diff --git a/src/pages/api/services/proxy.js b/src/pages/api/services/proxy.js
index 8aab61fd7..123794854 100644
--- a/src/pages/api/services/proxy.js
+++ b/src/pages/api/services/proxy.js
@@ -63,6 +63,8 @@ export default async function handler(req, res) {
     if (serviceProxyHandler instanceof Function) {
       // quick return for no endpoint services, calendar is an exception
       if (!req.query.endpoint || serviceProxyHandler === calendarProxyHandler) {
+        req.method = "GET";
+        req.body = undefined;
         return await serviceProxyHandler(req, res);
       }
 
@@ -86,7 +88,7 @@ export default async function handler(req, res) {
         }
 
         req.method = mapping?.method || "GET";
-        if (mapping?.body) req.body = mapping?.body;
+        req.body = mapping?.body;
         req.query.endpoint = endpoint;
 
         if (mapping.segments || req.query.segments) {
@@ -125,6 +127,8 @@ export default async function handler(req, res) {
 
       if (widget.allowedEndpoints instanceof RegExp) {
         if (widget.allowedEndpoints.test(req.query.endpoint)) {
+          req.method = "GET";
+          req.body = undefined;
           return await serviceProxyHandler(req, res);
         }
       }
diff --git a/src/pages/api/services/proxy.test.js b/src/pages/api/services/proxy.test.js
new file mode 100644
index 000000000..3c5336040
--- /dev/null
+++ b/src/pages/api/services/proxy.test.js
@@ -0,0 +1,229 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+
+import createMockRes from "test-utils/create-mock-res";
+
+const { getServiceWidget, logger, genericHandler, allowedHandler, mappedHandler, calendarHandler } = vi.hoisted(() => ({
+  getServiceWidget: vi.fn(),
+  logger: { debug: vi.fn(), error: vi.fn() },
+  genericHandler: vi.fn(),
+  allowedHandler: vi.fn(),
+  mappedHandler: vi.fn(),
+  calendarHandler: vi.fn(),
+}));
+
+vi.mock("utils/logger", () => ({
+  default: () => logger,
+}));
+vi.mock("utils/config/service-helpers", () => ({
+  default: getServiceWidget,
+}));
+vi.mock("widgets/calendar/proxy", () => ({
+  default: calendarHandler,
+}));
+
+vi.mock("widgets/widgets", () => ({
+  default: {
+    noendpoint: {
+      api: "{url}",
+      proxyHandler: genericHandler,
+    },
+    allowed: {
+      api: "{url}/api/{endpoint}",
+      proxyHandler: allowedHandler,
+      allowedEndpoints: /^status$/,
+    },
+    mapped: {
+      api: "{url}/{endpoint}",
+      proxyHandler: mappedHandler,
+      mappings: {
+        Sessions: {
+          endpoint: "Sessions",
+        },
+        Pause: {
+          method: "POST",
+          endpoint: "Sessions/Playing/Pause",
+          body: "mapping-body",
+        },
+        Refresh: {
+          method: "POST",
+          endpoint: "Sessions/Refresh",
+        },
+      },
+    },
+    ical: {
+      api: "{url}",
+      proxyHandler: calendarHandler,
+    },
+  },
+}));
+
+import handler from "./proxy";
+
+function createReq({ method = "GET", body, query = {} } = {}) {
+  return { method, body, query };
+}
+
+describe("pages/api/services/proxy", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  describe("client request shaping", () => {
+    it("forces GET and drops the body on the no-endpoint quick return", async () => {
+      getServiceWidget.mockResolvedValue({ type: "noendpoint", url: "http://example" });
+
+      const req = createReq({
+        method: "POST",
+        body: '{"cmd":"delete_all"}',
+        query: { group: "g", service: "svc", index: "0" },
+      });
+
+      await handler(req, createMockRes());
+
+      expect(genericHandler).toHaveBeenCalledTimes(1);
+      const forwarded = genericHandler.mock.calls[0][0];
+      expect(forwarded.method).toBe("GET");
+      expect(forwarded.body).toBeUndefined();
+    });
+
+    it.each(["PUT", "DELETE", "PATCH"])("forces GET for a %s on the no-endpoint quick return", async (method) => {
+      getServiceWidget.mockResolvedValue({ type: "noendpoint", url: "http://example" });
+
+      const req = createReq({ method, body: "payload", query: { group: "g", service: "svc", index: "0" } });
+
+      await handler(req, createMockRes());
+
+      const forwarded = genericHandler.mock.calls[0][0];
+      expect(forwarded.method).toBe("GET");
+      expect(forwarded.body).toBeUndefined();
+    });
+
+    it("forces GET and drops the body on the allowedEndpoints path", async () => {
+      getServiceWidget.mockResolvedValue({ type: "allowed", url: "http://example" });
