diff --git a/packages/frontend/editor-ui/src/features/agents/__tests__/AgentBuilder.readonly.test.ts b/packages/frontend/editor-ui/src/features/agents/__tests__/AgentBuilder.readonly.test.ts
index 0b25afbec60..6220889b172 100644
--- a/packages/frontend/editor-ui/src/features/agents/__tests__/AgentBuilder.readonly.test.ts
+++ b/packages/frontend/editor-ui/src/features/agents/__tests__/AgentBuilder.readonly.test.ts
@@ -187,6 +187,78 @@ describe('AgentChatPanel — read-only build chat input', () => {
 		expect(chatInput.props('placeholder')).toBe('agents.builder.readonly.placeholder');
 	});
 
+	it('does not auto-send a seeded initialMessage when the build chat is read-only', async () => {
+		const sendMessage = vi.fn();
+		const loadHistory = vi.fn();
+		// Reset module cache so the doMock below replaces the stream mock set up
+		// by the earlier test in this describe block — without this, the cached
+		// AgentChatPanel.vue would keep using the previous mock and our
+		// `loadHistory` assertion would observe zero calls on the wrong fn.
+		vi.resetModules();
+		vi.doMock('../composables/useAgentChatStream', () => ({
+			useAgentChatStream: () => ({
+				messages: ref([]),
+				isStreaming: ref(false),
+				messagingState: ref('idle'),
+				fatalError: ref(null),
+				loadHistory,
+				sendMessage,
+				stopGenerating: vi.fn(),
+				resume: vi.fn(),
+				dismissFatalError: vi.fn(),
+			}),
+		}));
+		vi.doMock('../composables/useAgentTelemetry', () => ({
+			useAgentTelemetry: () => ({ trackSubmittedMessage: vi.fn() }),
+		}));
+		vi.doMock('../composables/agentTelemetry.utils', () => ({
+			buildAgentConfigFingerprint: vi.fn().mockResolvedValue({}),
+		}));
+
+		const beforeSend = vi.fn();
+		const { default: AgentChatPanel } = await import('../components/AgentChatPanel.vue');
+
+		const wrapper = mount(AgentChatPanel, {
+			props: {
+				projectId: 'p1',
+				agentId: 'a1',
+				endpoint: 'build',
+				agentConfig: null,
+				agentStatus: 'draft',
+				connectedTriggers: [],
+				canEditAgent: false,
+				initialMessage: 'seed build prompt',
+				beforeSend,
+			},
+			global: {
+				stubs: {
+					N8nButton: { template: '<button><slot /></button>' },
+					N8nCallout: { template: '<div><slot /></div>' },
+					N8nIconButton: { template: '<button />' },
+					AgentChatEmptyState: { template: '<div data-testid="stub-empty-state" />' },
+					AgentChatMessageList: { template: '<div />' },
+					ChatInputBase: {
+						name: 'ChatInputBase',
+						template: '<div data-testid="stub-chat-input" />',
+						props: ['modelValue', 'placeholder', 'isStreaming', 'canSubmit', 'disabled'],
+					},
+				},
+			},
+		});
+
+		await vi.waitFor(() => {
+			// Setup-time auto-send has run if it was going to.
+			expect(wrapper.exists()).toBe(true);
+		});
+
+		expect(sendMessage).not.toHaveBeenCalled();
+		expect(beforeSend).not.toHaveBeenCalled();
+		expect(wrapper.emitted('initial-consumed')).toBeUndefined();
+		// History is loaded instead of auto-sending — so any existing thread
+		// renders rather than showing a misleading "build your agent" empty state.
+		expect(loadHistory).toHaveBeenCalledTimes(1);
+	});
+
 	it('does not disable ChatInputBase for endpoint=chat (test mode) regardless of canEditAgent', async () => {
 		const { default: AgentChatPanel } = await import('../components/AgentChatPanel.vue');
 
diff --git a/packages/frontend/editor-ui/src/features/agents/__tests__/AgentChatPanel.test.ts b/packages/frontend/editor-ui/src/features/agents/__tests__/AgentChatPanel.test.ts
index 4498ae809ba..a4a59f9a613 100644
--- a/packages/frontend/editor-ui/src/features/agents/__tests__/AgentChatPanel.test.ts
+++ b/packages/frontend/editor-ui/src/features/agents/__tests__/AgentChatPanel.test.ts
@@ -210,6 +210,37 @@ describe('AgentChatPanel', () => {
 		expect(wrapper.emitted('initial-consumed')).toBeUndefined();
 	});
 
