acp: Support session modes (e.g. CC plan mode) (#37632)

Adds support for [ACP session
modes](zed-industries/agent-client-protocol#67)
enabling plan and other permission modes in CC:


https://github.com/user-attachments/assets/dea18d82-4da6-465e-983b-02b77c6dcf15


Release Notes:

- Claude Code: Add support for plan mode, and all other permission modes

---------

Co-authored-by: Bennet Bo Fenner <[email protected]>
Co-authored-by: Richard Feldman <[email protected]>
Co-authored-by: Danilo Leal <[email protected]>

Author: 4 people

Cargo.lock

@@ -433,7 +433,7 @@ zlog_settings = { path = "crates/zlog_settings" }
 # External crates
 #
 
-agent-client-protocol = { version = "0.2.0-alpha.6", features = ["unstable"]}
+agent-client-protocol = { version = "0.2.0-alpha.8", features = ["unstable"] }
 aho-corasick = "1.1"
 alacritty_terminal = { git = "https://github.com/zed-industries/alacritty.git", branch = "add-hush-login-flag" }
 any_vec = "0.14"

Cargo.toml

@@ -328,14 +328,20 @@
       "enter": "agent::AcceptSuggestedContext"
     }
   },
+  {
+    "context": "AcpThread > ModeSelector",
+    "bindings": {
+      "ctrl-enter": "menu::Confirm"
+    }
+  },
   {
     "context": "AcpThread > Editor && !use_modifier_to_send",
     "use_key_equivalents": true,
     "bindings": {
       "enter": "agent::Chat",
       "shift-ctrl-r": "agent::OpenAgentDiff",
       "ctrl-shift-y": "agent::KeepAll",
-      "ctrl-shift-n": "agent::RejectAll"
+      "ctrl-shift-n": "agent::RejectAll",
     }
   },
   {
@@ -345,7 +351,8 @@
       "ctrl-enter": "agent::Chat",
       "shift-ctrl-r": "agent::OpenAgentDiff",
       "ctrl-shift-y": "agent::KeepAll",
-      "ctrl-shift-n": "agent::RejectAll"
+      "ctrl-shift-n": "agent::RejectAll",
+      "shift-tab": "agent::CycleModeSelector"
     }
   },
   {

assets/keymaps/default-linux.json

@@ -378,14 +378,21 @@
       "ctrl--": "pane::GoBack"
     }
   },
+  {
+    "context": "AcpThread > ModeSelector",
+    "bindings": {
+      "cmd-enter": "menu::Confirm"
+    }
+  },
   {
     "context": "AcpThread > Editor && !use_modifier_to_send",
     "use_key_equivalents": true,
     "bindings": {
       "enter": "agent::Chat",
       "shift-ctrl-r": "agent::OpenAgentDiff",
       "cmd-shift-y": "agent::KeepAll",
-      "cmd-shift-n": "agent::RejectAll"
+      "cmd-shift-n": "agent::RejectAll",
+      "shift-tab": "agent::CycleModeSelector"
     }
   },
   {
@@ -395,7 +402,8 @@
       "cmd-enter": "agent::Chat",
       "shift-ctrl-r": "agent::OpenAgentDiff",
       "cmd-shift-y": "agent::KeepAll",
-      "cmd-shift-n": "agent::RejectAll"
+      "cmd-shift-n": "agent::RejectAll",
+      "shift-tab": "agent::CycleModeSelector"
     }
   },
   {

assets/keymaps/default-macos.json

@@ -336,14 +336,21 @@
       "enter": "agent::AcceptSuggestedContext"
     }
   },
+  {
+    "context": "AcpThread > ModeSelector",
+    "bindings": {
+      "ctrl-enter": "menu::Confirm"
+    }
+  },
   {
     "context": "AcpThread > Editor",
     "use_key_equivalents": true,
     "bindings": {
       "enter": "agent::Chat",
       "ctrl-shift-r": "agent::OpenAgentDiff",
       "ctrl-shift-y": "agent::KeepAll",
-      "ctrl-shift-n": "agent::RejectAll"
+      "ctrl-shift-n": "agent::RejectAll",
+      "shift-tab": "agent::CycleModeSelector"
     }
   },
   {

