diff --git a/.changeset/project-default-agent.md b/.changeset/project-default-agent.md
new file mode 100644
index 00000000..6ff8437c
--- /dev/null
+++ b/.changeset/project-default-agent.md
@@ -0,0 +1,5 @@
+---
+'@inkeep/open-knowledge': patch
+---
+
+Use `agents.defaultAgent` in a project config to choose Codex or Pi for the Ask AI composer on machines that have no locally remembered agent choice. A user-selected agent continues to take precedence.
diff --git a/packages/app/src/components/BottomComposer.tsx b/packages/app/src/components/BottomComposer.tsx
index 14c43230..47247fac 100644
--- a/packages/app/src/components/BottomComposer.tsx
+++ b/packages/app/src/components/BottomComposer.tsx
@@ -54,6 +54,7 @@ import {
 } from '@/editor/selection-context';
 import type { EditorSurface } from '@/editor/selection-stats';
 import { useSelectionContext } from '@/hooks/use-selection-context';
+import { useConfigContextOptional } from '@/lib/config-context';
 import { resolveDefaultCli } from '@/lib/default-cli-resolver';
 import { VISIBLE_TARGETS } from '@/lib/handoff/targets';
 import { matchesKeyboardShortcut } from '@/lib/keyboard-shortcuts';
@@ -61,6 +62,7 @@ import { recordOnboardingAskedAi } from '@/lib/onboarding-signals';
 import {
   loadStickyAgent,
   parseStickyCliId,
+  resolveInitialAgentPreference,
   resolveStickyAgent,
   saveStickyAgent,
   terminalCliId,
@@ -199,6 +201,7 @@ export function BottomComposer({
   const effectiveSurface: EditorSurface = surface ?? 'wysiwyg';
   const reduced = useReducedMotion();
   const workspace = useWorkspace();
+  const projectDefaultAgent = useConfigContextOptional()?.projectConfig?.agents?.defaultAgent;
   const { pageMeta } = usePageList();
   const { states } = useInstalledAgents();
   const { dispatch } = useHandoffDispatch();
@@ -465,7 +468,7 @@ export function BottomComposer({
   // sentinel (`terminal-cli:<cli>`) only resolves to terminal mode when the
   // launcher is available, so a sticky CLI pick degrades to the first app target
   // on the web host.
-  const effectiveId = selectedId ?? stickyId;
+  const effectiveId = selectedId ?? resolveInitialAgentPreference(stickyId, projectDefaultAgent);
   // An explicit CLI pick (sticky or this session) launches that CLI regardless of
   // install state — a missing binary just prints "command not found".
   const explicitCli: TerminalCli | null =
diff --git a/packages/app/src/lib/unified-agent-store.test.ts b/packages/app/src/lib/unified-agent-store.test.ts
index a149a21e..e9a4e2fc 100644
--- a/packages/app/src/lib/unified-agent-store.test.ts
+++ b/packages/app/src/lib/unified-agent-store.test.ts
@@ -14,6 +14,7 @@ import {
 import {
   loadStickyAgent,
   parseStickyCliId,
+  resolveInitialAgentPreference,
   resolveStickyAgent,
   saveStickyAgent,
   TERMINAL_CLI_ID,
@@ -50,6 +51,16 @@ function states(
   ) as Record<HandoffTarget, InstallState>;
 }
 
+describe('resolveInitialAgentPreference', () => {
+  test('uses the project default when this machine has no local selection', () => {
+    expect(resolveInitialAgentPreference(null, 'terminal-cli:pi')).toBe('terminal-cli:pi');
+  });
+
+  test('keeps the local user selection over a project default', () => {
+    expect(resolveInitialAgentPreference('codex', 'terminal-cli:pi')).toBe('codex');
+  });
+});
+
 describe('unified-agent-store — load/save round-trip', () => {
   test('round-trips through the unified key', () => {
     const storage = makeStorage();
diff --git a/packages/app/src/lib/unified-agent-store.ts b/packages/app/src/lib/unified-agent-store.ts
index 75de091f..f50f9678 100644
--- a/packages/app/src/lib/unified-agent-store.ts
+++ b/packages/app/src/lib/unified-agent-store.ts
@@ -135,6 +135,14 @@ export function saveStickyAgent(id: HandoffTarget | string, storage?: StickyAgen
   }
 }
 
+/** Browser-local user choice wins over an installer-provided workspace default. */
+export function resolveInitialAgentPreference(
+  stickyId: string | null,
+  projectDefault: string | null | undefined,
+): string | null {
+  return stickyId ?? projectDefault ?? null;
+}
+
 /**
  * Resolve which app agent the composer should target, given live install state
  * and the sticky preference:
diff --git a/packages/core/src/config/schema.ts b/packages/core/src/config/schema.ts
index ca830d88..1b0a1cd1 100644
--- a/packages/core/src/config/schema.ts
+++ b/packages/core/src/config/schema.ts
@@ -375,6 +375,17 @@ export const ConfigSchema = z.looseObject({
   // config paths are a user-facing `~/.ok/global.yml` contract and hard to rename.
   agents: z
     .looseObject({
+      // A workspace-provided initial handoff preference. It is intentionally a
+      // PROJECT field so an installer can select the runtime that owns this
+      // knowledge base without modifying a user's browser-local last-used
+      // choice. The app uses it only when no local preference exists.
+      defaultAgent: z.enum(['codex', 'pi', 'terminal-cli:pi']).optional().register(fieldRegistry, {
+        scope: 'project',
+        agentSettable: false,
+        defaultScope: 'project',
+        description:
+          'Initial agent for this workspace when this machine has no locally remembered choice. Allowed values are codex, pi, and terminal-cli:pi. A local user selection always takes precedence.',
+      }),
       autoApproveOkTools: z
         .boolean()
         .register(fieldRegistry, {