Revert the outbound MCP SDK v2 migration

apps/cli/package.json

@@ -30,7 +30,6 @@
     "@executor-js/runtime-quickjs": "workspace:*",
     "@executor-js/sdk": "workspace:*",
     "@jitl/quickjs-wasmfile-release-sync": "catalog:",
-    "@modelcontextprotocol/client": "2.0.0",
     "@modelcontextprotocol/sdk": "^1.29.0",
     "@sentry/bun": "^10.57.0",
     "effect": "catalog:",

apps/cli/src/main.ts

@@ -75,7 +75,7 @@ import type { PlatformError } from "effect/PlatformError";
 import * as Effect from "effect/Effect";
 import * as Option from "effect/Option";
 import * as Cause from "effect/Cause";
-import { StreamableHTTPClientTransport } from "@modelcontextprotocol/client";
+import { StreamableHTTPClientTransport } from "@modelcontextprotocol/sdk/client/streamableHttp.js";
 import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
 import type { JSONRPCMessage } from "@modelcontextprotocol/sdk/types.js";
 

apps/cloud/src/auth/handlers.ts

@@ -631,9 +631,6 @@ export const CloudSessionAuthHandlers = HttpApiBuilder.group(
         Effect.gen(function* () {
           const owner = yield* requireSelectedOrganization;
           const stub = getMcpSessionStub(params.mcpSessionId);
-          if (!stub) {
-            return yield* new McpExecutionNotFoundError({ executionId: params.executionId });
-          }
           const result = yield* Effect.promise(() =>
             stub.getPausedExecutionForApproval(params.executionId, {
               accountId: owner.accountId,
@@ -655,9 +652,6 @@ export const CloudSessionAuthHandlers = HttpApiBuilder.group(
         Effect.gen(function* () {
           const owner = yield* requireSelectedOrganization;
           const stub = getMcpSessionStub(params.mcpSessionId);
-          if (!stub) {
-            return yield* new McpExecutionNotFoundError({ executionId: params.executionId });
-          }
           const result = yield* Effect.promise(() =>
             stub.resumeExecutionForApproval(
               params.executionId,

apps/cloud/src/env-augment.d.ts

@@ -91,10 +91,6 @@ declare global {
       MCP_RESOURCE_ORIGIN?: string;
       MCP_SESSION_TIMEOUT_MS?: string;
       MCP_PAUSED_SESSION_IDLE_TIMEOUT_MS?: string;
-      /** HMAC key for MCP 2026-07-28 continuation state (32+ byte secret). */
-      MCP_REQUEST_STATE_KEY?: string;
-      /** Emergency rollback for inbound MCP 2026-07-28 traffic only. */
-      MCP_2026_07_28_ENABLED?: string;
       NODE_ENV?: string;
 
       // Shared with frontend

apps/cloud/src/mcp-session.e2e.node.test.ts

@@ -6,7 +6,7 @@
 //     FumaDB/Drizzle handle (the 2026-04-16 prod outage was a schema spread bug
 //     here; see db/db.schema.test.ts)
 //   - `createExecutionEngine` with an in-process code executor
-//   - `buildMcpServer` for the MCP request surface
+//   - `createExecutorMcpServer` for the MCP request surface
 //   - Real `@modelcontextprotocol/sdk` Client → server round-trips
 //
 // This test replicates the DO's init path (minus the WorkerTransport and
@@ -22,7 +22,7 @@ import { InMemoryTransport } from "@modelcontextprotocol/sdk/inMemory.js";
 import { ElicitRequestSchema } from "@modelcontextprotocol/sdk/types.js";
 import type { ClientCapabilities } from "@modelcontextprotocol/sdk/types.js";
 
-import { buildMcpServer } from "@executor-js/host-mcp/tool-server";
+import { createExecutorMcpServer } from "@executor-js/host-mcp/tool-server";
 import { createExecutionEngine } from "@executor-js/execution";
 import { makeQuickJsExecutor } from "@executor-js/runtime-quickjs";
 import { collectTables } from "@executor-js/api/server";
@@ -138,12 +138,8 @@ const openSession = (
     Effect.gen(function* () {
       const executor = yield* buildScopedExecutor(organizationId, `Org ${organizationId}`, options);
       const engine = createExecutionEngine({ executor, codeExecutor: makeQuickJsExecutor() });
-      const mcpServer = yield* buildMcpServer({
+      const mcpServer = yield* createExecutorMcpServer({
         engine,
-        appsEnabled: false,
-        requestStateSigningKey: new Uint8Array(32).fill(23),
-        requestStatePrincipal: `cloud-mcp-test:${organizationId}`,
-        sessionful: true,
         elicitationMode: options.elicitationMode ? { mode: options.elicitationMode } : undefined,
       });
       const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();