+	it('does not consume a seeded initial message in a read-only build chat', async () => {
+		const beforeSend = vi.fn();
+
+		const wrapper = mount(AgentChatPanel, {
+			props: {
+				projectId: 'p1',
+				agentId: 'a1',
+				endpoint: 'build',
+				canEditAgent: false,
+				initialMessage: 'seed build prompt',
+				agentConfig: {
+					name: 'Agent',
+					model: 'anthropic/claude-sonnet-4-5',
+					instructions: 'Help.',
+				},
+				agentStatus: 'draft',
+				connectedTriggers: [],
+				beforeSend,
+			},
+		});
+
+		await flushPromises();
+
+		expect(beforeSend).not.toHaveBeenCalled();
+		expect(sendMessageMock).not.toHaveBeenCalled();
+		expect(wrapper.emitted('initial-consumed')).toBeUndefined();
+		// History is loaded instead so any existing thread renders, rather than
+		// the misleading "describe your agent" empty state.
+		expect(loadHistoryMock).toHaveBeenCalledTimes(1);
+	});
+
 	it('disables chat and blocks sending while an interactive question is unresolved', async () => {
 		messagesMock.value = [openInteractiveMessage()];
 
diff --git a/packages/frontend/editor-ui/src/features/agents/__tests__/useAgentPermissions.test.ts b/packages/frontend/editor-ui/src/features/agents/__tests__/useAgentPermissions.test.ts
new file mode 100644
index 00000000000..2e5458fbbac
--- /dev/null
+++ b/packages/frontend/editor-ui/src/features/agents/__tests__/useAgentPermissions.test.ts
@@ -0,0 +1,140 @@
+import { createTestingPinia } from '@pinia/testing';
+import { setActivePinia } from 'pinia';
+import type { Scope } from '@n8n/permissions';
+import { mockedStore } from '@/__tests__/utils';
+import { useProjectsStore } from '@/features/collaboration/projects/projects.store';
+import { useUsersStore } from '@/features/settings/users/users.store';
+import { useSourceControlStore } from '@/features/integrations/sourceControl.ee/sourceControl.store';
+import type { ProjectListItem } from '@/features/collaboration/projects/projects.types';
+import { ProjectTypes } from '@/features/collaboration/projects/projects.types';
+import { useAgentPermissions } from '../composables/useAgentPermissions';
+
+const PROJECT_ID = 'project-1';
+
+const makeProject = (scopes: Scope[]): ProjectListItem => ({
+	id: PROJECT_ID,
+	name: 'Team Alpha',
+	icon: { type: 'icon', value: 'folder' },
+	type: ProjectTypes.Team,
+	createdAt: '2024-01-01T00:00:00.000Z',
+	updatedAt: '2024-01-01T00:00:00.000Z',
+	role: 'project:editor',
+	scopes,
+});
+
+describe('useAgentPermissions', () => {
+	let projectsStore: ReturnType<typeof mockedStore<typeof useProjectsStore>>;
+	let usersStore: ReturnType<typeof mockedStore<typeof useUsersStore>>;
+	let sourceControlStore: ReturnType<typeof mockedStore<typeof useSourceControlStore>>;
+
+	beforeEach(() => {
+		setActivePinia(createTestingPinia());
+		projectsStore = mockedStore(useProjectsStore);
+		usersStore = mockedStore(useUsersStore);
+		sourceControlStore = mockedStore(useSourceControlStore);
+		projectsStore.myProjects = [];
+		usersStore.currentUser = null;
+		sourceControlStore.preferences = { branchReadOnly: false } as never;
+	});
+
+	it('grants permissions from project scopes when global scopes are absent', () => {
+		projectsStore.myProjects = [
+			makeProject([
+				'agent:create',
+				'agent:update',
+				'agent:delete',
+				'agent:publish',
+				'agent:unpublish',
+			]),
+		];
+
+		const { canCreate, canUpdate, canDelete, canPublish, canUnpublish } =
+			useAgentPermissions(PROJECT_ID);
+
+		expect(canCreate.value).toBe(true);
+		expect(canUpdate.value).toBe(true);
+		expect(canDelete.value).toBe(true);
+		expect(canPublish.value).toBe(true);
+		expect(canUnpublish.value).toBe(true);
+	});
+
+	it('grants permissions from global scopes when no project is found', () => {
+		usersStore.currentUser = {
+			globalScopes: [
+				'agent:create',
+				'agent:update',
+				'agent:delete',
+				'agent:publish',
+				'agent:unpublish',
+			],
+		} as never;
+
+		const { canCreate, canUpdate, canDelete, canPublish, canUnpublish } =
+			useAgentPermissions(PROJECT_ID);
+
+		expect(canCreate.value).toBe(true);
+		expect(canUpdate.value).toBe(true);
+		expect(canDelete.value).toBe(true);
+		expect(canPublish.value).toBe(true);
+		expect(canUnpublish.value).toBe(true);
+	});
+
+	it('grants permissions when either scope source allows the action', () => {
+		projectsStore.myProjects = [makeProject(['agent:create', 'agent:update'])];
+		usersStore.currentUser = {
+			globalScopes: ['agent:delete'],
+		} as never;
+
+		const { canCreate, canUpdate, canDelete, canPublish } = useAgentPermissions(PROJECT_ID);
+
+		expect(canCreate.value).toBe(true);
+		expect(canUpdate.value).toBe(true);
+		expect(canDelete.value).toBe(true);
+		expect(canPublish.value).toBe(false);
+	});
+
+	it('returns false for every flag when no scopes match', () => {
+		projectsStore.myProjects = [makeProject([])];
+		usersStore.currentUser = { globalScopes: [] } as never;
+
+		const { canCreate, canUpdate, canDelete, canPublish, canUnpublish } =
+			useAgentPermissions(PROJECT_ID);
+
+		expect(canCreate.value).toBe(false);
+		expect(canUpdate.value).toBe(false);
+		expect(canDelete.value).toBe(false);
+		expect(canPublish.value).toBe(false);
+		expect(canUnpublish.value).toBe(false);
+	});
+
+	it('blocks every flag when source control puts the branch in read-only mode', () => {
+		projectsStore.myProjects = [
+			makeProject([
+				'agent:create',
+				'agent:update',
+				'agent:delete',
+				'agent:publish',
+				'agent:unpublish',
+			]),
+		];
+		usersStore.currentUser = {
+			globalScopes: [
+				'agent:create',
+				'agent:update',
+				'agent:delete',
+				'agent:publish',
+				'agent:unpublish',
+			],
+		} as never;
+		sourceControlStore.preferences = { branchReadOnly: true } as never;
+
+		const { canCreate, canUpdate, canDelete, canPublish, canUnpublish } =
+			useAgentPermissions(PROJECT_ID);
+
+		expect(canCreate.value).toBe(false);
+		expect(canUpdate.value).toBe(false);
+		expect(canDelete.value).toBe(false);
+		expect(canPublish.value).toBe(false);
+		expect(canUnpublish.value).toBe(false);
+	});
+});
diff --git a/packages/frontend/editor-ui/src/features/agents/components/AgentChatPanel.vue b/packages/frontend/editor-ui/src/features/agents/components/AgentChatPanel.vue
index b1f240d221f..119dde853e1 100644
--- a/packages/frontend/editor-ui/src/features/agents/components/AgentChatPanel.vue
+++ b/packages/frontend/editor-ui/src/features/agents/components/AgentChatPanel.vue
@@ -203,17 +203,19 @@ async function sendSeedMessage(message: string): Promise<void> {
 	}
 }
 
