agy parity T7 — agy workers can't resume, be nudged, or auto-resume: implement splice_prompt/2

apps/arbiter/lib/arbiter/mcp/tools/worker.ex

@@ -494,6 +494,8 @@ defmodule Arbiter.MCP.Tools.Worker do
       model: run.model,
       provider: run.provider,
       provider_fallback: run.provider_fallback,
+      session_id: run.session_id,
+      resumed_from_run_id: run.resumed_from_run_id,
       started_at: Tools.iso(run.started_at),
       completed_at: Tools.iso(run.completed_at),
       exit_code: run.exit_code,

apps/arbiter/test/arbiter/mcp/tools_test.exs

@@ -3354,6 +3354,50 @@ defmodule Arbiter.MCP.ToolsTest do
       assert entry.difficulty_at_dispatch == 3
     end
 
+    # bd-b7e33c post-merge finding (2026-09-22): only `provider` was surfaced
+    # here; `session_id` and `resumed_from_run_id` were silently dropped, the
+    # same gap the REST `/api/workers/history` endpoint had — which is what
+    # made the 04:26Z production verification misread a captured agy
+    # conversation id as NULL. Surface both so resume continuity is directly
+    # observable through this tool too.
+    test "surfaces session_id and resumed_from_run_id", ctx do
+      {:ok, task} = Ash.create(Issue, %{title: "session fields target", workspace_id: ctx.ws.id})
+
+      {:ok, prior} =
+        Ash.create(Arbiter.Workers.Run, %{
+          task_id: task.id,
+          repo: "arbiter",
+          workspace_id: ctx.ws.id,
+          status: :completed,
+          provider: "gemini",
+          session_id: "25df47b0-054e-434e-84c1-6876fd9f77de",
+          started_at: DateTime.add(DateTime.utc_now(), -600, :second)
+        })
+
+      {:ok, resumed} =
+        Ash.create(Arbiter.Workers.Run, %{
+          task_id: task.id,
+          repo: "arbiter",
+          workspace_id: ctx.ws.id,
+          status: :completed,
+          provider: "gemini",
+          session_id: "89a2b784-6bd5-46e6-a971-2178ca58cdcd",
+          resumed_from_run_id: prior.id,
+          started_at: DateTime.utc_now()
+        })
+
+      assert {:ok, %{runs: [resumed_entry, prior_entry]}} =
+               Tools.worker_runs(ctx.coordinator, %{"task_id" => task.id})
+
+      assert prior_entry.id == prior.id
+      assert prior_entry.session_id == "25df47b0-054e-434e-84c1-6876fd9f77de"
+      assert prior_entry.resumed_from_run_id == nil
+
+      assert resumed_entry.id == resumed.id
+      assert resumed_entry.session_id == "89a2b784-6bd5-46e6-a971-2178ca58cdcd"
+      assert resumed_entry.resumed_from_run_id == prior.id
+    end
+
     test "honors a bounded limit", ctx do
       {:ok, task} = Ash.create(Issue, %{title: "many runs", workspace_id: ctx.ws.id})
 

apps/arbiter_web/lib/arbiter_web/controllers/api/run_json.ex

@@ -34,7 +34,10 @@ defmodule ArbiterWeb.Api.RunJSON do
       routing_policy: r.routing_policy,
       model_tier: r.model_tier,
       thinking: r.thinking,
-      difficulty_at_dispatch: r.difficulty_at_dispatch
+      difficulty_at_dispatch: r.difficulty_at_dispatch,
+      provider: r.provider,
+      session_id: r.session_id,
+      resumed_from_run_id: r.resumed_from_run_id
     }
   end
 

apps/arbiter_web/test/arbiter_web/controllers/api/run_controller_test.exs

@@ -137,6 +137,45 @@ defmodule ArbiterWeb.Api.RunControllerTest do
       assert entry["thinking"] == "medium"
       assert entry["difficulty_at_dispatch"] == 2
     end
+
+    # bd-b7e33c post-merge finding (2026-09-22): the 04:26Z production
+    # verification misread an agy run as having `session_id: NULL` /
+    # `provider: null` because `arb worker runs --json` (this endpoint) never
+    # surfaced those columns at all — they were silently dropped from the
+    # summary, not actually null in `worker_runs`. Surface them so a resume's
+    # conversation continuity (or lack of it) is directly observable from the
+    # CLI/API without reaching into the DB.
+    test "lists provider/session_id/resumed_from_run_id", %{conn: conn} do
+      now = DateTime.utc_now()
+
+      prior =
+        insert_run!(%{
+          task_id: "bd-session-fields",
+          provider: "gemini",
+          session_id: "25df47b0-054e-434e-84c1-6876fd9f77de",
+          started_at: DateTime.add(now, -600, :second)
+        })
+
+      _resumed =
+        insert_run!(%{
+          task_id: "bd-session-fields",
+          provider: "gemini",
+          session_id: "89a2b784-6bd5-46e6-a971-2178ca58cdcd",
+          resumed_from_run_id: prior.id,
+          started_at: now
+        })
+
+      conn = get(conn, ~p"/api/workers/history", %{task_id: "bd-session-fields"})
+      [resumed_entry, prior_entry] = json_response(conn, 200)["data"]
+
+      assert prior_entry["provider"] == "gemini"
+      assert prior_entry["session_id"] == "25df47b0-054e-434e-84c1-6876fd9f77de"
+      assert prior_entry["resumed_from_run_id"] == nil
+
+      assert resumed_entry["provider"] == "gemini"
+      assert resumed_entry["session_id"] == "89a2b784-6bd5-46e6-a971-2178ca58cdcd"
+      assert resumed_entry["resumed_from_run_id"] == prior.id
+    end
   end
 
   describe "GET /api/workers/history/:id" do