feat: Handle MCP server notification messages (#2613)

Co-authored-by: Michael Neale <michael.neale@gmail.com>

Cargo.lock

@@ -3435,6 +3435,7 @@ dependencies = [
  "tokenizers",
  "tokio",
  "tokio-cron-scheduler",
+ "tokio-stream",
  "tracing",
  "tracing-subscriber",
  "url",
@@ -3486,6 +3487,7 @@ dependencies = [
  "goose",
  "goose-bench",
  "goose-mcp",
+ "indicatif",
  "mcp-client",
  "mcp-core",
  "mcp-server",

crates/goose-cli/Cargo.toml

@@ -55,6 +55,7 @@ regex = "1.11.1"
 minijinja = "2.8.0"
 nix = { version = "0.30.1", features = ["process", "signal"] }
 tar = "0.4"
+indicatif = "0.17.11"
 
 [target.'cfg(target_os = "windows")'.dependencies]
 winapi = { version = "0.3", features = ["wincred"] }

crates/goose-cli/src/session/mod.rs

@@ -7,6 +7,7 @@ mod thinking;
 
 pub use builder::{build_session, SessionBuilderConfig};
 use console::Color;
+use goose::agents::AgentEvent;
 use goose::permission::permission_confirmation::PrincipalType;
 use goose::permission::Permission;
 use goose::permission::PermissionConfirmation;
@@ -26,6 +27,8 @@ use input::InputResult;
 use mcp_core::handler::ToolError;
 use mcp_core::prompt::PromptMessage;
 
+use mcp_core::protocol::JsonRpcMessage;
+use mcp_core::protocol::JsonRpcNotification;
 use rand::{distributions::Alphanumeric, Rng};
 use serde_json::Value;
 use std::collections::HashMap;
@@ -713,12 +716,15 @@ impl Session {
             )
             .await?;
 
+        let mut progress_bars = output::McpSpinners::new();
+
         use futures::StreamExt;
         loop {
             tokio::select! {
                 result = stream.next() => {
+                    let _ = progress_bars.hide();
                     match result {
-                        Some(Ok(message)) => {
+                        Some(Ok(AgentEvent::Message(message))) => {
                             // If it's a confirmation request, get approval but otherwise do not render/persist
                             if let Some(MessageContent::ToolConfirmationRequest(confirmation)) = message.content.first() {
                                 output::hide_thinking();
@@ -846,6 +852,51 @@ impl Session {
                                 if interactive {output::show_thinking()};
                             }
                         }
+                        Some(Ok(AgentEvent::McpNotification((_id, message)))) => {
+                                if let JsonRpcMessage::Notification(JsonRpcNotification{
+                                    method,
+                                    params: Some(Value::Object(o)),
+                                    ..
+                                }) = message {
+                                match method.as_str() {
+                                    "notifications/message" => {
+                                        let data = o.get("data").unwrap_or(&Value::Null);
+                                        let message = match data {
+                                            Value::String(s) => s.clone(),
+                                            Value::Object(o) => {
+                                                if let Some(Value::String(output)) = o.get("output") {
+                                                    output.to_owned()
+                                                } else {
+                                                    data.to_string()
+                                                }
+                                            },
+                                            v => {
+                                                    v.to_string()
+                                            },
+                                        };
+                                        // output::render_text_no_newlines(&message, None, true);
+                                        progress_bars.log(&message);
+                                    },
+                                    "notifications/progress" => {
+                                        let progress = o.get("progress").and_then(|v| v.as_f64());
+                                        let token = o.get("progressToken").map(|v| v.to_string());
+                                        let message = o.get("message").and_then(|v| v.as_str());
+                                        let total = o
+                                            .get("total")
+                                            .and_then(|v| v.as_f64());
+                                        if let (Some(progress), Some(token)) = (progress, token) {
+                                            progress_bars.update(
+                                                token.as_str(),
+                                                progress,
+                                                total,
+                                                message,
+                                            );
+                                        }
+                                    },
+                                    _ => (),
+                                }
+                            }
+                        }
                         Some(Err(e)) => {
                             eprintln!("Error: {}", e);
                             drop(stream);
@@ -872,6 +923,7 @@ impl Session {
                 }
             }
         }
+
         Ok(())
     }
 

crates/goose-cli/src/session/output.rs

@@ -2,12 +2,15 @@ use bat::WrappingMode;
 use console::{style, Color};
 use goose::config::Config;
 use goose::message::{Message, MessageContent, ToolRequest, ToolResponse};
+use indicatif::{MultiProgress, ProgressBar, ProgressStyle};
 use mcp_core::prompt::PromptArgument;
 use mcp_core::tool::ToolCall;
 use serde_json::Value;
 use std::cell::RefCell;
 use std::collections::HashMap;
+use std::io::Error;
 use std::path::Path;
+use std::time::Duration;
 
 // Re-export theme for use in main
 #[derive(Clone, Copy)]
@@ -144,6 +147,10 @@ pub fn render_message(message: &Message, debug: bool) {
 }
 
 pub fn render_text(text: &str, color: Option<Color>, dim: bool) {
+    render_text_no_newlines(format!("\n{}\n\n", text).as_str(), color, dim);
+}
+
+pub fn render_text_no_newlines(text: &str, color: Option<Color>, dim: bool) {
     let mut styled_text = style(text);
     if dim {
         styled_text = styled_text.dim();
@@ -153,7 +160,7 @@ pub fn render_text(text: &str, color: Option<Color>, dim: bool) {
     } else {
         styled_text = styled_text.green();
     }
-    println!("\n{}\n", styled_text);
+    print!("{}", styled_text);
 }
 
 pub fn render_enter_plan_mode() {
@@ -359,7 +366,6 @@ fn render_shell_request(call: &ToolCall, debug: bool) {
         }
         _ => print_params(&call.arguments, 0, debug),
     }
-    println!();
 }
 
 fn render_default_request(call: &ToolCall, debug: bool) {
@@ -568,6 +574,64 @@ pub fn display_greeting() {
     println!("\nGoose is running! Enter your instructions, or try asking what goose can do.\n");
 }
 
+pub struct McpSpinners {
+    bars: HashMap<String, ProgressBar>,
+    log_spinner: Option<ProgressBar>,
+
+    multi_bar: MultiProgress,
+}
+
+impl McpSpinners {
+    pub fn new() -> Self {
+        McpSpinners {
+            bars: HashMap::new(),
+            log_spinner: None,
+            multi_bar: MultiProgress::new(),
+        }
+    }
+
+    pub fn log(&mut self, message: &str) {
+        let spinner = self.log_spinner.get_or_insert_with(|| {
+            let bar = self.multi_bar.add(
+                ProgressBar::new_spinner()
+                    .with_style(
+                        ProgressStyle::with_template("{spinner:.green} {msg}")
+                            .unwrap()
+                            .tick_chars("⠋⠙⠚⠛⠓⠒⠊⠉"),
+                    )
+                    .with_message(message.to_string()),
+            );
+            bar.enable_steady_tick(Duration::from_millis(100));
+            bar
+        });
+
+        spinner.set_message(message.to_string());
+    }
+
+    pub fn update(&mut self, token: &str, value: f64, total: Option<f64>, message: Option<&str>) {
+        let bar = self.bars.entry(token.to_string()).or_insert_with(|| {
+            if let Some(total) = total {
+                self.multi_bar.add(
+                    ProgressBar::new((total * 100.0) as u64).with_style(
+                        ProgressStyle::with_template("[{elapsed}] {bar:40} {pos:>3}/{len:3} {msg}")
+                            .unwrap(),
+                    ),
+                )
+            } else {
+                self.multi_bar.add(ProgressBar::new_spinner())
+            }
+        });
+        bar.set_position((value * 100.0) as u64);
+        if let Some(msg) = message {
+            bar.set_message(msg.to_string());
+        }
+    }
+
+    pub fn hide(&mut self) -> Result<(), Error> {
+        self.multi_bar.clear()
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

crates/goose-ffi/src/lib.rs

@@ -3,7 +3,7 @@ use std::ptr;
 use std::sync::Arc;
 
 use futures::StreamExt;
-use goose::agents::Agent;
+use goose::agents::{Agent, AgentEvent};
 use goose::message::Message;
 use goose::model::ModelConfig;
 use goose::providers::databricks::DatabricksProvider;
@@ -256,13 +256,16 @@ pub unsafe extern "C" fn goose_agent_send_message(
 
         while let Some(message_result) = stream.next().await {
             match message_result {
-                Ok(message) => {
+                Ok(AgentEvent::Message(message)) => {
                     // Get text or serialize to JSON
                     // Note: Message doesn't have as_text method, we'll serialize to JSON
                     if let Ok(json) = serde_json::to_string(&message) {
                         full_response.push_str(&json);
                     }
                 }
+                Ok(AgentEvent::McpNotification(_)) => {
+                    // TODO: Handle MCP notifications.
+                }
                 Err(e) => {
                     full_response.push_str(&format!("\nError in message stream: {}", e));
                 }

crates/goose-mcp/src/computercontroller/mod.rs

@@ -6,7 +6,7 @@ use serde_json::{json, Value};
 use std::{
     collections::HashMap, fs, future::Future, path::PathBuf, pin::Pin, sync::Arc, sync::Mutex,
 };
-use tokio::process::Command;
+use tokio::{process::Command, sync::mpsc};
 
 #[cfg(unix)]
 use std::os::unix::fs::PermissionsExt;
@@ -14,7 +14,7 @@ use std::os::unix::fs::PermissionsExt;
 use mcp_core::{
     handler::{PromptError, ResourceError, ToolError},
     prompt::Prompt,
-    protocol::ServerCapabilities,
+    protocol::{JsonRpcMessage, ServerCapabilities},
     resource::Resource,
     tool::{Tool, ToolAnnotations},
     Content,
@@ -1155,6 +1155,7 @@ impl Router for ComputerControllerRouter {
         &self,
         tool_name: &str,
         arguments: Value,
+        _notifier: mpsc::Sender<JsonRpcMessage>,
     ) -> Pin<Box<dyn Future<Output = Result<Vec<Content>, ToolError>> + Send + 'static>> {
         let this = self.clone();
         let tool_name = tool_name.to_string();

crates/goose-mcp/src/developer/mod.rs

@@ -13,13 +13,17 @@ use std::{
     path::{Path, PathBuf},
     pin::Pin,
 };
-use tokio::process::Command;
+use tokio::{
+    io::{AsyncBufReadExt, BufReader},
+    process::Command,
+    sync::mpsc,
+};
 use url::Url;
 
 use include_dir::{include_dir, Dir};
 use mcp_core::{
     handler::{PromptError, ResourceError, ToolError},
-    protocol::ServerCapabilities,
+    protocol::{JsonRpcMessage, JsonRpcNotification, ServerCapabilities},
     resource::Resource,
     tool::Tool,
     Content,
@@ -456,7 +460,11 @@ impl DeveloperRouter {
     }
 
     // Shell command execution with platform-specific handling
-    async fn bash(&self, params: Value) -> Result<Vec<Content>, ToolError> {
+    async fn bash(
+        &self,
+        params: Value,
+        notifier: mpsc::Sender<JsonRpcMessage>,
+    ) -> Result<Vec<Content>, ToolError> {
         let command =
             params
                 .get("command")
@@ -488,27 +496,92 @@ impl DeveloperRouter {
 
         // Get platform-specific shell configuration
         let shell_config = get_shell_config();
-        let cmd_with_redirect = format_command_for_platform(command);
+        let cmd_str = format_command_for_platform(command);
 
         // Execute the command using platform-specific shell
-        let child = Command::new(&shell_config.executable)
+        let mut child = Command::new(&shell_config.executable)
             .stdout(Stdio::piped())
             .stderr(Stdio::piped())
             .stdin(Stdio::null())
             .kill_on_drop(true)
             .arg(&shell_config.arg)
-            .arg(cmd_with_redirect)
+            .arg(cmd_str)
             .spawn()
             .map_err(|e| ToolError::ExecutionError(e.to_string()))?;
 
+        let stdout = child.stdout.take().unwrap();
+        let stderr = child.stderr.take().unwrap();
+
+        let mut stdout_reader = BufReader::new(stdout);
+        let mut stderr_reader = BufReader::new(stderr);
+
+        let output_task = tokio::spawn(async move {
+            let mut combined_output = String::new();
+
+            let mut stdout_buf = Vec::new();
+            let mut stderr_buf = Vec::new();
+
+            loop {
+                tokio::select! {
+                    n = stdout_reader.read_until(b'\n', &mut stdout_buf) => {
+                        if n? == 0 {
+                            break;
+                        }
+                        let line = String::from_utf8_lossy(&stdout_buf);
+
+                        notifier.try_send(JsonRpcMessage::Notification(JsonRpcNotification {
+                            jsonrpc: "2.0".to_string(),
+                            method: "notifications/message".to_string(),
+                            params: Some(json!({
+                                "data": {
+                                    "type": "shell",
+                                    "stream": "stdout",
+                                    "output": line.to_string(),
+                                }
+                            })),
+                        }))
+                        .ok();
+
+                        combined_output.push_str(&line);
+                        stdout_buf.clear();
+                    }
+                    n = stderr_reader.read_until(b'\n', &mut stderr_buf) => {
+                        if n? == 0 {
+                            break;
+                        }
+                        let line = String::from_utf8_lossy(&stderr_buf);
+
+                        notifier.try_send(JsonRpcMessage::Notification(JsonRpcNotification {
+                            jsonrpc: "2.0".to_string(),
+                            method: "notifications/message".to_string(),
+                            params: Some(json!({
+                                "data": {
+                                    "type": "shell",
+                                    "stream": "stderr",
+                                    "output": line.to_string(),
+                                }
+                            })),
+                        }))
+                        .ok();
+
+                        combined_output.push_str(&line);
+                        stderr_buf.clear();
+                    }
+                }
+            }
+            Ok::<_, std::io::Error>(combined_output)
+        });
+
         // Wait for the command to complete and get output
-        let output = child
-            .wait_with_output()
+        child
+            .wait()
             .await
             .map_err(|e| ToolError::ExecutionError(e.to_string()))?;
 
-        let stdout_str = String::from_utf8_lossy(&output.stdout);
-        let output_str = stdout_str;
+        let output_str = match output_task.await {
+            Ok(result) => result.map_err(|e| ToolError::ExecutionError(e.to_string()))?,
+            Err(e) => return Err(ToolError::ExecutionError(e.to_string())),
+        };
 