-if (seedMessage) {
-	void sendSeedMessage(seedMessage);
+// Skip the seed when the build chat is read-only
+const consumesSeed = !!seedMessage && !isBuilderReadOnly.value;
+if (consumesSeed) {
+	void sendSeedMessage(seedMessage as string);
 }
 
 onMounted(() => {
-	// A supplied `initialMessage` means the parent just minted a fresh session
-	// and wants us to seed it with the first message — there's no thread to
-	// load yet, and hitting the history endpoint would 404. The seed was
-	// already sent synchronously during setup (see the `seedMessage` block
-	// above).
-	if (seedMessage) {
+	// When we actually seeded a message, there's no prior thread to load —
+	// the agent was just created in this panel and the history endpoint
+	// would 404. Otherwise (including the read-only suppression path) load
+	// whatever history exists so the panel shows real content instead of a
+	// misleading "describe your agent" empty state.
+	if (consumesSeed) {
 		return;
 	}
 	void loadHistory();
diff --git a/packages/frontend/editor-ui/src/features/agents/composables/useAgentPermissions.ts b/packages/frontend/editor-ui/src/features/agents/composables/useAgentPermissions.ts
index e3663c98e5b..aa0add49b6d 100644
--- a/packages/frontend/editor-ui/src/features/agents/composables/useAgentPermissions.ts
+++ b/packages/frontend/editor-ui/src/features/agents/composables/useAgentPermissions.ts
@@ -2,16 +2,23 @@ import { computed, toValue, type ComputedRef, type MaybeRefOrGetter } from 'vue'
 import { getResourcePermissions } from '@n8n/permissions';
 import { useProjectsStore } from '@/features/collaboration/projects/projects.store';
 import { useUsersStore } from '@/features/settings/users/users.store';
+import { useSourceControlStore } from '@/features/integrations/sourceControl.ee/sourceControl.store';
 
