feat(transport): support streamable http server (#152)

* feat(transport): support streamable http server

* refactor(transport): add common module for shared transport utilities

* perf(tracing): add more log for streamable http session

* fix(test): fix port conflict in test with js

* fix(transport): fix id generating and session management

1. cancel when deleting
2. use `wrapping` and `saturating` correctly

* chore(naming): rename sse server to streamable http server
This commit is contained in:
4t145 2025-05-08 13:57:51 +08:00 committed by GitHub
parent 0847c17fa1
commit 57e14c56e8
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17 changed files with 1247 additions and 20 deletions

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@ -199,6 +199,7 @@ See [examples](examples/README.md)
- `transport-sse-server`: Server SSE transport
- `transport-child-process`: Client stdio transport
- `transport-sse`: Client sse transport
- `transport-streamable-http-server` streamable http server transport
## Related Resources

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@ -48,10 +48,11 @@ tower-service = { version = "0.3", optional = true }
# for ws transport
# tokio-tungstenite ={ version = "0.26", optional = true }
# for sse-server transport
# for http-server transport
axum = { version = "0.8", features = [], optional = true }
rand = { version = "0.9", optional = true }
tokio-stream = { version = "0.1", optional = true }
uuid = { version = "1", features = ["v4"], optional = true }
# macro
rmcp-macros = { version = "0.1", workspace = true, optional = true }
@ -72,6 +73,16 @@ transport-sse-server = [
"dep:axum",
"dep:rand",
"dep:tokio-stream",
"uuid",
]
transport-streamable-http-server = [
"transport-streamable-http-server-session",
"dep:axum",
"uuid",
]
transport-streamable-http-server-session = [
"transport-async-rw",
"dep:tokio-stream",
]
# transport-ws = ["transport-io", "dep:tokio-tungstenite"]
tower = ["dep:tower-service"]
@ -102,7 +113,7 @@ path = "tests/test_with_python.rs"
[[test]]
name = "test_with_js"
required-features = ["server", "client", "transport-sse-server", "transport-child-process"]
required-features = ["server", "client", "transport-sse-server", "transport-child-process", "transport-streamable-http-server"]
path = "tests/test_with_js.rs"
[[test]]

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@ -186,7 +186,7 @@ impl<'de> Deserialize<'de> for NumberOrString {
pub type RequestId = NumberOrString;
#[derive(Debug, Serialize, Deserialize, Clone, PartialEq)]
#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Hash, Eq)]
#[serde(transparent)]
pub struct ProgressToken(pub NumberOrString);
#[derive(Debug, Clone)]

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@ -591,7 +591,7 @@ where
}
};
tracing::debug!(?evt, "new event");
tracing::trace!(?evt, "new event");
match evt {
// response and error
Event::ToSink(m) => {
@ -657,7 +657,7 @@ where
Event::PeerMessage(JsonRpcMessage::Request(JsonRpcRequest {
id, request, ..
})) => {
tracing::info!(%id, ?request, "received request");
tracing::debug!(%id, ?request, "received request");
{
let service = shared_service.clone();
let sink = sink_proxy_tx.clone();
@ -675,7 +675,7 @@ where
let result = service.handle_request(request, context).await;
let response = match result {
Ok(result) => {
tracing::info!(%id, ?result, "response message");
tracing::debug!(%id, ?result, "response message");
JsonRpcMessage::response(result, id)
}
Err(error) => {

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@ -76,6 +76,13 @@ pub use auth::{AuthError, AuthorizationManager, AuthorizationSession, Authorized
// #[cfg(feature = "transport-ws")]
// pub mod ws;
#[cfg(feature = "transport-streamable-http-server-session")]
pub mod streamable_http_server;
#[cfg(feature = "transport-streamable-http-server")]
pub use streamable_http_server::axum::StreamableHttpServer;
/// Common use codes
pub mod common;
pub trait IntoTransport<R, E, A>: Send + 'static
where

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@ -0,0 +1,5 @@
#[cfg(any(
feature = "transport-streamable-http-server",
feature = "transport-sse-server"
))]
pub mod axum;

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@ -0,0 +1,9 @@
use std::{sync::Arc, time::Duration};
pub type SessionId = Arc<str>;
pub fn session_id() -> SessionId {
uuid::Uuid::new_v4().to_string().into()
}
pub const DEFAULT_AUTO_PING_INTERVAL: Duration = Duration::from_secs(15);

