+use buffa::{Message, MessageFullName};
+
+#[test]
+fn test_full_name_const_matches_proto_fqn() {
+    assert_eq!(Empty::FULL_NAME, "basic.Empty");
+    assert_eq!(Person::FULL_NAME, "basic.Person");
+    assert_eq!(AllScalars::FULL_NAME, "basic.AllScalars");
+}
 
 #[test]
 fn test_empty_message_encodes_to_zero_bytes() {
diff --git a/buffa-types/src/generated/google.protobuf.any.rs b/buffa-types/src/generated/google.protobuf.any.rs
index f9e6b9d..bc680a2 100644
--- a/buffa-types/src/generated/google.protobuf.any.rs
+++ b/buffa-types/src/generated/google.protobuf.any.rs
@@ -164,6 +164,9 @@ impl ::buffa::DefaultInstance for Any {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for Any {
+    const FULL_NAME: &'static str = "google.protobuf.Any";
+}
 impl ::buffa::Message for Any {
     /// Returns the total encoded size in bytes.
     ///
diff --git a/buffa-types/src/generated/google.protobuf.duration.rs b/buffa-types/src/generated/google.protobuf.duration.rs
index 793792b..4735845 100644
--- a/buffa-types/src/generated/google.protobuf.duration.rs
+++ b/buffa-types/src/generated/google.protobuf.duration.rs
@@ -107,6 +107,9 @@ impl ::buffa::DefaultInstance for Duration {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for Duration {
+    const FULL_NAME: &'static str = "google.protobuf.Duration";
+}
 impl ::buffa::Message for Duration {
     /// Returns the total encoded size in bytes.
     ///
diff --git a/buffa-types/src/generated/google.protobuf.empty.rs b/buffa-types/src/generated/google.protobuf.empty.rs
index af554f5..3767363 100644
--- a/buffa-types/src/generated/google.protobuf.empty.rs
+++ b/buffa-types/src/generated/google.protobuf.empty.rs
@@ -34,6 +34,9 @@ impl ::buffa::DefaultInstance for Empty {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for Empty {
+    const FULL_NAME: &'static str = "google.protobuf.Empty";
+}
 impl ::buffa::Message for Empty {
     /// Returns the total encoded size in bytes.
     ///
diff --git a/buffa-types/src/generated/google.protobuf.field_mask.rs b/buffa-types/src/generated/google.protobuf.field_mask.rs
index 062dd7c..5502a26 100644
--- a/buffa-types/src/generated/google.protobuf.field_mask.rs
+++ b/buffa-types/src/generated/google.protobuf.field_mask.rs
@@ -252,6 +252,9 @@ impl ::buffa::DefaultInstance for FieldMask {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for FieldMask {
+    const FULL_NAME: &'static str = "google.protobuf.FieldMask";
+}
 impl ::buffa::Message for FieldMask {
     /// Returns the total encoded size in bytes.
     ///
diff --git a/buffa-types/src/generated/google.protobuf.struct.rs b/buffa-types/src/generated/google.protobuf.struct.rs
index f4eaca3..0868257 100644
--- a/buffa-types/src/generated/google.protobuf.struct.rs
+++ b/buffa-types/src/generated/google.protobuf.struct.rs
@@ -78,6 +78,9 @@ impl ::buffa::DefaultInstance for Struct {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for Struct {
+    const FULL_NAME: &'static str = "google.protobuf.Struct";
+}
 impl ::buffa::Message for Struct {
     /// Returns the total encoded size in bytes.
     ///
@@ -349,6 +352,9 @@ impl ::buffa::DefaultInstance for Value {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for Value {
+    const FULL_NAME: &'static str = "google.protobuf.Value";
+}
 impl ::buffa::Message for Value {
     /// Returns the total encoded size in bytes.
     ///
@@ -760,6 +766,9 @@ impl ::buffa::DefaultInstance for ListValue {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for ListValue {
+    const FULL_NAME: &'static str = "google.protobuf.ListValue";
+}
 impl ::buffa::Message for ListValue {
     /// Returns the total encoded size in bytes.