         // Check the character count of the output
         const MAX_CHAR_COUNT: usize = 400_000; // 409600 chars = 400KB
@@ -1048,12 +1121,13 @@ impl Router for DeveloperRouter {
         &self,
         tool_name: &str,
         arguments: Value,
+        notifier: mpsc::Sender<JsonRpcMessage>,
     ) -> Pin<Box<dyn Future<Output = Result<Vec<Content>, ToolError>> + Send + 'static>> {
         let this = self.clone();
         let tool_name = tool_name.to_string();
         Box::pin(async move {
             match tool_name.as_str() {
-                "shell" => this.bash(arguments).await,
+                "shell" => this.bash(arguments, notifier).await,
                 "text_editor" => this.text_editor(arguments).await,
                 "list_windows" => this.list_windows(arguments).await,
                 "screen_capture" => this.screen_capture(arguments).await,
@@ -1195,6 +1269,10 @@ mod tests {
             .await
     }
 
+    fn dummy_sender() -> mpsc::Sender<JsonRpcMessage> {
+        mpsc::channel(1).0
+    }
+
     #[tokio::test]
     #[serial]
     async fn test_shell_missing_parameters() {
@@ -1202,7 +1280,7 @@ mod tests {
         std::env::set_current_dir(&temp_dir).unwrap();
 
         let router = get_router().await;
-        let result = router.call_tool("shell", json!({})).await;
+        let result = router.call_tool("shell", json!({}), dummy_sender()).await;
 
         assert!(result.is_err());
         let err = result.err().unwrap();
@@ -1263,6 +1341,7 @@ mod tests {
                         "command": "view",
                         "path": large_file_str
                     }),
+                    dummy_sender(),
                 )
                 .await;
 
@@ -1288,6 +1367,7 @@ mod tests {
                         "command": "view",
                         "path": many_chars_str
                     }),
+                    dummy_sender(),
                 )
                 .await;
 
@@ -1319,6 +1399,7 @@ mod tests {
                     "path": file_path_str,
                     "file_text": "Hello, world!"
                 }),
+                dummy_sender(),
             )
             .await
             .unwrap();
@@ -1331,6 +1412,7 @@ mod tests {
                     "command": "view",
                     "path": file_path_str
                 }),
+                dummy_sender(),
             )
             .await
             .unwrap();
@@ -1369,6 +1451,7 @@ mod tests {
                     "path": file_path_str,
                     "file_text": "Hello, world!"
                 }),
+                dummy_sender(),
             )
             .await
             .unwrap();
@@ -1383,6 +1466,7 @@ mod tests {
                     "old_str": "world",
                     "new_str": "Rust"
                 }),
+                dummy_sender(),
             )
             .await
             .unwrap();
@@ -1407,6 +1491,7 @@ mod tests {
                     "command": "view",
                     "path": file_path_str
                 }),
+                dummy_sender(),
             )
             .await
             .unwrap();
@@ -1444,6 +1529,7 @@ mod tests {
                     "path": file_path_str,
                     "file_text": "First line"
                 }),
+                dummy_sender(),
             )
             .await
             .unwrap();
@@ -1458,6 +1544,7 @@ mod tests {
                     "old_str": "First line",
                     "new_str": "Second line"
                 }),
+                dummy_sender(),
             )
             .await
             .unwrap();
@@ -1470,6 +1557,7 @@ mod tests {
                     "command": "undo_edit",
                     "path": file_path_str
                 }),
+                dummy_sender(),
             )
             .await
             .unwrap();
@@ -1485,6 +1573,7 @@ mod tests {
                     "command": "view",
                     "path": file_path_str
                 }),
+                dummy_sender(),
             )
             .await
             .unwrap();
@@ -1583,6 +1672,7 @@ mod tests {
                     "path": temp_dir.path().join("secret.txt").to_str().unwrap(),
                     "file_text": "test content"
                 }),
+                dummy_sender(),
             )
             .await;
 
@@ -1601,6 +1691,7 @@ mod tests {
                     "path": temp_dir.path().join("allowed.txt").to_str().unwrap(),
                     "file_text": "test content"
                 }),
+                dummy_sender(),
             )
             .await;
 
@@ -1642,6 +1733,7 @@ mod tests {
                 json!({
                     "command": format!("cat {}", secret_file_path.to_str().unwrap())
                 }),
+                dummy_sender(),
             )
             .await;
 
@@ -1658,6 +1750,7 @@ mod tests {
                 json!({
                     "command": format!("cat {}", allowed_file_path.to_str().unwrap())
                 }),
+                dummy_sender(),
             )
             .await;
 

crates/goose-mcp/src/developer/shell.rs

@@ -4,7 +4,6 @@ use std::env;
 pub struct ShellConfig {
     pub executable: String,
     pub arg: String,
-    pub redirect_syntax: String,
 }
 
 impl Default for ShellConfig {
@@ -14,13 +13,11 @@ impl Default for ShellConfig {
             Self {
                 executable: "powershell.exe".to_string(),
                 arg: "-NoProfile -NonInteractive -Command".to_string(),
-                redirect_syntax: "2>&1".to_string(),
             }
         } else {
             Self {
                 executable: "bash".to_string(),
                 arg: "-c".to_string(),
-                redirect_syntax: "2>&1".to_string(),
             }
         }
     }
@@ -31,13 +28,12 @@ pub fn get_shell_config() -> ShellConfig {
 }
 
 pub fn format_command_for_platform(command: &str) -> String {
-    let config = get_shell_config();
     if cfg!(windows) {
         // For PowerShell, wrap the command in braces to handle special characters
-        format!("{{ {} }} {}", command, config.redirect_syntax)
+        format!("{{ {} }}", command)
     } else {
         // For other shells, no braces needed
-        format!("{} {}", command, config.redirect_syntax)
+        command.to_string()
     }
 }
 

crates/goose-mcp/src/google_drive/mod.rs

@@ -7,6 +7,7 @@ use base64::Engine;
 use chrono::NaiveDate;
 use indoc::indoc;
 use lazy_static::lazy_static;
+use mcp_core::protocol::JsonRpcMessage;
 use mcp_core::tool::ToolAnnotations;
 use oauth_pkce::PkceOAuth2Client;
 use regex::Regex;
@@ -14,6 +15,7 @@ use serde_json::{json, Value};
 use std::io::Cursor;
 use std::{env, fs, future::Future, path::Path, pin::Pin, sync::Arc};
 use storage::CredentialsManager;
+use tokio::sync::mpsc;
 
 use mcp_core::content::Content;
 use mcp_core::{
@@ -3281,6 +3283,7 @@ impl Router for GoogleDriveRouter {
         &self,
         tool_name: &str,
         arguments: Value,
+        _notifier: mpsc::Sender<JsonRpcMessage>,
     ) -> Pin<Box<dyn Future<Output = Result<Vec<Content>, ToolError>> + Send + 'static>> {
         let this = self.clone();
         let tool_name = tool_name.to_string();

crates/goose-mcp/src/jetbrains/mod.rs

@@ -5,7 +5,7 @@ use mcp_core::{
     content::Content,
     handler::{PromptError, ResourceError, ToolError},
     prompt::Prompt,
-    protocol::ServerCapabilities,
+    protocol::{JsonRpcMessage, ServerCapabilities},
     resource::Resource,
     role::Role,
     tool::Tool,
@@ -16,7 +16,7 @@ use serde_json::Value;
 use std::future::Future;
 use std::pin::Pin;
 use std::sync::Arc;
-use tokio::sync::Mutex;
+use tokio::sync::{mpsc, Mutex};
 use tokio::time::{sleep, Duration};
 use tracing::error;
 
@@ -158,6 +158,7 @@ impl Router for JetBrainsRouter {
         &self,
         tool_name: &str,
         arguments: Value,
+        _notifier: mpsc::Sender<JsonRpcMessage>,
     ) -> Pin<Box<dyn Future<Output = Result<Vec<Content>, ToolError>> + Send + 'static>> {
         let this = self.clone();
         let tool_name = tool_name.to_string();

crates/goose-mcp/src/memory/mod.rs

@@ -10,11 +10,12 @@ use std::{
     path::PathBuf,
     pin::Pin,
 };
+use tokio::sync::mpsc;
 
 use mcp_core::{
     handler::{PromptError, ResourceError, ToolError},
     prompt::Prompt,
-    protocol::ServerCapabilities,
+    protocol::{JsonRpcMessage, ServerCapabilities},
     resource::Resource,
     tool::{Tool, ToolAnnotations, ToolCall},
     Content,
@@ -520,6 +521,7 @@ impl Router for MemoryRouter {
         &self,
         tool_name: &str,
         arguments: Value,
+        _notifier: mpsc::Sender<JsonRpcMessage>,
     ) -> Pin<Box<dyn Future<Output = Result<Vec<Content>, ToolError>> + Send + 'static>> {
         let this = self.clone();
         let tool_name = tool_name.to_string();

crates/goose-mcp/src/tutorial/mod.rs

@@ -3,11 +3,12 @@ use include_dir::{include_dir, Dir};
 use indoc::formatdoc;
 use serde_json::{json, Value};
 use std::{future::Future, pin::Pin};
+use tokio::sync::mpsc;
 
 use mcp_core::{
     handler::{PromptError, ResourceError, ToolError},
     prompt::Prompt,
-    protocol::ServerCapabilities,
+    protocol::{JsonRpcMessage, ServerCapabilities},
     resource::Resource,
     role::Role,
     tool::{Tool, ToolAnnotations},
@@ -130,6 +131,7 @@ impl Router for TutorialRouter {
         &self,
         tool_name: &str,
         arguments: Value,
+        _notifier: mpsc::Sender<JsonRpcMessage>,
     ) -> Pin<Box<dyn Future<Output = Result<Vec<Content>, ToolError>> + Send + 'static>> {
         let this = self.clone();
         let tool_name = tool_name.to_string();

crates/goose-server/src/routes/reply.rs

@@ -10,7 +10,7 @@ use axum::{
 use bytes::Bytes;
 use futures::{stream::StreamExt, Stream};
 use goose::{
-    agents::SessionConfig,
+    agents::{AgentEvent, SessionConfig},
     message::{Message, MessageContent},
     permission::permission_confirmation::PrincipalType,
 };
@@ -18,7 +18,7 @@ use goose::{
     permission::{Permission, PermissionConfirmation},
     session,
 };
-use mcp_core::{role::Role, Content, ToolResult};
+use mcp_core::{protocol::JsonRpcMessage, role::Role, Content, ToolResult};
 use serde::{Deserialize, Serialize};
 use serde_json::json;
 use serde_json::Value;
@@ -79,9 +79,19 @@ impl IntoResponse for SseResponse {
 #[derive(Debug, Serialize)]
 #[serde(tag = "type")]
 enum MessageEvent {
-    Message { message: Message },
-    Error { error: String },
-    Finish { reason: String },
+    Message {
+        message: Message,
+    },
+    Error {
+        error: String,
+    },
+    Finish {
+        reason: String,
+    },
+    Notification {
+        request_id: String,
+        message: JsonRpcMessage,
+    },
 }
 
 async fn stream_event(
@@ -200,7 +210,7 @@ async fn handler(
             tokio::select! {
                 response = timeout(Duration::from_millis(500), stream.next()) => {
                     match response {
-                        Ok(Some(Ok(message))) => {
+                        Ok(Some(Ok(AgentEvent::Message(message)))) => {
                             all_messages.push(message.clone());
                             if let Err(e) = stream_event(MessageEvent::Message { message }, &tx).await {
                                 tracing::error!("Error sending message through channel: {}", e);
@@ -223,6 +233,20 @@ async fn handler(
                                 }
                             });
                         }
+                        Ok(Some(Ok(AgentEvent::McpNotification((request_id, n))))) => {
+                            if let Err(e) = stream_event(MessageEvent::Notification{
+                                request_id: request_id.clone(),
+                                message: n,
+                            }, &tx).await {
+                                tracing::error!("Error sending message through channel: {}", e);
+                                let _ = stream_event(
+                                    MessageEvent::Error {
+                                        error: e.to_string(),
+                                    },
+                                    &tx,
+                                ).await;
+                            }
+                        }
                         Ok(Some(Err(e))) => {
                             tracing::error!("Error processing message: {}", e);
                             let _ = stream_event(
@@ -317,7 +341,7 @@ async fn ask_handler(
 
     while let Some(response) = stream.next().await {
         match response {
-            Ok(message) => {
+            Ok(AgentEvent::Message(message)) => {
                 if message.role == Role::Assistant {
                     for content in &message.content {
                         if let MessageContent::Text(text) = content {
@@ -328,6 +352,10 @@ async fn ask_handler(
                     }
                 }
             }
+            Ok(AgentEvent::McpNotification(n)) => {
+                // Handle notifications if needed
+                tracing::info!("Received notification: {:?}", n);
+            }
             Err(e) => {
                 tracing::error!("Error processing as_ai message: {}", e);
                 return Err(StatusCode::INTERNAL_SERVER_ERROR);

crates/goose/Cargo.toml

@@ -71,10 +71,10 @@ aws-sdk-bedrockruntime = "1.74.0"
 # For GCP Vertex AI provider auth
 jsonwebtoken = "9.3.1"
 
-# Added blake3 hashing library as a dependency
 blake3 = "1.5"
 fs2 = "0.4.3"
 futures-util = "0.3.31"
+tokio-stream = "0.1.17"
 
