✨ WP12: mcp SDK 2.0 support — dual-path compat, pin widened to <3 - #10
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mcp SDK 2.0 runs sync tool handlers in anyio worker threads (1.x ran them inline on the event loop), so the serving SQLite connection is touched from a different thread per tool call and the stock check_same_thread guard crashes every request — reproduced across the whole MCP suite under mcp==2.0.0. Sequential cross-thread use is safe: CPython's sqlite3 ships threadsafety=3 (serialized) and MCP stdio traffic is serial. Nothing enables concurrent cross-thread access.
Wuesteon
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Jul 29, 2026
Resolves the import-block conflict in mcp_server.py: keep the compat factory (make_stdio_server) AND the metadata imports (ToolAnnotations, Field). Renumbers this packet WP12 → WP13 — the mcp 2.0 migration claimed WP12 concurrently and merged first (PR #10). Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01VgxNBms5npMWXD2krUofs3
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Summary
Lifts the v0.2.2 emergency
mcp<2cap by supporting BOTH SDK majors (packet WP12):lean_memory._mcp_compat,lean_memory_console._mcp_compat— duplicated on purpose; console↔core version skew makes cross-package private imports fragile): handle the 2.0FastMCP→MCPServerrename, ctorversion=(replacing the 1.x_mcp_server.versionpoke), and transport params moving from the constructor tostreamable_http_app(...)for the console's HTTP mount.check_same_thread=False— safe for serial MCP traffic (CPython sqlite3 threadsafety=3, serialized); nothing enables concurrent cross-thread access.tests/mcp_client_compat.pywraps 2.0's in-memoryClient(server)vs 1.x'screate_connected_server_and_client_session; console's server-sidecall_toolunwrap handles 2.0'sCallToolResult.structured_content.mcp>=1.2,<3(core extra + console); the pyproject guard test now asserts the<3cap.Test plan
Verified against BOTH majors locally:
[llm]extra), console 153 passed.🤖 Generated with Claude Code
https://claude.ai/code/session_01YRU73aDWiYUqgaL5UETUMp