gateway: return actionable error for send channel webchat (openclaw#15703) thanks @rodrigouroz

Verified:
- pnpm build
- pnpm check (fails on current main with unrelated type errors in src/memory/embedding-manager.test-harness.ts)
- pnpm test:macmini (not run after pnpm check failure)
- pnpm test -- src/gateway/server-methods/send.test.ts

Co-authored-by: rodrigouroz <165576107+rodrigouroz@users.noreply.github.com>
Co-authored-by: Tak Hoffman <781889+Takhoffman@users.noreply.github.com>

CHANGELOG.md

@@ -17,6 +17,7 @@ Docs: https://docs.openclaw.ai
 - TUI: suppress false `(no output)` placeholders for non-local empty final events during concurrent runs, preventing external-channel replies from showing empty assistant bubbles while a local run is still streaming. (#5782) Thanks @LagWizard and @vignesh07.
 - Auto-reply/WhatsApp/TUI/Web: when a final assistant message is `NO_REPLY` and a messaging tool send succeeded, mirror the delivered messaging-tool text into session-visible assistant output so TUI/Web no longer show `NO_REPLY` placeholders. (#7010) Thanks @Morrowind-Xie.
 - Gateway/Chat: harden `chat.send` inbound message handling by rejecting null bytes, stripping unsafe control characters, and normalizing Unicode to NFC before dispatch. (#8593) Thanks @fr33d3m0n.
+- Gateway/Send: return an actionable error when `send` targets internal-only `webchat`, guiding callers to use `chat.send` or a deliverable channel. (#15703) Thanks @rodrigouroz.
 - Gateway/Security: redact sensitive session/path details from `status` responses for non-admin clients; full details remain available to `operator.admin`. (#8590) Thanks @fr33d3m0n.
 - Agents: return an explicit timeout error reply when an embedded run times out before producing any payloads, preventing silent dropped turns during slow cache-refresh transitions. (#16659) Thanks @liaosvcaf and @vignesh07.
 - Agents/OpenAI: force `store=true` for direct OpenAI Responses/Codex runs to preserve multi-turn server-side conversation state, while leaving proxy/non-OpenAI endpoints unchanged. (#16803) Thanks @mark9232 and @vignesh07.

src/gateway/server-methods/send.test.ts

@@ -19,7 +19,7 @@ vi.mock("../../config/config.js", async () => {
 
 vi.mock("../../channels/plugins/index.js", () => ({
   getChannelPlugin: () => ({ outbound: {} }),
-  normalizeChannelId: (value: string) => value,
+  normalizeChannelId: (value: string) => (value === "webchat" ? null : value),
 }));
 
 vi.mock("../../infra/outbound/targets.js", () => ({
@@ -108,6 +108,39 @@ describe("gateway send mirroring", () => {
     );
   });
 
+  it("returns actionable guidance when channel is internal webchat", async () => {
+    const respond = vi.fn();
+    await sendHandlers.send({
+      params: {
+        to: "x",
+        message: "hi",
+        channel: "webchat",
+        idempotencyKey: "idem-webchat",
+      },
+      respond,
+      context: makeContext(),
+      req: { type: "req", id: "1", method: "send" },
+      client: null,
+      isWebchatConnect: () => false,
+    });
+
+    expect(mocks.deliverOutboundPayloads).not.toHaveBeenCalled();
+    expect(respond).toHaveBeenCalledWith(
+      false,
+      undefined,
+      expect.objectContaining({
+        message: expect.stringContaining("unsupported channel: webchat"),
+      }),
+    );
+    expect(respond).toHaveBeenCalledWith(
+      false,
+      undefined,
+      expect.objectContaining({
+        message: expect.stringContaining("Use `chat.send`"),
+      }),
+    );
+  });
+
   it("does not mirror when delivery returns no results", async () => {
     mocks.deliverOutboundPayloads.mockResolvedValue([]);
 

src/gateway/server-methods/send.ts

@@ -106,6 +106,18 @@ export const sendHandlers: GatewayRequestHandlers = {
     const channelInput = typeof request.channel === "string" ? request.channel : undefined;
     const normalizedChannel = channelInput ? normalizeChannelId(channelInput) : null;
     if (channelInput && !normalizedChannel) {
+      const normalizedInput = channelInput.trim().toLowerCase();
+      if (normalizedInput === "webchat") {
+        respond(
+          false,
+          undefined,
+          errorShape(
+            ErrorCodes.INVALID_REQUEST,
+            "unsupported channel: webchat (internal-only). Use `chat.send` for WebChat UI messages or choose a deliverable channel.",
+          ),
+        );
+        return;
+      }
       respond(
         false,
         undefined,