engine/app.py

@@ -51,6 +51,7 @@ def run_pipeline_mode(preset_name: str = "demo"):
     from engine.fetch import fetch_all, fetch_poetry, load_cache
     from engine.pipeline.adapters import (
         RenderStage,
+        SourceItemsToBufferStage,
         create_items_stage,
         create_stage_from_display,
         create_stage_from_effect,
@@ -85,6 +86,16 @@ def run_pipeline_mode(preset_name: str = "demo"):
     )
 
     print("  \033[38;5;245mFetching content...\033[0m")
+
+    # Handle special sources that don't need traditional fetching
+    introspection_source = None
+    if preset.source == "pipeline-inspect":
+        items = []
+        print("  \033[38;5;245mUsing pipeline introspection source\033[0m")
+    elif preset.source == "empty":
+        items = []
+        print("  \033[38;5;245mUsing empty source (no content)\033[0m")
+    else:
         cached = load_cache()
         if cached:
             items = cached
@@ -108,7 +119,34 @@ def run_pipeline_mode(preset_name: str = "demo"):
 
     effect_registry = get_registry()
 
+    # Create source stage based on preset source type
+    if preset.source == "pipeline-inspect":
+        from engine.data_sources.pipeline_introspection import (
+            PipelineIntrospectionSource,
+        )
+        from engine.pipeline.adapters import DataSourceStage
+
+        introspection_source = PipelineIntrospectionSource(
+            pipeline=None,  # Will be set after pipeline.build()
+            viewport_width=80,
+            viewport_height=24,
+        )
+        pipeline.add_stage(
+            "source", DataSourceStage(introspection_source, name="pipeline-inspect")
+        )
+    elif preset.source == "empty":
+        from engine.data_sources.sources import EmptyDataSource
+        from engine.pipeline.adapters import DataSourceStage
+
+        empty_source = EmptyDataSource(width=80, height=24)
+        pipeline.add_stage("source", DataSourceStage(empty_source, name="empty"))
+    else:
         pipeline.add_stage("source", create_items_stage(items, preset.source))
+
+    # Add appropriate render stage
+    if preset.source in ("pipeline-inspect", "empty"):
+        pipeline.add_stage("render", SourceItemsToBufferStage(name="items-to-buffer"))
+    else:
         pipeline.add_stage(
             "render",
             RenderStage(
@@ -132,6 +170,10 @@ def run_pipeline_mode(preset_name: str = "demo"):
 
     pipeline.build()
 
+    # For pipeline-inspect, set the pipeline after build to avoid circular dependency
+    if introspection_source is not None:
+        introspection_source.set_pipeline(pipeline)
+
     if not pipeline.initialize():
         print("  \033[38;5;196mFailed to initialize pipeline\033[0m")
         sys.exit(1)
@@ -162,7 +204,7 @@ def run_pipeline_mode(preset_name: str = "demo"):
 
             result = pipeline.execute(items)
             if result.success:
-                display.show(result.data)
+                display.show(result.data, border=params.border)
 
             if hasattr(display, "is_quit_requested") and display.is_quit_requested():
                 if hasattr(display, "clear_quit_request"):

engine/display/backends/multi.py

@@ -30,9 +30,9 @@ class MultiDisplay:
         for d in self.displays:
             d.init(width, height, reuse=reuse)
 
-    def show(self, buffer: list[str]) -> None:
+    def show(self, buffer: list[str], border: bool = False) -> None:
         for d in self.displays:
-            d.show(buffer)
+            d.show(buffer, border=border)
 
     def clear(self) -> None:
         for d in self.displays:

engine/display/backends/websocket.py

@@ -24,7 +24,7 @@ class Display(Protocol):
         """Initialize display with dimensions."""
         ...
 
-    def show(self, buffer: list[str]) -> None:
+    def show(self, buffer: list[str], border: bool = False) -> None:
         """Show buffer on display."""
         ...
 

tests/test_display.py

@@ -165,10 +165,10 @@ class TestMultiDisplay:
         multi = MultiDisplay([mock_display1, mock_display2])
 
         buffer = ["line1", "line2"]
-        multi.show(buffer)
+        multi.show(buffer, border=False)
 
-        mock_display1.show.assert_called_once_with(buffer)
+        mock_display1.show.assert_called_once_with(buffer, border=False)
-        mock_display2.show.assert_called_once_with(buffer)
+        mock_display2.show.assert_called_once_with(buffer, border=False)
 
     def test_clear_forwards_to_all_displays(self):
         """clear forwards to all displays."""