refactor(agents): drop dead cron-channel A2A arm, gate on canonical key only (#92257)

harjothkhara · harjothkhara · commit 426774aebed8 · 2026-06-20T12:44:11.000-07:00
The requesterChannel === "cron" arm was unreachable: agentChannel is always a
DeliverableMessageChannel from resolveGatewayMessageChannel(messageProvider),
never the literal "cron". The channel: "cron" in src/cron/isolated-agent/run.ts
labels diagnostics events/lifecycle, not the tool channel. Gate on
isCronRunSessionKey alone and fix the misleading comment.

Tests drove the dead arm via agentChannel/requesterChannel "cron" plus a
non-canonical key (agent:main:cron:run:abc, which isCronRunSessionKey rejects).
Switch them to a canonical cron-run key (agent:main:cron:job:run:abc) and a
normal delivery channel so they exercise the real production gate.
diff --git a/src/agents/tools/sessions-send-tool.a2a.test.ts b/src/agents/tools/sessions-send-tool.a2a.test.ts
@@ -340,7 +340,7 @@ describe("runSessionsSendA2AFlow announce delivery", () => {
   });
 
   it("with maxPingPongTurns 0 and requester != target, never steps the requester session but still announces in the target (#92257)", async () => {
-    const requesterSessionKey = "agent:main:cron:run:abc";
+    const requesterSessionKey = "agent:main:cron:job:run:abc";
     const targetSessionKey = "agent:other:discord:group:ops";
 
     await runSessionsSendA2AFlow({
@@ -350,7 +350,7 @@ describe("runSessionsSendA2AFlow announce delivery", () => {
       announceTimeoutMs: 10_000,
       maxPingPongTurns: 0,
       requesterSessionKey,
-      requesterChannel: "cron",
+      requesterChannel: "telegram",
       roundOneReply: "Worker completed successfully",
     });
 
@@ -381,8 +381,8 @@ describe("runSessionsSendA2AFlow announce delivery", () => {
       message: "Test message",
       announceTimeoutMs: 10_000,
       maxPingPongTurns: 0,
-      requesterSessionKey: "agent:main:cron:run:abc",
-      requesterChannel: "cron",
+      requesterSessionKey: "agent:main:cron:job:run:abc",
+      requesterChannel: "telegram",
       baseline: {
         text: "pre-existing cron output",
         fingerprint: "pre-existing-cron-output",
diff --git a/src/agents/tools/sessions-send-tool.ts b/src/agents/tools/sessions-send-tool.ts
@@ -557,13 +557,11 @@ export function createSessionsSendTool(opts?: {
       const sameSessionA2A = requesterSessionKey === resolvedKey;
       // An isolated cron run is the only requester for which the A2A ping-pong
       // is harmful: feeding the target's reply back as a new turn corrupts the
-      // isolated run (#92257). Detect it with the canonical cron-run classifier
-      // and the cron channel marker (see src/cron/isolated-agent/run.ts), not a
-      // raw `:cron:` substring: a normal requester whose key merely contains
-      // that segment (e.g. agent:main:slack:cron:job:run:uuid) must keep its
-      // intended cross-session ping-pong.
-      const isIsolatedCronRequester =
-        isCronRunSessionKey(requesterSessionKey) || requesterChannel === "cron";
+      // isolated run (#92257). Detect it with the canonical cron-run classifier,
+      // not a raw `:cron:` substring: a normal requester whose key merely
+      // contains that segment (e.g. agent:main:slack:cron:job:run:uuid) must
+      // keep its intended cross-session ping-pong.
+      const isIsolatedCronRequester = isCronRunSessionKey(requesterSessionKey);
 
       // Capture the pre-run assistant snapshot before starting the nested run.
       // Fast in-process test doubles and short-circuit agent paths can finish
diff --git a/src/agents/tools/sessions.test.ts b/src/agents/tools/sessions.test.ts
@@ -1112,7 +1112,9 @@ describe("sessions_send gating", () => {
   it("forces maxPingPongTurns to 0 for fire-and-forget sends from an isolated cron requester (#92257)", async () => {
     const { runSessionsSendA2AFlow } = await import("./sessions-send-tool.a2a.js");
     vi.mocked(runSessionsSendA2AFlow).mockClear();
-    const requesterSessionKey = "agent:main:cron:run:abc";
+    // Canonical isolated-cron run key (agent:<id>:cron:<job>:run:<run>); the
+    // gate fires on isCronRunSessionKey alone, with a normal delivery channel.
+    const requesterSessionKey = "agent:main:cron:job:run:abc";
     const targetSessionKey = "agent:other:discord:group:ops";
     loadConfigMock.mockReturnValue({
       session: { scope: "per-sender", mainKey: "main", agentToAgent: { maxPingPongTurns: 5 } },
@@ -1123,7 +1125,7 @@ describe("sessions_send gating", () => {
     });
     const tool = createSessionsSendTool({
       agentSessionKey: requesterSessionKey,
-      agentChannel: "cron",
+      agentChannel: "telegram",
     });
 
     callGatewayMock.mockImplementation(async (opts: unknown) => {
