diff --git a/src/lettermint/endpoints/api.py b/src/lettermint/endpoints/api.py
index 78e730f..8d52cc3 100644
--- a/src/lettermint/endpoints/api.py
+++ b/src/lettermint/endpoints/api.py
@@ -96,9 +96,9 @@ def cancel(self, message_id: str) -> lm_types.RescheduleMessageResponse:
             ),
         )
 
-    def process(self, message_id: str) -> dict[str, Any]:
+    def process(self, message_id: str) -> lm_types.ProcessInboundMessageResponse:
         return cast(
-            dict[str, Any],
+            lm_types.ProcessInboundMessageResponse,
             self._client.post(
                 self._path("/messages/{messageId}/process", messageId=message_id), data={}
             ),
@@ -382,9 +382,9 @@ async def cancel(self, message_id: str) -> lm_types.RescheduleMessageResponse:
             ),
         )
 
-    async def process(self, message_id: str) -> dict[str, Any]:
+    async def process(self, message_id: str) -> lm_types.ProcessInboundMessageResponse:
         return cast(
-            dict[str, Any],
+            lm_types.ProcessInboundMessageResponse,
             await self._client.post(
                 self._path("/messages/{messageId}/process", messageId=message_id), data={}
             ),
diff --git a/src/lettermint/types.py b/src/lettermint/types.py
index 7d2c641..4b012f5 100644
--- a/src/lettermint/types.py
+++ b/src/lettermint/types.py
@@ -887,6 +887,12 @@
 )
 
 MessageShowResponse: TypeAlias = MessageData
+ProcessInboundMessageResponse = TypedDict(
+    "ProcessInboundMessageResponse",
+    {
+        "data": "Required[dict[str, str | int]]",
+    },
+)
 MessageEventsResponse = TypedDict(
     "MessageEventsResponse",
     {