     ///
diff --git a/buffa-types/src/generated/google.protobuf.timestamp.rs b/buffa-types/src/generated/google.protobuf.timestamp.rs
index db64a11..108043c 100644
--- a/buffa-types/src/generated/google.protobuf.timestamp.rs
+++ b/buffa-types/src/generated/google.protobuf.timestamp.rs
@@ -142,6 +142,9 @@ impl ::buffa::DefaultInstance for Timestamp {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for Timestamp {
+    const FULL_NAME: &'static str = "google.protobuf.Timestamp";
+}
 impl ::buffa::Message for Timestamp {
     /// Returns the total encoded size in bytes.
     ///
diff --git a/buffa-types/src/generated/google.protobuf.wrappers.rs b/buffa-types/src/generated/google.protobuf.wrappers.rs
index 6aceba3..e49e362 100644
--- a/buffa-types/src/generated/google.protobuf.wrappers.rs
+++ b/buffa-types/src/generated/google.protobuf.wrappers.rs
@@ -32,6 +32,9 @@ impl ::buffa::DefaultInstance for DoubleValue {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for DoubleValue {
+    const FULL_NAME: &'static str = "google.protobuf.DoubleValue";
+}
 impl ::buffa::Message for DoubleValue {
     /// Returns the total encoded size in bytes.
     ///
@@ -171,6 +174,9 @@ impl ::buffa::DefaultInstance for FloatValue {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for FloatValue {
+    const FULL_NAME: &'static str = "google.protobuf.FloatValue";
+}
 impl ::buffa::Message for FloatValue {
     /// Returns the total encoded size in bytes.
     ///
@@ -310,6 +316,9 @@ impl ::buffa::DefaultInstance for Int64Value {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for Int64Value {
+    const FULL_NAME: &'static str = "google.protobuf.Int64Value";
+}
 impl ::buffa::Message for Int64Value {
     /// Returns the total encoded size in bytes.
     ///
@@ -449,6 +458,9 @@ impl ::buffa::DefaultInstance for UInt64Value {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for UInt64Value {
+    const FULL_NAME: &'static str = "google.protobuf.UInt64Value";
+}
 impl ::buffa::Message for UInt64Value {
     /// Returns the total encoded size in bytes.
     ///
@@ -588,6 +600,9 @@ impl ::buffa::DefaultInstance for Int32Value {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for Int32Value {
+    const FULL_NAME: &'static str = "google.protobuf.Int32Value";
+}
 impl ::buffa::Message for Int32Value {
     /// Returns the total encoded size in bytes.
     ///
@@ -727,6 +742,9 @@ impl ::buffa::DefaultInstance for UInt32Value {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for UInt32Value {
+    const FULL_NAME: &'static str = "google.protobuf.UInt32Value";
+}
 impl ::buffa::Message for UInt32Value {
     /// Returns the total encoded size in bytes.
     ///
@@ -866,6 +884,9 @@ impl ::buffa::DefaultInstance for BoolValue {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for BoolValue {
+    const FULL_NAME: &'static str = "google.protobuf.BoolValue";
+}
 impl ::buffa::Message for BoolValue {
     /// Returns the total encoded size in bytes.
     ///
@@ -1005,6 +1026,9 @@ impl ::buffa::DefaultInstance for StringValue {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for StringValue {
+    const FULL_NAME: &'static str = "google.protobuf.StringValue";
+}
 impl ::buffa::Message for StringValue {
     /// Returns the total encoded size in bytes.
     ///
@@ -1147,6 +1171,9 @@ impl ::buffa::DefaultInstance for BytesValue {
         VALUE.get_or_init(|| ::buffa::alloc::boxed::Box::new(Self::default()))
     }
 }
+impl ::buffa::MessageFullName for BytesValue {
+    const FULL_NAME: &'static str = "google.protobuf.BytesValue";
+}
 impl ::buffa::Message for BytesValue {
     /// Returns the total encoded size in bytes.
