Feature/mcp spec polish

.github/workflows/rust.yml

@@ -10,8 +10,17 @@ env:
   CARGO_TERM_COLOR: always
 
 jobs:
+  check_format:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Check formatting
+        run: cargo fmt --all -- --check
+
   clippy_check:
     runs-on: ubuntu-latest
+    needs: check_format
+
     steps:
       - uses: actions/checkout@v4
       - name: Run all features

CHANGELOG.md

@@ -5,10 +5,17 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/).
 
+## 0.2.8
+
+### Fixed
+* Fixed JSON-RPC 2.0 protocol violation: server no longer sends a response to client notifications (§4 — notifications must never be replied to)
+* Fixed `notifications/cancelled`: request cancellation now actually fires for both stdio and Streamable HTTP transports
+* Fixed Streamable HTTP transport silently dropping notifications without processing them
+
 ## 0.2.7
 
 ### Added
 * JSON-RPC Batch Support for client and server
 
-## Fixed
-* Fixed broken Streamable HTTP server implementation
+### Fixed
+* Fixed broken Streamable HTTP server implementation

Cargo.toml

@@ -11,7 +11,7 @@ exclude = [
 ]
 
 [workspace.package]
-version = "0.2.7"
+version = "0.2.8"
 license = "MIT"
 edition = "2024"
 rust-version = "1.90.0"
@@ -20,7 +20,7 @@ repository = "https://github.com/RomanEmreis/neva"
 documentation = "https://docs.rs/neva"
 
 [workspace.dependencies]
-neva_macros = { path = "neva_macros", version = "0.2.7" }
+neva_macros = { path = "neva_macros", version = "0.2.8" }
 
 [workspace.lints.rust]
 unsafe_code = "forbid"

README.md

@@ -4,8 +4,8 @@ Blazingly fast and easily configurable [Model Context Protocol (MCP)](https://mo
 With simple configuration and ergonomic APIs, it provides everything you need to quickly build MCP clients and servers, 
 fully aligned with the latest MCP specification.
 
-[![latest](https://img.shields.io/badge/latest-0.2.7-d8eb34)](https://crates.io/crates/neva)
-[![latest](https://img.shields.io/badge/rustc-1.90+-964B00)](https://crates.io/crates/neva)
+[![latest](https://img.shields.io/badge/latest-0.2.8-d8eb34)](https://crates.io/crates/neva)
+[![latest](https://img.shields.io/badge/rustc-1.90+-964B00)](https://releases.rs/docs/1.90.0/)
 [![License: MIT](https://img.shields.io/badge/License-MIT-624bd1.svg)](https://github.com/RomanEmreis/neva/blob/main/LICENSE)
 [![CI](https://github.com/RomanEmreis/neva/actions/workflows/rust.yml/badge.svg)](https://github.com/RomanEmreis/neva/actions/workflows/rust.yml)
 [![Release](https://github.com/RomanEmreis/neva/actions/workflows/release.yml/badge.svg)](https://github.com/RomanEmreis/neva/actions/workflows/release.yml)
@@ -28,7 +28,7 @@ fully aligned with the latest MCP specification.
 #### Dependencies
 ```toml
 [dependencies]
-neva = { version = "0.2.7", features = ["client-full"] }
+neva = { version = "0.2.8", features = ["client-full"] }
 tokio = { version = "1", features = ["full"] }
 ```
 
@@ -66,7 +66,7 @@ async fn main() -> Result<(), Error> {
 #### Dependencies
 ```toml
 [dependencies]
-neva = { version = "0.2.7", features = ["server-full"] }
+neva = { version = "0.2.8", features = ["server-full"] }
 tokio = { version = "1", features = ["full"] }
 ```
 #### Code

examples/client/src/main.rs

@@ -4,8 +4,8 @@
 //! cargo run -p example-client
 //! ```
 
-use std::time::Duration;
 use neva::prelude::*;
+use std::time::Duration;
 use tracing_subscriber::prelude::*;
 
