@@ -30,6 +30,12 @@ vi.mock('@/ee/access-requests/lib/application/requests', () => ({
   },
   createAccessRequest: { operation: { id: 'access_requests.create' }, execute: mocks.create },
   cancelAccessRequest: { operation: { id: 'access_requests.cancel' }, execute: mocks.cancel },
+  workspaceAccessRequestUseCases: {
+    discover: { operation: { id: 'access_requests.discover' }, execute: mocks.discover },
+    listMine: { operation: { id: 'access_requests.list_mine' }, execute: mocks.listMine },
+    create: { operation: { id: 'access_requests.create' }, execute: mocks.create },
+    cancel: { operation: { id: 'access_requests.cancel' }, execute: mocks.cancel },
+  },
   listOrganizationAccessRequests: {
     operation: { id: 'access_requests.list_organization' },
     execute: mocks.listOrganization,
 
@@ -2,7 +2,7 @@ import { v2CancelWorkspaceAccessRequestContract } from '@/lib/api/contracts/v2/a
 import { defineV2JsonRoute, v2ApiKeyAuth, v2RateLimits } from '@/lib/api/server/routes'
 import { v2AccessRequestErrorPolicy } from '@/lib/api/server/routes/access-requests'
 import { accessRequestOperations } from '@/ee/access-requests/lib/application/operations'
-import { cancelAccessRequest } from '@/ee/access-requests/lib/application/requests'
+import { workspaceAccessRequestUseCases } from '@/ee/access-requests/lib/application/requests'
 
 export const POST = defineV2JsonRoute({
   contract: v2CancelWorkspaceAccessRequestContract,
@@ -14,6 +14,6 @@ export const POST = defineV2JsonRoute({
     requestId: params.requestId,
     scope: { kind: 'workspace' as const, workspaceId: params.workspaceId },
   }),
-  useCase: cancelAccessRequest,
+  useCase: workspaceAccessRequestUseCases.cancel,
   present: ({ request }) => ({ data: request }),
 })
@@ -4,7 +4,7 @@ import { defineV2JsonRoute, v2ApiKeyAuth, v2RateLimits } from '@/lib/api/server/
 import { v2AccessRequestErrorPolicy } from '@/lib/api/server/routes/access-requests'
 import { cursorSortKey, decodeOffsetCursor, encodeOffsetCursor } from '@/app/api/v2/lib/response'
 import { accessRequestOperations } from '@/ee/access-requests/lib/application/operations'
-import { discoverAccessRequests } from '@/ee/access-requests/lib/application/requests'
+import { workspaceAccessRequestUseCases } from '@/ee/access-requests/lib/application/requests'
 
 function cursorFilters(
   params: { workspaceId: string },
@@ -33,7 +33,7 @@ export const GET = defineV2JsonRoute({
       cursorFilters(params, query)
     ),
   }),
-  useCase: discoverAccessRequests,
+  useCase: workspaceAccessRequestUseCases.discover,
   present: ({ entries, hasMore }, { params, query }) => ({
     data: entries,
     nextCursor: hasMore
 
@@ -7,10 +7,7 @@ import { defineV2JsonRoute, v2ApiKeyAuth, v2RateLimits } from '@/lib/api/server/
 import { v2AccessRequestErrorPolicy } from '@/lib/api/server/routes/access-requests'
 import { readSortedCursor, writeSortedCursor } from '@/app/api/v2/lib/response'
 import { accessRequestOperations } from '@/ee/access-requests/lib/application/operations'
-import {
-  createAccessRequest,
-  listMyAccessRequests,
-} from '@/ee/access-requests/lib/application/requests'
+import { workspaceAccessRequestUseCases } from '@/ee/access-requests/lib/application/requests'
 
 function cursorFilters(params: { workspaceId: string }, query: { status?: string }) {
   return cursorScopeKey(cursorRoute(v2ListMyWorkspaceAccessRequestsContract, params), {
@@ -40,7 +37,7 @@ export const GET = defineV2JsonRoute({
       ),
     },
   }),
-  useCase: listMyAccessRequests,
+  useCase: workspaceAccessRequestUseCases.listMine,
   present: ({ requests, nextCursorKeys }, { params, query }) => ({
     data: requests,
     nextCursor: writeSortedCursor(
@@ -62,6 +59,6 @@ export const POST = defineV2JsonRoute({
     ...body,
     scope: { kind: 'workspace' as const, workspaceId: params.workspaceId },
   }),
-  useCase: createAccessRequest,
+  useCase: workspaceAccessRequestUseCases.create,
   present: ({ request }) => ({ data: request }),
 })
@@ -2,6 +2,7 @@ import { db } from '@sim/db'
 import { member, permissions, user, workspace } from '@sim/db/schema'
 import { dbChainMockFns, queueTableRows, resetDbChainMock } from '@sim/testing'
 import {
+  createDelegatedPrincipal,
   createPersonalApiKeyPrincipal,
   createSessionPrincipal,
 } from '@sim/testing/factories/principal.factory'
@@ -185,6 +186,18 @@ describe('access request scope authorization', () => {
     expect(dbChainMockFns.select).not.toHaveBeenCalled()
   })
 
