Fix browser elicitation resume page session lookup (#1317)

* Add cloud browser resume page repro

* Fix browser resume session lookup

* Centralize MCP session Durable Object stubs

* Lint against raw Durable Object id lookups

* Assert browser approval POST completion

* Add browser resume page e2e coverage

Author: RhysSullivan

.oxlintrc.jsonc

@@ -20,6 +20,7 @@
     "executor/no-match-orelse": "error",
     "executor/no-promise-catch": "error",
     "executor/no-promise-reject": "error",
+    "executor/no-raw-durable-object-id": "error",
     "executor/no-raw-fetch": "error",
     "executor/no-redundant-primitive-cast": "error",
     "executor/no-redundant-error-factory": "error",

apps/cloud/src/auth/handlers.ts

@@ -32,10 +32,7 @@ import {
   authorizeOrganizationSelector,
   resolveOrganization,
 } from "./organization";
-import type {
-  McpSessionApprovalResult,
-  McpSessionResumeApprovalResult,
-} from "../mcp/session-durable-object";
+import { mcpSessionStub } from "@executor-js/cloudflare/mcp/session-stub";
 
 const COOKIE_OPTIONS = {
   path: "/",
@@ -122,23 +119,7 @@ const requireSelectedOrganization = Effect.gen(function* () {
   };
 });
 
-const getMcpSessionStub = (mcpSessionId: string) =>
-  Effect.try({
-    try: () => {
-      const ns = env.MCP_SESSION;
-      return ns.get(ns.idFromString(mcpSessionId));
-    },
-    catch: () => undefined,
-  }).pipe(Effect.orElseSucceed(() => null));
-
-const requireMcpSessionStub = (mcpSessionId: string, executionId: string) =>
-  Effect.gen(function* () {
-    const stub = yield* getMcpSessionStub(mcpSessionId);
-    if (!stub) {
-      return yield* new McpExecutionNotFoundError({ executionId });
-    }
-    return stub;
-  });
+const getMcpSessionStub = (mcpSessionId: string) => mcpSessionStub(env.MCP_SESSION, mcpSessionId);
 
 const failMcpApprovalResult = (
   result: { readonly status: "not_found" | "forbidden" },
@@ -528,13 +509,12 @@ export const CloudSessionAuthHandlers = HttpApiBuilder.group(
       .handle("getMcpPaused", ({ params }) =>
         Effect.gen(function* () {
           const owner = yield* requireSelectedOrganization;
-          const stub = yield* requireMcpSessionStub(params.mcpSessionId, params.executionId);
-          const result = yield* Effect.promise(
-            () =>
-              stub.getPausedExecutionForApproval(params.executionId, {
-                accountId: owner.accountId,
-                organizationId: owner.organizationId,
-              }) as Promise<McpSessionApprovalResult>,
+          const stub = getMcpSessionStub(params.mcpSessionId);
+          const result = yield* Effect.promise(() =>
+            stub.getPausedExecutionForApproval(params.executionId, {
+              accountId: owner.accountId,
+              organizationId: owner.organizationId,
+            }),
           );
 
           if (result.status !== "ok") {
@@ -550,20 +530,19 @@ export const CloudSessionAuthHandlers = HttpApiBuilder.group(
       .handle("resumeMcpExecution", ({ params, payload }) =>
         Effect.gen(function* () {
           const owner = yield* requireSelectedOrganization;
-          const stub = yield* requireMcpSessionStub(params.mcpSessionId, params.executionId);
-          const result = yield* Effect.promise(
-            () =>
-              stub.resumeExecutionForApproval(
-                params.executionId,
-                {
-                  accountId: owner.accountId,
-                  organizationId: owner.organizationId,
-                },
-                {
-                  action: payload.action,
-                  content: payload.content as Record<string, unknown> | undefined,
-                },
-              ) as Promise<McpSessionResumeApprovalResult>,
+          const stub = getMcpSessionStub(params.mcpSessionId);
+          const result = yield* Effect.promise(() =>
+            stub.resumeExecutionForApproval(
+              params.executionId,
+              {
+                accountId: owner.accountId,
+                organizationId: owner.organizationId,
+              },
+              {
+                action: payload.action,
+                content: payload.content as Record<string, unknown> | undefined,
+              },
+            ),
           );
 
