From 5575b10fc8b1dcf69243410a43057e6b07cd21e3 Mon Sep 17 00:00:00 2001
From: Rhys Sullivan <39114868+RhysSullivan@users.noreply.github.com>
Date: Wed, 19 Aug 2026 10:13:33 -0700
Subject: [PATCH] Drop the MCP Durable Object from the SSR app graph

app.ts imported McpSessionDOSqlite only to pass it through as mcpExport
and re-export it. ExecutorApp.make documents mcpExport as passed back
out untouched, its result cloudMcpExport has no consumers, and server.ts
imports the DO class directly for Cloudflare's required export. So the
import was dead weight that pulled the MCP DO stack and the QuickJS WASM
into TanStack Start's loadEntries closure (9.22MB -> 8.58MB without it).

No measured latency win: loadEntries cost does not track closure size,
same as isolate startup. Kept as dead-code removal and because the SSR
graph should not depend on the MCP session DO.
---
 apps/cloud/src/app.ts | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/apps/cloud/src/app.ts b/apps/cloud/src/app.ts
index 77afa9c7f9..19b0213ead 100644
--- a/apps/cloud/src/app.ts
+++ b/apps/cloud/src/app.ts
@@ -13,7 +13,6 @@ import { ApiKeyService } from "./auth/api-keys";
 import { cloudIdentityFailureStrategy, workosIdentityLayer } from "./auth/workos-auth-provider";
 import { DbService } from "./db/db";
 import { cloudMcpAuth } from "./mcp";
-import { McpSessionDOSqlite } from "./mcp/session-durable-object";
 import { ErrorCaptureLive } from "./observability";
 import { AutumnService } from "./extensions/billing/service";
 import {
@@ -31,7 +30,7 @@ import { WorkerTelemetryLive } from "./observability/telemetry";
 // The whole scenario in 60 seconds: WorkOS identity (api-key Bearer OR sealed-
 // session cookie, api-key wins) over a per-request Hyperdrive→Postgres socket,
 // the Cloudflare dynamic-worker code substrate, MCP served by a Durable-Object
-// session store (the DO surfaced via `config.mcpExport`), console+Sentry error
+// session store (the DO class is exported straight from server.ts), console+Sentry error
 // capture — and Autumn BILLING entering ONLY as extensions: the engine
 // metering decorator, the account seat-gate, the `/api/billing/*` proxy route,
 // and the createOrganization free-limit gate. `diff` against
@@ -66,7 +65,7 @@ const controlPlane = Layer.mergeAll(CoreSharedServices, apiKeyService);
 // satisfied by `boot`, `DbService` per request via `requestScoped`).
 const cloudDb: Layer.Layer<DbProvider, never, DbService | AutumnService> = CloudDbProvider;
 
-const { appLayer, toWebHandler, mcpExport } = ExecutorApp.make({
+const { appLayer, toWebHandler } = ExecutorApp.make({
   plugins: cloudPlugins,
   providers: {
     // Identity: the NEUTRAL `IdentityProvider`. WorkOS api-key Bearer BEATS
@@ -112,7 +111,6 @@ const { appLayer, toWebHandler, mcpExport } = ExecutorApp.make({
     failure: cloudIdentityFailureStrategy,
     // The MCP session Durable Object class — a top-level Workers export a Layer
     // can't return; surfaced so `server.ts` can re-export it.
-    mcpExport: McpSessionDOSqlite,
   },
   // The long-lived (boot-scoped) context provideMerge'd under everything: the
   // WorkOS control plane (the raw `WorkOSClient` + `ApiKeyService` the per-request
@@ -135,10 +133,7 @@ const { appLayer, toWebHandler, mcpExport } = ExecutorApp.make({
   requestScoped: RequestScopedServicesLive,
 });
 
-export { McpSessionDOSqlite };
-
 export const CloudAppLayer = appLayer;
-export const cloudMcpExport = mcpExport;
 
 // The unified cloud web handler: serves /api/* (incl. /api/billing/*, /api/docs),
 // /mcp, /.well-known/* — everything the worker dispatches.