+
+      const req = createReq({
+        method: "DELETE",
+        body: "payload",
+        query: { group: "g", service: "svc", endpoint: "status", index: "0" },
+      });
+
+      await handler(req, createMockRes());
+
+      expect(allowedHandler).toHaveBeenCalledTimes(1);
+      const forwarded = allowedHandler.mock.calls[0][0];
+      expect(forwarded.method).toBe("GET");
+      expect(forwarded.body).toBeUndefined();
+    });
+
+    it("forces GET and drops the body on the calendar exception path", async () => {
+      getServiceWidget.mockResolvedValue({ type: "calendar", url: "http://example" });
+
+      const req = createReq({
+        method: "POST",
+        body: "payload",
+        query: { group: "g", service: "svc", endpoint: "events", index: "0" },
+      });
+
+      await handler(req, createMockRes());
+
+      expect(calendarHandler).toHaveBeenCalledTimes(1);
+      const forwarded = calendarHandler.mock.calls[0][0];
+      expect(forwarded.method).toBe("GET");
+      expect(forwarded.body).toBeUndefined();
+    });
+
+    it("forces GET for a mapping that does not declare a method", async () => {
+      getServiceWidget.mockResolvedValue({ type: "mapped", url: "http://example" });
+
+      const req = createReq({
+        method: "POST",
+        body: "payload",
+        query: { group: "g", service: "svc", endpoint: "Sessions", index: "0" },
+      });
+
+      await handler(req, createMockRes());
+
+      const forwarded = mappedHandler.mock.calls[0][0];
+      expect(forwarded.method).toBe("GET");
+      expect(forwarded.body).toBeUndefined();
+    });
+
+    it("drops a client body when a non-GET mapping does not declare one", async () => {
+      getServiceWidget.mockResolvedValue({ type: "mapped", url: "http://example" });
+
+      const req = createReq({
+        method: "POST",
+        body: "attacker-controlled",
+        query: { group: "g", service: "svc", endpoint: "Refresh", index: "0" },
+      });
+
+      await handler(req, createMockRes());
+
+      const forwarded = mappedHandler.mock.calls[0][0];
+      expect(forwarded.method).toBe("POST");
+      expect(forwarded.body).toBeUndefined();
+    });
+  });
+
+  describe("mapping opt-in", () => {
+    it("still allows a mapping to declare a non-GET method and body", async () => {
+      getServiceWidget.mockResolvedValue({ type: "mapped", url: "http://example" });
+
+      const req = createReq({
+        method: "POST",
+        query: { group: "g", service: "svc", endpoint: "Pause", index: "0" },
+      });
+
+      await handler(req, createMockRes());
+
+      expect(mappedHandler).toHaveBeenCalledTimes(1);
+      const forwarded = mappedHandler.mock.calls[0][0];
+      expect(forwarded.method).toBe("POST");
+      expect(forwarded.body).toBe("mapping-body");
+      expect(forwarded.query.endpoint).toBe("Sessions/Playing/Pause");
+    });
+
+    it("rejects a method that does not match the mapping", async () => {
+      getServiceWidget.mockResolvedValue({ type: "mapped", url: "http://example" });
+
+      const req = createReq({
+        method: "GET",
+        query: { group: "g", service: "svc", endpoint: "Pause", index: "0" },
+      });
+      const res = createMockRes();
+
+      await handler(req, res);
+
+      expect(mappedHandler).not.toHaveBeenCalled();
+      expect(res.statusCode).toBe(403);
+      expect(res.body).toEqual({ error: "Unsupported method" });
+    });
+  });
+
+  describe("dispatch guards", () => {
+    it("rejects an endpoint that fails the allowedEndpoints test", async () => {
+      getServiceWidget.mockResolvedValue({ type: "allowed", url: "http://example" });
+
+      const req = createReq({ query: { group: "g", service: "svc", endpoint: "shutdown", index: "0" } });
+      const res = createMockRes();
+
+      await handler(req, res);
+
+      expect(allowedHandler).not.toHaveBeenCalled();
+      expect(res.statusCode).toBe(403);
+      expect(res.body).toEqual({ error: "Unmapped proxy request." });
+    });
+
+    it("rejects an unknown widget type", async () => {
+      getServiceWidget.mockResolvedValue({ type: "nope", url: "http://example" });
+
+      const req = createReq({ query: { group: "g", service: "svc", index: "0" } });
+      const res = createMockRes();
+
+      await handler(req, res);
+
+      expect(res.statusCode).toBe(403);
+      expect(res.body).toEqual({ error: "Unknown proxy service type" });
+    });
+  });
+});