 #[allow(dead_code)]
@@ -21,28 +21,28 @@ async fn main() -> Result<(), Error> {
     tracing_subscriber::registry()
         .with(tracing_subscriber::fmt::layer())
         .init();
-
-    let mut client = Client::new()
-        .with_options(|opt| opt
-            .with_stdio("npx", ["-y", "@modelcontextprotocol/server-everything"])
+
+    let mut client = Client::new().with_options(|opt| {
+        opt.with_stdio("npx", ["-y", "@modelcontextprotocol/server-everything"])
             .with_roots(|roots| roots.with_list_changed())
             .with_timeout(Duration::from_secs(5))
-            .with_mcp_version("2025-11-25"));
-
+            .with_mcp_version("2025-11-25")
+    });
+
     client.connect().await?;
-    
+
     // Ping command
     tracing::info!("--- PING ---");
     let resp = client.ping().await?;
     tracing::info!("{:?}", resp);
-    
+
     // List tools
     tracing::info!("--- LIST TOOLS ---");
     let tools = client.list_tools(None).await?;
     for tool in tools.tools.iter() {
         tracing::info!("- {}", tool.name);
     }
-    
+
     // Call a tool
     tracing::info!("--- CALL TOOL ---");
     let args = ("message", "Hello MCP!");
@@ -54,11 +54,9 @@ async fn main() -> Result<(), Error> {
     let tool = tools.get("get-structured-content").unwrap();
     let args = ("location", "New York");
     let result = client.call_tool(&tool.name, args).await?;
-    let weather: Weather = tool
-        .validate(&result)
-        .and_then(|res| res.as_json())?;
+    let weather: Weather = tool.validate(&result).and_then(|res| res.as_json())?;
     tracing::info!("{:?}", weather);
-    
+
     // List resources
     tracing::info!("--- LIST RESOURCES ---");
     let resources = client.list_resources(None).await?;
@@ -73,7 +71,7 @@ async fn main() -> Result<(), Error> {
     for res in resources.resources {
         tracing::info!("- {}: {:?}", res.name, res.uri);
     }
-    
+
     // List templates
     tracing::info!("--- LIST RESOURCE TEMPLATES ---");
     let templates = client.list_resource_templates(None).await?;
@@ -83,27 +81,26 @@ async fn main() -> Result<(), Error> {
 
     // Read resource
     tracing::info!("--- READ RESOURCE ---");
-    let resource = client.read_resource("demo://resource/static/document/architecture.md").await?;
+    let resource = client
+        .read_resource("demo://resource/static/document/architecture.md")
+        .await?;
     tracing::info!("{:?}", resource.contents);
-    
+
     // List prompts
     tracing::info!("--- LIST PROMPTS ---");
     let prompts = client.list_prompts(None).await?;
     for prompt in prompts.prompts {
         tracing::info!("- {}, {:?}", prompt.name, prompt.args);
     }
-    
+
     // Get prompt
     tracing::info!("--- GET PROMPT ---");
-    let args = [
-        ("city", "New York"),
-        ("state", "NY")
-    ];
+    let args = [("city", "New York"), ("state", "NY")];
     let prompt = client.get_prompt("args-prompt", args).await?;
     tracing::info!("{:?}: {:?}", prompt.descr, prompt.messages);
-    
+
     // This can be uncommented to check the log notifications from MCP server
     //tokio::time::sleep(Duration::from_secs(60)).await;
-    
+
     client.disconnect().await
 }

examples/http/src/main.rs

@@ -1,12 +1,12 @@
 //! Run with:
-//! 
+//!
 //! ```no_rust
 //! npx @modelcontextprotocol/inspector
-//! 
+//!
 //! cargo run -p example-http
 //! ```
 use neva::prelude::*;
-use tracing_subscriber::{filter, reload, prelude::*};
+use tracing_subscriber::{filter, prelude::*, reload};
 
 #[tool]
 async fn remote_tool(name: String, mut ctx: Context) {
@@ -22,13 +22,12 @@ async fn main() {
         .with(filter)
         .with(notification::fmt::layer())
         .init();
-    
+
     App::new()
-        .with_options(|opt| opt
-            .with_http(|http| http
-                .bind("127.0.0.1:3000")
-                .with_endpoint("/mcp"))
-            .with_logging(handle))
+        .with_options(|opt| {
+            opt.with_http(|http| http.bind("127.0.0.1:3000").with_endpoint("/mcp"))
+                .with_logging(handle)
+        })
         .run()
         .await;
 }

examples/large_resources_server/src/main.rs

@@ -1,7 +1,7 @@
 //! Run with:
 //!
 //! ```no_rust
-//! npx @modelcontextprotocol/inspector 
+//! npx @modelcontextprotocol/inspector
 //!
 //! cargo run -p large_resources_server
 //! ```
@@ -12,16 +12,14 @@ use neva::prelude::*;
 async fn resource_meta(name: String) -> ResourceContents {
     let uri: Uri = format!("file://{name}").into();
     let res = get_res_info(uri.clone(), name.clone());
-
-    ResourceContents::new(uri)
-        .with_title(name)
-        .with_json(res)
+
+    ResourceContents::new(uri).with_title(name).with_json(res)
 }
 
