Stata MCP Server

# Claude Desktop vs Claude Code: MCP Streaming Support **Date:** October 23, 2025 **Question:** Does Claude Desktop support real-time streaming output better than Claude Code? --- ## Answer: **NO - Both have the same limitation** Neither Claude Desktop nor Claude Code currently displays `notifications/message` in the chat interface during tool execution. --- ## Detailed Comparison ### Claude Desktop **Transport:** SSE (Server-Sent Events) **Endpoint:** `http://localhost:4000/mcp` **Configuration:** ```json { "stata-mcp": { "url": "http://localhost:4000/mcp", "transport": "sse" } } ``` **Notification Behavior:** - ✅ Receives `notifications/message` via SSE - ❌ Does NOT display them in chat - ⚠️ Can use OS-level notification servers (sounds/popups) as workaround ### Claude Code **Transport:** HTTP Streamable (SSE over HTTP) **Endpoint:** `http://localhost:4000/mcp-streamable` **Configuration:** Via VSCode extension **Notification Behavior:** - ✅ Receives `notifications/message` via SSE chunks - ❌ Does NOT display them in chat - 🐛 **Issue #3174**: Notifications received but not displayed - 🐛 **Issue #5960**: Only first streaming chunk shown --- ## What the Server Sends (Both Clients) Your server sends identical notifications to both: ```json { "method": "notifications/message", "params": { "level": "notice", "logger": "stata-mcp", "data": "⏱️ 6s elapsed / 600s timeout\n\n📝 Recent output:\nProgress: Completed iteration 6" }, "jsonrpc": "2.0" } ``` **Frequency:** Every 6 seconds during execution **Content:** Elapsed time + recent Stata output **Total:** ~26 notifications for a 72-second execution --- ## MCP Specification From MCP Spec 2025-06-18: > "Clients **MAY**: Present log messages in the UI" Both Claude Desktop and Claude Code **choose not to** implement this optional feature. --- ## Available Workarounds ### For Claude Desktop **1. OS-Level Notifications** Use a notification MCP server like `notifications-mcp-server`: - Plays sounds when tasks start/complete - Shows macOS Notification Center alerts - Does NOT show progress during execution - Only notifies at start/end **2. Monitor Log File** ```bash tail -f ~/.vscode/extensions/deepecon.stata-mcp-*/logs/test_timeout_mcp.log ``` ### For Claude Code **1. Monitor Log File** (same as above) **2. Web Viewer** (if implemented) Serve a web page showing live Stata output: ```bash open http://localhost:4000/viewer?script=test_timeout.do ``` --- ## Why Neither Client Shows Real-Time Output ### Technical Reason **MCP Protocol:** - Tools return a single final result (atomic) - No mechanism for progressive tool responses - Notifications are separate from tool results **Client Implementation:** - Both clients treat tool calls as "loading" states - UI only updates when tool completes - Notifications go to backend, not UI ### Business Reason Anthropic likely wants to: - Keep chat interface clean/focused - Avoid overwhelming users with technical details - Prioritize conversational flow --- ## What Actually Works ### ✅ MCP Python SDK ```python async with ClientSession(..., logging_callback=my_callback) as session: result = await session.call_tool("stata_run_file", ...) # my_callback receives all 26 notifications in real-time! ``` **Why it works:** You explicitly register a callback function. ### ❌ Claude Desktop & Claude Code No way to register a callback - they don't provide this UI feature. --- ## Recommendations ### Short Term: Document the Limitation Add to your README: ```markdown ## Known Limitation: No Real-Time Progress Display Due to limitations in Claude Desktop and Claude Code, Stata output only appears after execution completes. Progress notifications are sent by the server but not currently displayed. **Workarounds:** - Monitor log file: `tail -f logs/your_script_mcp.log` - Use OS notifications (Claude Desktop only) for start/end alerts **Future:** When Anthropic implements notification display (issue #3174), real-time updates will work automatically without server changes. ``` ### Medium Term: Build a Web Viewer Create a simple web interface: ```python @app.get("/viewer") async def viewer(script: str): """Live view of Stata execution""" # Stream log file contents via SSE # Users open in browser alongside Claude ``` ### Long Term: Wait for Anthropic Track these issues: - **anthropics/claude-code#3174** - Notification display - **anthropics/claude-code#5960** - Streaming HTTP When fixed, your server will work immediately (no changes needed). --- ## Summary | Feature | Claude Desktop | Claude Code | MCP Python SDK | |---------|---------------|-------------|----------------| | Transport | SSE | HTTP Streamable | Both | | Receives notifications | ✅ | ✅ | ✅ | | Displays in chat | ❌ | ❌ | ✅ | | OS notifications | ✅ (with plugin) | ❌ | N/A | | Real-time output | ❌ | ❌ | ✅ | **Conclusion:** Your server works correctly. Both Claude clients just don't display the notifications. Use Claude Desktop with OS notification plugin for start/end alerts, or build a web viewer for true real-time monitoring.