tablet 55: the row that was a label — the Sanhedrin's example request crashed its own gate

Verified live 2026-10-19: Tamid's own example for POST /chatzer/sanhedrin
(a case with `sides`) answered 500. The router passed the sides LIST as
the case context; halt_monitor:check_avodah_zarah/1 reads a map, maps:get
raised, and the halt monitor and escalation gen_servers died with the
caller's input (supervisor restarted them; health stayed 8/8). The router
then matched {:ok, decision} on the error and made a 500 of its own.

- sanhedrin/src/halt_monitor.erl: do_check_case refuses a non-map
  context as {halt, malformed_case, _} and stays standing. EUnit 49/0
  with the new halt_malformed_context_test.
- router.ex process_sanhedrin: sides validated at the kiyor (422 on a bad
  shape), carried as context %{sides: sides}; a Sanhedrin refusal answers
  422 SANHEDRIN_HALTED, a failure 503 SANHEDRIN_UNAVAILABLE. Two new
  router tests, one asserting the gate processes survive the example.
  Elixir 624/0.
- specs/broken_tablets/README.md: tablet 55, including what is NOT fixed
  — a panel of one accepting on zero references under a grounded-
  sounding sentence, the ignored complexity hint, no panel manna spent,
  no L3 record. The row in Tamid is still larger than the thing behind it.

Doorpost pin unchanged (no @spec_files touched; scripts/doorpost_check.py
passes).

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

sanhedrin/src/halt_monitor.erl

@@ -145,13 +145,29 @@ handle_info(_Info, State) ->
 %% Internal — gate-keeper checks
 %%====================================================================
 
-do_check_case(Case) ->
-    Context = Case#sanhedrin_case.context,
+%% The context is a map (authority_source, action, ...). Anything else is
+%% a malformed case, refused here — never reasoned about, never a crash.
+%% Tablet 55 (2026-10-19): the Tamid's own example request carried a
+%% LIST as context; maps:get raised, and this gen_server and escalation
+%% died with the caller's input. A gate that can be felled by what it is
+%% handed is not a gate. Fail closed, stay standing.
+do_check_case(#sanhedrin_case{context = Context}) when is_map(Context) ->
     with_chain([
         fun() -> check_avodah_zarah(Context) end,
         fun() -> check_shfichut_damim(Context) end,
         fun() -> check_gilui_arayot(Context) end
-    ]).
+    ]);
+do_check_case(#sanhedrin_case{context = Other}) ->
+    {halt, malformed_case,
+     iolist_to_binary([<<"case context must be a map, got ">>,
+                       atom_to_binary(type_name(Other), utf8)])}.
+
+type_name(T) when is_list(T)   -> list;
+type_name(T) when is_binary(T) -> binary;
+type_name(T) when is_atom(T)   -> atom;
+type_name(T) when is_tuple(T)  -> tuple;
+type_name(T) when is_number(T) -> number;
+type_name(_)                   -> other.
 
 do_check_vote(_Vote) ->
     %% Vote-level halt detection is the responsibility of the upstream

sanhedrin/test/sanhedrin_SUITE.erl

@@ -58,6 +58,16 @@ halt_clear_test() ->
     ?assertEqual(clear, halt_monitor:check_case(Case)),
     cleanup(ok).
 
+%% Tablet 55: a non-map context is refused, and the monitor survives it.
+halt_malformed_context_test() ->
+    {ok, _} = application:ensure_all_started(sanhedrin),
+    Sides = [#{<<"position">> => <<"a">>, <<"evidence">> => [<<"x">>]}],
+    Case = make_case_with_context(simple, <<"question">>, Sides),
+    ?assertMatch({halt, malformed_case, _}, halt_monitor:check_case(Case)),
+    %% still standing, and still judging
+    ?assertEqual(clear, halt_monitor:check_case(make_case(simple, <<"q">>))),
+    ok.
+
 halt_avodah_zarah_test() ->
     setup(),
     Case = make_case_with_context(simple, <<"question">>,

