agent: Support initial prompt via zed://agent URL schema (#47959)

Adds `zed://agent?prompt=<url_encoded_text>` URL support to open the
Agent Panel with a pre-filled prompt.

Release Notes:

- Added support for opening the Agent Panel with an initial prompt via
`zed://agent?prompt=<url_encoded_text>` URL.

crates/agent_ui/src/acp/thread_view.rs

@@ -78,10 +78,10 @@ use crate::user_slash_command::{
 };
 use crate::{
     AgentDiffPane, AgentPanel, AllowAlways, AllowOnce, AuthorizeToolCall, ClearMessageQueue,
-    CycleFavoriteModels, CycleModeSelector, EditFirstQueuedMessage, ExpandMessageEditor, Follow,
-    KeepAll, NewThread, OpenAddContextMenu, OpenAgentDiff, OpenHistory, RejectAll, RejectOnce,
-    RemoveFirstQueuedMessage, SelectPermissionGranularity, SendImmediately, SendNextQueuedMessage,
-    ToggleProfileSelector, ToggleThinkingMode,
+    CycleFavoriteModels, CycleModeSelector, EditFirstQueuedMessage, ExpandMessageEditor,
+    ExternalAgentInitialContent, Follow, KeepAll, NewThread, OpenAddContextMenu, OpenAgentDiff,
+    OpenHistory, RejectAll, RejectOnce, RemoveFirstQueuedMessage, SelectPermissionGranularity,
+    SendImmediately, SendNextQueuedMessage, ToggleProfileSelector, ToggleThinkingMode,
 };
 
 const STOPWATCH_THRESHOLD: Duration = Duration::from_secs(30);
@@ -388,7 +388,7 @@ impl AcpThreadView {
     pub fn new(
         agent: Rc<dyn AgentServer>,
         resume_thread: Option<AgentSessionInfo>,
-        summarize_thread: Option<AgentSessionInfo>,
+        initial_content: Option<ExternalAgentInitialContent>,
         workspace: WeakEntity<Workspace>,
         project: Entity<Project>,
         thread_store: Option<Entity<ThreadStore>>,
@@ -430,8 +430,19 @@ impl AcpThreadView {
                 window,
                 cx,
             );
-            if let Some(entry) = summarize_thread {
-                editor.insert_thread_summary(entry, window, cx);
+            if let Some(content) = initial_content {
+                match content {
+                    ExternalAgentInitialContent::ThreadSummary(entry) => {
+                        editor.insert_thread_summary(entry, window, cx);
+                    }
+                    ExternalAgentInitialContent::Text(prompt) => {
+                        editor.set_message(
+                            vec![acp::ContentBlock::Text(acp::TextContent::new(prompt))],
+                            window,
+                            cx,
+                        );
+                    }
+                }
             }
             editor
         });

crates/agent_ui/src/agent_panel.rs

@@ -30,7 +30,10 @@ use crate::{
     acp::{AcpThreadHistory, ThreadHistoryEvent},
     text_thread_history::{TextThreadHistory, TextThreadHistoryEvent},
 };
-use crate::{ExternalAgent, NewExternalAgentThread, NewNativeAgentThreadFromSummary};
+use crate::{
+    ExternalAgent, ExternalAgentInitialContent, NewExternalAgentThread,
+    NewNativeAgentThreadFromSummary,
+};
 use agent_settings::AgentSettings;
 use ai_onboarding::AgentPanelOnboarding;
 use anyhow::{Result, anyhow};
@@ -742,7 +745,7 @@ impl AgentPanel {
         self.external_thread(
             Some(ExternalAgent::NativeAgent),
             None,
-            Some(thread),
+            Some(ExternalAgentInitialContent::ThreadSummary(thread)),
             window,
             cx,
         );
@@ -795,7 +798,7 @@ impl AgentPanel {
         &mut self,
         agent_choice: Option<crate::ExternalAgent>,
         resume_thread: Option<AgentSessionInfo>,
-        summarize_thread: Option<AgentSessionInfo>,
+        initial_content: Option<ExternalAgentInitialContent>,
         window: &mut Window,
         cx: &mut Context<Self>,
     ) {
@@ -857,7 +860,7 @@ impl AgentPanel {
                 agent_panel._external_thread(
                     server,
                     resume_thread,
-                    summarize_thread,
+                    initial_content,
                     workspace,
                     project,
                     ext_agent,
@@ -1414,6 +1417,21 @@ impl AgentPanel {
         }
     }
 