 type AgentPermissionKey = 'create' | 'update' | 'delete' | 'publish' | 'unpublish';
 
 export type AgentPermissions = Record<`can${Capitalize<AgentPermissionKey>}`, ComputedRef<boolean>>;
 
+// All five permissions gate mutations, so we additionally block them whenever
+// source control puts the instance in a read-only branch. Agents themselves
+// aren't tracked by source control, but `branchReadOnly` doubles as the
+// instance-wide "no writes" signal — matching how other resource views
+// (workflows, credentials, data tables) combine scopes with this flag.
 export function useAgentPermissions(
 	projectId: MaybeRefOrGetter<string | undefined>,
 ): AgentPermissions {
 	const projectsStore = useProjectsStore();
 	const usersStore = useUsersStore();
+	const sourceControlStore = useSourceControlStore();
 
 	const projectScopes = computed(
 		() =>
@@ -22,9 +29,12 @@ export function useAgentPermissions(
 	const globalScopes = computed(
 		() => getResourcePermissions(usersStore.currentUser?.globalScopes).agent,
 	);
+	const isReadOnly = computed(() => sourceControlStore.preferences.branchReadOnly);
 
 	const pick = (key: AgentPermissionKey): ComputedRef<boolean> =>
-		computed(() => Boolean(globalScopes.value[key] ?? projectScopes.value[key]));
+		computed(
+			() => !isReadOnly.value && Boolean(globalScopes.value[key] ?? projectScopes.value[key]),
+		);
 
 	return {
 		canCreate: pick('create'),
diff --git a/packages/frontend/editor-ui/src/features/agents/views/AgentsListView.vue b/packages/frontend/editor-ui/src/features/agents/views/AgentsListView.vue
index b604e4ff18a..85d8ce48c43 100644
--- a/packages/frontend/editor-ui/src/features/agents/views/AgentsListView.vue
+++ b/packages/frontend/editor-ui/src/features/agents/views/AgentsListView.vue
@@ -11,9 +11,8 @@ import InsightsSummary from '@/features/execution/insights/components/InsightsSu
 import { useInsightsStore } from '@/features/execution/insights/insights.store';
 import { useProjectPages } from '@/features/collaboration/projects/composables/useProjectPages';
 import { useDocumentTitle } from '@/app/composables/useDocumentTitle';
-import { useSourceControlStore } from '@/features/integrations/sourceControl.ee/sourceControl.store';
-import { getResourcePermissions } from '@n8n/permissions';
 import { listAgents } from '../composables/useAgentApi';
+import { useAgentPermissions } from '../composables/useAgentPermissions';
 import type { AgentResource } from '../types';
 import { AGENT_BUILDER_VIEW, NEW_AGENT_VIEW } from '../constants';
 import AgentCard from '../components/AgentCard.vue';
@@ -27,15 +26,10 @@ const rootStore = useRootStore();
 const projectsStore = useProjectsStore();
 const insightsStore = useInsightsStore();
 const projectPages = useProjectPages();
-const sourceControlStore = useSourceControlStore();
 
 const homeProject = computed(() => projectsStore.currentProject ?? projectsStore.personalProject);
 
-const canCreateAgent = computed(
-	() =>
-		!sourceControlStore.preferences.branchReadOnly &&
-		!!getResourcePermissions(homeProject.value?.scopes)?.agent?.create,
-);
+const { canCreate: canCreateAgent } = useAgentPermissions(() => homeProject.value?.id);
 
