From 3409a41d8534e00f30ea1f40fc35c176848c3bd9 Mon Sep 17 00:00:00 2001
From: marfrit <fritsche.markus@gmail.com>
Date: Sun, 9 Aug 2026 00:06:46 +0200
Subject: [PATCH] versions.lua: MCP protocol-version gate, built by the bullpen
 society

Phase B, third attempt. The contract is the head of tests/phase_b_acceptance.lua;
this is the module that satisfies it.

M.SUPPORTED = {"2025-06-18"} -- and that list is not a guess. The acceptance test
anchors it against a LIVE server: it calls initialize and compares M.SUPPORTED to
the protocolVersion the server actually reports. The first attempt shipped
{"2025-06-18","2025-11-25"} and passed 14/14, because the test then only compared
the list against itself; lmcp does not speak 2025-11-25. Answering HTTP 200 to a
version header proves nothing -- the same endpoint answers 200 to 1999-01-01.

Provenance, all of it in marfrit/bullpen room.jsonl:
  #218/#234  @coder wrote the module (qwen3.6-coding), two passes rejected first:
             pass 1 implemented M.is_supported instead of the contract's M.check
             and embedded its own self-test; pass 2 arrived without a certificate.
  #246       @testdesigner refused to materialise the file in the clone root --
             writing the subject and then greening it yourself collapses the
             implementer/tester split. The refusal was correct.
  #256       two certificates, both from container `testdesign`, same test
             (sha256 78a4758d706a2539, commit e8c18f1e3b03):
               empty state -> ROT rc 2 (subject absent)
               these bytes -> GRUEN rc 0, 17/17, live anchor included
  #283       @deus lifted it out through the room; sha256 byte-identical.

sha256 of this file: e5bb0739b84a2354422842cc1be28d2d8ad407307b84e3f05e79faa30e68e5da
---
 versions.lua | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)
 create mode 100644 versions.lua

diff --git a/versions.lua b/versions.lua
new file mode 100644
index 0000000..3dce55d
--- /dev/null
+++ b/versions.lua
@@ -0,0 +1,36 @@
+-- versions.lua
+-- Modul zur Versionspruefung gemaess LMCP-Vertrag
+
+local M = {}
+
+M.SUPPORTED = {"2025-06-18"}
+
+--- Prueft, ob eine Version unterstuetzt wird.
+-- @param version Die zu pruefende Version (String oder nil)
+-- @return boolean true wenn unterstuetzt, sonst false
+-- @return table|nil Fehlerdetails bei Nichtunterstuetzung
+function M.check(version)
+    -- (a) version == nil oder "" -> true, nil
+    if version == nil or version == "" then
+        return true, nil
+    end
+
+    -- (b) exakter Treffer in M.SUPPORTED -> true, nil
+    for _, supported_version in ipairs(M.SUPPORTED) do
+        if version == supported_version then
+            return true, nil
+        end
+    end
+
+    -- (c) alles andere -> false, { code = -32022, data = { supported = M.SUPPORTED } }
+    return false, {
+        code = -32022,
+        data = {
+            supported = M.SUPPORTED
+        }
+    }
+end
+
+-- Keine neuen Globalen, keine Seiteneffekte, M.SUPPORTED wird nicht geaendert
+
+return M