 # Vector database for tool selection
 lancedb = "0.13"

crates/goose/examples/agent.rs

@@ -2,7 +2,7 @@ use std::sync::Arc;
 
 use dotenv::dotenv;
 use futures::StreamExt;
-use goose::agents::{Agent, ExtensionConfig};
+use goose::agents::{Agent, AgentEvent, ExtensionConfig};
 use goose::config::{DEFAULT_EXTENSION_DESCRIPTION, DEFAULT_EXTENSION_TIMEOUT};
 use goose::message::Message;
 use goose::providers::databricks::DatabricksProvider;
@@ -20,10 +20,11 @@ async fn main() {
 
     let config = ExtensionConfig::stdio(
         "developer",
-        "./target/debug/developer",
+        "./target/debug/goose",
         DEFAULT_EXTENSION_DESCRIPTION,
         DEFAULT_EXTENSION_TIMEOUT,
-    );
+    )
+    .with_args(vec!["mcp", "developer"]);
     agent.add_extension(config).await.unwrap();
 
     println!("Extensions:");
@@ -35,11 +36,8 @@ async fn main() {
         .with_text("can you summarize the readme.md in this dir using just a haiku?")];
 
     let mut stream = agent.reply(&messages, None).await.unwrap();
-    while let Some(message) = stream.next().await {
-        println!(
-            "{}",
-            serde_json::to_string_pretty(&message.unwrap()).unwrap()
-        );
+    while let Some(Ok(AgentEvent::Message(message))) = stream.next().await {
+        println!("{}", serde_json::to_string_pretty(&message).unwrap());
         println!("\n");
     }
 }

crates/goose/src/agents/agent.rs

@@ -1,9 +1,14 @@
 use std::collections::HashMap;
+use std::future::Future;
+use std::pin::Pin;
 use std::sync::Arc;
 
 use anyhow::{anyhow, Result};
 use futures::stream::BoxStream;
-use futures::TryStreamExt;
+use futures::{FutureExt, Stream, TryStreamExt};
+use futures_util::stream;
+use futures_util::stream::StreamExt;
+use mcp_core::protocol::JsonRpcMessage;
 
 use crate::config::{Config, ExtensionConfigManager, PermissionManager};
 use crate::message::Message;
@@ -39,7 +44,7 @@ use mcp_core::{
 
 use super::platform_tools;
 use super::router_tools;
-use super::tool_execution::{ToolFuture, CHAT_MODE_TOOL_SKIPPED_RESPONSE, DECLINED_RESPONSE};
+use super::tool_execution::{ToolCallResult, CHAT_MODE_TOOL_SKIPPED_RESPONSE, DECLINED_RESPONSE};
 
 /// The main goose Agent
 pub struct Agent {
@@ -56,6 +61,12 @@ pub struct Agent {
     pub(super) router_tool_selector: Mutex<Option<Arc<Box<dyn RouterToolSelector>>>>,
 }
 
+#[derive(Clone, Debug)]
+pub enum AgentEvent {
+    Message(Message),
+    McpNotification((String, JsonRpcMessage)),
+}
+
 impl Agent {
     pub fn new() -> Self {
         // Create channels with buffer size 32 (adjust if needed)
@@ -100,6 +111,40 @@ impl Default for Agent {
     }
 }
 
+pub enum ToolStreamItem<T> {
+    Message(JsonRpcMessage),
+    Result(T),
+}
+
+pub type ToolStream = Pin<Box<dyn Stream<Item = ToolStreamItem<ToolResult<Vec<Content>>>> + Send>>;
+
+// tool_stream combines a stream of JsonRpcMessages with a future representing the
+// final result of the tool call. MCP notifications are not request-scoped, but
+// this lets us capture all notifications emitted during the tool call for
+// simpler consumption
+pub fn tool_stream<S, F>(rx: S, done: F) -> ToolStream
+where
+    S: Stream<Item = JsonRpcMessage> + Send + Unpin + 'static,
+    F: Future<Output = ToolResult<Vec<Content>>> + Send + 'static,
+{
+    Box::pin(async_stream::stream! {
+        tokio::pin!(done);
+        let mut rx = rx;
+
+        loop {
+            tokio::select! {
+                Some(msg) = rx.next() => {
+                    yield ToolStreamItem::Message(msg);
+                }
+                r = &mut done => {
+                    yield ToolStreamItem::Result(r);
+                    break;
+                }
+            }
+        }
+    })
+}
+
 impl Agent {
     /// Get a reference count clone to the provider
     pub async fn provider(&self) -> Result<Arc<dyn Provider>, anyhow::Error> {
@@ -143,7 +188,7 @@ impl Agent {
         &self,
         tool_call: mcp_core::tool::ToolCall,
         request_id: String,
-    ) -> (String, Result<Vec<Content>, ToolError>) {
+    ) -> (String, Result<ToolCallResult, ToolError>) {
         // Check if this tool call should be allowed based on repetition monitoring
         if let Some(monitor) = self.tool_monitor.lock().await.as_mut() {
             let tool_call_info = ToolCall::new(tool_call.name.clone(), tool_call.arguments.clone());
@@ -171,52 +216,65 @@ impl Agent {
                 .and_then(|v| v.as_str())
                 .unwrap_or("")
                 .to_string();
-            return self
+            let (request_id, result) = self
                 .manage_extensions(action, extension_name, request_id)
                 .await;
+
+            return (request_id, Ok(ToolCallResult::from(result)));
         }
 
         let extension_manager = self.extension_manager.lock().await;
-        let result = if tool_call.name == PLATFORM_READ_RESOURCE_TOOL_NAME {
+        let result: ToolCallResult = if tool_call.name == PLATFORM_READ_RESOURCE_TOOL_NAME {
             // Check if the tool is read_resource and handle it separately
-            extension_manager
-                .read_resource(tool_call.arguments.clone())
-                .await
+            ToolCallResult::from(
+                extension_manager
+                    .read_resource(tool_call.arguments.clone())
+                    .await,
+            )
         } else if tool_call.name == PLATFORM_LIST_RESOURCES_TOOL_NAME {
-            extension_manager
-                .list_resources(tool_call.arguments.clone())
-                .await
+            ToolCallResult::from(
+                extension_manager
+                    .list_resources(tool_call.arguments.clone())
+                    .await,
+            )
         } else if tool_call.name == PLATFORM_SEARCH_AVAILABLE_EXTENSIONS_TOOL_NAME {
-            extension_manager.search_available_extensions().await
+            ToolCallResult::from(extension_manager.search_available_extensions().await)
         } else if self.is_frontend_tool(&tool_call.name).await {
             // For frontend tools, return an error indicating we need frontend execution
-            Err(ToolError::ExecutionError(
+            ToolCallResult::from(Err(ToolError::ExecutionError(
                 "Frontend tool execution required".to_string(),
-            ))
+            )))
         } else if tool_call.name == ROUTER_VECTOR_SEARCH_TOOL_NAME {
             let selector = self.router_tool_selector.lock().await.clone();
-            if let Some(selector) = selector {
+            ToolCallResult::from(if let Some(selector) = selector {
                 selector.select_tools(tool_call.arguments.clone()).await
             } else {
                 Err(ToolError::ExecutionError(
                     "Encountered vector search error.".to_string(),
                 ))
-            }
+            })
         } else {
-            extension_manager
+            // Clone the result to ensure no references to extension_manager are returned
+            let result = extension_manager
                 .dispatch_tool_call(tool_call.clone())
-                .await
+                .await;
+            match result {
+                Ok(call_result) => call_result,
+                Err(e) => ToolCallResult::from(Err(ToolError::ExecutionError(e.to_string()))),
+            }
         };
 
-        debug!(
-            "input" = serde_json::to_string(&tool_call).unwrap(),
-            "output" = serde_json::to_string(&result).unwrap(),
-        );
-
-        // Process the response to handle large text content
-        let processed_result = super::large_response_handler::process_tool_response(result);
-
-        (request_id, processed_result)
+        (
+            request_id,
+            Ok(ToolCallResult {
+                notification_stream: result.notification_stream,
+                result: Box::new(
+                    result
+                        .result
+                        .map(super::large_response_handler::process_tool_response),
+                ),
+            }),
+        )
     }
 
     pub(super) async fn manage_extensions(
@@ -466,7 +524,7 @@ impl Agent {
         &self,
         messages: &[Message],
         session: Option<SessionConfig>,
-    ) -> anyhow::Result<BoxStream<'_, anyhow::Result<Message>>> {
+    ) -> anyhow::Result<BoxStream<'_, anyhow::Result<AgentEvent>>> {
         let mut messages = messages.to_vec();
         let reply_span = tracing::Span::current();
 
@@ -532,9 +590,8 @@ impl Agent {
                                 }
                             }
                         }
-
                         // Yield the assistant's response with frontend tool requests filtered out
-                        yield filtered_response.clone();
+                        yield AgentEvent::Message(filtered_response.clone());
 
                         tokio::task::yield_now().await;
 
@@ -556,7 +613,7 @@ impl Agent {
                         // execution is yeield back to this reply loop, and is of the same Message
                         // type, so we can yield that back up to be handled
                         while let Some(msg) = frontend_tool_stream.try_next().await? {
-                            yield msg;
+                            yield AgentEvent::Message(msg);
                         }
 
                         // Clone goose_mode once before the match to avoid move issues
@@ -584,13 +641,23 @@ impl Agent {
                                 self.provider().await?).await;
 
                             // Handle pre-approved and read-only tools in parallel
-                            let mut tool_futures: Vec<ToolFuture> = Vec::new();
+                            let mut tool_futures: Vec<(String, ToolStream)> = Vec::new();
 
                             // Skip the confirmation for approved tools
                             for request in &permission_check_result.approved {
                                 if let Ok(tool_call) = request.tool_call.clone() {
-                                    let tool_future = self.dispatch_tool_call(tool_call, request.id.clone());
-                                    tool_futures.push(Box::pin(tool_future));
+                                    let (req_id, tool_result) = self.dispatch_tool_call(tool_call, request.id.clone()).await;
+
+                                    tool_futures.push((req_id, match tool_result {
+                                        Ok(result) => tool_stream(
+                                            result.notification_stream.unwrap_or_else(|| Box::new(stream::empty())),
+                                            result.result,
+                                        ),
+                                        Err(e) => tool_stream(
+                                            Box::new(stream::empty()),
+                                            futures::future::ready(Err(e)),
+                                        ),
+                                    }));
                                 }
                             }
 
@@ -618,7 +685,7 @@ impl Agent {
                             // type, so we can yield the Message back up to be handled and grab any
                             // confirmations or denials
                             while let Some(msg) = tool_approval_stream.try_next().await? {
-                                yield msg;
+                                yield AgentEvent::Message(msg);
                             }
 
                             tool_futures = {
@@ -628,16 +695,30 @@ impl Agent {
                                 futures_lock.drain(..).collect::<Vec<_>>()
                             };
 
-                            // Wait for all tool calls to complete
-                            let results = futures::future::join_all(tool_futures).await;
+                            let with_id = tool_futures
+                                .into_iter()
+                                .map(|(request_id, stream)| {
+                                    stream.map(move |item| (request_id.clone(), item))
+                                })
+                                .collect::<Vec<_>>();
+
+                            let mut combined = stream::select_all(with_id);
+
                             let mut all_install_successful = true;
 
-                            for (request_id, output) in results.into_iter() {
-                                if enable_extension_request_ids.contains(&request_id) && output.is_err(){
-                                    all_install_successful = false;
+                            while let Some((request_id, item)) = combined.next().await {
+                                match item {
+                                    ToolStreamItem::Result(output) => {
+                                        if enable_extension_request_ids.contains(&request_id) && output.is_err(){
+                                            all_install_successful = false;
+                                        }
+                                        let mut response = message_tool_response.lock().await;
+                                        *response = response.clone().with_tool_response(request_id, output);
+                                    },
+                                    ToolStreamItem::Message(msg) => {
+                                        yield AgentEvent::McpNotification((request_id, msg))
+                                    }
                                 }
-                                let mut response = message_tool_response.lock().await;
-                                *response = response.clone().with_tool_response(request_id, output);
                             }
 
                             // Update system prompt and tools if installations were successful
@@ -647,7 +728,7 @@ impl Agent {
                         }
 
                         let final_message_tool_resp = message_tool_response.lock().await.clone();
-                        yield final_message_tool_resp.clone();
+                        yield AgentEvent::Message(final_message_tool_resp.clone());
 
                         messages.push(response);
                         messages.push(final_message_tool_resp);
@@ -656,15 +737,15 @@ impl Agent {
                         // At this point, the last message should be a user message
                         // because call to provider led to context length exceeded error
                         // Immediately yield a special message and break
-                        yield Message::assistant().with_context_length_exceeded(
+                        yield AgentEvent::Message(Message::assistant().with_context_length_exceeded(
                             "The context length of the model has been exceeded. Please start a new session and try again.",
-                        );
+                        ));
                         break;
                     },
                     Err(e) => {
                         // Create an error message & terminate the stream
                         error!("Error: {}", e);
-                        yield Message::assistant().with_text(format!("Ran into this error: {e}.\n\nPlease retry if you think this is a transient or recoverable error."));
+                        yield AgentEvent::Message(Message::assistant().with_text(format!("Ran into this error: {e}.\n\nPlease retry if you think this is a transient or recoverable error.")));
                         break;
                     }
                 }

crates/goose/src/agents/extension_manager.rs

@@ -1,8 +1,7 @@
 use anyhow::Result;
 use chrono::{DateTime, TimeZone, Utc};
-use futures::future;
 use futures::stream::{FuturesUnordered, StreamExt};
-use mcp_client::McpService;
+use futures::{future, FutureExt};
 use mcp_core::protocol::GetPromptResult;
 use std::collections::{HashMap, HashSet};
 use std::sync::Arc;
@@ -10,15 +9,17 @@ use std::sync::LazyLock;
 use std::time::Duration;
 use tokio::sync::Mutex;
 use tokio::task;
-use tracing::{debug, error, warn};
+use tokio_stream::wrappers::ReceiverStream;
+use tracing::{error, warn};
 
 use super::extension::{ExtensionConfig, ExtensionError, ExtensionInfo, ExtensionResult, ToolInfo};
+use super::tool_execution::ToolCallResult;
 use crate::agents::extension::Envs;
 use crate::config::{Config, ExtensionConfigManager};
 use crate::prompt_template;
 use mcp_client::client::{ClientCapabilities, ClientInfo, McpClient, McpClientTrait};
 use mcp_client::transport::{SseTransport, StdioTransport, Transport};
-use mcp_core::{prompt::Prompt, Content, Tool, ToolCall, ToolError, ToolResult};
+use mcp_core::{prompt::Prompt, Content, Tool, ToolCall, ToolError};
 use serde_json::Value;
 
 // By default, we set it to Jan 1, 2020 if the resource does not have a timestamp
@@ -113,7 +114,8 @@ impl ExtensionManager {
     /// Add a new MCP extension based on the provided client type
     // TODO IMPORTANT need to ensure this times out if the extension command is broken!
     pub async fn add_extension(&mut self, config: ExtensionConfig) -> ExtensionResult<()> {
-        let sanitized_name = normalize(config.key().to_string());
+        let config_name = config.key().to_string();
+        let sanitized_name = normalize(config_name.clone());
 