 #[resource(uri = "file://{name}")]
 async fn resource_data(uri: Uri, name: String) -> ResourceContents {
     // get resource from somewhere
-    
+
     ResourceContents::new(uri.clone())
         .with_title(name.clone())
         .with_blob("large file")

examples/logging/src/main.rs

@@ -5,7 +5,7 @@
 //! ```
 
 use neva::prelude::*;
-use tracing_subscriber::{filter, reload, prelude::*};
+use tracing_subscriber::{filter, prelude::*, reload};
 
 #[tool]
 async fn trace_tool() {
@@ -18,19 +18,19 @@ async fn trace_tool() {
 async fn main() {
     // Configure logging filter
     let (filter, handle) = reload::Layer::new(filter::LevelFilter::DEBUG);
-    
+
     // Configure logging
     tracing_subscriber::registry()
-        .with(filter)                                           // Specify the default logging level
-        .with(tracing_subscriber::fmt::layer()
-            .event_format(notification::NotificationFormatter)) // Specify the MCP notification formatter
+        .with(filter) // Specify the default logging level
+        .with(tracing_subscriber::fmt::layer().event_format(notification::NotificationFormatter)) // Specify the MCP notification formatter
         .init();
-    
+
     App::new()
-        .with_options(|opt| opt
-            .with_stdio()
-            .with_mcp_version("2024-11-05")
-            .with_logging(handle))
+        .with_options(|opt| {
+            opt.with_stdio()
+                .with_mcp_version("2024-11-05")
+                .with_logging(handle)
+        })
         .run()
         .await;
 }

examples/middlewares/src/main.rs

@@ -5,7 +5,7 @@
 //! ```
 
 use neva::prelude::*;
-use tracing_subscriber::{prelude::*, filter, reload};
+use tracing_subscriber::{filter, prelude::*, reload};
 
 #[tool(middleware = [specific_middleware])]
 async fn greeter(name: String) -> String {
@@ -19,20 +19,17 @@ async fn hello_world() -> &'static str {
 
 #[resource(uri = "res://{name}")]
 async fn resource(name: String) -> ResourceContents {
-    ResourceContents::new(name)
-        .with_text("Hello, world!")
+    ResourceContents::new(name).with_text("Hello, world!")
 }
 
 #[prompt(middleware = [specific_middleware])]
 async fn prompt(topic: String) -> PromptMessage {
-    PromptMessage::user()
-        .with(format!("Sample prompt of {topic}"))
+    PromptMessage::user().with(format!("Sample prompt of {topic}"))
 }
 
 #[prompt]
 async fn another_prompt(topic: String) -> PromptMessage {
-    PromptMessage::user()
-        .with(format!("Another sample prompt of {topic}"))
+    PromptMessage::user().with(format!("Another sample prompt of {topic}"))
 }
 
 #[handler(command = "ping", middleware = [specific_middleware])]
@@ -43,9 +40,9 @@ async fn ping_handler() {
 async fn logging_middleware(ctx: MwContext, next: Next) -> Response {
     let id = ctx.id();
     tracing::info!("Request start: {id:?}");
-    
+
     let resp = next(ctx).await;
-    
+
     tracing::info!("Request end: {id:?}");
     resp
 }
@@ -55,7 +52,7 @@ async fn global_tool_middleware(ctx: MwContext, next: Next) -> Response {
     next(ctx).await
 }
 
-// Wraps all requests for the "greeter" tool, "prompt" prompt and ping handler 
+// Wraps all requests for the "greeter" tool, "prompt" prompt and ping handler
 async fn specific_middleware(ctx: MwContext, next: Next) -> Response {
     tracing::info!("Hello from specific middleware");
     next(ctx).await
@@ -65,16 +62,13 @@ async fn specific_middleware(ctx: MwContext, next: Next) -> Response {
 async fn main() {
     let (filter, handle) = reload::Layer::new(filter::LevelFilter::DEBUG);
     tracing_subscriber::registry()
-        .with(filter) 
-        .with(tracing_subscriber::fmt::layer()
-            .event_format(notification::NotificationFormatter))
+        .with(filter)
+        .with(tracing_subscriber::fmt::layer().event_format(notification::NotificationFormatter))
         .init();
-    
+
     App::new()
-        .with_options(|opt| opt
-            .with_stdio()
-            .with_logging(handle))
-        .wrap(logging_middleware)           // Wraps all requests that pass through the server
+        .with_options(|opt| opt.with_stdio().with_logging(handle))
+        .wrap(logging_middleware) // Wraps all requests that pass through the server
         .wrap_tools(global_tool_middleware) // Wraps all tools/call requests that pass through the server
         .run()
         .await;