Not a generic diagram: every node below names an artefact of this harness — the pinned package it installed, the runner files it started, the case files it streamed, and the counts it wrote out.

Every exported symbol of the upstream package, and what the port offers for it. The upstream list is derived mechanically, never from a README: cd python (1) the MCP wire-method inventory: every literal `method` value declared by a Request/Notification model in the pinned mcp package ./.venv/bin/python - <<'PY' import inspect, typing, mcp.types as t methods = set() for name, obj in vars(t).items(): if inspect.isclass(obj) and (name.endswith("Request") or name.endswith("Notification")): f = getattr(obj, "model_fields", {}).get("method") if f is not None: args = typing.get_args(f.annotation) if args: methods.add(args[0]) print(len(methods)); print("\n".join(sorted(methods))) PY…. A symbol with no case is untested, never a match.

Every case the harness streamed to both runners, with the exact upstream symbol and Go symbol it exercised. A deliberate, documented difference is a deviation and is counted apart from a mismatch.