     ///
diff --git a/buffa-types/src/lib.rs b/buffa-types/src/lib.rs
index 3b63f04..ff472bf 100644
--- a/buffa-types/src/lib.rs
+++ b/buffa-types/src/lib.rs
@@ -87,3 +87,24 @@ pub use timestamp_ext::TimestampError;
 
 // Re-export the WKT registry function for `Any` JSON + text support.
 pub use any_ext::register_wkt_types;
+
+#[cfg(test)]
+mod full_name_tests {
+    use super::google::protobuf::*;
+    use buffa::MessageFullName;
+
+    // Regression test: the WKT FQNs are baked into Any type-URLs, JSON
+    // serialization, and the type registry. Codegen must keep emitting them
+    // verbatim — these strings are observable on the wire.
+    #[test]
+    fn well_known_types_full_names_match_proto() {
+        assert_eq!(Timestamp::FULL_NAME, "google.protobuf.Timestamp");
+        assert_eq!(Duration::FULL_NAME, "google.protobuf.Duration");
+        assert_eq!(Any::FULL_NAME, "google.protobuf.Any");
+        assert_eq!(Empty::FULL_NAME, "google.protobuf.Empty");
+        assert_eq!(FieldMask::FULL_NAME, "google.protobuf.FieldMask");
+        assert_eq!(Struct::FULL_NAME, "google.protobuf.Struct");
+        assert_eq!(Value::FULL_NAME, "google.protobuf.Value");
+        assert_eq!(ListValue::FULL_NAME, "google.protobuf.ListValue");
+    }
+}
diff --git a/buffa/src/extension.rs b/buffa/src/extension.rs
index d6643c1..e433fcb 100644
--- a/buffa/src/extension.rs
+++ b/buffa/src/extension.rs
@@ -215,6 +215,18 @@ pub trait ExtensionSet {
     /// Checked against [`Extension::extendee`] on every `extension()`,
     /// `set_extension()`, and `clear_extension()` call. A mismatch panics:
     /// passing an extension for the wrong message is a bug in the caller.
+    ///
+    /// Equal to [`MessageFullName::FULL_NAME`](crate::MessageFullName::FULL_NAME)
+    /// for generated messages — both come from the same `proto_fqn` in
+    /// codegen. Hand-written impls that implement both traits must keep the
+    /// two strings in sync; a mismatch surfaces as a runtime panic on
+    /// extension access rather than at compile time.
+    ///
+    /// If you only need the message's full name (no extension access), prefer
+    /// [`MessageFullName::FULL_NAME`](crate::MessageFullName::FULL_NAME): it
+    /// is a standalone trait that doesn't require the extension machinery or
+    /// the `unknown_fields=true` codegen option (which adds an
+    /// `__buffa_unknown_fields` storage field to the generated struct).
     const PROTO_FQN: &'static str;
 
     /// Immutable access to the extendee's unknown-field storage.
diff --git a/buffa/src/lib.rs b/buffa/src/lib.rs
index 77e888e..78bb575 100644
--- a/buffa/src/lib.rs
+++ b/buffa/src/lib.rs
@@ -83,6 +83,7 @@
 //! | Type | Purpose |
 //! |------|---------|
 //! | [`Message`] | Core trait for encode / decode / merge |
+//! | [`MessageFullName`] | Compile-time `FULL_NAME` const (`"pkg.Msg"`) for generic dispatch |
 //! | [`DecodeOptions`] | Configurable recursion and size limits |
 //! | [`MessageField<T>`](MessageField) | Optional sub-message with transparent `Deref` to default |
 //! | [`EnumValue<E>`](EnumValue) | Open enum wrapper (`Known(E)` / `Unknown(i32)`) |
@@ -199,7 +200,7 @@ pub mod view;
 pub use enumeration::{EnumValue, Enumeration};
 pub use error::{DecodeError, EncodeError};
 pub use extension::{Extension, ExtensionCodec, ExtensionSet};
-pub use message::{DecodeOptions, Message, RECURSION_LIMIT};
+pub use message::{DecodeOptions, Message, MessageFullName, RECURSION_LIMIT};
 pub use message_field::{DefaultInstance, MessageField};
 pub use oneof::Oneof;
 pub use size_cache::SizeCache;
diff --git a/buffa/src/message.rs b/buffa/src/message.rs
index 248b7fb..50c5043 100644
--- a/buffa/src/message.rs
+++ b/buffa/src/message.rs
@@ -417,6 +417,40 @@ pub trait Message: DefaultInstance + Clone + PartialEq + Send + Sync {
     fn clear(&mut self);
 }
 
+/// Provides compile-time access to a generated message's protobuf full name.