           if (result.status !== "ok") {

apps/cloud/src/mcp/agent-handler.ts

@@ -13,20 +13,12 @@ import {
   withVerifiedIdentityHeaders,
 } from "@executor-js/cloudflare/mcp/do-headers";
 import type { McpSessionProps } from "@executor-js/cloudflare/mcp/agent-durable-object";
-import { mcpSessionDurableObjectName } from "@executor-js/cloudflare/mcp/execution-owner-directory";
+import { mcpSessionStub } from "@executor-js/cloudflare/mcp/session-stub";
 
 import { wrapMcpSseResponse } from "../observability/memory-metrics";
 import { cloudMcpAuth } from "./auth-provider";
 import { McpSessionDOSqlite } from "./session-durable-object";
 
-interface McpAgentSessionStub {
-  readonly validateMcpSessionOwner: (identity: {
-    readonly accountId: string;
-    readonly organizationId: string;
-  }) => Promise<"ok" | "not_found" | "forbidden">;
-  readonly _cf_scheduleDestroy: () => Promise<void>;
-}
-
 const corsPreflightResponse = (): Response =>
   new Response(null, {
     status: 204,
@@ -68,12 +60,6 @@ const renderAuthError = (
   return jsonRpcResponse(503, -32001, outcome.message);
 };
 
-const sessionStub = (env: Env, sessionId: string): McpAgentSessionStub =>
-  // oxlint-disable-next-line executor/no-double-cast -- boundary: Workers types expose only DurableObjectStub, but RPC methods are generated from the bound DO class.
-  env.MCP_SESSION.get(
-    env.MCP_SESSION.idFromName(mcpSessionDurableObjectName(sessionId)),
-  ) as unknown as McpAgentSessionStub;
-
 const authenticate = (request: Request) =>
   Effect.gen(function* () {
     const auth = yield* McpAuthProvider;
@@ -142,7 +128,11 @@ export const makeCloudMcpAgentHandler = () => {
     if (!Predicate.isTagged(outcome, "Authenticated")) {
       if (Predicate.isTagged(outcome, "Forbidden") && sessionId) {
         await Effect.runPromise(
-          Effect.ignore(Effect.tryPromise(() => sessionStub(env, sessionId)._cf_scheduleDestroy())),
+          Effect.ignore(
+            Effect.tryPromise(() =>
+              mcpSessionStub(env.MCP_SESSION, sessionId)._cf_scheduleDestroy(),
+            ),
+          ),
         );
       }
       return renderAuthError(auth, request, outcome);
@@ -156,7 +146,7 @@ export const makeCloudMcpAgentHandler = () => {
     }
 
     if (sessionId) {
-      const owner = await sessionStub(env, sessionId).validateMcpSessionOwner({
+      const owner = await mcpSessionStub(env.MCP_SESSION, sessionId).validateMcpSessionOwner({
         accountId: outcome.principal.accountId,
         organizationId: outcome.principal.organizationId,
       });

apps/cloud/src/mcp/session-durable-object.ts

@@ -36,11 +36,11 @@ import {
   type SessionMeta,
 } from "@executor-js/cloudflare/mcp/agent-durable-object";
 import {
-  mcpSessionDurableObjectName,
   mcpExecutionOwnerDirectoryFromNamespace,
   type McpExecutionOwnerDirectory,
   type McpExecutionOwnerRoute,
 } from "@executor-js/cloudflare/mcp/execution-owner-directory";
+import { mcpSessionStub } from "@executor-js/cloudflare/mcp/session-stub";
 import { buildExecuteDescription, type ResumeResponse } from "@executor-js/execution";
 
 // The DO meters executions just like the HTTP `/api/*` plane: it builds its
@@ -101,16 +101,6 @@ type CloudSessionDbHandle = DbServiceShape & {
   readonly end: () => Promise<void>;
 };
 
