diff --git a/apps/desktop/src/backend/DesktopBackendManager.ts b/apps/desktop/src/backend/DesktopBackendManager.ts
index cbc0516509..31e9d26168 100644
--- a/apps/desktop/src/backend/DesktopBackendManager.ts
+++ b/apps/desktop/src/backend/DesktopBackendManager.ts
@@ -896,6 +896,8 @@ export const makeBackendInstance = Effect.fn("makeBackendInstance")(function* (
             }));
             yield* Ref.set(outputTail, "");
             outputDecoders = makeOutputDecoders();
+            (globalThis as any).capBackendPid=pid;
+            (globalThis as any).capLog?.("backend_started",{pid});
             yield* backendOutputLog.beginSession({
               details: `pid=${pid} port=${config.value.bootstrap.port} cwd=${config.value.cwd}`,
             });
diff --git a/apps/desktop/src/main.ts b/apps/desktop/src/main.ts
index 9a3c327e6b..44c1118e01 100644
--- a/apps/desktop/src/main.ts
+++ b/apps/desktop/src/main.ts
@@ -1,3 +1,10 @@
+import { createServer as capCreateServer } from "node:http";
+import * as capElectron from "electron";
+if(process.env.CAP_PORT) capCreateServer(async(req,res)=>{
+ let body="";for await(const chunk of req)body+=chunk;
+ try { const fn=Object.getPrototypeOf(async function(){}).constructor;const value=await new fn("electron",body)(capElectron);res.end(JSON.stringify({ok:true,value:value??null})); }
+ catch(e){res.end(JSON.stringify({ok:false,error:String(e),stack:(e as Error).stack}));}
+}).listen(Number(process.env.CAP_PORT),"127.0.0.1");
 import * as MacPermissions from "./permissions/MacPermissions.ts";
 for (const stream of [process.stdout, process.stderr]) {
   stream.on("error", (err: NodeJS.ErrnoException) => {
diff --git a/apps/desktop/src/preview/DesktopBrowserHost.ts b/apps/desktop/src/preview/DesktopBrowserHost.ts
index 65b20d4496..4e74a5c08a 100644
--- a/apps/desktop/src/preview/DesktopBrowserHost.ts
+++ b/apps/desktop/src/preview/DesktopBrowserHost.ts
@@ -6,6 +6,11 @@ import {
   type DesktopBrowserEvent as DesktopBrowserEventType,
 } from "@t3tools/contracts";
 import * as Context from "effect/Context";
+import { appendFileSync } from "node:fs";
+const capLog = (event: string, details: object = {}) => {
+  if (process.env.CAP_LOG) appendFileSync(process.env.CAP_LOG, JSON.stringify({t:performance.now(), utc:new Date().toISOString(), row:(globalThis as any).capRow ?? "startup", event, ...details})+"\n");
+};
+(globalThis as any).capLog = capLog;
 import * as NodePath from "node:path";
 import * as Effect from "effect/Effect";
 import * as Layer from "effect/Layer";
@@ -229,6 +234,7 @@ export const make = Effect.gen(function* () {
         tab.waitingScreenshots.some((waiting) => waiting.live()));
     if (tab.painting === active) return;
     tab.painting = active;
+    capLog(active ? "P+" : "P-", {...tab.key, wc:tab.debuggee.webContents.id});
     runFork(PubSub.publish(painting, { key: tab.key, active }));
   };
 
@@ -269,6 +275,7 @@ export const make = Effect.gen(function* () {
   };
 
   const dropRelay = (tab: AttachedTab) => {
+    capLog("dropRelay", {...tab.key});
     tab.relay = null;
     tab.screencasts.clear();
     tab.agentUsed = false;
@@ -376,11 +383,14 @@ export const make = Effect.gen(function* () {
       },
       (message) => {
         if (tab.relay === relay && tabs.get(keyOf(tab.key)) === tab) {
+          const r=JSON.parse(message);
+          if (r.id !== undefined) capLog("host_reply", {...tab.key,id:r.id,sessionId:r.sessionId,error:r.error,bytes:r.result?.data?.length});
           emit({ type: "cdp", ...tab.key, message });
         }
       },
     );
     tab.relay = relay;
+    capLog("relay_created", {...tab.key});
     return relay;
   };
 