+///
+/// This exists for generic code that needs to name message types without going
+/// through runtime reflection or descriptor APIs.
+///
+/// Bring `buffa::MessageFullName` into scope to use `MyMessage::FULL_NAME`.
+/// Without the trait in scope, use
+/// `<MyMessage as buffa::MessageFullName>::FULL_NAME`.
+///
+/// Codegen emits this for every generated message. Hand-written [`Message`]
+/// implementations can opt in by also implementing `MessageFullName`; it is
+/// a separate trait specifically so that omitting it stays non-breaking.
+///
+/// For messages that also implement [`ExtensionSet`](crate::ExtensionSet),
+/// this value is guaranteed equal to
+/// [`ExtensionSet::PROTO_FQN`](crate::ExtensionSet::PROTO_FQN) — both come
+/// from the same `proto_fqn` source in codegen.
+///
+/// Because the only item is an associated `const`, this trait is **not**
+/// object-safe (`dyn MessageFullName` does not compile). Use it as a
+/// generic bound (`fn foo<T: MessageFullName>()`), not a trait object.
+pub trait MessageFullName: Message {
+    /// The protobuf full name for the generated message type.
+    ///
+    /// Fully-qualified, with no leading dot. For a message `Foo` declared in
+    /// package `my.pkg` this is `"my.pkg.Foo"`. For a nested message
+    /// `my.pkg.Outer.Inner` it is `"my.pkg.Outer.Inner"`. For a message in
+    /// the unnamed root package it is the bare message name (e.g. `"Foo"`).
+    ///
+    /// Resolves at compile time — `T::FULL_NAME` is a `&'static str` literal
+    /// in the binary's read-only data, with no runtime cost.
+    const FULL_NAME: &'static str;
+}
+
 /// Options for configuring message decoding behavior.
 ///
 /// Use this to set custom recursion depth limits or maximum message sizes
diff --git a/docs/guide.md b/docs/guide.md
index abca78d..491fc96 100644
--- a/docs/guide.md
+++ b/docs/guide.md
@@ -1555,6 +1555,13 @@ Note what's *not* needed:
 
 - **`UnknownFields`** — omitted since this is a simple leaf type where round-trip preservation of unknown fields isn't important. Unknown tags are silently skipped via `skip_field`.
 - **Any size-caching field** — sizes live in the external `SizeCache` threaded through `compute_size` / `write_to`. A leaf type like this doesn't touch the cache; types with nested message fields reserve a slot before recursing (see the `compute_size` comment above).
+- **`MessageFullName`** — opt-in. Implement it on your extern-mapped type if you have generic code that dispatches on `T::FULL_NAME` (event stores, type registries, `Any` type-URL construction); otherwise leave it off:
+
+  ```rust,ignore
+  impl buffa::MessageFullName for Int64Range {
+      const FULL_NAME: &'static str = "my.common.Int64Range";
+  }
+  ```
 
 ### View types for custom implementations
 
diff --git a/examples/logging/src/gen/buffa.examples.context.v1.mod.rs b/examples/logging/src/gen/buffa.examples.context.v1.mod.rs
index 571428b..1f41483 100644
--- a/examples/logging/src/gen/buffa.examples.context.v1.mod.rs
+++ b/examples/logging/src/gen/buffa.examples.context.v1.mod.rs
@@ -5,6 +5,7 @@ include!("context.v1.context.rs");
     non_camel_case_types,
     dead_code,
     unused_imports,
+    unused_qualifications,
     clippy::derivable_impls,
     clippy::match_single_binding,
     clippy::uninlined_format_args,
diff --git a/examples/logging/src/gen/buffa.examples.log.v1.mod.rs b/examples/logging/src/gen/buffa.examples.log.v1.mod.rs
index c6c5cfa..70fc688 100644
--- a/examples/logging/src/gen/buffa.examples.log.v1.mod.rs
+++ b/examples/logging/src/gen/buffa.examples.log.v1.mod.rs
@@ -5,6 +5,7 @@ include!("log.v1.log.rs");
     non_camel_case_types,
     dead_code,
     unused_imports,
+    unused_qualifications,
     clippy::derivable_impls,
     clippy::match_single_binding,
     clippy::uninlined_format_args,
diff --git a/examples/logging/src/gen/mod.rs b/examples/logging/src/gen/mod.rs
index 03ada66..b64f0d8 100644
--- a/examples/logging/src/gen/mod.rs
+++ b/examples/logging/src/gen/mod.rs
@@ -1,25 +1,25 @@
 // @generated by buffa-codegen. DO NOT EDIT.