         /// Helper function to merge environment variables from direct envs and keychain-stored env_keys
         async fn merge_environments(
@@ -183,13 +185,15 @@ impl ExtensionManager {
                 let all_envs = merge_environments(envs, env_keys, &sanitized_name).await?;
                 let transport = SseTransport::new(uri, all_envs);
                 let handle = transport.start().await?;
-                let service = McpService::with_timeout(
-                    handle,
-                    Duration::from_secs(
-                        timeout.unwrap_or(crate::config::DEFAULT_EXTENSION_TIMEOUT),
-                    ),
-                );
-                Box::new(McpClient::new(service))
+                Box::new(
+                    McpClient::connect(
+                        handle,
+                        Duration::from_secs(
+                            timeout.unwrap_or(crate::config::DEFAULT_EXTENSION_TIMEOUT),
+                        ),
+                    )
+                    .await?,
+                )
             }
             ExtensionConfig::Stdio {
                 cmd,
@@ -202,13 +206,15 @@ impl ExtensionManager {
                 let all_envs = merge_environments(envs, env_keys, &sanitized_name).await?;
                 let transport = StdioTransport::new(cmd, args.to_vec(), all_envs);
                 let handle = transport.start().await?;
-                let service = McpService::with_timeout(
-                    handle,
-                    Duration::from_secs(
-                        timeout.unwrap_or(crate::config::DEFAULT_EXTENSION_TIMEOUT),
-                    ),
-                );
-                Box::new(McpClient::new(service))
+                Box::new(
+                    McpClient::connect(
+                        handle,
+                        Duration::from_secs(
+                            timeout.unwrap_or(crate::config::DEFAULT_EXTENSION_TIMEOUT),
+                        ),
+                    )
+                    .await?,
+                )
             }
             ExtensionConfig::Builtin {
                 name,
@@ -227,13 +233,15 @@ impl ExtensionManager {
                     HashMap::new(),
                 );
                 let handle = transport.start().await?;
-                let service = McpService::with_timeout(
-                    handle,
-                    Duration::from_secs(
-                        timeout.unwrap_or(crate::config::DEFAULT_EXTENSION_TIMEOUT),
-                    ),
-                );
-                Box::new(McpClient::new(service))
+                Box::new(
+                    McpClient::connect(
+                        handle,
+                        Duration::from_secs(
+                            timeout.unwrap_or(crate::config::DEFAULT_EXTENSION_TIMEOUT),
+                        ),
+                    )
+                    .await?,
+                )
             }
             _ => unreachable!(),
         };
@@ -609,7 +617,7 @@ impl ExtensionManager {
         }
     }
 
-    pub async fn dispatch_tool_call(&self, tool_call: ToolCall) -> ToolResult<Vec<Content>> {
+    pub async fn dispatch_tool_call(&self, tool_call: ToolCall) -> Result<ToolCallResult> {
         // Dispatch tool call based on the prefix naming convention
         let (client_name, client) = self
             .get_client_for_tool(&tool_call.name)
@@ -620,22 +628,26 @@ impl ExtensionManager {
             .name
             .strip_prefix(client_name)
             .and_then(|s| s.strip_prefix("__"))
-            .ok_or_else(|| ToolError::NotFound(tool_call.name.clone()))?;
+            .ok_or_else(|| ToolError::NotFound(tool_call.name.clone()))?
+            .to_string();
 
-        let client_guard = client.lock().await;
+        let arguments = tool_call.arguments.clone();
+        let client = client.clone();
+        let notifications_receiver = client.lock().await.subscribe().await;
 
-        let result = client_guard
-            .call_tool(tool_name, tool_call.clone().arguments)
-            .await
-            .map(|result| result.content)
-            .map_err(|e| ToolError::ExecutionError(e.to_string()));
+        let fut = async move {
+            let client_guard = client.lock().await;
+            client_guard
+                .call_tool(&tool_name, arguments)
+                .await
+                .map(|call| call.content)
+                .map_err(|e| ToolError::ExecutionError(e.to_string()))
+        };
 
-        debug!(
-            "input" = serde_json::to_string(&tool_call).unwrap(),
-            "output" = serde_json::to_string(&result).unwrap(),
-        );
-
-        result
+        Ok(ToolCallResult {
+            result: Box::new(fut.boxed()),
+            notification_stream: Some(Box::new(ReceiverStream::new(notifications_receiver))),
+        })
     }
 
     pub async fn list_prompts_from_extension(
@@ -793,10 +805,11 @@ mod tests {
     use mcp_client::client::Error;
     use mcp_client::client::McpClientTrait;
     use mcp_core::protocol::{
-        CallToolResult, GetPromptResult, InitializeResult, ListPromptsResult, ListResourcesResult,
-        ListToolsResult, ReadResourceResult,
+        CallToolResult, GetPromptResult, InitializeResult, JsonRpcMessage, ListPromptsResult,
+        ListResourcesResult, ListToolsResult, ReadResourceResult,
     };
     use serde_json::json;
+    use tokio::sync::mpsc;
 
     struct MockClient {}
 
@@ -849,6 +862,10 @@ mod tests {
         ) -> Result<GetPromptResult, Error> {
             Err(Error::NotInitialized)
         }
+
+        async fn subscribe(&self) -> mpsc::Receiver<JsonRpcMessage> {
+            mpsc::channel(1).1
+        }
     }
 
     #[test]
@@ -970,6 +987,9 @@ mod tests {
 
         let result = extension_manager
             .dispatch_tool_call(invalid_tool_call)
+            .await
+            .unwrap()
+            .result
             .await;
         assert!(matches!(
             result.err().unwrap(),
@@ -986,6 +1006,11 @@ mod tests {
         let result = extension_manager
             .dispatch_tool_call(invalid_tool_call)
             .await;
-        assert!(matches!(result.err().unwrap(), ToolError::NotFound(_)));
+        if let Err(err) = result {
+            let tool_err = err.downcast_ref::<ToolError>().expect("Expected ToolError");
+            assert!(matches!(tool_err, ToolError::NotFound(_)));
+        } else {
+            panic!("Expected ToolError::NotFound");
+        }
     }
 }

crates/goose/src/agents/mod.rs

@@ -13,7 +13,7 @@ mod tool_router_index_manager;
 pub(crate) mod tool_vectordb;
 mod types;
 
-pub use agent::Agent;
+pub use agent::{Agent, AgentEvent};
 pub use extension::ExtensionConfig;
 pub use extension_manager::ExtensionManager;
 pub use prompt_manager::PromptManager;

crates/goose/src/agents/tool_execution.rs

@@ -1,23 +1,35 @@
 use std::future::Future;
-use std::pin::Pin;
 use std::sync::Arc;
 
 use async_stream::try_stream;
-use futures::stream::BoxStream;
-use futures::StreamExt;
+use futures::stream::{self, BoxStream};
+use futures::{Stream, StreamExt};
+use mcp_core::protocol::JsonRpcMessage;
 use tokio::sync::Mutex;
 
 use crate::config::permission::PermissionLevel;
 use crate::config::PermissionManager;
 use crate::message::{Message, ToolRequest};
 use crate::permission::Permission;
-use mcp_core::{Content, ToolError};
+use mcp_core::{Content, ToolResult};
 
-// Type alias for ToolFutures - used in the agent loop to join all futures together
-pub(crate) type ToolFuture<'a> =
-    Pin<Box<dyn Future<Output = (String, Result<Vec<Content>, ToolError>)> + Send + 'a>>;
-pub(crate) type ToolFuturesVec<'a> = Arc<Mutex<Vec<ToolFuture<'a>>>>;
+// ToolCallResult combines the result of a tool call with an optional notification stream that
+// can be used to receive notifications from the tool.
+pub struct ToolCallResult {
+    pub result: Box<dyn Future<Output = ToolResult<Vec<Content>>> + Send + Unpin>,
+    pub notification_stream: Option<Box<dyn Stream<Item = JsonRpcMessage> + Send + Unpin>>,
+}
 
+impl From<ToolResult<Vec<Content>>> for ToolCallResult {
+    fn from(result: ToolResult<Vec<Content>>) -> Self {
+        Self {
+            result: Box::new(futures::future::ready(result)),
+            notification_stream: None,
+        }
+    }
+}
+
+use super::agent::{tool_stream, ToolStream};
 use crate::agents::Agent;
 
 pub const DECLINED_RESPONSE: &str = "The user has declined to run this tool. \
@@ -37,7 +49,7 @@ impl Agent {
     pub(crate) fn handle_approval_tool_requests<'a>(
         &'a self,
         tool_requests: &'a [ToolRequest],
-        tool_futures: ToolFuturesVec<'a>,
+        tool_futures: Arc<Mutex<Vec<(String, ToolStream)>>>,
         permission_manager: &'a mut PermissionManager,
         message_tool_response: Arc<Mutex<Message>>,
     ) -> BoxStream<'a, anyhow::Result<Message>> {
@@ -56,9 +68,19 @@ impl Agent {
                     while let Some((req_id, confirmation)) = rx.recv().await {
                         if req_id == request.id {
                             if confirmation.permission == Permission::AllowOnce || confirmation.permission == Permission::AlwaysAllow {
-                                let tool_future = self.dispatch_tool_call(tool_call.clone(), request.id.clone());
+                                let (req_id, tool_result) = self.dispatch_tool_call(tool_call.clone(), request.id.clone()).await;
                                 let mut futures = tool_futures.lock().await;
-                                futures.push(Box::pin(tool_future));
+
+                                futures.push((req_id, match tool_result {
+                                    Ok(result) => tool_stream(
+                                        result.notification_stream.unwrap_or_else(|| Box::new(stream::empty())),
+                                        result.result,
+                                    ),
+                                    Err(e) => tool_stream(
+                                        Box::new(stream::empty()),
+                                        futures::future::ready(Err(e)),
+                                    ),
+                                }));
 
                                 if confirmation.permission == Permission::AlwaysAllow {
                                     permission_manager.update_user_permission(&tool_call.name, PermissionLevel::AlwaysAllow);

crates/goose/src/scheduler.rs

@@ -11,6 +11,7 @@ use serde::{Deserialize, Serialize};
 use tokio::sync::Mutex;
 use tokio_cron_scheduler::{job::JobId, Job, JobScheduler as TokioJobScheduler};
 
+use crate::agents::AgentEvent;
 use crate::agents::{Agent, SessionConfig};
 use crate::config::{self, Config};
 use crate::message::Message;
@@ -1102,12 +1103,15 @@ async fn run_scheduled_job_internal(
                     tokio::task::yield_now().await;
 
                     match message_result {
-                        Ok(msg) => {
+                        Ok(AgentEvent::Message(msg)) => {
                             if msg.role == mcp_core::role::Role::Assistant {
                                 tracing::info!("[Job {}] Assistant: {:?}", job.id, msg.content);
                             }
                             all_session_messages.push(msg);
                         }
+                        Ok(AgentEvent::McpNotification(_)) => {
+                            // Handle notifications if needed
+                        }
                         Err(e) => {
                             tracing::error!(
                                 "[Job {}] Error receiving message from agent: {}",

crates/goose/tests/agent.rs

@@ -4,7 +4,7 @@ use std::sync::Arc;
 
 use anyhow::Result;
 use futures::StreamExt;
-use goose::agents::Agent;
+use goose::agents::{Agent, AgentEvent};
 use goose::message::Message;
 use goose::model::ModelConfig;
 use goose::providers::base::Provider;
@@ -132,7 +132,10 @@ async fn run_truncate_test(
     let mut responses = Vec::new();
     while let Some(response_result) = reply_stream.next().await {
         match response_result {
-            Ok(response) => responses.push(response),
+            Ok(AgentEvent::Message(response)) => responses.push(response),
+            Ok(AgentEvent::McpNotification(n)) => {
+                println!("MCP Notification: {n:?}");
+            }
             Err(e) => {
                 println!("Error: {:?}", e);
                 return Err(e);

crates/mcp-client/examples/clients.rs

@@ -1,7 +1,6 @@
 use mcp_client::{
     client::{ClientCapabilities, ClientInfo, McpClient, McpClientTrait},
     transport::{SseTransport, StdioTransport, Transport},
-    McpService,
 };
 use rand::Rng;
 use rand::SeedableRng;
@@ -20,18 +19,15 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
 
     let transport1 = StdioTransport::new("uvx", vec!["mcp-server-git".to_string()], HashMap::new());
     let handle1 = transport1.start().await?;
-    let service1 = McpService::with_timeout(handle1, Duration::from_secs(30));
-    let client1 = McpClient::new(service1);
+    let client1 = McpClient::connect(handle1, Duration::from_secs(30)).await?;
 
     let transport2 = StdioTransport::new("uvx", vec!["mcp-server-git".to_string()], HashMap::new());
     let handle2 = transport2.start().await?;
-    let service2 = McpService::with_timeout(handle2, Duration::from_secs(30));
-    let client2 = McpClient::new(service2);
+    let client2 = McpClient::connect(handle2, Duration::from_secs(30)).await?;
 
     let transport3 = SseTransport::new("http://localhost:8000/sse", HashMap::new());
     let handle3 = transport3.start().await?;
-    let service3 = McpService::with_timeout(handle3, Duration::from_secs(10));
-    let client3 = McpClient::new(service3);
+    let client3 = McpClient::connect(handle3, Duration::from_secs(10)).await?;
 