+    pub fn new_external_thread_with_text(
+        &mut self,
+        initial_text: Option<String>,
+        window: &mut Window,
+        cx: &mut Context<Self>,
+    ) {
+        self.external_thread(
+            None,
+            None,
+            initial_text.map(ExternalAgentInitialContent::Text),
+            window,
+            cx,
+        );
+    }
+
     pub fn new_agent_thread(
         &mut self,
         agent: AgentType,
@@ -1476,7 +1494,7 @@ impl AgentPanel {
         &mut self,
         server: Rc<dyn AgentServer>,
         resume_thread: Option<AgentSessionInfo>,
-        summarize_thread: Option<AgentSessionInfo>,
+        initial_content: Option<ExternalAgentInitialContent>,
         workspace: WeakEntity<Workspace>,
         project: Entity<Project>,
         ext_agent: ExternalAgent,
@@ -1498,7 +1516,7 @@ impl AgentPanel {
             crate::acp::AcpThreadView::new(
                 server,
                 resume_thread,
-                summarize_thread,
+                initial_content,
                 workspace.clone(),
                 project,
                 thread_store,

crates/agent_ui/src/agent_ui.rs

@@ -217,6 +217,12 @@ impl ExternalAgent {
     }
 }
 
+/// Content to initialize new external agent with.
+pub enum ExternalAgentInitialContent {
+    ThreadSummary(acp_thread::AgentSessionInfo),
+    Text(String),
+}
+
 /// Opens the profile management interface for configuring agent tools and settings.
 #[derive(PartialEq, Clone, Default, Debug, Deserialize, JsonSchema, Action)]
 #[action(namespace = agent)]

crates/zed/src/main.rs

@@ -846,13 +846,15 @@ fn handle_open_request(request: OpenRequest, app_state: Arc<AppState>, cx: &mut
                 })
                 .detach_and_log_err(cx);
             }
-            OpenRequestKind::AgentPanel => {
+            OpenRequestKind::AgentPanel { initial_prompt } => {
                 cx.spawn(async move |cx| {
                     let workspace =
                         workspace::get_any_active_workspace(app_state, cx.clone()).await?;
                     workspace.update(cx, |workspace, window, cx| {
-                        if let Some(panel) = workspace.panel::<AgentPanel>(cx) {
-                            panel.focus_handle(cx).focus(window, cx);
+                        if let Some(panel) = workspace.focus_panel::<AgentPanel>(window, cx) {
+                            panel.update(cx, |panel, cx| {
+                                panel.new_external_thread_with_text(initial_prompt, window, cx);
+                            });
                         }
                     })
                 })

crates/zed/src/zed/open_listener.rs

@@ -48,7 +48,9 @@ pub enum OpenRequestKind {
     Extension {
         extension_id: String,
     },
-    AgentPanel,
+    AgentPanel {
+        initial_prompt: Option<String>,
+    },
     SharedAgentThread {
         session_id: String,
     },
@@ -108,8 +110,8 @@ impl OpenRequest {
                 this.kind = Some(OpenRequestKind::Extension {
                     extension_id: extension_id.to_string(),
                 });
-            } else if url == "zed://agent" {
-                this.kind = Some(OpenRequestKind::AgentPanel);
+            } else if let Some(agent_path) = url.strip_prefix("zed://agent") {
+                this.parse_agent_url(agent_path)
             } else if let Some(session_id_str) = url.strip_prefix("zed://agent/shared/") {
                 if uuid::Uuid::parse_str(session_id_str).is_ok() {
                     this.kind = Some(OpenRequestKind::SharedAgentThread {
@@ -160,6 +162,17 @@ impl OpenRequest {
         }
     }
 
+    fn parse_agent_url(&mut self, agent_path: &str) {
+        // Format: "" or "?prompt=<text>"
+        let initial_prompt = agent_path.strip_prefix('?').and_then(|query| {
+            url::form_urlencoded::parse(query.as_bytes())
+                .find_map(|(key, value)| (key == "prompt").then_some(value))
+                .filter(|s| !s.is_empty())
+                .map(|s| s.into_owned())
+        });
+        self.kind = Some(OpenRequestKind::AgentPanel { initial_prompt });
+    }
+
     fn parse_git_clone_url(&mut self, clone_path: &str) -> Result<()> {
         // Format: /?repo=<url> or ?repo=<url>
         let clone_path = clone_path.strip_prefix('/').unwrap_or(clone_path);