Exercise the SEP-2575 stateless probes and SEP-2243 resource/prompt headers in the conformance fixtures (#3442)

examples/clients/simple-chatbot/README.md

@@ -0,0 +1,113 @@
+# MCP Simple Chatbot
+
+This example demonstrates how to integrate the Model Context Protocol (MCP) into a simple CLI chatbot. The implementation showcases MCP's flexibility by supporting multiple tools through MCP servers and is compatible with any LLM provider that follows OpenAI API standards.
+
+## Requirements
+
+- Python 3.10
+- `python-dotenv`
+- `requests`
+- `mcp`
+- `uvicorn`
+
+## Installation
+
+1. **Install the dependencies:**
+
+   ```bash
+   pip install -r requirements.txt
+   ```
+
+2. **Set up environment variables:**
+
+   Create a `.env` file in the root directory and add your API key:
+
+   ```plaintext
+   LLM_API_KEY=your_api_key_here
+   ```
+
+   **Note:** The current implementation is configured to use the Groq API endpoint (`https://api.groq.com/openai/v1/chat/completions`) with the `llama-3.2-90b-vision-preview` model. If you plan to use a different LLM provider, you'll need to modify the `LLMClient` class in `main.py` to use the appropriate endpoint URL and model parameters.
+
+3. **Configure servers:**
+
+   The `servers_config.json` follows the same structure as Claude Desktop, allowing for easy integration of multiple servers.
+   Here's an example:
+
+   ```json
+   {
+     "mcpServers": {
+       "sqlite": {
+         "command": "uvx",
+         "args": ["mcp-server-sqlite", "--db-path", "./test.db"]
+       },
+       "puppeteer": {
+         "command": "npx",
+         "args": ["-y", "@modelcontextprotocol/server-puppeteer"]
+       }
+     }
+   }
+   ```
+
+   Environment variables are supported as well. Pass them as you would with the Claude Desktop App.
+
+   Example:
+
+   ```json
+   {
+     "mcpServers": {
+       "server_name": {
+         "command": "uvx",
+         "args": ["mcp-server-name", "--additional-args"],
+         "env": {
+           "API_KEY": "your_api_key_here"
+         }
+       }
+     }
+   }
+   ```
+
+## Usage
+
+1. **Run the client:**
+
+   ```bash
+   python main.py
+   ```
+
+2. **Interact with the assistant:**
+
+   The assistant will automatically detect available tools and can respond to queries based on the tools provided by the configured servers.
+
+3. **Exit the session:**
+
+   Type `quit` or `exit` to end the session.
+
+## Architecture
+
+- **Tool Discovery**: Tools are automatically discovered from configured servers.
+- **System Prompt**: Tools are dynamically included in the system prompt, allowing the LLM to understand available capabilities.
+- **Server Integration**: Supports any MCP-compatible server, tested with various server implementations including Uvicorn and Node.js.
+
+### Class Structure
+
+- **Configuration**: Manages environment variables and server configurations
+- **Server**: Handles MCP server initialization, tool discovery, and execution
+- **Tool**: Represents individual tools with their properties and formatting
+- **LLMClient**: Manages communication with the LLM provider
+- **ChatSession**: Orchestrates the interaction between user, LLM, and tools
+
+### Logic Flow
+
+1. **Tool Integration**:
+   - Tools are dynamically discovered from MCP servers
+   - Tool descriptions are automatically included in system prompt
+   - Tool execution is handled through standardized MCP protocol
+
+2. **Runtime Flow**:
+   - User input is received
+   - Input is sent to LLM with context of available tools
+   - LLM response is parsed:
+     - If it's a tool call → execute tool and return result
+     - If it's a direct response → return to user
+   - Tool results are sent back to LLM for interpretation
+   - Final response is presented to user

examples/servers/everything-server/mcp_everything_server/server.py

@@ -12,7 +12,7 @@ from typing import Annotated, Any
 
 import click
 from mcp.server import ServerRequestContext
-from mcp.server.mcpserver import Context, MCPServer, RequestStateSecurity
+from mcp.server.mcpserver import Context, Elicit, ElicitationResult, MCPServer, RequestStateSecurity, Resolve
 from mcp.server.mcpserver.exceptions import ToolError
 from mcp.server.mcpserver.prompts.base import Prompt, UserMessage
 from mcp.server.streamable_http import EventCallback, EventMessage, EventStore
@@ -350,6 +350,9 @@ def test_x_mcp_header(
     return f"region={region}"
 
 
+# SEP-2575 server-stateless diagnostics (the conformance scenario probes these tools by name)
+
+
 @mcp.tool()
 async def test_missing_capability(ctx: Context) -> str:
     """Tests that a handler-raised MISSING_REQUIRED_CLIENT_CAPABILITY surfaces as a top-level JSON-RPC error.
@@ -370,6 +373,33 @@ async def test_missing_capability(ctx: Context) -> str:
     return "Client declared sampling capability; proceeding."
 
 
+def _ask_stream_probe() -> Elicit[UserResponse]:
+    return Elicit("The stateless streaming probe asks for a word", UserResponse)
+
+
+@mcp.tool()
+async def test_streaming_elicitation(
+    answer: Annotated[ElicitationResult[UserResponse], Resolve(_ask_stream_probe)],
+) -> str:
+    """A tool that needs elicitation, asked through a resolver (SEP-2575 / SEP-2322).
+
+    On 2026-07-28 the question is returned as an InputRequiredResult rather than sent
+    on the response stream; on earlier versions it is a mid-call elicitation request.
+    """
+    return f"elicitation {answer.action}"
+
+
+@mcp.tool()
+async def test_logging_tool(ctx: Context) -> str:
+    """Logs once on the request-scoped channel (SEP-2575).
+
+    On 2026-07-28 the message is delivered only when the request's `_meta` sets
+    `io.modelcontextprotocol/logLevel`.
+    """
+    await ctx.info("test_logging_tool ran")  # pyright: ignore[reportDeprecated]
+    return "logged through the request-scoped, logLevel-gated channel"
+
+
 # SEP-2322 InputRequiredResult fixtures (multi-round-trip / ephemeral workflow)
 
 NAME_SCHEMA = {"type": "object", "properties": {"name": {"type": "string"}}, "required": ["name"]}