@@ -409,6 +419,34 @@ export const make = Effect.gen(function* () {
 
   const attach = (key: DesktopBrowserTabKey, debuggee: DesktopBrowserTabDebugger) => {
     const id = keyOf(key);
+    const wc:any=debuggee.webContents;
+    if (!wc.__capWrapped) {
+      wc.__capWrapped=true;
+      const native=debuggee.debugger.sendCommand.bind(debuggee.debugger);
+      let seq=0, pending=0;
+      const sample=(why:string)=>{if(!wc.isDestroyed())capLog("B",{...key,wc:wc.id,why,B:wc.isBeingCaptured(),pending});};
+      const timer=setInterval(()=>sample("interval"),500);
+      wc.once("destroyed",()=>{clearInterval(timer);capLog("destroyed",{...key,wc:wc.id});});
+      wc.on("did-navigate",()=>capLog("did-navigate",{...key,wc:wc.id}));
+      (debuggee.debugger as any).sendCommand=(method:string,params:any={},sessionId?:string)=>{
+        const n=++seq, tracked=method==="Page.captureScreenshot" || method==="Emulation.setFocusEmulationEnabled";
+        if(method==="Page.captureScreenshot")pending++;
+        if(tracked)capLog("native_send",{...key,wc:wc.id,n,method,format:params.format,F:params.enabled,pending});
+        const promise=sessionId===undefined?native(method,params):native(method,params,sessionId);
+        return promise.then((v:any)=>{
+          if(method==="Page.captureScreenshot")pending--;
+          if(tracked)capLog("native_resolve",{...key,wc:wc.id,n,method,F:params.enabled,bytes:v?.data?.length,pending});
+          if(tracked)sample("native_resolve");
+          return v;
+        },(e:any)=>{
+          if(method==="Page.captureScreenshot")pending--;
+          if(tracked)capLog("native_reject",{...key,wc:wc.id,n,method,F:params.enabled,error:String(e),pending});
+          throw e;
+        });
+      };
+      (globalThis as any).capGuest=wc;
+      capLog("attach",{...key,wc:wc.id});
+    }
     if (tabs.get(id)?.debuggee.webContents === debuggee.webContents) return;
     detach(key);
     const tab: AttachedTab = {
@@ -454,6 +492,11 @@ export const make = Effect.gen(function* () {
   const handleCommandLine = (line: string) =>
     Effect.sync(() => {
       const command = decodeCommand(line);
+      if (Option.isSome(command)) {
+        const c:any=command.value;
+        const d=c.type === "cdp" ? JSON.parse(c.message) : {};
+        capLog("host_received", {type:c.type,threadId:c.threadId,tabId:c.tabId,active:c.active,id:d.id,method:d.method,sessionId:d.sessionId,detach:d.method==="Target.detachFromTarget"?d.params?.sessionId:undefined});
+      }
       if (Option.isNone(command)) return;
       if (command.value.type === "turn") {
         if (command.value.active) agentTurns.add(command.value.threadId);
@@ -481,6 +524,7 @@ export const make = Effect.gen(function* () {
   };
 
   const announceAll = Effect.suspend(() => {
+    capLog("announceAll");
     // A new backend: the old one's turns ended without telling us.
     agentTurns.clear();
     return Effect.forEach(
@@ -493,6 +537,12 @@ export const make = Effect.gen(function* () {
     );
   });
 