assets/keymaps/default-windows.json

@@ -828,6 +828,9 @@
       // }
     ],
     // When enabled, the agent can run potentially destructive actions without asking for your confirmation.
+    //
+    // Note: This setting has no effect on external agents that support permission modes, such as Claude Code.
+    //       You can set `agent_servers.claude.default_mode` to `bypassPermissions` to skip all permission requests.
     "always_allow_tool_actions": false,
     // When enabled, the agent will stream edits.
     "stream_edits": false,

assets/settings/default.json

@@ -18,8 +18,8 @@ test-support = ["gpui/test-support", "project/test-support", "dep:parking_lot"]
 [dependencies]
 action_log.workspace = true
 agent-client-protocol.workspace = true
-anyhow.workspace = true
 agent_settings.workspace = true
+anyhow.workspace = true
 buffer_diff.workspace = true
 collections.workspace = true
 editor.workspace = true

crates/acp_thread/Cargo.toml

@@ -805,6 +805,7 @@ pub enum AcpThreadEvent {
     PromptCapabilitiesUpdated,
     Refusal,
     AvailableCommandsUpdated(Vec<acp::AvailableCommand>),
+    ModeUpdated(acp::SessionModeId),
 }
 
 impl EventEmitter<AcpThreadEvent> for AcpThread {}
@@ -1007,6 +1008,9 @@ impl AcpThread {
             acp::SessionUpdate::AvailableCommandsUpdate { available_commands } => {
                 cx.emit(AcpThreadEvent::AvailableCommandsUpdated(available_commands))
             }
+            acp::SessionUpdate::CurrentModeUpdate { current_mode_id } => {
+                cx.emit(AcpThreadEvent::ModeUpdated(current_mode_id))
+            }
         }
         Ok(())
     }
@@ -1303,11 +1307,12 @@ impl AcpThread {
         &mut self,
         tool_call: acp::ToolCallUpdate,
         options: Vec<acp::PermissionOption>,
+        respect_always_allow_setting: bool,
         cx: &mut Context<Self>,
     ) -> Result<BoxFuture<'static, acp::RequestPermissionOutcome>> {
         let (tx, rx) = oneshot::channel();
 
-        if AgentSettings::get_global(cx).always_allow_tool_actions {
+        if respect_always_allow_setting && AgentSettings::get_global(cx).always_allow_tool_actions {
             // Don't use AllowAlways, because then if you were to turn off always_allow_tool_actions,
             // some tools would (incorrectly) continue to auto-accept.
             if let Some(allow_once_option) = options.iter().find_map(|option| {

crates/acp_thread/src/acp_thread.rs

@@ -75,6 +75,15 @@ pub trait AgentConnection {
     fn telemetry(&self) -> Option<Rc<dyn AgentTelemetry>> {
         None
     }
+
+    fn session_modes(
+        &self,
+        _session_id: &acp::SessionId,
+        _cx: &App,
+    ) -> Option<Rc<dyn AgentSessionModes>> {
+        None
+    }
+
     fn into_any(self: Rc<Self>) -> Rc<dyn Any>;
 }
 
@@ -109,6 +118,14 @@ pub trait AgentTelemetry {
     ) -> Task<Result<serde_json::Value>>;
 }
 
+pub trait AgentSessionModes {
+    fn current_mode(&self) -> acp::SessionModeId;
+
+    fn all_modes(&self) -> Vec<acp::SessionMode>;
+
+    fn set_mode(&self, mode: acp::SessionModeId, cx: &mut App) -> Task<Result<()>>;
+}
+
 #[derive(Debug)]
 pub struct AuthRequired {
     pub description: Option<String>,
@@ -397,6 +414,7 @@ mod test_support {
                                     thread.request_tool_call_authorization(
                                         tool_call.clone().into(),
                                         options.clone(),
+                                        false,
                                         cx,
                                     )
                                 })??

crates/acp_thread/src/connection.rs

@@ -771,7 +771,9 @@ impl NativeAgentConnection {
                                 response,
                             }) => {
                                 let outcome_task = acp_thread.update(cx, |thread, cx| {
-                                    thread.request_tool_call_authorization(tool_call, options, cx)
+                                    thread.request_tool_call_authorization(
+                                        tool_call, options, true, cx,
+                                    )
                                 })??;
                                 cx.background_spawn(async move {
                                     if let acp::RequestPermissionOutcome::Selected { option_id } =