     // Initialize both clients
     let mut clients: Vec<Box<dyn McpClientTrait>> =

crates/mcp-client/examples/integration_test.rs

@@ -0,0 +1,122 @@
+use anyhow::Result;
+use futures::lock::Mutex;
+use mcp_client::client::{ClientCapabilities, ClientInfo, McpClient, McpClientTrait};
+use mcp_client::transport::{SseTransport, Transport};
+use mcp_client::StdioTransport;
+use std::collections::HashMap;
+use std::sync::Arc;
+use std::time::Duration;
+use tracing_subscriber::EnvFilter;
+
+#[tokio::main]
+async fn main() -> Result<()> {
+    // Initialize logging
+    tracing_subscriber::fmt()
+        .with_env_filter(
+            EnvFilter::from_default_env()
+                .add_directive("mcp_client=debug".parse().unwrap())
+                .add_directive("eventsource_client=info".parse().unwrap()),
+        )
+        .init();
+
+    test_transport(sse_transport().await?).await?;
+    test_transport(stdio_transport().await?).await?;
+
+    Ok(())
+}
+
+async fn sse_transport() -> Result<SseTransport> {
+    let port = "60053";
+
+    tokio::process::Command::new("npx")
+        .env("PORT", port)
+        .arg("@modelcontextprotocol/server-everything")
+        .arg("sse")
+        .spawn()?;
+    tokio::time::sleep(Duration::from_secs(1)).await;
+
+    Ok(SseTransport::new(
+        format!("http://localhost:{}/sse", port),
+        HashMap::new(),
+    ))
+}
+
+async fn stdio_transport() -> Result<StdioTransport> {
+    Ok(StdioTransport::new(
+        "npx",
+        vec!["@modelcontextprotocol/server-everything"]
+            .into_iter()
+            .map(|s| s.to_string())
+            .collect(),
+        HashMap::new(),
+    ))
+}
+
+async fn test_transport<T>(transport: T) -> Result<()>
+where
+    T: Transport + Send + 'static,
+{
+    // Start transport
+    let handle = transport.start().await?;
+
+    // Create client
+    let mut client = McpClient::connect(handle, Duration::from_secs(10)).await?;
+    println!("Client created\n");
+
+    let mut receiver = client.subscribe().await;
+    let events = Arc::new(Mutex::new(Vec::new()));
+    let events_clone = events.clone();
+    tokio::spawn(async move {
+        while let Some(event) = receiver.recv().await {
+            println!("Received event: {event:?}");
+            events_clone.lock().await.push(event);
+        }
+    });
+
+    // Initialize
+    let server_info = client
+        .initialize(
+            ClientInfo {
+                name: "test-client".into(),
+                version: "1.0.0".into(),
+            },
+            ClientCapabilities::default(),
+        )
+        .await?;
+    println!("Connected to server: {server_info:?}\n");
+
+    // Sleep for 100ms to allow the server to start - surprisingly this is required!
+    tokio::time::sleep(Duration::from_millis(500)).await;
+
+    // List tools
+    let tools = client.list_tools(None).await?;
+    println!("Available tools: {tools:#?}\n");
+
+    // Call tool
+    let tool_result = client
+        .call_tool("echo", serde_json::json!({ "message": "honk" }))
+        .await?;
+    println!("Tool result: {tool_result:#?}\n");
+
+    let collected_eventes_before = events.lock().await.len();
+    let n_steps = 5;
+    let long_op = client
+        .call_tool(
+            "longRunningOperation",
+            serde_json::json!({ "duration": 3, "steps": n_steps }),
+        )
+        .await?;
+    println!("Long op result: {long_op:#?}\n");
+    let collected_events_after = events.lock().await.len();
+    assert_eq!(collected_events_after - collected_eventes_before, n_steps);
+
+    // List resources
+    let resources = client.list_resources(None).await?;
+    println!("Resources: {resources:#?}\n");
+
+    // Read resource
+    let resource = client.read_resource("test://static/resource/1").await?;
+    println!("Resource: {resource:#?}\n");
+
+    Ok(())
+}

crates/mcp-client/examples/sse.rs

@@ -1,7 +1,6 @@
 use anyhow::Result;
 use mcp_client::client::{ClientCapabilities, ClientInfo, McpClient, McpClientTrait};
 use mcp_client::transport::{SseTransport, Transport};
-use mcp_client::McpService;
 use std::collections::HashMap;
 use std::time::Duration;
 use tracing_subscriber::EnvFilter;
@@ -23,11 +22,8 @@ async fn main() -> Result<()> {
     // Start transport
     let handle = transport.start().await?;
 
-    // Create the service with timeout middleware
-    let service = McpService::with_timeout(handle, Duration::from_secs(3));
-
     // Create client
-    let mut client = McpClient::new(service);
+    let mut client = McpClient::connect(handle, Duration::from_secs(3)).await?;
     println!("Client created\n");
 
     // Initialize

crates/mcp-client/examples/stdio.rs

@@ -2,7 +2,7 @@ use std::collections::HashMap;
 
 use anyhow::Result;
 use mcp_client::{
-    ClientCapabilities, ClientInfo, Error as ClientError, McpClient, McpClientTrait, McpService,
+    ClientCapabilities, ClientInfo, Error as ClientError, McpClient, McpClientTrait,
     StdioTransport, Transport,
 };
 use std::time::Duration;
@@ -25,11 +25,8 @@ async fn main() -> Result<(), ClientError> {
     // 2) Start the transport to get a handle
     let transport_handle = transport.start().await?;
 
-    // 3) Create the service with timeout middleware
-    let service = McpService::with_timeout(transport_handle, Duration::from_secs(10));
-
-    // 4) Create the client with the middleware-wrapped service
-    let mut client = McpClient::new(service);
+    // 3) Create the client with the middleware-wrapped service
+    let mut client = McpClient::connect(transport_handle, Duration::from_secs(10)).await?;
 
     // Initialize
     let server_info = client

crates/mcp-client/examples/stdio_integration.rs

@@ -5,7 +5,6 @@ use mcp_client::client::{
     ClientCapabilities, ClientInfo, Error as ClientError, McpClient, McpClientTrait,
 };
 use mcp_client::transport::{StdioTransport, Transport};
-use mcp_client::McpService;
 use std::collections::HashMap;
 use std::time::Duration;
 use tracing_subscriber::EnvFilter;
@@ -34,11 +33,8 @@ async fn main() -> Result<(), ClientError> {
     // Start the transport to get a handle
     let transport_handle = transport.start().await.unwrap();
 
-    // Create the service with timeout middleware
-    let service = McpService::with_timeout(transport_handle, Duration::from_secs(10));
-
     // Create client
-    let mut client = McpClient::new(service);
+    let mut client = McpClient::connect(transport_handle, Duration::from_secs(10)).await?;
 
     // Initialize
     let server_info = client

crates/mcp-client/src/client.rs

@@ -4,11 +4,16 @@ use mcp_core::protocol::{
     ListResourcesResult, ListToolsResult, ReadResourceResult, ServerCapabilities, METHOD_NOT_FOUND,
 };
 use serde::{Deserialize, Serialize};
-use serde_json::Value;
-use std::sync::atomic::{AtomicU64, Ordering};
+use serde_json::{json, Value};
+use std::sync::{
+    atomic::{AtomicU64, Ordering},
+    Arc,
+};
 use thiserror::Error;
-use tokio::sync::Mutex;
-use tower::{Service, ServiceExt}; // for Service::ready()
+use tokio::sync::{mpsc, Mutex};
+use tower::{timeout::TimeoutLayer, Layer, Service, ServiceExt};
+
+use crate::{McpService, TransportHandle};
 
 pub type BoxError = Box<dyn std::error::Error + Sync + Send>;
 
@@ -97,34 +102,67 @@ pub trait McpClientTrait: Send + Sync {
     async fn list_prompts(&self, next_cursor: Option<String>) -> Result<ListPromptsResult, Error>;
 
     async fn get_prompt(&self, name: &str, arguments: Value) -> Result<GetPromptResult, Error>;
+
+    async fn subscribe(&self) -> mpsc::Receiver<JsonRpcMessage>;
 }
 
 /// The MCP client is the interface for MCP operations.
-pub struct McpClient<S>
+pub struct McpClient<T>
 where
-    S: Service<JsonRpcMessage, Response = JsonRpcMessage> + Clone + Send + Sync + 'static,
-    S::Error: Into<Error>,
-    S::Future: Send,
+    T: TransportHandle + Send + Sync + 'static,
 {
-    service: Mutex<S>,
+    service: Mutex<tower::timeout::Timeout<McpService<T>>>,
     next_id: AtomicU64,
     server_capabilities: Option<ServerCapabilities>,
     server_info: Option<Implementation>,
+    notification_subscribers: Arc<Mutex<Vec<mpsc::Sender<JsonRpcMessage>>>>,
 }
 
-impl<S> McpClient<S>
+impl<T> McpClient<T>
 where
-    S: Service<JsonRpcMessage, Response = JsonRpcMessage> + Clone + Send + Sync + 'static,
-    S::Error: Into<Error>,
-    S::Future: Send,
+    T: TransportHandle + Send + Sync + 'static,
 {
-    pub fn new(service: S) -> Self {
-        Self {
-            service: Mutex::new(service),
+    pub async fn connect(transport: T, timeout: std::time::Duration) -> Result<Self, Error> {
+        let service = McpService::new(transport.clone());
+        let service_ptr = service.clone();
+        let notification_subscribers =
+            Arc::new(Mutex::new(Vec::<mpsc::Sender<JsonRpcMessage>>::new()));
+        let subscribers_ptr = notification_subscribers.clone();
+
+        tokio::spawn(async move {
+            loop {
+                match transport.receive().await {
+                    Ok(message) => {
+                        tracing::info!("Received message: {:?}", message);
+                        match message {
+                            JsonRpcMessage::Response(JsonRpcResponse { id: Some(id), .. }) => {
+                                service_ptr.respond(&id.to_string(), Ok(message)).await;
+                            }
+                            _ => {
+                                let mut subs = subscribers_ptr.lock().await;
+                                subs.retain(|sub| sub.try_send(message.clone()).is_ok());
+                            }
+                        }
+                    }
+                    Err(e) => {
+                        tracing::error!("transport error: {:?}", e);
+                        service_ptr.hangup().await;
+                        subscribers_ptr.lock().await.clear();
+                        break;
+                    }
+                }
+            }
+        });
+
+        let middleware = TimeoutLayer::new(timeout);
+
+        Ok(Self {
+            service: Mutex::new(middleware.layer(service)),
             next_id: AtomicU64::new(1),
             server_capabilities: None,
             server_info: None,
-        }
+            notification_subscribers,
+        })
     }
 
     /// Send a JSON-RPC request and check we don't get an error response.
@@ -134,13 +172,18 @@ where
     {
         let mut service = self.service.lock().await;
         service.ready().await.map_err(|_| Error::NotReady)?;
-
         let id = self.next_id.fetch_add(1, Ordering::SeqCst);
+
+        let mut params = params.clone();
+        params["_meta"] = json!({
+            "progressToken": format!("prog-{}", id),
+        });
+
         let request = JsonRpcMessage::Request(JsonRpcRequest {
             jsonrpc: "2.0".to_string(),
             id: Some(id),
             method: method.to_string(),
-            params: Some(params.clone()),
+            params: Some(params),
         });
 
         let response_msg = service
@@ -154,7 +197,7 @@ where
                     .unwrap_or("".to_string()),
                 method: method.to_string(),
                 // we don't need include params because it can be really large
-                source: Box::new(e.into()),
+                source: Box::<Error>::new(e.into()),
             })?;
 
         match response_msg {
@@ -220,7 +263,7 @@ where
                     .unwrap_or("".to_string()),
                 method: method.to_string(),
                 // we don't need include params because it can be really large
-                source: Box::new(e.into()),
+                source: Box::<Error>::new(e.into()),
             })?;
 
         Ok(())
@@ -233,11 +276,9 @@ where
 }
 
 #[async_trait::async_trait]
-impl<S> McpClientTrait for McpClient<S>
+impl<T> McpClientTrait for McpClient<T>
 where
-    S: Service<JsonRpcMessage, Response = JsonRpcMessage> + Clone + Send + Sync + 'static,
-    S::Error: Into<Error>,
-    S::Future: Send,
+    T: TransportHandle + Send + Sync + 'static,
 {
     async fn initialize(
         &mut self,
@@ -388,4 +429,10 @@ where
 
         self.send_request("prompts/get", params).await
     }
+
+    async fn subscribe(&self) -> mpsc::Receiver<JsonRpcMessage> {
+        let (tx, rx) = mpsc::channel(16);
+        self.notification_subscribers.lock().await.push(tx);
+        rx
+    }
 }

crates/mcp-client/src/service.rs

@@ -1,7 +1,9 @@
 use futures::future::BoxFuture;
-use mcp_core::protocol::JsonRpcMessage;
+use mcp_core::protocol::{JsonRpcMessage, JsonRpcRequest};
+use std::collections::HashMap;
 use std::sync::Arc;
 use std::task::{Context, Poll};
+use tokio::sync::{oneshot, RwLock};
 use tower::{timeout::Timeout, Service, ServiceBuilder};
 
 use crate::transport::{Error, TransportHandle};
@@ -10,14 +12,24 @@ use crate::transport::{Error, TransportHandle};
 #[derive(Clone)]
 pub struct McpService<T: TransportHandle> {
     inner: Arc<T>,
+    pending_requests: Arc<PendingRequests>,
 }
 
 impl<T: TransportHandle> McpService<T> {
     pub fn new(transport: T) -> Self {
         Self {
             inner: Arc::new(transport),
+            pending_requests: Arc::new(PendingRequests::default()),
         }
     }
+
+    pub async fn respond(&self, id: &str, response: Result<JsonRpcMessage, Error>) {
+        self.pending_requests.respond(id, response).await
+    }
+
+    pub async fn hangup(&self) {
+        self.pending_requests.broadcast_close().await
+    }
 }
 
 impl<T> Service<JsonRpcMessage> for McpService<T>
@@ -35,7 +47,31 @@ where
 
     fn call(&mut self, request: JsonRpcMessage) -> Self::Future {
         let transport = self.inner.clone();
-        Box::pin(async move { transport.send(request).await })
+        let pending_requests = self.pending_requests.clone();
+
+        Box::pin(async move {
+            match request {
+                JsonRpcMessage::Request(JsonRpcRequest { id: Some(id), .. }) => {
+                    // Create a channel to receive the response
+                    let (sender, receiver) = oneshot::channel();
+                    pending_requests.insert(id.to_string(), sender).await;
+
+                    transport.send(request).await?;
+                    receiver.await.map_err(|_| Error::ChannelClosed)?
+                }
+                JsonRpcMessage::Request(_) => {
+                    // Handle notifications without waiting for a response
+                    transport.send(request).await?;
+                    Ok(JsonRpcMessage::Nil)
+                }
+                JsonRpcMessage::Notification(_) => {
+                    // Handle notifications without waiting for a response
+                    transport.send(request).await?;
+                    Ok(JsonRpcMessage::Nil)
+                }
+                _ => Err(Error::UnsupportedMessage),
+            }
+        })
     }
 }
 
