diff --git a/pdl-live-react/src/pdl_ast.d.ts b/pdl-live-react/src/pdl_ast.d.ts
index 45c3b24b8..a8d769932 100644
--- a/pdl-live-react/src/pdl_ast.d.ts
+++ b/pdl-live-react/src/pdl_ast.d.ts
@@ -697,7 +697,7 @@ export type Fallback5 =
   | EmptyBlock
   | null
 /**
- * Role of associated to the message.
+ * Role associated to the block and sub-blocks.
  * Typical roles are `system`, `user`, and `assistant`,
  * but there may be other roles such as `available_tools`.
  */
@@ -716,7 +716,7 @@ export type Context5 =
  *
  */
 export type PdlId5 = string | null
-export type PdlIsLeaf5 = false
+export type PdlIsLeaf5 = true
 export type Kind5 = "message"
 export type Content =
   | boolean
@@ -3491,7 +3491,7 @@ export interface MessageBlock {
   contribute?: Contribute5
   parser?: Parser5
   fallback?: Fallback5
-  role: Role5
+  role?: Role5
   context?: Context5
   pdl__id?: PdlId5
   pdl__result?: unknown
diff --git a/src/pdl/pdl-schema.json b/src/pdl/pdl-schema.json
index 334e18911..d04826128 100644
--- a/src/pdl/pdl-schema.json
+++ b/src/pdl/pdl-schema.json
@@ -7981,7 +7981,8 @@
               "type": "null"
             }
           ],
-          "description": "Role of associated to the message.\nTypical roles are `system`, `user`, and `assistant`,\nbut there may be other roles such as `available_tools`.",
+          "default": null,
+          "description": "Role associated to the block and sub-blocks.\nTypical roles are `system`, `user`, and `assistant`,\nbut there may be other roles such as `available_tools`.",
           "title": "Role"
         },
         "context": {
@@ -8048,8 +8049,8 @@
           "default": null
         },
         "pdl__is_leaf": {
-          "const": false,
-          "default": false,
+          "const": true,
+          "default": true,
           "title": "Pdl  Is Leaf",
           "type": "boolean"
         },
@@ -8176,7 +8177,6 @@
         }
       },
       "required": [
-        "role",
         "content"
       ],
       "title": "MessageBlock",
diff --git a/src/pdl/pdl_ast.py b/src/pdl/pdl_ast.py
index 27b4f95c3..481dba588 100644
--- a/src/pdl/pdl_ast.py
+++ b/src/pdl/pdl_ast.py
@@ -580,15 +580,10 @@ class ObjectBlock(StructuredBlock):
     object: dict[str, "BlockType"] | list["BlockType"]
 
 
-class MessageBlock(StructuredBlock):
+class MessageBlock(LeafBlock):
     """Create a message."""
 
     kind: Literal[BlockKind.MESSAGE] = BlockKind.MESSAGE
-    role: RoleType  # pyright: ignore
-    """Role of associated to the message.
-    Typical roles are `system`, `user`, and `assistant`,
-    but there may be other roles such as `available_tools`.
-    """  # pyright: ignore
     content: "BlockType"
     """Content of the message."""
     name: Optional[ExpressionType[str]] = None
diff --git a/src/pdl/pdl_interpreter.py b/src/pdl/pdl_interpreter.py
index 973d9eed7..f6bacc23b 100644
--- a/src/pdl/pdl_interpreter.py
+++ b/src/pdl/pdl_interpreter.py
@@ -570,28 +570,26 @@ def process_block_body(
             if state.yield_result and not iteration_state.yield_result:
                 yield_result(result, block.kind)
         case MessageBlock():
-            content, background, scope, trace = process_block_of(
+            content, _, scope, trace = process_block_of(
                 block,
                 "content",
                 state,
                 scope,
                 loc,
             )
-            name, block = process_expr_of(
-                block, "name", scope, loc  # pyright: ignore
-            )  # pyright: ignore
-            tool_call_id, block = process_expr_of(
-                block, "tool_call_id", scope, loc  # pyright: ignore
-            )  # pyright: ignore
-            result = PdlDict(
-                {
-                    "role": state.role,
-                    "content": content,
-                    "name": name,
-                    "tool_call_id": tool_call_id,
-                    "defsite": block.pdl__id,
-                }
-            )
+            d = {
+                "role": state.role,
+                "content": content,
+                "defsite": block.pdl__id,
+            }
+            if block.name is not None:
+                name, block = process_expr_of(block, "name", scope, loc)
+                d["name"] = name
+            if block.tool_call_id is not None:
+                tool_call_id, block = process_expr_of(block, "tool_call_id", scope, loc)
+                d["tool_call_id"] = tool_call_id
+            result = PdlDict(d)
+            background = PdlList([result])
         case IfBlock():
             b, if_trace = process_condition_of(block, "condition", scope, loc, "if")
             if b:
diff --git a/tests/test_messages.py b/tests/test_messages.py
index 828488435..b02badf82 100644
--- a/tests/test_messages.py
+++ b/tests/test_messages.py
@@ -1,7 +1,7 @@
 from pdl.pdl import exec_str
 
 
-def test_messages1():
+def test_message1():
     prog_str = """
 description: Messages block
 array:
@@ -17,15 +17,11 @@ def test_messages1():
             "role": "system",
             "content": "You are a helpful software engineer. You write clear, concise, well-commented code.",
             "defsite": "array.0.message",
-            "name": None,
-            "tool_call_id": None,
         },
         {
             "role": "user",
             "content": "Write a Python function that implement merge sort.",
             "defsite": "array.1.message",
-            "name": None,
-            "tool_call_id": None,
         },
     ]
     assert context == [
@@ -40,3 +36,73 @@ def test_messages1():
             "defsite": "array.1.message",
         },
     ]
+
+
+def test_message2():
+    prog_str = """
+description: Messages block
+role: user
+content:
+    array:
+    - Hello
+    - Bye
+"""
+    result = exec_str(prog_str, output="all")
+    context = result["scope"]["pdl_context"]
+    assert result["result"] == {
+        "role": "user",
+        "content": ["Hello", "Bye"],
+        "defsite": "message",
+    }
+    assert context == [
+        {
+            "role": "user",
+            "content": ["Hello", "Bye"],
+            "defsite": "message",
+        },
+    ]
+
+
+def test_message3():
+    prog_str = """
+description: Messages block
+content:
+    data: {"a": 1}
+"""
+    result = exec_str(prog_str, output="all")
+    context = result["scope"]["pdl_context"]
+    assert result["result"] == {
+        "role": "user",
+        "content": {"a": 1},
+        "defsite": "message",
+    }
+    assert context == [
+        {
+            "role": "user",
+            "content": {"a": 1},
+            "defsite": "message",
+        },
+    ]
+
+
+def test_message4():
+    prog_str = """
+description: Messages block
+content:
+    text:
+      data: {"a": 1}
+"""
+    result = exec_str(prog_str, output="all")
+    context = result["scope"]["pdl_context"]
+    assert result["result"] == {
+        "role": "user",
+        "content": '{"a": 1}',
+        "defsite": "message",
+    }
+    assert context == [
+        {
+            "role": "user",
+            "content": '{"a": 1}',
+            "defsite": "message",
+        },
+    ]