diff --git a/CLAUDE.md b/CLAUDE.md
index 2c5ba23..3c3ec47 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -224,6 +224,8 @@ When the generated client receives a status in `refreshOn`, it calls the wired r
 
 The refresh callback re-invokes the custom strategy's `authenticate()` rather than re-bootstrapping `/session`. `settings.json` `auth.refreshOn` takes precedence over `sessionAuth.refreshOn` when both are set.
 
+`.apijack/settings.json` only applies to consumers of the shared `apijack` binary; a project with its own `bin/<cli>.ts` sets the same option programmatically instead: `createCli({ refreshOn: [401], /* ... */ })`.
+
 ### Dropping base-strategy headers post-handshake (opt-in)
 
 By default, `SessionAuthStrategy` mirrors the wrapped base strategy's headers (e.g. `Authorization: Basic …` from `BasicAuthStrategy`) onto every post-handshake API request. For stateful backends — Spring Security with 2FA, for instance — re-presenting the base credentials on every call re-triggers the auth filter and either re-prompts, 401s, or invalidates the active session. Opt in to `dropBaseHeaders` to strip them:
@@ -250,7 +252,7 @@ The `.apijack/` directory at a project root is auto-loaded when the CLI runs ins
 | `.apijack/auth.ts` | Project-level `AuthStrategy` and optional `onChallenge` |
 | `.apijack/plugins.ts` | Project-level plugin registrations (`default: ApijackPlugin[]` — each entry passed to `cli.use(...)`) |
 | `.apijack/routines/*.yaml` | Routines available via `routine run <name>` |
-| `.apijack/settings.json` | Framework defaults (see below) |
+| `.apijack/settings.json` | Framework defaults (see below; also `auth.refreshOn` — see "Stale-session refresh and retry" above) |
 | `.apijack/aliases.json` | Project-local command aliases (see below) |
 
 ### Command aliases
diff --git a/src/auth/refresh-wiring.ts b/src/auth/refresh-wiring.ts
index 8b22a9c..e962ad2 100644
--- a/src/auth/refresh-wiring.ts
+++ b/src/auth/refresh-wiring.ts
@@ -36,5 +36,11 @@ export function resolveRefreshWiring(
     const mergedSessionAuth = rawSessionAuth?.session?.endpoint ? rawSessionAuth : undefined;
     const refreshOn = options.refreshOn ?? rawSessionAuth?.refreshOn;
 
+    if (rawSessionAuth && !mergedSessionAuth) {
+        console.warn(
+            '[apijack] sessionAuth is set but missing session.endpoint — SessionAuthStrategy will not be used.',
+        );
+    }
+
     return { mergedSessionAuth, refreshOn };
 }
diff --git a/tests/auth/refresh-wiring.test.ts b/tests/auth/refresh-wiring.test.ts
index c9acce3..0f0c6d7 100644
--- a/tests/auth/refresh-wiring.test.ts
+++ b/tests/auth/refresh-wiring.test.ts
@@ -1,4 +1,4 @@
-import { describe, test, expect } from 'bun:test';
+import { describe, test, expect, spyOn } from 'bun:test';
 import { resolveRefreshWiring } from '../../src/auth/refresh-wiring';
 import type { SessionAuthConfig } from '../../src/auth/types';
 
@@ -50,11 +50,17 @@ describe('resolveRefreshWiring', () => {
         // Not expressible through the SessionAuthConfig type from a fully-typed
         // caller, but envConfig.sessionAuth is only a Partial<SessionAuthConfig> —
         // a JS/dynamic caller could still hand cli-builder a refreshOn-only block.
+        const warnSpy = spyOn(console, 'warn').mockImplementation(() => {});
         const refreshOnlySessionAuth = { refreshOn: [401] } as unknown as SessionAuthConfig;
-        const result = resolveRefreshWiring({ sessionAuth: refreshOnlySessionAuth }, undefined);
-        expect(result.mergedSessionAuth).toBeUndefined();
-        // refreshOn still surfaces from the raw (unguarded) merge.
-        expect(result.refreshOn).toEqual([401]);
+
+        try {
+            const result = resolveRefreshWiring({ sessionAuth: refreshOnlySessionAuth }, undefined);
+            expect(result.mergedSessionAuth).toBeUndefined();
+            // refreshOn still surfaces from the raw (unguarded) merge.
+            expect(result.refreshOn).toEqual([401]);
+        } finally {
+            warnSpy.mockRestore();
+        }
     });
 
     test('does not mutate inputs', () => {
@@ -65,4 +71,41 @@ describe('resolveRefreshWiring', () => {
         );
         expect(fullSessionAuth).toEqual(sessionAuthCopy);
     });
+
+    describe('missing session.endpoint diagnostic warning', () => {
+        test('warns when sessionAuth is set but has no session.endpoint', () => {
+            const warnSpy = spyOn(console, 'warn').mockImplementation(() => {});
+            const refreshOnlySessionAuth = { refreshOn: [401] } as unknown as SessionAuthConfig;
+
+            try {
+                resolveRefreshWiring({ sessionAuth: refreshOnlySessionAuth }, undefined);
+                expect(warnSpy).toHaveBeenCalledTimes(1);
+                expect(warnSpy.mock.calls[0]![0]).toContain('session.endpoint');
+            } finally {
+                warnSpy.mockRestore();
+            }
+        });
+
+        test('does not warn when there is no sessionAuth at all', () => {
+            const warnSpy = spyOn(console, 'warn').mockImplementation(() => {});
+
+            try {
+                resolveRefreshWiring({ refreshOn: [401] }, undefined);
+                expect(warnSpy).not.toHaveBeenCalled();
+            } finally {
+                warnSpy.mockRestore();
+            }
+        });
+
+        test('does not warn when sessionAuth has a session.endpoint', () => {
+            const warnSpy = spyOn(console, 'warn').mockImplementation(() => {});
+
+            try {
+                resolveRefreshWiring({ sessionAuth: fullSessionAuth }, undefined);
+                expect(warnSpy).not.toHaveBeenCalled();
+            } finally {
+                warnSpy.mockRestore();
+            }
+        });
+    });
 });