@@ -50,3 +86,50 @@ where
             .service(McpService::new(transport))
     }
 }
+
+// A data structure to store pending requests and their response channels
+pub struct PendingRequests {
+    requests: RwLock<HashMap<String, oneshot::Sender<Result<JsonRpcMessage, Error>>>>,
+}
+
+impl Default for PendingRequests {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl PendingRequests {
+    pub fn new() -> Self {
+        Self {
+            requests: RwLock::new(HashMap::new()),
+        }
+    }
+
+    pub async fn insert(&self, id: String, sender: oneshot::Sender<Result<JsonRpcMessage, Error>>) {
+        self.requests.write().await.insert(id, sender);
+    }
+
+    pub async fn respond(&self, id: &str, response: Result<JsonRpcMessage, Error>) {
+        if let Some(tx) = self.requests.write().await.remove(id) {
+            let _ = tx.send(response);
+        }
+    }
+
+    pub async fn broadcast_close(&self) {
+        for (_, tx) in self.requests.write().await.drain() {
+            let _ = tx.send(Err(Error::ChannelClosed));
+        }
+    }
+
+    pub async fn clear(&self) {
+        self.requests.write().await.clear();
+    }
+
+    pub async fn len(&self) -> usize {
+        self.requests.read().await.len()
+    }
+
+    pub async fn is_empty(&self) -> bool {
+        self.len().await == 0
+    }
+}

crates/mcp-client/src/transport/mod.rs

@@ -1,8 +1,7 @@
 use async_trait::async_trait;
 use mcp_core::protocol::JsonRpcMessage;
-use std::collections::HashMap;
 use thiserror::Error;
-use tokio::sync::{mpsc, oneshot, RwLock};
+use tokio::sync::{mpsc, oneshot};
 
 pub type BoxError = Box<dyn std::error::Error + Sync + Send>;
 /// A generic error type for transport operations.
@@ -57,74 +56,20 @@ pub trait Transport {
 
 #[async_trait]
 pub trait TransportHandle: Send + Sync + Clone + 'static {
-    async fn send(&self, message: JsonRpcMessage) -> Result<JsonRpcMessage, Error>;
+    async fn send(&self, message: JsonRpcMessage) -> Result<(), Error>;
+    async fn receive(&self) -> Result<JsonRpcMessage, Error>;
 }
 
-// Helper function that contains the common send implementation
-pub async fn send_message(
-    sender: &mpsc::Sender<TransportMessage>,
+pub async fn serialize_and_send(
+    sender: &mpsc::Sender<String>,
     message: JsonRpcMessage,
-) -> Result<JsonRpcMessage, Error> {
-    match message {
-        JsonRpcMessage::Request(request) => {
-            let (respond_to, response) = oneshot::channel();
-            let msg = TransportMessage {
-                message: JsonRpcMessage::Request(request),
-                response_tx: Some(respond_to),
-            };
-            sender.send(msg).await.map_err(|_| Error::ChannelClosed)?;
-            Ok(response.await.map_err(|_| Error::ChannelClosed)??)
+) -> Result<(), Error> {
+    match serde_json::to_string(&message).map_err(Error::Serialization) {
+        Ok(msg) => sender.send(msg).await.map_err(|_| Error::ChannelClosed),
+        Err(e) => {
+            tracing::error!(error = ?e, "Error serializing message");
+            Err(e)
         }
-        JsonRpcMessage::Notification(notification) => {
-            let msg = TransportMessage {
-                message: JsonRpcMessage::Notification(notification),
-                response_tx: None,
-            };
-            sender.send(msg).await.map_err(|_| Error::ChannelClosed)?;
-            Ok(JsonRpcMessage::Nil)
-        }
-        _ => Err(Error::UnsupportedMessage),
-    }
-}
-
-// A data structure to store pending requests and their response channels
-pub struct PendingRequests {
-    requests: RwLock<HashMap<String, oneshot::Sender<Result<JsonRpcMessage, Error>>>>,
-}
-
-impl Default for PendingRequests {
-    fn default() -> Self {
-        Self::new()
-    }
-}
-
-impl PendingRequests {
-    pub fn new() -> Self {
-        Self {
-            requests: RwLock::new(HashMap::new()),
-        }
-    }
-
-    pub async fn insert(&self, id: String, sender: oneshot::Sender<Result<JsonRpcMessage, Error>>) {
-        self.requests.write().await.insert(id, sender);
-    }
-
-    pub async fn respond(&self, id: &str, response: Result<JsonRpcMessage, Error>) {
-        if let Some(tx) = self.requests.write().await.remove(id) {
-            let _ = tx.send(response);
-        }
-    }
-
-    pub async fn clear(&self) {
-        self.requests.write().await.clear();
-    }
-
-    pub async fn len(&self) -> usize {
-        self.requests.read().await.len()
-    }
-
-    pub async fn is_empty(&self) -> bool {
-        self.len().await == 0
     }
 }
 

crates/mcp-client/src/transport/sse.rs

@@ -1,17 +1,17 @@
-use crate::transport::{Error, PendingRequests, TransportMessage};
+use crate::transport::Error;
 use async_trait::async_trait;
 use eventsource_client::{Client, SSE};
 use futures::TryStreamExt;
-use mcp_core::protocol::{JsonRpcMessage, JsonRpcRequest};
+use mcp_core::protocol::JsonRpcMessage;
 use reqwest::Client as HttpClient;
 use std::collections::HashMap;
 use std::sync::Arc;
-use tokio::sync::{mpsc, RwLock};
+use tokio::sync::{mpsc, Mutex, RwLock};
 use tokio::time::{timeout, Duration};
 use tracing::warn;
 use url::Url;
 
-use super::{send_message, Transport, TransportHandle};
+use super::{serialize_and_send, Transport, TransportHandle};
 
 // Timeout for the endpoint discovery
 const ENDPOINT_TIMEOUT_SECS: u64 = 5;
@@ -21,9 +21,9 @@ const ENDPOINT_TIMEOUT_SECS: u64 = 5;
 /// - Sends outgoing messages via HTTP POST (once the post endpoint is known).
 pub struct SseActor {
     /// Receives messages (requests/notifications) from the handle
-    receiver: mpsc::Receiver<TransportMessage>,
-    /// Map of request-id -> oneshot sender
-    pending_requests: Arc<PendingRequests>,
+    receiver: mpsc::Receiver<String>,
+    /// Sends messages (responses) back to the handle
+    sender: mpsc::Sender<JsonRpcMessage>,
     /// Base SSE URL
     sse_url: String,
     /// For sending HTTP POST requests
@@ -34,14 +34,14 @@ pub struct SseActor {
 
 impl SseActor {
     pub fn new(
-        receiver: mpsc::Receiver<TransportMessage>,
-        pending_requests: Arc<PendingRequests>,
+        receiver: mpsc::Receiver<String>,
+        sender: mpsc::Sender<JsonRpcMessage>,
         sse_url: String,
         post_endpoint: Arc<RwLock<Option<String>>>,
     ) -> Self {
         Self {
             receiver,
-            pending_requests,
+            sender,
             sse_url,
             post_endpoint,
             http_client: HttpClient::new(),
@@ -54,15 +54,14 @@ impl SseActor {
     pub async fn run(self) {
         tokio::join!(
             Self::handle_incoming_messages(
+                self.sender,
                 self.sse_url.clone(),
-                Arc::clone(&self.pending_requests),
                 Arc::clone(&self.post_endpoint)
             ),
             Self::handle_outgoing_messages(
                 self.receiver,
                 self.http_client.clone(),
                 Arc::clone(&self.post_endpoint),
-                Arc::clone(&self.pending_requests),
             )
         );
     }
@@ -72,14 +71,13 @@ impl SseActor {
     /// - If a `message` event is received, parse it as `JsonRpcMessage`
     ///   and respond to pending requests if it's a `Response`.
     async fn handle_incoming_messages(
+        sender: mpsc::Sender<JsonRpcMessage>,
         sse_url: String,
-        pending_requests: Arc<PendingRequests>,
         post_endpoint: Arc<RwLock<Option<String>>>,
     ) {
         let client = match eventsource_client::ClientBuilder::for_url(&sse_url) {
             Ok(builder) => builder.build(),
             Err(e) => {
-                pending_requests.clear().await;
                 warn!("Failed to connect SSE client: {}", e);
                 return;
             }
@@ -105,84 +103,54 @@ impl SseActor {
         }
 
         // Now handle subsequent events
-        while let Ok(Some(event)) = stream.try_next().await {
-            match event {
-                SSE::Event(e) if e.event_type == "message" => {
-                    // Attempt to parse the SSE data as a JsonRpcMessage
-                    match serde_json::from_str::<JsonRpcMessage>(&e.data) {
-                        Ok(message) => {
-                            match &message {
-                                JsonRpcMessage::Response(response) => {
-                                    if let Some(id) = &response.id {
-                                        pending_requests
-                                            .respond(&id.to_string(), Ok(message))
-                                            .await;
-                                    }
+        loop {
+            match stream.try_next().await {
+                Ok(Some(event)) => {
+                    match event {
+                        SSE::Event(e) if e.event_type == "message" => {
+                            // Attempt to parse the SSE data as a JsonRpcMessage
+                            match serde_json::from_str::<JsonRpcMessage>(&e.data) {
+                                Ok(message) => {
+                                    let _ = sender.send(message).await;
                                 }
-                                JsonRpcMessage::Error(error) => {
-                                    if let Some(id) = &error.id {
-                                        pending_requests
-                                            .respond(&id.to_string(), Ok(message))
-                                            .await;
-                                    }
+                                Err(err) => {
+                                    warn!("Failed to parse SSE message: {err}");
                                 }
-                                _ => {} // TODO: Handle other variants (Request, etc.)
                             }
                         }
-                        Err(err) => {
-                            warn!("Failed to parse SSE message: {err}");
-                        }
+                        _ => { /* ignore other events */ }
                     }
                 }
-                _ => { /* ignore other events */ }
+                Ok(None) => {
+                    // Stream ended
+                    tracing::info!("SSE stream ended.");
+                    break;
+                }
+                Err(e) => {
+                    warn!("Error reading SSE stream: {e}");
+                    break;
+                }
             }
         }
 
-        // SSE stream ended or errored; signal any pending requests
-        tracing::error!("SSE stream ended or encountered an error; clearing pending requests.");
-        pending_requests.clear().await;
+        tracing::error!("SSE stream ended or encountered an error.");
     }
 
-    /// Continuously receives messages from the `mpsc::Receiver`.
-    /// - If it's a request, store the oneshot in `pending_requests`.
-    /// - POST the message to the discovered endpoint (once known).
     async fn handle_outgoing_messages(
-        mut receiver: mpsc::Receiver<TransportMessage>,
+        mut receiver: mpsc::Receiver<String>,
         http_client: HttpClient,
         post_endpoint: Arc<RwLock<Option<String>>>,
-        pending_requests: Arc<PendingRequests>,
     ) {
-        while let Some(transport_msg) = receiver.recv().await {
+        while let Some(message_str) = receiver.recv().await {
             let post_url = match post_endpoint.read().await.as_ref() {
                 Some(url) => url.clone(),
                 None => {
-                    if let Some(response_tx) = transport_msg.response_tx {
-                        let _ = response_tx.send(Err(Error::NotConnected));
-                    }
+                    // TODO: the endpoint isn't discovered yet. This shouldn't happen -- we only return the handle
+                    // after the endpoint is set.
                     continue;
                 }
             };
 
-            // Serialize the JSON-RPC message
-            let message_str = match serde_json::to_string(&transport_msg.message) {
-                Ok(s) => s,
-                Err(e) => {
-                    if let Some(tx) = transport_msg.response_tx {
-                        let _ = tx.send(Err(Error::Serialization(e)));
-                    }
-                    continue;
-                }
-            };
-
-            // If it's a request, store the channel so we can respond later
-            if let Some(response_tx) = transport_msg.response_tx {
-                if let JsonRpcMessage::Request(JsonRpcRequest { id: Some(id), .. }) =
-                    &transport_msg.message
-                {
-                    pending_requests.insert(id.to_string(), response_tx).await;
-                }
-            }
-
             // Perform the HTTP POST
             match http_client
                 .post(&post_url)
@@ -209,26 +177,25 @@ impl SseActor {
             }
         }
 
-        // mpsc channel closed => no more outgoing messages
-        let pending = pending_requests.len().await;
-        if pending > 0 {
-            tracing::error!("SSE stream ended or encountered an error with {pending} unfulfilled pending requests.");
-            pending_requests.clear().await;
-        } else {
-            tracing::info!("SseActor shutdown cleanly. No pending requests.");
-        }
+        tracing::info!("SseActor shut down.");
     }
 }
 
 #[derive(Clone)]
 pub struct SseTransportHandle {
-    sender: mpsc::Sender<TransportMessage>,
+    sender: mpsc::Sender<String>,
+    receiver: Arc<Mutex<mpsc::Receiver<JsonRpcMessage>>>,
 }
 
 #[async_trait::async_trait]
 impl TransportHandle for SseTransportHandle {
-    async fn send(&self, message: JsonRpcMessage) -> Result<JsonRpcMessage, Error> {
-        send_message(&self.sender, message).await
+    async fn send(&self, message: JsonRpcMessage) -> Result<(), Error> {
+        serialize_and_send(&self.sender, message).await
+    }
+
+    async fn receive(&self) -> Result<JsonRpcMessage, Error> {
+        let mut receiver = self.receiver.lock().await;
+        receiver.recv().await.ok_or(Error::ChannelClosed)
     }
 }
 
@@ -279,17 +246,13 @@ impl Transport for SseTransport {
 
         // Create a channel for outgoing TransportMessages
         let (tx, rx) = mpsc::channel(32);
+        let (otx, orx) = mpsc::channel(32);
 
         let post_endpoint: Arc<RwLock<Option<String>>> = Arc::new(RwLock::new(None));
         let post_endpoint_clone = Arc::clone(&post_endpoint);
 
         // Build the actor
-        let actor = SseActor::new(
-            rx,
-            Arc::new(PendingRequests::new()),
-            self.sse_url.clone(),
-            post_endpoint,
-        );
+        let actor = SseActor::new(rx, otx, self.sse_url.clone(), post_endpoint);
 
         // Spawn the actor task
         tokio::spawn(actor.run());
@@ -301,7 +264,10 @@ impl Transport for SseTransport {
         )
         .await
         {
-            Ok(_) => Ok(SseTransportHandle { sender: tx }),
+            Ok(_) => Ok(SseTransportHandle {
+                sender: tx,
+                receiver: Arc::new(Mutex::new(orx)),
+            }),
             Err(e) => Err(Error::SseConnection(e.to_string())),
         }
     }

crates/mcp-client/src/transport/stdio.rs

@@ -14,7 +14,7 @@ use nix::sys::signal::{kill, Signal};
 #[cfg(unix)]
 use nix::unistd::{getpgid, Pid};
 
-use super::{send_message, Error, PendingRequests, Transport, TransportHandle, TransportMessage};
+use super::{serialize_and_send, Error, Transport, TransportHandle};
 
