1 files changed, 30 insertions, 4 deletions
diff --git a/src/mcp_sd15/schema.py b/src/mcp_sd15/schema.py
index e22450d..184cc8d 100644
--- a/src/mcp_sd15/schema.py
+++ b/src/mcp_sd15/schema.py
@@ -49,6 +49,14 @@ def _size(value: str | ImageSize | None, default: str) -> ImageSize:
         raise InvalidRequestError(f"unsupported size: {value}") from exc
 
 
+def _combine(base: str, user: str, *, separator: str) -> str:
+    if not base:
+        return user
+    if not user:
+        return base
+    return f"{base}{separator}{user}"
+
+
 @dataclass(frozen=True)
 class TextToImageRequest:
     positive_prompt: str
@@ -63,10 +71,14 @@ class TextToImageRequest:
         size: str | ImageSize | None = None,
         *,
         default_size: str = ImageSize.SQUARE_512,
+        base_positive: str = "",
+        base_negative: str = "",
     ) -> TextToImageRequest:
+        user_positive = _prompt(positive_prompt, "positive_prompt", required=True)
+        user_negative = _prompt(negative_prompt, "negative_prompt", required=False)
         return cls(
-            _prompt(positive_prompt, "positive_prompt", required=True),
-            _prompt(negative_prompt, "negative_prompt", required=False),
+            _combine(base_positive, user_positive, separator=", "),
+            _combine(base_negative, user_negative, separator="\n"),
             _size(size, default_size),
         )
 
@@ -89,9 +101,16 @@ class GuidedImageRequest:
         size: str | ImageSize | None = None,
         *,
         default_size: str = ImageSize.SQUARE_512,
+        base_positive: str = "",
+        base_negative: str = "",
     ) -> GuidedImageRequest:
         base = TextToImageRequest.create(
-            positive_prompt, negative_prompt, size, default_size=default_size
+            positive_prompt,
+            negative_prompt,
+            size,
+            default_size=default_size,
+            base_positive=base_positive,
+            base_negative=base_negative,
         )
         try:
             mode = ControlMode(control_mode)
@@ -120,9 +139,16 @@ class InpaintImageRequest:
         size: str | ImageSize | None = None,
         *,
         default_size: str = ImageSize.SQUARE_512,
+        base_positive: str = "",
+        base_negative: str = "",
     ) -> InpaintImageRequest:
         base = TextToImageRequest.create(
-            positive_prompt, negative_prompt, size, default_size=default_size
+            positive_prompt,
+            negative_prompt,
+            size,
+            default_size=default_size,
+            base_positive=base_positive,
+            base_negative=base_negative,
         )
         for label, value in (("input_image", input_image), ("mask_image", mask_image)):
             if not isinstance(value, str) or not value.strip():