specs/broken_tablets/README.md

@@ -132,3 +132,49 @@ make. The fence held throughout — each forgery was stripped and named by
 a verdict the builder did not write — which is the design proving itself
 on its builder: the check has to stand outside the model, because the
 model's own intention is subject to the same pull it is meant to catch.
+
+## Tablet 55 — the row that was a label (2026-10-19)
+
+Tamid promises `POST /chatzer/sanhedrin`: a case, optional sides, a
+panel of three, a majority of two and a minority of one with their
+sources. The row had stood since the endpoint was written. The build
+state carried a line beside it — "never verified on prod" — for months.
+On 2026-10-19 the builder sent the spec's own example request to the
+live system, as the roadmap's rule asks: a spec row is a claim to test,
+not a label.
+
+The first request answered 500. The router had handed the `sides` list
+to the Sanhedrin as the case's *context*, where the halt monitor reads a
+map of `authority_source` and `action`; `maps:get` raised, and the halt
+monitor and the escalation server died with the caller's input. The
+supervisor restarted them; health stayed 8/8 the whole time. A gate that
+can be felled by what it is handed is not a gate, and a health check
+that cannot see the gate fall is not watching it. The router then
+pattern-matched `{:ok, decision}` on an error and turned the refusal
+into a 500 of its own.
+
+The second request, without sides, answered 200 — and the answer was
+hollow. A panel of one, not three. Field names the spec does not use.
+An outcome of "accepted" on zero roots and zero references examined,
+under the sentence "Torah references ground this interpretation". That
+is the shape the bedikah names golden_calf when a model says it: a
+confident claim standing on nothing. Here the system said it in its own
+voice, through its own inner court. The complexity hint was ignored, no
+panel manna was spent, and nothing was engraved in L3.
+
+Fixed in this tablet: the halt monitor refuses a non-map context as
+`malformed_case` and stays standing; the router carries the sides inside
+the context map, checks their shape at the kiyor (422), and answers a
+Sanhedrin refusal (422 SANHEDRIN_HALTED) or failure (503
+SANHEDRIN_UNAVAILABLE) instead of crashing. The spec's own example now
+deliberates, and the test asserts that the gate is still there
+afterwards.
+
+Not fixed, and recorded here so it is not mistaken for fixed: the
+panel of one, the empty references under a grounded-sounding sentence,
+the ignored hint, the unspent manna, the unrecorded case. The row in
+Tamid is still larger than the thing behind it. The lesson is tablet
+37's again — a spec row is a claim to test — with one thing added: the
+system's own inner court is held to the same check as a model at the
+gate. When the Sanhedrin accepts on nothing, it is the calf, whoever
+cast it.

vav_pipeline/lib/vav_pipeline/bigdei_kodesh/router.ex

@@ -1084,32 +1084,83 @@ defmodule VavPipeline.BigdeiKodesh.Router do
         resubmit: true
       })
     else
-      case_ref = generate_id()
+      # Tablet 55: the sides are the caller's arguments, not the halt
+      # gate's context. The gate reads a MAP (authority_source, action);
+      # handing it the sides list crashed the halt monitor and escalation
+      # with the Tamid's own example request. The sides ride inside the
+      # map, their shape checked at the door; and a refusal from the
+      # Sanhedrin is answered, not matched into a 500.
+      with {:ok, sides} <- sanhedrin_sides(params["sides"]) do
+        case_ref = generate_id()
 
-      {:ok, decision} =
-        VavPipeline.SanhedrinClient.submit_case(%{
-          case_ref: case_ref,
-          complexity: :simple,
-          question: case_text,
-          context: params["sides"] || %{},
-          requested_by: "chatzer"
-        })
+        case VavPipeline.SanhedrinClient.submit_case(%{
+               case_ref: case_ref,
+               complexity: :simple,
+               question: case_text,
+               context: %{sides: sides},
+               requested_by: "chatzer"
+             }) do
+          {:ok, decision} ->
+            send_json(conn, 200, %{
+              case_ref: decision.case_ref,
+              deliberation: %{
+                panel_size: decision.panel_size,
+                majority: decision.majority,
+                minority: decision.minority,
+                outcome: decision.outcome,
+                processing_time_ms: decision.deliberation_time_ms
+              },
+              note: "This is the system's reasoning, not a binding ruling. A human beit din may reach a different conclusion.",
+              disclosure: disclosure()
+            })
 