-interface McpModelResumeStub {
-  readonly resumeExecutionForModel: (
-    executionId: string,
-    identity: McpApprovalOwner,
-    response: ResumeResponse,
-  ) => Promise<McpSessionModelResumeResult>;
-}
-
-const toMcpModelResumeStub = (stub: unknown): McpModelResumeStub => stub as McpModelResumeStub;
-
 class OrganizationNotFoundError extends Data.TaggedError("OrganizationNotFoundError")<{
   readonly organizationId: string;
 }> {}
@@ -213,11 +203,11 @@ export class McpSessionDOSqlite extends McpAgentSessionDOBase<Env, CloudSessionD
   ): Effect.Effect<McpSessionModelResumeResult, unknown> {
     return Effect.tryPromise({
       try: () =>
-        toMcpModelResumeStub(
-          env.MCP_SESSION.get(
-            env.MCP_SESSION.idFromName(mcpSessionDurableObjectName(owner.sessionId)),
-          ),
-        ).resumeExecutionForModel(executionId, identity, response),
+        mcpSessionStub(env.MCP_SESSION, owner.sessionId).resumeExecutionForModel(
+          executionId,
+          identity,
+          response,
+        ),
       catch: (cause) => new McpModelResumeForwardError({ cause }),
     });
   }

apps/host-cloudflare/src/mcp/agent-handler.ts

@@ -13,20 +13,12 @@ import {
   withVerifiedIdentityHeaders,
 } from "@executor-js/cloudflare/mcp/do-headers";
 import type { McpSessionProps } from "@executor-js/cloudflare/mcp/agent-durable-object";
-import { mcpSessionDurableObjectName } from "@executor-js/cloudflare/mcp/execution-owner-directory";
+import { mcpSessionStub } from "@executor-js/cloudflare/mcp/session-stub";
 
 import type { CloudflareConfig, CloudflareEnv } from "../config";
 import { cloudflareAccessMcpAuth } from "./auth";
 import { McpSessionDO } from "./session-durable-object";
 
-interface McpAgentSessionStub {
-  readonly validateMcpSessionOwner: (identity: {
-    readonly accountId: string;
-    readonly organizationId: string;
-  }) => Promise<"ok" | "not_found" | "forbidden">;
-  readonly _cf_scheduleDestroy: () => Promise<void>;
-}
-
 const corsPreflightResponse = (): Response =>
   new Response(null, {
     status: 204,
@@ -68,12 +60,6 @@ const renderAuthError = (
   return jsonRpcResponse(503, -32001, outcome.message);
 };
 
-const sessionStub = (env: CloudflareEnv, sessionId: string): McpAgentSessionStub =>
-  // oxlint-disable-next-line executor/no-double-cast -- boundary: Workers types expose only DurableObjectStub, but RPC methods are generated from the bound DO class.
-  env.MCP_SESSION.get(
-    env.MCP_SESSION.idFromName(mcpSessionDurableObjectName(sessionId)),
-  ) as unknown as McpAgentSessionStub;
-
 const authenticate = (request: Request, config: CloudflareConfig) =>
   Effect.gen(function* () {
     const auth = yield* McpAuthProvider;
@@ -116,7 +102,11 @@ export const makeCloudflareMcpAgentHandler = (config: CloudflareConfig) => {
     if (!Predicate.isTagged(outcome, "Authenticated")) {
       if (Predicate.isTagged(outcome, "Forbidden") && sessionId) {
         await Effect.runPromise(
-          Effect.ignore(Effect.tryPromise(() => sessionStub(env, sessionId)._cf_scheduleDestroy())),
+          Effect.ignore(
+            Effect.tryPromise(() =>
+              mcpSessionStub(env.MCP_SESSION, sessionId)._cf_scheduleDestroy(),
+            ),
+          ),
         );
       }
       return renderAuthError(auth, request, outcome);
@@ -127,7 +117,7 @@ export const makeCloudflareMcpAgentHandler = (config: CloudflareConfig) => {
     }
 
     if (sessionId) {
-      const owner = await sessionStub(env, sessionId).validateMcpSessionOwner({
+      const owner = await mcpSessionStub(env.MCP_SESSION, sessionId).validateMcpSessionOwner({
         accountId: outcome.principal.accountId,
         organizationId: outcome.principal.organizationId,
       });

apps/host-cloudflare/src/mcp/index.ts

@@ -1,13 +1,8 @@
 import { Effect } from "effect";
 
 import { decodeResumeResponse } from "@executor-js/host-mcp/browser-approval";
-import type {
-  McpApprovalOwner,
-  McpSessionApprovalResult,
-  McpSessionResumeApprovalResult,
-} from "@executor-js/cloudflare/mcp/agent-durable-object";
-import { mcpSessionDurableObjectName } from "@executor-js/cloudflare/mcp/execution-owner-directory";
-import type { ResumeResponse } from "@executor-js/execution";
+import type { McpApprovalOwner } from "@executor-js/cloudflare/mcp/agent-durable-object";
+import { mcpSessionStub } from "@executor-js/cloudflare/mcp/session-stub";
 
 import type { CloudflareConfig, CloudflareEnv } from "../config";
 import { makeAccessVerifier } from "../auth/cloudflare-access";
@@ -16,20 +11,6 @@ export { cloudflareAccessMcpAuth } from "./auth";
 export { McpSessionDO } from "./session-durable-object";
 export { McpExecutionOwnerDirectoryDO } from "@executor-js/cloudflare/mcp/execution-owner-directory";
 