+  it("refuses Chat on a member's organization-scoped request before any lookup", async () => {
+    const chat = createDelegatedPrincipal({
+      subjectUserId: 'person',
+      workspaceId: 'workspace',
+      audience: 'sim:settings',
+    })
+    await expect(
+      authorizeAccessRequestScope(chat, accessRequestOperations.create, organizationScope)
+    ).rejects.toMatchObject({ detailCode: 'PRINCIPAL_KIND_NOT_PERMITTED' })
+    expect(dbChainMockFns.select).not.toHaveBeenCalled()
+  })
+
   it('conceals an archived or removed workspace before membership lookup', async () => {
     queueTableRows(workspace, [])
     await expect(
 
@@ -1,3 +1,4 @@
+import { requirePrincipalSubjectUserId } from '@sim/auth/principal'
 import { db } from '@sim/db'
 import { member, permissions, user, workspace } from '@sim/db/schema'
 import {
@@ -10,13 +11,15 @@ import { isAccountBlocked } from '@/lib/auth/ban'
 import { authorizeOrganizationOperation } from '@/lib/core/application/organization-authorization'
 import {
   authorizeWorkspaceOperation,
+  PrincipalKindAuthorizationError,
   requireAllowedWorkspacePrincipal,
 } from '@/lib/core/application/workspace-authorization'
 import { OrchestrationError } from '@/lib/core/orchestration/types'
 import type { DbOrTx } from '@/lib/db/types'
-import type {
-  AccessRequestOperation,
-  AccessRequestPrincipal,
+import {
+  ACCESS_REQUEST_DELEGATION_AUDIENCE,
+  type AccessRequestOperation,
+  type AccessRequestPrincipal,
 } from '@/ee/access-requests/lib/application/operations'
 import type { AccessRequestScope } from '@/ee/access-requests/lib/targets'
 
@@ -95,6 +98,10 @@ export async function authorizeAccessRequestScope(
   if (operation.admin && scope.kind !== 'organization') {
     throw new OrchestrationError('forbidden', 'Organization administrator access is required')
   }
+  if (principal.kind === 'delegated' && scope.kind !== 'workspace') {
+    throw new PrincipalKindAuthorizationError(principal.kind, operation.id)
+  }
+  const actorUserId = requirePrincipalSubjectUserId(principal)
   let canonicalWorkspace:
     | Pick<typeof workspace.$inferSelect, 'id' | 'organizationId' | 'allowPersonalApiKeys'>
     | undefined
@@ -119,7 +126,7 @@ export async function authorizeAccessRequestScope(
   }
   const membership = await loadAccessRequestMembership(
     executor,
-    principal.userId,
+    actorUserId,
     scope,
     organizationId,
     forUpdate
@@ -136,7 +143,11 @@ export async function authorizeAccessRequestScope(
         workspaceOrganizationId: canonicalWorkspace.organizationId,
         allowPersonalApiKeys: canonicalWorkspace.allowPersonalApiKeys,
       },
-      { executor, forUpdate }
+      {
+        executor,
+        forUpdate,
+        delegation: { audience: ACCESS_REQUEST_DELEGATION_AUDIENCE, isWithinScope: () => true },
+      }
     )
   } else if (scope.kind === 'organization') {
     await authorizeOrganizationOperation(
 