-      send_json(conn, 200, %{
-        case_ref: decision.case_ref,
-        deliberation: %{
-          panel_size: decision.panel_size,
-          majority: decision.majority,
-          minority: decision.minority,
-          outcome: decision.outcome,
-          processing_time_ms: decision.deliberation_time_ms
-        },
-        note: "This is the system's reasoning, not a binding ruling. A human beit din may reach a different conclusion.",
-        disclosure: disclosure()
-      })
+          {:error, "Halted" <> _ = reason} ->
+            send_error(conn, 422, "SANHEDRIN_HALTED", %{
+              issue: reason,
+              correction: "The case was refused at the gate before deliberation. Amend it and resubmit.",
+              resubmit: true
+            })
+
+          {:error, reason} ->
+            send_error(conn, 503, "SANHEDRIN_UNAVAILABLE", %{
+              issue: reason,
+              correction: "The Sanhedrin did not deliberate. Retry; if it recurs, the kohanim will find it in the log.",
+              resubmit: true
+            })
+        end
+      else
+        {:error, issue} ->
+          send_error(conn, 422, "KIYOR_VALIDATION_FAILED", %{
+            issue: issue,
+            correction: "'sides' is an optional list of {\"position\": string, \"evidence\": [string]}",
+            resubmit: true
+          })
+      end
     end
   end
 
+  # The optional sides: absent → []; a list of maps each with a string
+  # "position" and an optional list of string "evidence" → kept as given;
+  # anything else → refused at the kiyor.
+  defp sanhedrin_sides(nil), do: {:ok, []}
+
+  defp sanhedrin_sides(sides) when is_list(sides) do
+    if Enum.all?(sides, &side_ok?/1),
+      do: {:ok, sides},
+      else: {:error, "'sides' must be a list of {position, evidence[]} objects"}
+  end
+
+  defp sanhedrin_sides(_), do: {:error, "'sides' must be a list"}
+
+  defp side_ok?(%{"position" => p} = side) when is_binary(p) do
+    case Map.get(side, "evidence", []) do
+      ev when is_list(ev) -> Enum.all?(ev, &is_binary/1)
+      _ -> false
+    end
+  end
+
+  defp side_ok?(_), do: false
+
   # ============================================================
   # Internal — Health and Status
   # ============================================================

vav_pipeline/test/bigdei_kodesh_test.exs

@@ -317,6 +317,43 @@ defmodule VavPipeline.BigdeiKodeshTest do
       assert body["deliberation"]["outcome"] in ["accepted", "rejected", "teiku"]
       assert body["note"] =~ "not a binding ruling"
     end
+
+    # Tablet 55: the Tamid's own example — a case WITH sides — returned
+    # 500 and took the halt monitor and escalation down with it.
+    test "POST /chatzer/sanhedrin with sides (the Tamid's example) deliberates" do
+      conn =
+        conn(:post, "/chatzer/sanhedrin", Jason.encode!(%{
+          case: "A borrower repaid before one witness; the lender denies receipt. Who bears the burden?",
+          sides: [
+            %{position: "the borrower is believed", evidence: ["the money was handed over before a witness"]},
+            %{position: "the lender is believed", evidence: ["one witness does not establish payment"]}
+          ],
+          complexity_hint: "monetary"
+        }))
+        |> put_req_header("content-type", "application/json")
+        |> put_req_header("authorization", "Bearer chatzer-test-token")
+        |> Router.call(@opts)
+
+      assert conn.status == 200
+      body = Jason.decode!(conn.resp_body)
+      assert body["deliberation"]["outcome"] in ["accepted", "rejected", "teiku"]
+      # and the gate is still standing afterwards
+      assert Process.whereis(:halt_monitor) != nil
+      assert Process.whereis(:escalation) != nil
+    end
+
+    test "POST /chatzer/sanhedrin with malformed sides returns 422, not 500" do
+      for bad <- ["not a list", [%{"no_position" => 1}], [%{"position" => "p", "evidence" => "not a list"}]] do
+        conn =
+          conn(:post, "/chatzer/sanhedrin", Jason.encode!(%{case: "x", sides: bad}))
+          |> put_req_header("content-type", "application/json")
+          |> put_req_header("authorization", "Bearer chatzer-test-token")
+          |> Router.call(@opts)
+
+        assert conn.status == 422, "expected 422 for sides=#{inspect(bad)}, got #{conn.status}"
+        assert Jason.decode!(conn.resp_body)["error"]["code"] == "KIYOR_VALIDATION_FAILED"
+      end
+    end
   end
 
   # ============================================================