-#![allow(non_camel_case_types, dead_code, unused_imports, clippy::derivable_impls, clippy::match_single_binding, clippy::uninlined_format_args, clippy::doc_lazy_continuation, clippy::module_inception)]
+#![allow(non_camel_case_types, dead_code, unused_imports, unused_qualifications, clippy::derivable_impls, clippy::match_single_binding, clippy::uninlined_format_args, clippy::doc_lazy_continuation, clippy::module_inception)]
 
-#[allow(non_camel_case_types, dead_code, unused_imports, clippy::derivable_impls, clippy::match_single_binding, clippy::uninlined_format_args, clippy::doc_lazy_continuation, clippy::module_inception)]
+#[allow(non_camel_case_types, dead_code, unused_imports, unused_qualifications, clippy::derivable_impls, clippy::match_single_binding, clippy::uninlined_format_args, clippy::doc_lazy_continuation, clippy::module_inception)]
 pub mod buffa {
     use super::*;
-    #[allow(non_camel_case_types, dead_code, unused_imports, clippy::derivable_impls, clippy::match_single_binding, clippy::uninlined_format_args, clippy::doc_lazy_continuation, clippy::module_inception)]
+    #[allow(non_camel_case_types, dead_code, unused_imports, unused_qualifications, clippy::derivable_impls, clippy::match_single_binding, clippy::uninlined_format_args, clippy::doc_lazy_continuation, clippy::module_inception)]
     pub mod examples {
         use super::*;
-        #[allow(non_camel_case_types, dead_code, unused_imports, clippy::derivable_impls, clippy::match_single_binding, clippy::uninlined_format_args, clippy::doc_lazy_continuation, clippy::module_inception)]
+        #[allow(non_camel_case_types, dead_code, unused_imports, unused_qualifications, clippy::derivable_impls, clippy::match_single_binding, clippy::uninlined_format_args, clippy::doc_lazy_continuation, clippy::module_inception)]
         pub mod context {
             use super::*;
-            #[allow(non_camel_case_types, dead_code, unused_imports, clippy::derivable_impls, clippy::match_single_binding, clippy::uninlined_format_args, clippy::doc_lazy_continuation, clippy::module_inception)]
+            #[allow(non_camel_case_types, dead_code, unused_imports, unused_qualifications, clippy::derivable_impls, clippy::match_single_binding, clippy::uninlined_format_args, clippy::doc_lazy_continuation, clippy::module_inception)]
             pub mod v1 {
                 use super::*;
                 include!("buffa.examples.context.v1.mod.rs");
             }
         }
-        #[allow(non_camel_case_types, dead_code, unused_imports, clippy::derivable_impls, clippy::match_single_binding, clippy::uninlined_format_args, clippy::doc_lazy_continuation, clippy::module_inception)]
+        #[allow(non_camel_case_types, dead_code, unused_imports, unused_qualifications, clippy::derivable_impls, clippy::match_single_binding, clippy::uninlined_format_args, clippy::doc_lazy_continuation, clippy::module_inception)]
         pub mod log {
             use super::*;
-            #[allow(non_camel_case_types, dead_code, unused_imports, clippy::derivable_impls, clippy::match_single_binding, clippy::uninlined_format_args, clippy::doc_lazy_continuation, clippy::module_inception)]
+            #[allow(non_camel_case_types, dead_code, unused_imports, unused_qualifications, clippy::derivable_impls, clippy::match_single_binding, clippy::uninlined_format_args, clippy::doc_lazy_continuation, clippy::module_inception)]
             pub mod v1 {
                 use super::*;
                 include!("buffa.examples.log.v1.mod.rs");