Extend resolver DI to sampling and roots requests (#3049)

docs_src/sampling_and_roots/tutorial001.py

@@ -0,0 +1,22 @@
+from typing import Annotated
+
+from mcp_types import CreateMessageResult, SamplingMessage, TextContent
+
+from mcp.server import MCPServer
+from mcp.server.mcpserver import Resolve, Sample
+
+mcp = MCPServer("Bookshop")
+
+
+def draft_blurb(title: str) -> Sample:
+    prompt = f"Write a one-sentence blurb for the book {title!r}."
+    return Sample(
+        [SamplingMessage(role="user", content=TextContent(type="text", text=prompt))],
+        max_tokens=60,
+    )
+
+
+@mcp.tool()
+async def blurb(title: str, draft: Annotated[CreateMessageResult, Resolve(draft_blurb)]) -> str:
+    """Draft a blurb for a book."""
+    return draft.content.text if draft.content.type == "text" else "No blurb."

docs_src/sampling_and_roots/tutorial002.py

@@ -0,0 +1,20 @@
+from typing import Annotated
+
+from mcp_types import ListRootsResult
+
+from mcp.server import MCPServer
+from mcp.server.mcpserver import ListRoots, Resolve
+
+mcp = MCPServer("Bookshop")
+
+
+def workspace_roots() -> ListRoots:
+    return ListRoots()
+
+
+@mcp.tool()
+async def catalog_folder(roots: Annotated[ListRootsResult, Resolve(workspace_roots)]) -> str:
+    """Pick the folder the catalog export should go to."""
+    if not roots.roots:
+        return "No workspace folders shared."
+    return str(roots.roots[0].uri)