 // Global to track process groups we've created
 static PROCESS_GROUP: AtomicI32 = AtomicI32::new(-1);
@@ -23,8 +23,8 @@ static PROCESS_GROUP: AtomicI32 = AtomicI32::new(-1);
 ///
 /// It uses channels for message passing and handles responses asynchronously through a background task.
 pub struct StdioActor {
-    receiver: Option<mpsc::Receiver<TransportMessage>>,
-    pending_requests: Arc<PendingRequests>,
+    receiver: Option<mpsc::Receiver<String>>,
+    sender: Option<mpsc::Sender<JsonRpcMessage>>,
     process: Child, // we store the process to keep it alive
     error_sender: mpsc::Sender<Error>,
     stdin: Option<ChildStdin>,
@@ -55,11 +55,11 @@ impl StdioActor {
 
         let stdout = self.stdout.take().expect("stdout should be available");
         let stdin = self.stdin.take().expect("stdin should be available");
-        let receiver = self.receiver.take().expect("receiver should be available");
+        let msg_inbox = self.receiver.take().expect("receiver should be available");
+        let msg_outbox = self.sender.take().expect("sender should be available");
 
-        let incoming = Self::handle_incoming_messages(stdout, self.pending_requests.clone());
-        let outgoing =
-            Self::handle_outgoing_messages(receiver, stdin, self.pending_requests.clone());
+        let incoming = Self::handle_proc_output(stdout, msg_outbox);
+        let outgoing = Self::handle_proc_input(stdin, msg_inbox);
 
         // take ownership of futures for tokio::select
         pin!(incoming);
@@ -96,12 +96,9 @@ impl StdioActor {
                     .await;
             }
         }
-
-        // Clean up regardless of which path we took
-        self.pending_requests.clear().await;
     }
 
-    async fn handle_incoming_messages(stdout: ChildStdout, pending_requests: Arc<PendingRequests>) {
+    async fn handle_proc_output(stdout: ChildStdout, sender: mpsc::Sender<JsonRpcMessage>) {
         let mut reader = BufReader::new(stdout);
         let mut line = String::new();
         loop {
@@ -116,20 +113,12 @@ impl StdioActor {
                             message = ?message,
                             "Received incoming message"
                         );
-
-                        match &message {
-                            JsonRpcMessage::Response(response) => {
-                                if let Some(id) = &response.id {
-                                    pending_requests.respond(&id.to_string(), Ok(message)).await;
-                                }
-                            }
-                            JsonRpcMessage::Error(error) => {
-                                if let Some(id) = &error.id {
-                                    pending_requests.respond(&id.to_string(), Ok(message)).await;
-                                }
-                            }
-                            _ => {} // TODO: Handle other variants (Request, etc.)
-                        }
+                        let _ = sender.send(message).await;
+                    } else {
+                        tracing::warn!(
+                            message = ?line,
+                            "Failed to parse incoming message"
+                        );
                     }
                     line.clear();
                 }
@@ -141,44 +130,20 @@ impl StdioActor {
         }
     }
 
-    async fn handle_outgoing_messages(
-        mut receiver: mpsc::Receiver<TransportMessage>,
-        mut stdin: ChildStdin,
-        pending_requests: Arc<PendingRequests>,
-    ) {
-        while let Some(mut transport_msg) = receiver.recv().await {
-            let message_str = match serde_json::to_string(&transport_msg.message) {
-                Ok(s) => s,
-                Err(e) => {
-                    if let Some(tx) = transport_msg.response_tx.take() {
-                        let _ = tx.send(Err(Error::Serialization(e)));
-                    }
-                    continue;
-                }
-            };
-
-            tracing::debug!(message = ?transport_msg.message, "Sending outgoing message");
-
-            if let Some(response_tx) = transport_msg.response_tx.take() {
-                if let JsonRpcMessage::Request(request) = &transport_msg.message {
-                    if let Some(id) = &request.id {
-                        pending_requests.insert(id.to_string(), response_tx).await;
-                    }
-                }
-            }
+    async fn handle_proc_input(mut stdin: ChildStdin, mut receiver: mpsc::Receiver<String>) {
+        while let Some(message_str) = receiver.recv().await {
+            tracing::debug!(message = ?message_str, "Sending outgoing message");
 
             if let Err(e) = stdin
                 .write_all(format!("{}\n", message_str).as_bytes())
                 .await
             {
                 tracing::error!(error = ?e, "Error writing message to child process");
-                pending_requests.clear().await;
                 break;
             }
 
             if let Err(e) = stdin.flush().await {
                 tracing::error!(error = ?e, "Error flushing message to child process");
-                pending_requests.clear().await;
                 break;
             }
         }
@@ -187,18 +152,24 @@ impl StdioActor {
 
 #[derive(Clone)]
 pub struct StdioTransportHandle {
-    sender: mpsc::Sender<TransportMessage>,
+    sender: mpsc::Sender<String>,                         // to process
+    receiver: Arc<Mutex<mpsc::Receiver<JsonRpcMessage>>>, // from process
     error_receiver: Arc<Mutex<mpsc::Receiver<Error>>>,
 }
 
 #[async_trait::async_trait]
 impl TransportHandle for StdioTransportHandle {
-    async fn send(&self, message: JsonRpcMessage) -> Result<JsonRpcMessage, Error> {
-        let result = send_message(&self.sender, message).await;
+    async fn send(&self, message: JsonRpcMessage) -> Result<(), Error> {
+        let result = serialize_and_send(&self.sender, message).await;
         // Check for any pending errors even if send is successful
         self.check_for_errors().await?;
         result
     }
+
+    async fn receive(&self) -> Result<JsonRpcMessage, Error> {
+        let mut receiver = self.receiver.lock().await;
+        receiver.recv().await.ok_or(Error::ChannelClosed)
+    }
 }
 
 impl StdioTransportHandle {
@@ -289,12 +260,13 @@ impl Transport for StdioTransport {
 
     async fn start(&self) -> Result<Self::Handle, Error> {
         let (process, stdin, stdout, stderr) = self.spawn_process().await?;
-        let (message_tx, message_rx) = mpsc::channel(32);
+        let (outbox_tx, outbox_rx) = mpsc::channel(32);
+        let (inbox_tx, inbox_rx) = mpsc::channel(32);
         let (error_tx, error_rx) = mpsc::channel(1);
 
         let actor = StdioActor {
-            receiver: Some(message_rx),
-            pending_requests: Arc::new(PendingRequests::new()),
+            receiver: Some(outbox_rx), // client to process
+            sender: Some(inbox_tx),    // process to client
             process,
             error_sender: error_tx,
             stdin: Some(stdin),
@@ -305,7 +277,8 @@ impl Transport for StdioTransport {
         tokio::spawn(actor.run());
 
         let handle = StdioTransportHandle {
-            sender: message_tx,
+            sender: outbox_tx,                        // client to process
+            receiver: Arc::new(Mutex::new(inbox_rx)), // process to client
             error_receiver: Arc::new(Mutex::new(error_rx)),
         };
         Ok(handle)

crates/mcp-server/src/lib.rs

@@ -4,9 +4,13 @@ use std::{
 };
 
 use futures::{Future, Stream};
-use mcp_core::protocol::{JsonRpcError, JsonRpcMessage, JsonRpcRequest, JsonRpcResponse};
+use mcp_core::protocol::{JsonRpcError, JsonRpcMessage, JsonRpcResponse};
 use pin_project::pin_project;
-use tokio::io::{AsyncBufReadExt, AsyncRead, AsyncWrite, AsyncWriteExt, BufReader};
+use router::McpRequest;
+use tokio::{
+    io::{AsyncBufReadExt, AsyncRead, AsyncWrite, AsyncWriteExt, BufReader},
+    sync::mpsc,
+};
 use tower_service::Service;
 
 mod errors;
@@ -123,7 +127,7 @@ pub struct Server<S> {
 
 impl<S> Server<S>
 where
-    S: Service<JsonRpcRequest, Response = JsonRpcResponse> + Send,
+    S: Service<McpRequest, Response = JsonRpcResponse> + Send,
     S::Error: Into<BoxError>,
     S::Future: Send,
 {
@@ -134,8 +138,8 @@ where
     // TODO transport trait instead of byte transport if we implement others
     pub async fn run<R, W>(self, mut transport: ByteTransport<R, W>) -> Result<(), ServerError>
     where
-        R: AsyncRead + Unpin,
-        W: AsyncWrite + Unpin,
+        R: AsyncRead + Unpin + Send + 'static,
+        W: AsyncWrite + Unpin + Send + 'static,
     {
         use futures::StreamExt;
         let mut service = self.service;
@@ -160,7 +164,22 @@ where
                             );
 
                             // Process the request using our service
-                            let response = match service.call(request).await {
+                            let (notify_tx, mut notify_rx) = mpsc::channel(256);
+                            let mcp_request = McpRequest {
+                                request,
+                                notifier: notify_tx,
+                            };
+
+                            let transport_fut = tokio::spawn(async move {
+                                while let Some(notification) = notify_rx.recv().await {
+                                    if transport.write_message(notification).await.is_err() {
+                                        break;
+                                    }
+                                }
+                                transport
+                            });
+
+                            let response = match service.call(mcp_request).await {
                                 Ok(resp) => resp,
                                 Err(e) => {
                                     let error_msg = e.into().to_string();
@@ -178,6 +197,16 @@ where
                                 }
                             };
 
+                            transport = match transport_fut.await {
+                                Ok(transport) => transport,
+                                Err(e) => {
+                                    tracing::error!(error = %e, "Failed to spawn transport task");
+                                    return Err(ServerError::Transport(TransportError::Io(
+                                        e.into(),
+                                    )));
+                                }
+                            };
+
                             // Serialize response for logging
                             let response_json = serde_json::to_string(&response)
                                 .unwrap_or_else(|_| "Failed to serialize response".to_string());
@@ -247,7 +276,7 @@ where
 // Any router implements this
 pub trait BoundedService:
     Service<
-        JsonRpcRequest,
+        McpRequest,
         Response = JsonRpcResponse,
         Error = BoxError,
         Future = Pin<Box<dyn Future<Output = Result<JsonRpcResponse, BoxError>> + Send>>,
@@ -259,7 +288,7 @@ pub trait BoundedService:
 // Implement it for any type that meets the bounds
 impl<T> BoundedService for T where
     T: Service<
-            JsonRpcRequest,
+            McpRequest,
             Response = JsonRpcResponse,
             Error = BoxError,
             Future = Pin<Box<dyn Future<Output = Result<JsonRpcResponse, BoxError>> + Send>>,

crates/mcp-server/src/main.rs

@@ -2,12 +2,14 @@ use anyhow::Result;
 use mcp_core::content::Content;
 use mcp_core::handler::{PromptError, ResourceError};
 use mcp_core::prompt::{Prompt, PromptArgument};
+use mcp_core::protocol::JsonRpcMessage;
 use mcp_core::tool::ToolAnnotations;
 use mcp_core::{handler::ToolError, protocol::ServerCapabilities, resource::Resource, tool::Tool};
 use mcp_server::router::{CapabilitiesBuilder, RouterService};
 use mcp_server::{ByteTransport, Router, Server};
 use serde_json::Value;
 use std::{future::Future, pin::Pin, sync::Arc};
+use tokio::sync::mpsc;
 use tokio::{
     io::{stdin, stdout},
     sync::Mutex,
@@ -124,6 +126,7 @@ impl Router for CounterRouter {
         &self,
         tool_name: &str,
         _arguments: Value,
+        _notifier: mpsc::Sender<JsonRpcMessage>,
     ) -> Pin<Box<dyn Future<Output = Result<Vec<Content>, ToolError>> + Send + 'static>> {
         let this = self.clone();
         let tool_name = tool_name.to_string();

crates/mcp-server/src/router.rs

@@ -11,14 +11,15 @@ use mcp_core::{
     handler::{PromptError, ResourceError, ToolError},
     prompt::{Prompt, PromptMessage, PromptMessageRole},
     protocol::{
-        CallToolResult, GetPromptResult, Implementation, InitializeResult, JsonRpcRequest,
-        JsonRpcResponse, ListPromptsResult, ListResourcesResult, ListToolsResult,
+        CallToolResult, GetPromptResult, Implementation, InitializeResult, JsonRpcMessage,
+        JsonRpcRequest, JsonRpcResponse, ListPromptsResult, ListResourcesResult, ListToolsResult,
         PromptsCapability, ReadResourceResult, ResourcesCapability, ServerCapabilities,
         ToolsCapability,
     },
     ResourceContents,
 };
 use serde_json::Value;
+use tokio::sync::mpsc;
 use tower_service::Service;
 
 use crate::{BoxError, RouterError};
@@ -91,6 +92,7 @@ pub trait Router: Send + Sync + 'static {
         &self,
         tool_name: &str,
         arguments: Value,
+        notifier: mpsc::Sender<JsonRpcMessage>,
     ) -> Pin<Box<dyn Future<Output = Result<Vec<Content>, ToolError>> + Send + 'static>>;
     fn list_resources(&self) -> Vec<mcp_core::resource::Resource>;
     fn read_resource(
@@ -159,6 +161,7 @@ pub trait Router: Send + Sync + 'static {
     fn handle_tools_call(
         &self,
         req: JsonRpcRequest,
+        notifier: mpsc::Sender<JsonRpcMessage>,
     ) -> impl Future<Output = Result<JsonRpcResponse, RouterError>> + Send {
         async move {
             let params = req
@@ -172,7 +175,7 @@ pub trait Router: Send + Sync + 'static {
 
             let arguments = params.get("arguments").cloned().unwrap_or(Value::Null);
 
-            let result = match self.call_tool(name, arguments).await {
+            let result = match self.call_tool(name, arguments, notifier).await {
                 Ok(result) => CallToolResult {
                     content: result,
                     is_error: None,
@@ -394,7 +397,12 @@ pub trait Router: Send + Sync + 'static {
 
 pub struct RouterService<T>(pub T);
 
-impl<T> Service<JsonRpcRequest> for RouterService<T>
+pub struct McpRequest {
+    pub request: JsonRpcRequest,
+    pub notifier: mpsc::Sender<JsonRpcMessage>,
+}
+
+impl<T> Service<McpRequest> for RouterService<T>
 where
     T: Router + Clone + Send + Sync + 'static,
 {
@@ -406,21 +414,21 @@ where
         Poll::Ready(Ok(()))
     }
 
-    fn call(&mut self, req: JsonRpcRequest) -> Self::Future {
+    fn call(&mut self, req: McpRequest) -> Self::Future {
         let this = self.0.clone();
 
