diff --git a/crates/goose-acp/src/server.rs b/crates/goose-acp/src/server.rs
index ca5f475ebe..cb6d4be246 100644
--- a/crates/goose-acp/src/server.rs
+++ b/crates/goose-acp/src/server.rs
@@ -435,6 +435,7 @@ impl GooseAcpAgent {
             _ => None,
         };
         let skip_developer = acp_developer.is_some();
+        let sid_str = session_id.map(|s| s.0.to_string());
 
         for ext in extensions {
             if skip_developer && ext.name() == "developer" {
@@ -443,7 +444,7 @@ impl GooseAcpAgent {
             let name = ext.name().to_string();
             match agent
                 .extension_manager
-                .add_extension(ext, None, None, None)
+                .add_extension(ext, None, None, sid_str.as_deref())
                 .await
             {
                 Ok(_) => info!(extension = %name, "extension loaded"),
diff --git a/crates/goose-acp/tests/common_tests/mod.rs b/crates/goose-acp/tests/common_tests/mod.rs
index 2e52e1a2de..a58855c664 100644
--- a/crates/goose-acp/tests/common_tests/mod.rs
+++ b/crates/goose-acp/tests/common_tests/mod.rs
@@ -689,6 +689,43 @@ pub async fn run_prompt_mcp<C: Connection>() {
     expected_session_id.assert_matches(&session.session_id().0);
 }
 
+pub async fn run_prompt_skill<C: Connection>() {
+    let cwd = tempfile::tempdir().unwrap();
+    let skill_dir = cwd.path().join(".agents/skills/test-skill");
+    fs::create_dir_all(&skill_dir).unwrap();
+    fs::write(
+        skill_dir.join("SKILL.md"),
+        "---\nname: test-skill\ndescription: skill-loaded-in-acp-session\n---\nTest instructions\n",
+    )
+    .unwrap();
+
+    let expected_session_id = C::expected_session_id();
+    let openai = OpenAiFixture::new(
+        vec![(
+            "skill-loaded-in-acp-session".to_string(),
+            include_str!("../test_data/openai_basic.txt"),
+        )],
+        expected_session_id.clone(),
+    )
+    .await;
+
+    let config = TestConnectionConfig {
+        builtins: vec!["summon".to_string()],
+        cwd: Some(cwd),
+        ..Default::default()
+    };
+
+    let mut conn = C::new(config, openai).await;
+    let SessionResult { mut session, .. } = conn.new_session().await;
+    expected_session_id.set(&session.session_id().0);
+
+    let output = session
+        .prompt("what is 1+1", PermissionDecision::Cancel)
+        .await;
+    assert_eq!(output.text, "2");
+    expected_session_id.assert_matches(&session.session_id().0);
+}
+
 pub async fn run_mode_set_error<C: Connection>(
     mode_id: &str,
     session_id_override: Option<&str>,
diff --git a/crates/goose-acp/tests/fixtures/mod.rs b/crates/goose-acp/tests/fixtures/mod.rs
index fef698b6ae..1fe2f74257 100644
--- a/crates/goose-acp/tests/fixtures/mod.rs
+++ b/crates/goose-acp/tests/fixtures/mod.rs
@@ -276,6 +276,7 @@ pub struct TestConnectionConfig {
     pub mcp_servers: Vec<McpServer>,
     pub builtins: Vec<String>,
     pub goose_mode: GooseMode,
+    pub cwd: Option<tempfile::TempDir>,
     pub data_root: PathBuf,
     pub provider_factory: Option<ProviderConstructor>,
     pub read_text_file: Option<ReadTextFileHandler>,
@@ -288,6 +289,7 @@ impl Default for TestConnectionConfig {
             mcp_servers: Vec::new(),
             builtins: Vec::new(),
             goose_mode: GooseMode::default(),
+            cwd: None,
             data_root: PathBuf::new(),
             provider_factory: None,
             read_text_file: None,
diff --git a/crates/goose-acp/tests/fixtures/provider.rs b/crates/goose-acp/tests/fixtures/provider.rs
index 608b2d910b..a255597c73 100644
--- a/crates/goose-acp/tests/fixtures/provider.rs
+++ b/crates/goose-acp/tests/fixtures/provider.rs
@@ -27,6 +27,7 @@ pub struct ClientToProviderConnection {
     session_counter: usize,
     _openai: OpenAiFixture,
     _temp_dir: Option<tempfile::TempDir>,
+    _cwd: Option<tempfile::TempDir>,
 }
 
 #[allow(dead_code)]
@@ -128,12 +129,18 @@ impl Connection for ClientToProviderConnection {
         )
         .await;
 
