fix(core): Require workflow create scope for single node runs in n8n Assistant (#40908)

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

packages/cli/docs/adr/ADR-20261012-require-create-and-execute-scopes-for-standalone-node-runs.md

@@ -0,0 +1,59 @@
+# Require create and execute scopes for standalone node runs
+
+Date: 2026-10-12
+
+Status: Active
+
+Decision Owner: Assistant
+
+Source: https://linear.app/n8n/issue/AST-1705
+
+## Context
+
+The n8n Assistant can run one node standalone. The caller supplies the node type, the node
+parameters, the credentials, and the input items. The service puts the node in a temporary
+workflow in the target project, runs it, and deletes the workflow.
+
+`workflow:execute` lets a user run a workflow that already exists. The manual run endpoint
+loads the workflow from the database and ignores a definition in the request body. A user
+who has `workflow:execute` but not `workflow:create` or `workflow:update` can only run
+workflows that someone else wrote.
+
+A standalone node run does not run a stored workflow. The caller writes the node, so the
+run is workflow authoring and execution in one step.
+
+## Decision
+
+A standalone node run requires both `workflow:create` and `workflow:execute` in the target
+project. The user must hold both scopes. One of the two is not sufficient.
+
+The main reason: the caller defines the node. That is the same power as creating a workflow
+and running it. The required scopes match those two actions.
+
+The check runs before the service resolves the node or reads a credential.
+
+## Alternatives Considered
+
+1. **Keep `workflow:execute` alone.** We rejected it because it lets a role that cannot
+   author workflows run any node with any parameters. That breaks the contract of an
+   execute-only role.
+2. **Require `workflow:update` with `workflow:execute`.** We rejected it because
+   `workflow:update` applies to a workflow that exists, and this technically creates a new
+   workflow it runs.
+
+## Consequences
+
+1. A custom role that has `workflow:execute` but not `workflow:create` cannot use standalone
+   node runs. Such a user can still run stored workflows through the Assistant.
+2. The built-in project roles do not change in behavior. Each role that has
+   `workflow:execute` also has `workflow:create`. A personal project owner has both scopes.
+3. Any new path that runs a caller-defined node or workflow must require `workflow:create`
+   with `workflow:execute`.
+
+## Links
+
+RFC: -
+
+Documentation: -
+
+Related ADRs: -

packages/cli/src/modules/instance-ai/__tests__/instance-ai.adapter.service.test.ts

@@ -1970,7 +1970,7 @@ describe('executeNodeService adapter', () => {
 		mockedUserHasScopes.mockReset();
 	});
 
-	it('runs the node in the bound project after asserting execute scope there', async () => {
+	it('runs the node in the bound project after asserting create and execute scopes there', async () => {
 		mockedUserHasScopes.mockResolvedValue(true);
 		const executeNodeService = {
 			run: vi.fn().mockResolvedValue({ status: 'success', output: [] }),
@@ -1980,16 +1980,19 @@ describe('executeNodeService adapter', () => {
 		const context = service.createContext(mockUser, { projectId: 'team-project-1' });
 		await context.executeNodeService?.execute(executeRequest);
 
-		expect(mockedUserHasScopes).toHaveBeenCalledWith(mockUser, ['workflow:execute'], false, {
-			projectId: 'team-project-1',
-		});
+		expect(mockedUserHasScopes).toHaveBeenCalledWith(
+			mockUser,
+			['workflow:create', 'workflow:execute'],
+			false,
+			{ projectId: 'team-project-1' },
+		);
 		expect(executeNodeService.run).toHaveBeenCalledWith(
 			mockUser,
 			expect.objectContaining({ projectId: 'team-project-1' }),
 		);
 	});
 
-	it('does not run when the user lacks execute scope in the bound project', async () => {
+	it('does not run when the user lacks the required scopes in the bound project', async () => {
 		mockedUserHasScopes.mockResolvedValue(false);
 		const executeNodeService = { run: vi.fn() };
 		const { service, mockUser } = createNodeAdapterServiceForTests([], { executeNodeService });

packages/cli/src/modules/instance-ai/instance-ai.adapter.service.ts

@@ -888,7 +888,9 @@ export class InstanceAiAdapterService {
 		return {
 			execute: async (request) => {
 				this.assertInstanceNotReadOnly('executions');
-				const projectId = await resolveProjectId(['workflow:execute']);
+				// The caller supplies the node type and parameters, so a standalone run
+				// authors a workflow. See ADR-20261012-require-create-and-execute-scopes-for-standalone-node-runs.
+				const projectId = await resolveProjectId(['workflow:create', 'workflow:execute']);
 				const result = await executeNodeService.run(user, {
 					type: request.type,
 					version: request.version,

packages/quality/policy/code-health/src/index.ts

@@ -34,7 +34,7 @@ const defaultRuleSettings: RuleSettingsMap = {
 	'adr-conventions': {
 		enabled: true,
 		severity: 'error',
-		options: { allowedOwners: ['API & OEM', 'Catalysts'] },
+		options: { allowedOwners: ['API & OEM', 'Assistant', 'Catalysts'] },
 	},
 	'catalog-violations': {
 		enabled: true,