         Box::pin(async move {
-            let result = match req.method.as_str() {
-                "initialize" => this.handle_initialize(req).await,
-                "tools/list" => this.handle_tools_list(req).await,
-                "tools/call" => this.handle_tools_call(req).await,
-                "resources/list" => this.handle_resources_list(req).await,
-                "resources/read" => this.handle_resources_read(req).await,
-                "prompts/list" => this.handle_prompts_list(req).await,
-                "prompts/get" => this.handle_prompts_get(req).await,
+            let result = match req.request.method.as_str() {
+                "initialize" => this.handle_initialize(req.request).await,
+                "tools/list" => this.handle_tools_list(req.request).await,
+                "tools/call" => this.handle_tools_call(req.request, req.notifier).await,
+                "resources/list" => this.handle_resources_list(req.request).await,
+                "resources/read" => this.handle_resources_read(req.request).await,
+                "prompts/list" => this.handle_prompts_list(req.request).await,
+                "prompts/get" => this.handle_prompts_get(req.request).await,
                 _ => {
-                    let mut response = this.create_response(req.id);
-                    response.error = Some(RouterError::MethodNotFound(req.method).into());
+                    let mut response = this.create_response(req.request.id);
+                    response.error = Some(RouterError::MethodNotFound(req.request.method).into());
                     Ok(response)
                 }
             };

ui/desktop/src/components/ChatView.tsx

@@ -148,6 +148,7 @@ function ChatContent({
     handleInputChange: _handleInputChange,
     handleSubmit: _submitMessage,
     updateMessageStreamBody,
+    notifications,
   } = useMessageStream({
     api: getApiUrl('/reply'),
     initialMessages: chat.messages,
@@ -492,6 +493,16 @@ function ChatContent({
   const handleDragOver = (e: React.DragEvent<HTMLDivElement>) => {
     e.preventDefault();
   };
+
+  const toolCallNotifications = notifications.reduce((map, item) => {
+    const key = item.request_id;
+    if (!map.has(key)) {
+      map.set(key, []);
+    }
+    map.get(key).push(item);
+    return map;
+  }, new Map());
+
   return (
     <div className="flex flex-col w-full h-screen items-center justify-center">
       {/* Loader when generating recipe */}
@@ -571,6 +582,7 @@ function ChatContent({
                             const updatedMessages = [...messages, newMessage];
                             setMessages(updatedMessages);
                           }}
+                          toolCallNotifications={toolCallNotifications}
                         />
                       )}
                     </>
@@ -578,6 +590,7 @@ function ChatContent({
                 </div>
               ))}
             </SearchView>
+
             {error && (
               <div className="flex flex-col items-center justify-center p-4">
                 <div className="text-red-700 dark:text-red-300 bg-red-400/50 p-3 rounded-lg mb-2">

ui/desktop/src/components/GooseMessage.tsx

@@ -17,6 +17,7 @@ import {
 } from '../types/message';
 import ToolCallConfirmation from './ToolCallConfirmation';
 import MessageCopyLink from './MessageCopyLink';
+import { NotificationEvent } from '../hooks/useMessageStream';
 
 interface GooseMessageProps {
   // messages up to this index are presumed to be "history" from a resumed session, this is used to track older tool confirmation requests
@@ -25,6 +26,7 @@ interface GooseMessageProps {
   message: Message;
   messages: Message[];
   metadata?: string[];
+  toolCallNotifications: Map<string, NotificationEvent[]>;
   append: (value: string) => void;
   appendMessage: (message: Message) => void;
 }
@@ -34,6 +36,7 @@ export default function GooseMessage({
   message,
   metadata,
   messages,
+  toolCallNotifications,
   append,
   appendMessage,
 }: GooseMessageProps) {
@@ -158,6 +161,7 @@ export default function GooseMessage({
                   }
                   toolRequest={toolRequest}
                   toolResponse={toolResponsesMap.get(toolRequest.id)}
+                  notifications={toolCallNotifications.get(toolRequest.id)}
                 />
               </div>
             ))}

ui/desktop/src/components/ToolCallWithResponse.tsx

@@ -1,4 +1,4 @@
-import React from 'react';
+import React, { useEffect, useRef } from 'react';
 import { Card } from './ui/card';
 import { ToolCallArguments, ToolCallArgumentValue } from './ToolCallArguments';
 import MarkdownContent from './MarkdownContent';
@@ -6,17 +6,20 @@ import { Content, ToolRequestMessageContent, ToolResponseMessageContent } from '
 import { snakeToTitleCase } from '../utils';
 import Dot, { LoadingStatus } from './ui/Dot';
 import Expand from './ui/Expand';
+import { NotificationEvent } from '../hooks/useMessageStream';
 
 interface ToolCallWithResponseProps {
   isCancelledMessage: boolean;
   toolRequest: ToolRequestMessageContent;
   toolResponse?: ToolResponseMessageContent;
+  notifications?: NotificationEvent[];
 }
 
 export default function ToolCallWithResponse({
   isCancelledMessage,
   toolRequest,
   toolResponse,
+  notifications,
 }: ToolCallWithResponseProps) {
   const toolCall = toolRequest.toolCall.status === 'success' ? toolRequest.toolCall.value : null;
   if (!toolCall) {
@@ -26,7 +29,7 @@ export default function ToolCallWithResponse({
   return (
     <div className={'w-full text-textSubtle text-sm'}>
       <Card className="">
-        <ToolCallView {...{ isCancelledMessage, toolCall, toolResponse }} />
+        <ToolCallView {...{ isCancelledMessage, toolCall, toolResponse, notifications }} />
       </Card>
     </div>
   );
@@ -47,8 +50,9 @@ function ToolCallExpandable({
   children,
   className = '',
 }: ToolCallExpandableProps) {
-  const [isExpanded, setIsExpanded] = React.useState(isStartExpanded);
-  const toggleExpand = () => setIsExpanded((prev) => !prev);
+  const [isExpandedState, setIsExpanded] = React.useState<boolean | null>(null);
+  const isExpanded = isExpandedState === null ? isStartExpanded : isExpandedState;
+  const toggleExpand = () => setIsExpanded(!isExpanded);
   React.useEffect(() => {
     if (isForceExpand) setIsExpanded(true);
   }, [isForceExpand]);
@@ -71,9 +75,42 @@ interface ToolCallViewProps {
     arguments: Record<string, unknown>;
   };
   toolResponse?: ToolResponseMessageContent;
+  notifications?: NotificationEvent[];
 }
 
-function ToolCallView({ isCancelledMessage, toolCall, toolResponse }: ToolCallViewProps) {
+interface Progress {
+  progress: number;
+  progressToken: string;
+  total?: number;
+  message?: string;
+}
+
+const logToString = (logMessage: NotificationEvent) => {
+  const params = logMessage.message.params;
+
+  // Special case for the developer system shell logs
+  if (
+    params &&
+    params.data &&
+    typeof params.data === 'object' &&
+    'output' in params.data &&
+    'stream' in params.data
+  ) {
+    return `[${params.data.stream}] ${params.data.output}`;
+  }
+
+  return typeof params.data === 'string' ? params.data : JSON.stringify(params.data);
+};
+
+const notificationToProgress = (notification: NotificationEvent): Progress =>
+  notification.message.params as unknown as Progress;
+
+function ToolCallView({
+  isCancelledMessage,
+  toolCall,
+  toolResponse,
+  notifications,
+}: ToolCallViewProps) {
   const responseStyle = localStorage.getItem('response_style');
   const isExpandToolDetails = (() => {
     switch (responseStyle) {
@@ -103,6 +140,29 @@ function ToolCallView({ isCancelledMessage, toolCall, toolResponse }: ToolCallVi
           }))
       : [];
 
+  const logs = notifications
+    ?.filter((notification) => notification.message.method === 'notifications/message')
+    .map(logToString);
+
+  const progress = notifications
+    ?.filter((notification) => notification.message.method === 'notifications/progress')
+    .map(notificationToProgress)
+    .reduce((map, item) => {
+      const key = item.progressToken;
+      if (!map.has(key)) {
+        map.set(key, []);
+      }
+      map.get(key)!.push(item);
+      return map;
+    }, new Map<string, Progress[]>());
+
+  const progressEntries = [...(progress?.values() || [])].map(
+    (entries) => entries.sort((a, b) => b.progress - a.progress)[0]
+  );
+
+  const isRenderingProgress =
+    loadingStatus === 'loading' && (progressEntries.length > 0 || (logs || []).length > 0);
+
   const isShouldExpand = isExpandToolDetails || toolResults.some((v) => v.isExpandToolResults);
 
   // Function to create a compact representation of arguments
@@ -136,7 +196,7 @@ function ToolCallView({ isCancelledMessage, toolCall, toolResponse }: ToolCallVi
 
   return (
     <ToolCallExpandable
-      isStartExpanded={isShouldExpand}
+      isStartExpanded={isShouldExpand || isRenderingProgress}
       isForceExpand={isShouldExpand}
       label={
         <>
@@ -156,6 +216,24 @@ function ToolCallView({ isCancelledMessage, toolCall, toolResponse }: ToolCallVi
         </div>
       )}
 
+      {logs && logs.length > 0 && (
+        <div className="bg-bgStandard mt-1">
+          <ToolLogsView
+            logs={logs}
+            working={toolResults.length === 0}
+            isStartExpanded={toolResults.length === 0}
+          />
+        </div>
+      )}
+
+      {toolResults.length === 0 &&
+        progressEntries.length > 0 &&
+        progressEntries.map((entry, index) => (
+          <div className="p-2" key={index}>
+            <ProgressBar progress={entry.progress} total={entry.total} message={entry.message} />
+          </div>
+        ))}
+
       {/* Tool Output */}
       {!isCancelledMessage && (
         <>
@@ -234,3 +312,76 @@ function ToolResultView({ result, isStartExpanded }: ToolResultViewProps) {
     </ToolCallExpandable>
   );
 }
+
+function ToolLogsView({
+  logs,
+  working,
+  isStartExpanded,
+}: {
+  logs: string[];
+  working: boolean;
+  isStartExpanded?: boolean;
+}) {
+  const boxRef = useRef(null);
+
+  // Whenever logs update, jump to the newest entry
+  useEffect(() => {
+    if (boxRef.current) {
+      boxRef.current.scrollTop = boxRef.current.scrollHeight;
+    }
+  }, [logs]);
+
+  return (
+    <ToolCallExpandable
+      label={
+        <span className="pl-[19px] py-1">
+          <span>Logs</span>
+          {working && (
+            <div className="mx-2 inline-block">
+              <span
+                className="inline-block animate-spin rounded-full border-2 border-t-transparent border-current"
+                style={{ width: 8, height: 8 }}
+                role="status"
+                aria-label="Loading spinner"
+              />
+            </div>
+          )}
+        </span>
+      }
+      isStartExpanded={isStartExpanded}
+    >
+      <div
+        ref={boxRef}
+        className={`flex flex-col items-start space-y-2 overflow-y-auto ${working ? 'max-h-[4rem]' : 'max-h-[20rem]'} bg-bgApp`}
+      >
+        {logs.map((log, i) => (
+          <span key={i} className="font-mono text-sm text-textSubtle">
+            {log}
+          </span>
+        ))}
+      </div>
+    </ToolCallExpandable>
+  );
+}
+
+const ProgressBar = ({ progress, total, message }: Omit<Progress, 'progressToken'>) => {
+  const isDeterminate = typeof total === 'number';
+  const percent = isDeterminate ? Math.min((progress / total!) * 100, 100) : 0;
+
+  return (
+    <div className="w-full space-y-2">
+      {message && <div className="text-sm text-gray-700">{message}</div>}
+
+      <div className="w-full bg-gray-200 rounded-full h-4 overflow-hidden relative">
+        {isDeterminate ? (
+          <div
+            className="bg-blue-500 h-full transition-all duration-300"
+            style={{ width: `${percent}%` }}
+          />
+        ) : (
+          <div className="absolute inset-0 animate-indeterminate bg-blue-500" />
+        )}
+      </div>
+    </div>
+  );
+};

ui/desktop/src/hooks/useMessageStream.ts

@@ -6,11 +6,25 @@ import { Message, createUserMessage, hasCompletedToolCalls } from '../types/mess
 // Ensure TextDecoder is available in the global scope
 const TextDecoder = globalThis.TextDecoder;
 
+type JsonValue = string | number | boolean | null | JsonValue[] | { [key: string]: JsonValue };
+
+export interface NotificationEvent {
+  type: 'Notification';
+  request_id: string;
+  message: {
+    method: string;
+    params: {
+      [key: string]: JsonValue;
+    };
+  };
+}
+
 // Event types for SSE stream
 type MessageEvent =
   | { type: 'Message'; message: Message }
   | { type: 'Error'; error: string }
-  | { type: 'Finish'; reason: string };
+  | { type: 'Finish'; reason: string }
+  | NotificationEvent;
 
 export interface UseMessageStreamOptions {
   /**
@@ -124,6 +138,8 @@ export interface UseMessageStreamHelpers {
 
   /** Modify body (session id and/or work dir mid-stream) **/
   updateMessageStreamBody?: (newBody: object) => void;
+
+  notifications: NotificationEvent[];
 }
 
 /**
@@ -151,6 +167,8 @@ export function useMessageStream({
     fallbackData: initialMessages,
   });
 
+  const [notifications, setNotifications] = useState<NotificationEvent[]>([]);
+
   // expose a way to update the body so we can update the session id when CLE occurs
   const updateMessageStreamBody = useCallback((newBody: object) => {
     extraMetadataRef.current.body = {
@@ -247,6 +265,14 @@ export function useMessageStream({
                     break;
                   }
 
+                  case 'Notification': {
+                    const newNotification = {
+                      ...parsedEvent,
+                    };
+                    setNotifications((prev) => [...prev, newNotification]);
+                    break;
+                  }
+
                   case 'Error':
                     throw new Error(parsedEvent.error);
 
@@ -516,5 +542,6 @@ export function useMessageStream({
     isLoading: isLoading || false,
     addToolResult,
     updateMessageStreamBody,
+    notifications,
   };
 }

ui/desktop/tailwind.config.ts

@@ -44,10 +44,16 @@ export default {
           '0%': { transform: 'rotate(0deg)' },
           '100%': { transform: 'rotate(360deg)' },
         },
+        indeterminate: {
+          '0%': { left: '-40%', width: '40%' },
+          '50%': { left: '20%', width: '60%' },
+          '100%': { left: '100%', width: '80%' },
+        },
       },
       animation: {
         'shimmer-pulse': 'shimmer 4s ease-in-out infinite',
         'gradient-loader': 'loader 750ms ease-in-out infinite',
+        indeterminate: 'indeterminate 1.5s infinite linear',
       },
       colors: {
         bgApp: 'var(--background-app)',