chore: import upstream snapshot with attribution

examples/snippets/servers/completion.py

@@ -0,0 +1,50 @@
+from mcp_types import (
+    Completion,
+    CompletionArgument,
+    CompletionContext,
+    PromptReference,
+    ResourceTemplateReference,
+)
+
+from mcp.server.mcpserver import MCPServer
+
+mcp = MCPServer(name="Example")
+
+
+@mcp.resource("github://repos/{owner}/{repo}")
+def github_repo(owner: str, repo: str) -> str:
+    """GitHub repository resource."""
+    return f"Repository: {owner}/{repo}"
+
+
+@mcp.prompt(description="Code review prompt")
+def review_code(language: str, code: str) -> str:
+    """Generate a code review."""
+    return f"Review this {language} code:\n{code}"
+
+
+@mcp.completion()
+async def handle_completion(
+    ref: PromptReference | ResourceTemplateReference,
+    argument: CompletionArgument,
+    context: CompletionContext | None,
+) -> Completion | None:
+    """Provide completions for prompts and resources."""
+
+    # Complete programming languages for the prompt
+    if isinstance(ref, PromptReference):
+        if ref.name == "review_code" and argument.name == "language":
+            languages = ["python", "javascript", "typescript", "go", "rust"]
+            return Completion(
+                values=[lang for lang in languages if lang.startswith(argument.value)],
+                has_more=False,
+            )
+
+    # Complete repository names for GitHub resources
+    if isinstance(ref, ResourceTemplateReference):
+        if ref.uri == "github://repos/{owner}/{repo}" and argument.name == "repo":
+            if context and context.arguments and context.arguments.get("owner") == "modelcontextprotocol":
+                repos = ["python-sdk", "typescript-sdk", "specification"]
+                return Completion(values=repos, has_more=False)
+
+    return None