diff --git a/crates/ffi/src/apps.rs b/crates/ffi/src/apps.rs
index a55fae8e..5dad7cc2 100644
--- a/crates/ffi/src/apps.rs
+++ b/crates/ffi/src/apps.rs
@@ -1 +1,122 @@
-// App FFI functions
+use crate::convert::{app_info_to_c, c_to_str, free_app_info_fields, window_info_to_c};
+use crate::error::{clear_last_error, set_last_error, AdResult};
+use crate::types::{AdAppInfo, AdWindowInfo};
+use crate::AdAdapter;
+use std::os::raw::c_char;
+use std::ptr;
+
+/// # Safety
+/// `adapter` must be a valid pointer from `ad_adapter_create`.
+/// `out` and `out_count` must be valid writable pointers.
+#[no_mangle]
+pub unsafe extern "C" fn ad_list_apps(
+    adapter: *const AdAdapter,
+    out: *mut *mut AdAppInfo,
+    out_count: *mut u32,
+) -> AdResult {
+    *out = ptr::null_mut();
+    *out_count = 0;
+
+    let adapter = &*adapter;
+    match adapter.inner.list_apps() {
+        Ok(apps) => {
+            clear_last_error();
+            let c_apps: Vec<AdAppInfo> = apps.iter().map(app_info_to_c).collect();
+            let count = c_apps.len() as u32;
+            if c_apps.is_empty() {
+                return AdResult::Ok;
+            }
+            let mut boxed = c_apps.into_boxed_slice();
+            *out = boxed.as_mut_ptr();
+            *out_count = count;
+            std::mem::forget(boxed);
+            AdResult::Ok
+        }
+        Err(e) => {
+            set_last_error(&e);
+            crate::error::last_error_code()
+        }
+    }
+}
+
+/// # Safety
+/// `apps` must be null or a pointer previously returned by `ad_list_apps`.
+#[no_mangle]
+pub unsafe extern "C" fn ad_free_apps(apps: *mut AdAppInfo, count: u32) {
+    if apps.is_null() {
+        return;
+    }
+    let slice = std::slice::from_raw_parts_mut(apps, count as usize);
+    for app in slice.iter_mut() {
+        free_app_info_fields(app);
+    }
+    drop(Box::from_raw(
+        std::ptr::slice_from_raw_parts_mut(apps, count as usize),
+    ));
+}
+
+/// # Safety
+/// `adapter` must be valid. `id` must be a valid C string. `out` must be writable.
+#[no_mangle]
+pub unsafe extern "C" fn ad_launch_app(
+    adapter: *const AdAdapter,
+    id: *const c_char,
+    timeout_ms: u64,
+    out: *mut AdWindowInfo,
+) -> AdResult {
+    let adapter = &*adapter;
+    let id_str = match c_to_str(id) {
+        Some(s) => s,
+        None => {
+            set_last_error(&agent_desktop_core::error::AdapterError::new(
+                agent_desktop_core::error::ErrorCode::InvalidArgs,
+                "app id is null or invalid UTF-8",
+            ));
+            return AdResult::ErrInvalidArgs;
+        }
+    };
+
+    match adapter.inner.launch_app(id_str, timeout_ms) {
+        Ok(win) => {
+            clear_last_error();
+            *out = window_info_to_c(&win);
+            AdResult::Ok
+        }
+        Err(e) => {
+            set_last_error(&e);
+            crate::error::last_error_code()
+        }
+    }
+}
+
+/// # Safety
+/// `adapter` must be valid. `id` must be a valid C string.
+#[no_mangle]
+pub unsafe extern "C" fn ad_close_app(
+    adapter: *const AdAdapter,
+    id: *const c_char,
+    force: bool,
+) -> AdResult {
+    let adapter = &*adapter;
+    let id_str = match c_to_str(id) {
+        Some(s) => s,
+        None => {
+            set_last_error(&agent_desktop_core::error::AdapterError::new(
+                agent_desktop_core::error::ErrorCode::InvalidArgs,
+                "app id is null or invalid UTF-8",
+            ));
+            return AdResult::ErrInvalidArgs;
+        }
+    };
+
+    match adapter.inner.close_app(id_str, force) {
+        Ok(()) => {
+            clear_last_error();
+            AdResult::Ok
+        }
+        Err(e) => {
+            set_last_error(&e);
+            crate::error::last_error_code()
+        }
+    }
+}