+        let cwd_path = config
+            .cwd
+            .as_ref()
+            .map(|td| td.path().to_path_buf())
+            .unwrap_or(data_root);
+
         let provider_config = AcpProviderConfig {
             command: "unused".into(),
             args: vec![],
             env: vec![],
             env_remove: vec![],
-            work_dir: data_root,
+            work_dir: cwd_path,
             mcp_servers,
             session_mode_id: None,
             permission_mapping: PermissionMapping::default(),
@@ -159,6 +166,7 @@ impl Connection for ClientToProviderConnection {
             session_counter: 0,
             _openai: openai,
             _temp_dir: temp_dir,
+            _cwd: config.cwd,
         }
     }
 
diff --git a/crates/goose-acp/tests/fixtures/server.rs b/crates/goose-acp/tests/fixtures/server.rs
index 0c4180c0b2..edd72d2ded 100644
--- a/crates/goose-acp/tests/fixtures/server.rs
+++ b/crates/goose-acp/tests/fixtures/server.rs
@@ -20,6 +20,7 @@ pub struct ClientToAgentConnection {
     cx: JrConnectionCx<ClientToAgent>,
     // MCP servers from config, consumed by the first new_session call.
     pending_mcp_servers: Vec<McpServer>,
+    cwd: Option<tempfile::TempDir>,
     updates: Arc<Mutex<Vec<SessionNotification>>>,
     permission: Arc<Mutex<PermissionDecision>>,
     notify: Arc<Notify>,
@@ -222,6 +223,7 @@ impl Connection for ClientToAgentConnection {
         Self {
             cx,
             pending_mcp_servers: config.mcp_servers,
+            cwd: config.cwd,
             updates,
             permission,
             notify,
@@ -233,7 +235,10 @@ impl Connection for ClientToAgentConnection {
     }
 
     async fn new_session(&mut self) -> SessionResult<ClientToAgentSession> {
-        let work_dir = tempfile::tempdir().unwrap();
+        let work_dir = self
+            .cwd
+            .take()
+            .unwrap_or_else(|| tempfile::tempdir().unwrap());
         let mcp_servers = std::mem::take(&mut self.pending_mcp_servers);
         let response = self
             .cx
diff --git a/crates/goose-acp/tests/provider_test.rs b/crates/goose-acp/tests/provider_test.rs
index 34f0435a66..fea565886d 100644
--- a/crates/goose-acp/tests/provider_test.rs
+++ b/crates/goose-acp/tests/provider_test.rs
@@ -8,7 +8,7 @@ use common_tests::{
     run_fs_write_text_file_true, run_initialize_doesnt_hit_provider, run_load_mode, run_load_model,
     run_load_session_mcp, run_mode_set, run_model_list, run_model_set, run_permission_persistence,
     run_prompt_basic, run_prompt_codemode, run_prompt_image, run_prompt_image_attachment,
-    run_prompt_mcp,
+    run_prompt_mcp, run_prompt_skill,
 };
 
 tests_mode_set_error!(ClientToProviderConnection);
@@ -103,3 +103,8 @@ fn test_prompt_image_attachment() {
 fn test_prompt_mcp() {
     run_test(async { run_prompt_mcp::<ClientToProviderConnection>().await });
 }
+
+#[test]
+fn test_prompt_skill() {
+    run_test(async { run_prompt_skill::<ClientToProviderConnection>().await });
+}
diff --git a/crates/goose-acp/tests/server_test.rs b/crates/goose-acp/tests/server_test.rs
index c3a5ac7248..1a232d75a3 100644
--- a/crates/goose-acp/tests/server_test.rs
+++ b/crates/goose-acp/tests/server_test.rs
@@ -6,7 +6,7 @@ use common_tests::{
     run_fs_write_text_file_true, run_initialize_doesnt_hit_provider, run_load_mode, run_load_model,
     run_load_session_mcp, run_mode_set, run_model_list, run_model_set, run_permission_persistence,
     run_prompt_basic, run_prompt_codemode, run_prompt_image, run_prompt_image_attachment,
-    run_prompt_mcp,
+    run_prompt_mcp, run_prompt_skill,
 };
 
 tests_mode_set_error!(ClientToAgentConnection);
@@ -97,3 +97,8 @@ fn test_prompt_image_attachment() {
 fn test_prompt_mcp() {
     run_test(async { run_prompt_mcp::<ClientToAgentConnection>().await });
 }
+
+#[test]
+fn test_prompt_skill() {
+    run_test(async { run_prompt_skill::<ClientToAgentConnection>().await });
+}