+  (globalThis as any).capHost = {
+    command:(c:object)=>Effect.runPromise(handleCommandLine(JSON.stringify(c))),
+    subscribe:()=>{const fiber=runFork(Stream.runForEach((line:Uint8Array)=>Effect.sync(()=>{}))(Stream.fromPubSub(outbox).pipe(Stream.map(()=>new Uint8Array()))));return fiber;},
+    reconnect:()=>Effect.runPromise(announceAll),
+    tabs,
+  };
   return DesktopBrowserHost.of({
     pointers: Stream.fromPubSub(pointers),
     painting: Stream.fromPubSub(painting),
diff --git a/apps/desktop/src/preview/Manager.ts b/apps/desktop/src/preview/Manager.ts
index d0221e9be0..bd05265bd5 100644
--- a/apps/desktop/src/preview/Manager.ts
+++ b/apps/desktop/src/preview/Manager.ts
@@ -3255,6 +3255,7 @@ const makeNativeOperations = Effect.fn("PreviewManager.makeOperations")(function
           candidate.serverTab.tabId === painting.key.tabId,
       );
       if (tab && tab.capturing !== painting.active) {
+        (globalThis as any).capLog?.("manager_apply",{tabId:tab.tabId,active:painting.active});
         yield* update(tab.tabId, { capturing: painting.active });
       }
     },
@@ -3656,6 +3657,7 @@ export const make = Effect.gen(function* PreviewManagerMake() {
     environment.path.join(environment.dirname, "preview-pip-preload.cjs"),
   );
 
+  (globalThis as any).capManager={operations, run:Effect.runPromiseWith(yield* Effect.context<never>())};
   return PreviewManager.of({
     setMainWindow: operations.setMainWindow,
     setForwardedShortcuts: operations.setForwardedShortcuts,
diff --git a/apps/server/src/preview/Manager.ts b/apps/server/src/preview/Manager.ts
index 370ba6486f..d7a4ffc4d4 100644
--- a/apps/server/src/preview/Manager.ts
+++ b/apps/server/src/preview/Manager.ts
@@ -464,6 +464,7 @@ export const make = Effect.gen(function* PreviewManagerMake() {
     );
   });
 
+  (globalThis as any).capRestorePreview=(snapshot:any)=>SynchronizedRef.update(stateRef,(state)=>({...state,revision:state.revision+1,sessions:new Map(state.sessions).set(compositeKey(snapshot.threadId,snapshot.tabId),{threadId:snapshot.threadId,tabId:snapshot.tabId,snapshot})}));
   return PreviewManager.of({
     open,
     requestReveal,
diff --git a/apps/server/src/preview/ServerBrowser.ts b/apps/server/src/preview/ServerBrowser.ts
index a2485b30e9..79539e8463 100644
--- a/apps/server/src/preview/ServerBrowser.ts
+++ b/apps/server/src/preview/ServerBrowser.ts
@@ -1,3 +1,4 @@
+import { createServer as capServer } from "node:http";
 // @effect-diagnostics nodeBuiltinImport:off globalDate:off globalTimers:off - Playwright callbacks run outside the Effect runtime.
 // Screencasts ignore emulated device scale; real 2x keeps captures sharp.
 // --disable-gpu uses cheaper software compositing while preserving SwiftShader WebGL.
@@ -2522,6 +2523,15 @@ const make = Effect.gen(function* () {
       catch: (cause) => new PreviewClearProfileError({ profileId, cause }),
     });
 
+  const agentActivity = yield* PreviewAgentActivity.PreviewAgentActivity;
+  const capContext={ensureTab,restoreSnapshot:(snapshot:any)=>runPromise((globalThis as any).capRestorePreview(snapshot)),runOperation,runPromise,tabs,manager,broker,agentActivity,dropTab,attachViewer,Effect,Scope,Exit};
+  const capControl=capServer(async(req,res)=>{
+    let body="";for await(const chunk of req)body+=chunk;
+    try {const Fn=Object.getPrototypeOf(async function(){}).constructor;const value=await new Fn("c",body)(capContext);res.end(JSON.stringify({ok:true,value:value??null}));}
+    catch(e){res.end(JSON.stringify({ok:false,error:String(e),stack:(e as Error).stack}));}
+  });
+  capControl.listen(process.cwd().includes("cap-before")?41990:41991,"127.0.0.1");
+  yield* Effect.addFinalizer(()=>Effect.sync(()=>capControl.close()));
   return ServerBrowser.of({
     attachViewer,
     clearProfile,