@@ -1,6 +1,7 @@
 import type { Principal } from '@sim/auth/principal'
 import { db } from '@sim/db'
 import {
+  createDelegatedPrincipal,
   createPersonalApiKeyPrincipal,
   createSessionPrincipal,
   createWorkspaceApiKeyPrincipal,
@@ -95,6 +96,11 @@ describe('authorized access request execution', () => {
       scopes: ['api:write'],
       expiresAt: new Date('2099-01-01'),
     },
+    createDelegatedPrincipal({
+      subjectUserId: 'requester',
+      workspaceId: 'workspace',
+      audience: 'sim:settings',
+    }),
   ])(
     'preserves the $kind actor through preparation, transactional reauthorization and audit',
     async (caller) => {
@@ -110,7 +116,12 @@ describe('authorized access request execution', () => {
         projectAudit: () => audit,
       })
       await expect(useCase.execute({ principal: caller, input })).resolves.toBe('result')
-      expect(prepare).toHaveBeenCalledWith({ principal: caller, input, context })
+      expect(prepare).toHaveBeenCalledWith({
+        principal: caller,
+        actorUserId: 'requester',
+        input,
+        context,
+      })
       expect(mocks.authorize).toHaveBeenNthCalledWith(
         2,
         caller,
@@ -122,6 +133,7 @@ describe('authorized access request execution', () => {
       )
       expect(execute).toHaveBeenCalledWith({
         principal: caller,
+        actorUserId: 'requester',
         input,
         context,
         executor: transaction,
@@ -194,7 +206,12 @@ describe('authorized access request execution', () => {
       execute,
     })
     await expect(useCase.execute({ principal, input })).resolves.toEqual({ id: 'request' })
-    expect(prepare).toHaveBeenCalledExactlyOnceWith({ principal, input, context })
+    expect(prepare).toHaveBeenCalledExactlyOnceWith({
+      principal,
+      actorUserId: 'requester',
+      input,
+      context,
+    })
     expect(prepare.mock.invocationCallOrder[0]).toBeLessThan(
       vi.mocked(db.transaction).mock.invocationCallOrder[0]
     )
@@ -213,6 +230,7 @@ describe('authorized access request execution', () => {
     )
     expect(execute).toHaveBeenCalledExactlyOnceWith({
       principal,
+      actorUserId: 'requester',
       input,
       context,
       executor: transaction,
 
@@ -1,4 +1,4 @@
-import type { Principal } from '@sim/auth/principal'
+import { type Principal, requirePrincipalSubjectUserId } from '@sim/auth/principal'
 import { db } from '@sim/db'
 import { acquireOrganizationMutationLock } from '@/lib/billing/organizations/membership'
 import {
@@ -13,14 +13,17 @@ import {
   type AccessRequestContext,
   authorizeAccessRequestScope,
 } from '@/ee/access-requests/lib/application/authorization'
-import type {
-  AccessRequestOperation,
-  AccessRequestPrincipal,
+import {
+  ACCESS_REQUEST_DELEGATION_AUDIENCE,
+  type AccessRequestOperation,
+  type AccessRequestPrincipal,
 } from '@/ee/access-requests/lib/application/operations'
 import type { AccessRequestScope } from '@/ee/access-requests/lib/targets'
 
 interface AccessRequestPreparationArgs<I> {
   principal: AccessRequestPrincipal
+  /** The person acting: the caller, or the member Chat acts for. */
+  actorUserId: string
   input: I
   context: AccessRequestContext
 }
@@ -107,7 +110,8 @@ export function defineAuthorizedAccessRequestUseCase<I, R, P = undefined>(
       const scope = definition.scope(input)
       const initial = await authorizeAccessRequestScope(principal, definition.operation, scope)
       return runWithOutboundOrganization(initial.organizationId, async () => {
-        const preparation = { principal, input, context: initial }
+        const actorUserId = requirePrincipalSubjectUserId(principal)
+        const preparation = { principal, actorUserId, input, context: initial }
         let context = initial
         let result: R
         if (definition.mutation) {
@@ -124,19 +128,26 @@ export function defineAuthorizedAccessRequestUseCase<I, R, P = undefined>(
               true,
               initial
             )
-            return execute({ principal, input, context, executor })
+            return execute({ principal, actorUserId, input, context, executor })
           })
         } else {
           const execute = await prepareExecution(definition, preparation)
-          result = await execute({ principal, input, context, executor: db })
+          result = await execute({ principal, actorUserId, input, context, executor: db })
         }
         if (definition.projectAudit) {
           recordProjectedUseCaseAuditEntries(
             definition.operation,
             context.workspaceId,
             principal,
             request,
-            definition.projectAudit({ principal, input, context, executor: db, result }),
+            definition.projectAudit({
+              principal,
+              actorUserId,
+              input,
+              context,
+              executor: db,
+              result,
+            }),
             context.organizationId ?? undefined
           )
         }
@@ -145,3 +156,14 @@ export function defineAuthorizedAccessRequestUseCase<I, R, P = undefined>(
     },
   }
 }
+
+/**
+ * The workspace routes' copy of a member use case. Declaring the audience admits Chat acting for
+ * the requester, pinned to its own workspace; the organization routes keep the shared use case,
+ * so Chat never reaches them.
+ */
+export function admitWorkspaceDelegation<I, R>(
+  useCase: OperationUseCase<AccessRequestOperation, I, R>
+): OperationUseCase<AccessRequestOperation, I, R> {
+  return Object.freeze({ ...useCase, delegationAudience: ACCESS_REQUEST_DELEGATION_AUDIENCE })
+}