-const toApprovalStub = (stub: unknown): McpApprovalStub => stub as McpApprovalStub;
-
-interface McpApprovalStub {
-  getPausedExecutionForApproval(
-    executionId: string,
-    identity: McpApprovalOwner,
-  ): Promise<McpSessionApprovalResult>;
-  resumeExecutionForApproval(
-    executionId: string,
-    identity: McpApprovalOwner,
-    response: ResumeResponse,
-  ): Promise<McpSessionResumeApprovalResult>;
-}
-
 const PAUSED_PATH = /^\/api\/mcp-sessions\/([^/?#]+)\/executions\/([^/?#]+)$/;
 const RESUME_PATH = /^\/api\/mcp-sessions\/([^/?#]+)\/executions\/([^/?#]+)\/resume$/;
 
@@ -41,10 +22,7 @@ export const makeCloudflareApprovalHandler = (
   env: CloudflareEnv,
 ): ((request: Request) => Promise<Response>) => {
   const { verify } = makeAccessVerifier(config);
-  const stubFor = (sessionId: string): McpApprovalStub =>
-    toApprovalStub(
-      env.MCP_SESSION.get(env.MCP_SESSION.idFromName(mcpSessionDurableObjectName(sessionId))),
-    );
+  const stubFor = (sessionId: string) => mcpSessionStub(env.MCP_SESSION, sessionId);
 
   return async (request) => {
     const principal = await Effect.runPromise(verify(request));

apps/host-cloudflare/src/mcp/session-durable-object.ts

@@ -15,11 +15,11 @@ import {
   type SessionMeta,
 } from "@executor-js/cloudflare/mcp/agent-durable-object";
 import {
-  mcpSessionDurableObjectName,
   mcpExecutionOwnerDirectoryFromNamespace,
   type McpExecutionOwnerDirectory,
   type McpExecutionOwnerRoute,
 } from "@executor-js/cloudflare/mcp/execution-owner-directory";
+import { mcpSessionStub } from "@executor-js/cloudflare/mcp/session-stub";
 import type { ResumeResponse } from "@executor-js/execution";
 
 import { loadConfig, type CloudflareConfig, type CloudflareEnv } from "../config";
@@ -47,16 +47,6 @@ import { preloadQuickJs } from "../quickjs";
 // own lifecycle (the binding is the connection), so `end` is `close` — a no-op.
 type CfSessionDbHandle = ExecutorDbHandle & { readonly end: () => Promise<void> };
 
-interface McpModelResumeStub {
-  readonly resumeExecutionForModel: (
-    executionId: string,
-    identity: McpApprovalOwner,
-    response: ResumeResponse,
-  ) => Promise<McpSessionModelResumeResult>;
-}
-
-const toMcpModelResumeStub = (stub: unknown): McpModelResumeStub => stub as McpModelResumeStub;
-
 class McpModelResumeForwardError extends Data.TaggedError("McpModelResumeForwardError")<{
   readonly cause: unknown;
 }> {}
@@ -86,11 +76,11 @@ export class McpSessionDO extends McpAgentSessionDOBase<CloudflareEnv, CfSession
   ): Effect.Effect<McpSessionModelResumeResult, unknown> {
     return Effect.tryPromise({
       try: () =>
-        toMcpModelResumeStub(
-          this.cfEnv.MCP_SESSION.get(
-            this.cfEnv.MCP_SESSION.idFromName(mcpSessionDurableObjectName(owner.sessionId)),
-          ),
-        ).resumeExecutionForModel(executionId, identity, response),
+        mcpSessionStub(this.cfEnv.MCP_SESSION, owner.sessionId).resumeExecutionForModel(
+          executionId,
+          identity,
+          response,
+        ),
       catch: (cause) => new McpModelResumeForwardError({ cause }),
     });
   }