fix(gateway): block webchat session compaction mutations (#70716)

* fix(gateway): block webchat session compaction mutations

* docs(changelog): note webchat compaction guard (#70716)

CHANGELOG.md

@@ -241,6 +241,7 @@ Docs: https://docs.openclaw.ai
 - Gateway/Control UI: require authenticated Control UI read access before serving `/__openclaw/control-ui-config.json` when `gateway.auth` is enabled, so unauthenticated callers can no longer read bootstrap metadata. (#70247) Thanks @drobison00.
 - Gateway/restart: default session-scoped restart sentinels to a one-shot agent continuation, so chat-initiated Gateway restarts acknowledge successful boot automatically. (#70269) Thanks @obviyus.
 - Build/npm publish: fail postpublish verification when root `dist/*` files import bundled plugin runtime dependencies without mirroring them in the root package manifest, so Slack-style plugin deps cannot silently ship on the wrong module-resolution path again. (#60112) thanks @medns.
+- Gateway/sessions: extend the webchat session-mutation guard to `sessions.compact` and `sessions.compaction.restore`, so `WEBCHAT_UI` clients are rejected from compaction-side session mutations consistently with the existing patch/delete guards. (#70716) Thanks @drobison00.
 
 ## 2026.4.21
 

src/gateway/server-methods/sessions.ts

@@ -223,7 +223,7 @@ function emitSessionsChanged(
 }
 
 function rejectWebchatSessionMutation(params: {
-  action: "patch" | "delete";
+  action: "patch" | "delete" | "compact" | "restore";
   client: GatewayClient | null;
   isWebchatConnect: (params: GatewayClient["connect"] | null | undefined) => boolean;
   respond: RespondFn;
@@ -1101,6 +1101,9 @@ export const sessionsHandlers: GatewayRequestHandlers = {
     if (!key) {
       return;
     }
+    if (rejectWebchatSessionMutation({ action: "restore", client, isWebchatConnect, respond })) {
+      return;
+    }
     const checkpointId =
       typeof p.checkpointId === "string" && p.checkpointId.trim() ? p.checkpointId.trim() : "";
     if (!checkpointId) {
@@ -1495,6 +1498,9 @@ export const sessionsHandlers: GatewayRequestHandlers = {
     if (!key) {
       return;
     }
+    if (rejectWebchatSessionMutation({ action: "compact", client, isWebchatConnect, respond })) {
+      return;
+    }
 
     const maxLines =
       typeof p.maxLines === "number" && Number.isFinite(p.maxLines)

src/gateway/server.sessions.gateway-server-sessions-a.test.ts

@@ -3329,14 +3329,40 @@ describe("gateway server sessions", () => {
     ws.close();
   });
 
-  test("webchat clients cannot patch or delete sessions", async () => {
-    await createSessionStoreDir();
+  test("webchat clients cannot patch, delete, compact, or restore sessions", async () => {
+    const { dir } = await createSessionStoreDir();
+    const fixture = await createCheckpointFixture(dir);
 
     await writeSessionStore({
       entries: {
         main: {
-          sessionId: "sess-main",
+          sessionId: fixture.sessionId,
+          sessionFile: fixture.sessionFile,
           updatedAt: Date.now(),
+          compactionCheckpoints: [
+            {
+              checkpointId: "checkpoint-1",
+              sessionKey: "agent:main:main",
+              sessionId: fixture.sessionId,
+              createdAt: Date.now(),
+              reason: "manual",
+              tokensBefore: 123,
+              tokensAfter: 45,
+              summary: "checkpoint summary",
+              firstKeptEntryId: fixture.preCompactionLeafId,
+              preCompaction: {
+                sessionId: fixture.preCompactionSession.getSessionId(),
+                sessionFile: fixture.preCompactionSessionFile,
+                leafId: fixture.preCompactionLeafId,
+              },
+              postCompaction: {
+                sessionId: fixture.sessionId,
+                sessionFile: fixture.sessionFile,
+                leafId: fixture.postCompactionLeafId,
+                entryId: fixture.postCompactionLeafId,
+              },
+            },
+          ],
         },
         "discord:group:dev": {
           sessionId: "sess-group",
@@ -3373,6 +3399,20 @@ describe("gateway server sessions", () => {
     expect(deleted.ok).toBe(false);
     expect(deleted.error?.message ?? "").toMatch(/webchat clients cannot delete sessions/i);
 
+    const compacted = await rpcReq(ws, "sessions.compact", {
+      key: "main",
+      maxLines: 3,
+    });
+    expect(compacted.ok).toBe(false);
+    expect(compacted.error?.message ?? "").toMatch(/webchat clients cannot compact sessions/i);
+
+    const restored = await rpcReq(ws, "sessions.compaction.restore", {
+      key: "main",
+      checkpointId: "checkpoint-1",
+    });
+    expect(restored.ok).toBe(false);
+    expect(restored.error?.message ?? "").toMatch(/webchat clients cannot restore sessions/i);
+
     ws.close();
   });