refactor: add type field to SystemPromptPreset

Update SystemPromptPreset to include required type: "preset" field
alongside preset: "claude_code", matching the TypeScript SDK structure.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: ashwin-ant

examples/system_prompt.py

@@ -44,7 +44,7 @@ async def preset_system_prompt():
     print("=== Preset System Prompt (Default) ===")
 
     options = ClaudeCodeOptions(
-        system_prompt={"preset": "claude_code"},
+        system_prompt={"type": "preset", "preset": "claude_code"},
     )
 
     async for message in query(prompt="What is 2 + 2?", options=options):
@@ -61,6 +61,7 @@ async def preset_with_append():
 
     options = ClaudeCodeOptions(
         system_prompt={
+            "type": "preset",
             "preset": "claude_code",
             "append": "Always end your response with a fun fact.",
         },

src/claude_code_sdk/_internal/transport/subprocess_cli.py

@@ -90,7 +90,10 @@ def _build_command(self) -> list[str]:
         elif isinstance(self._options.system_prompt, str):
             cmd.extend(["--system-prompt", self._options.system_prompt])
         else:
-            if "append" in self._options.system_prompt:
+            if (
+                self._options.system_prompt.get("type") == "preset"
+                and "append" in self._options.system_prompt
+            ):
                 cmd.extend(
                     ["--append-system-prompt", self._options.system_prompt["append"]]
                 )

src/claude_code_sdk/types.py

@@ -21,6 +21,7 @@
 class SystemPromptPreset(TypedDict):
     """System prompt preset configuration."""
 
+    type: Literal["preset"]
     preset: Literal["claude_code"]
     append: NotRequired[str]
 

tests/test_transport.py

@@ -71,7 +71,7 @@ def test_build_command_with_system_prompt_preset(self):
         transport = SubprocessCLITransport(
             prompt="test",
             options=ClaudeCodeOptions(
-                system_prompt={"preset": "claude_code"},
+                system_prompt={"type": "preset", "preset": "claude_code"},
             ),
             cli_path="/usr/bin/claude",
         )
@@ -85,7 +85,11 @@ def test_build_command_with_system_prompt_preset_and_append(self):
         transport = SubprocessCLITransport(
             prompt="test",
             options=ClaudeCodeOptions(
-                system_prompt={"preset": "claude_code", "append": "Be concise."},
+                system_prompt={
+                    "type": "preset",
+                    "preset": "claude_code",
+                    "append": "Be concise.",
+                },
             ),
             cli_path="/usr/bin/claude",
         )

tests/test_types.py

@@ -117,16 +117,21 @@ def test_claude_code_options_with_system_prompt_string(self):
     def test_claude_code_options_with_system_prompt_preset(self):
         """Test Options with system prompt preset."""
         options = ClaudeCodeOptions(
-            system_prompt={"preset": "claude_code"},
+            system_prompt={"type": "preset", "preset": "claude_code"},
         )
-        assert options.system_prompt == {"preset": "claude_code"}
+        assert options.system_prompt == {"type": "preset", "preset": "claude_code"}
 
     def test_claude_code_options_with_system_prompt_preset_and_append(self):
         """Test Options with system prompt preset and append."""
         options = ClaudeCodeOptions(
-            system_prompt={"preset": "claude_code", "append": "Be concise."},
+            system_prompt={
+                "type": "preset",
+                "preset": "claude_code",
+                "append": "Be concise.",
+            },
         )
         assert options.system_prompt == {
+            "type": "preset",
             "preset": "claude_code",
             "append": "Be concise.",
         }