 const allAgents = ref<AgentResource[]>([]);
 const loading = ref(true);
diff --git a/packages/frontend/editor-ui/src/features/collaboration/projects/components/ProjectHeader.test.ts b/packages/frontend/editor-ui/src/features/collaboration/projects/components/ProjectHeader.test.ts
index 51a3e4d93ff..f7ba90fceb5 100644
--- a/packages/frontend/editor-ui/src/features/collaboration/projects/components/ProjectHeader.test.ts
+++ b/packages/frontend/editor-ui/src/features/collaboration/projects/components/ProjectHeader.test.ts
@@ -6,7 +6,7 @@ import * as router from 'vue-router';
 import type { RouteLocationNormalizedLoadedGeneric } from 'vue-router';
 import ProjectHeader from './ProjectHeader.vue';
 import { useProjectsStore } from '../projects.store';
-import type { Project } from '../projects.types';
+import type { Project, ProjectListItem } from '../projects.types';
 import { ProjectTypes } from '../projects.types';
 import { VIEWS } from '@/app/constants';
 import userEvent from '@testing-library/user-event';
@@ -306,9 +306,11 @@ describe('ProjectHeader', () => {
 	describe('new agent telemetry', () => {
 		beforeEach(() => {
 			settingsStore.isModuleActive = vi.fn().mockImplementation((mod) => mod === 'agents');
-			projectsStore.currentProject = createTestProject({
+			const project = createTestProject({
 				scopes: ['workflow:create', 'agent:create'],
 			});
+			projectsStore.currentProject = project;
+			projectsStore.myProjects = [project] as unknown as ProjectListItem[];
 		});
 
 		it('tracks source=button when the agent main button is clicked', async () => {
@@ -639,6 +641,7 @@ describe('ProjectHeader', () => {
 			settingsStore.isModuleActive = vi.fn().mockImplementation((mod) => mod === 'agents');
 			const project = createTestProject({ scopes: ['agent:create'] });
 			projectsStore.currentProject = project;
+			projectsStore.myProjects = [project] as unknown as ProjectListItem[];
 
 			const { getByTestId } = renderComponent({ props: { mainButton: 'agent' } });
 
@@ -650,6 +653,7 @@ describe('ProjectHeader', () => {
 			settingsStore.isModuleActive = vi.fn().mockImplementation((mod) => mod === 'agents');
 			const project = createTestProject({ scopes: [] });
 			projectsStore.currentProject = project;
+			projectsStore.myProjects = [project] as unknown as ProjectListItem[];
 
 			const { getByTestId } = renderComponent({ props: { mainButton: 'agent' } });
 
diff --git a/packages/frontend/editor-ui/src/features/collaboration/projects/components/ProjectHeader.vue b/packages/frontend/editor-ui/src/features/collaboration/projects/components/ProjectHeader.vue
index 75ce07245f6..901f11a9260 100644
--- a/packages/frontend/editor-ui/src/features/collaboration/projects/components/ProjectHeader.vue
+++ b/packages/frontend/editor-ui/src/features/collaboration/projects/components/ProjectHeader.vue
@@ -21,6 +21,7 @@ import { type IconOrEmoji, isIconOrEmoji } from '@n8n/design-system/components/N
 import { useUIStore } from '@/app/stores/ui.store';
 import { PROJECT_DATA_TABLES } from '@/features/core/dataTable/constants';
 import { NEW_AGENT_VIEW } from '@/features/agents/constants';
+import { useAgentPermissions } from '@/features/agents/composables/useAgentPermissions';
 import ReadyToRunButton from '@/features/workflows/readyToRun/components/ReadyToRunButton.vue';
 
 import { N8nButton, N8nHeading, N8nIconButton, N8nText, N8nTooltip } from '@n8n/design-system';
@@ -80,6 +81,8 @@ const headerIcon = computed((): IconOrEmoji => {
 
 const homeProject = computed(() => projectsStore.currentProject ?? projectsStore.personalProject);
 
+const { canCreate: canCreateAgent } = useAgentPermissions(() => homeProject.value?.id);
+
 const isPersonalProject = computed(() => {
 	return homeProject.value?.type === ProjectTypes.Personal;
 });
@@ -200,9 +203,7 @@ const createAgentButton = computed(() => ({
 	value: ACTION_TYPES.AGENT,
 	label: i18n.baseText('projects.header.create.agent'),
 	size: 'mini' as const,
-	disabled:
-		sourceControlStore.preferences.branchReadOnly ||
-		!getResourcePermissions(homeProject.value?.scopes).agent.create,
+	disabled: !canCreateAgent.value,
 }));
 
 const selectedMainButtonType = computed(() => {
@@ -297,9 +298,7 @@ const menu = computed(() => {
 		items.push({
 			value: ACTION_TYPES.AGENT,
 			label: i18n.baseText('projects.header.create.agent'),
-			disabled:
-				sourceControlStore.preferences.branchReadOnly ||
-				!getResourcePermissions(homeProject.value?.scopes).agent.create,
+			disabled: !canCreateAgent.value,
 		});
 	}