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@ -19,14 +19,13 @@ use crate::{
RoleServer, Service,
model::ClientJsonRpcMessage,
service::{RxJsonRpcMessage, TxJsonRpcMessage},
transport::common::axum::{DEFAULT_AUTO_PING_INTERVAL, SessionId, session_id},
};
type SessionId = Arc<str>;
type TxStore =
Arc<tokio::sync::RwLock<HashMap<SessionId, tokio::sync::mpsc::Sender<ClientJsonRpcMessage>>>>;
pub type TransportReceiver = ReceiverStream<RxJsonRpcMessage<RoleServer>>;
const DEFAULT_AUTO_PING_INTERVAL: Duration = Duration::from_secs(15);
#[derive(Clone)]
struct App {
txs: TxStore,
@ -56,11 +55,6 @@ impl App {
}
}
fn session_id() -> SessionId {
let id = format!("{:016x}", rand::random::<u128>());
Arc::from(id)
}
#[derive(Debug, serde::Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct PostEventQuery {

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@ -0,0 +1,3 @@
#[cfg(feature = "transport-streamable-http-server")]
pub mod axum;
pub mod session;

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@ -0,0 +1,335 @@
use std::{collections::HashMap, io, net::SocketAddr, sync::Arc, time::Duration};
use axum::{
Json, Router,
extract::State,
http::{HeaderMap, HeaderValue, StatusCode},
response::{
IntoResponse, Response,
sse::{Event, KeepAlive, Sse},
},
routing::get,
};
use futures::Stream;
use tokio_stream::wrappers::ReceiverStream;
use tokio_util::sync::CancellationToken;
use tracing::Instrument;
use super::session::{
EventId, HEADER_LAST_EVENT_ID, Session, SessionTransport, StreamableHttpMessageReceiver,
};
use crate::{
RoleServer, Service,
model::ClientJsonRpcMessage,
transport::{
common::axum::{DEFAULT_AUTO_PING_INTERVAL, SessionId, session_id},
streamable_http_server::session::HEADER_SESSION_ID,
},
};
type SessionManager = Arc<tokio::sync::RwLock<HashMap<SessionId, Session>>>;
#[derive(Clone)]
struct App {
session_manager: SessionManager,
transport_tx: tokio::sync::mpsc::UnboundedSender<SessionTransport>,
sse_ping_interval: Duration,
}
impl App {
pub fn new(
sse_ping_interval: Duration,
) -> (Self, tokio::sync::mpsc::UnboundedReceiver<SessionTransport>) {
let (transport_tx, transport_rx) = tokio::sync::mpsc::unbounded_channel();
(
Self {
session_manager: Default::default(),
transport_tx,
sse_ping_interval,
},
transport_rx,
)
}
}
fn receiver_as_stream(
receiver: StreamableHttpMessageReceiver,
) -> impl Stream<Item = Result<Event, io::Error>> {
use futures::StreamExt;
ReceiverStream::new(receiver.inner).map(|message| {
match serde_json::to_string(&message.message) {
Ok(bytes) => Ok(Event::default()
.event("message")
.data(&bytes)
.id(message.event_id.to_string())),
Err(e) => Err(io::Error::new(io::ErrorKind::InvalidData, e)),
}
})
}
async fn post_handler(
State(app): State<App>,
header_map: HeaderMap,
Json(message): Json<ClientJsonRpcMessage>,
) -> Result<Response, Response> {
use futures::StreamExt;
if let Some(session_id) = header_map.get(HEADER_SESSION_ID) {
let session_id = session_id
.to_str()
.map_err(|e| (StatusCode::BAD_REQUEST, e.to_string()).into_response())?;
tracing::debug!(session_id, ?message, "new client message");
let handle = {
let sm = app.session_manager.read().await;
let session = sm
.get(session_id)
.ok_or((StatusCode::NOT_FOUND, "session not found").into_response())?;
session.handle().clone()
};
match &message {
ClientJsonRpcMessage::Request(_) | ClientJsonRpcMessage::BatchRequest(_) => {
let receiver = handle.establish_request_wise_channel().await.map_err(|e| {
(
StatusCode::INTERNAL_SERVER_ERROR,
format!("fail to to establish request channel: {e}"),
)
.into_response()
})?;
let http_request_id = receiver.http_request_id;
if let Err(push_err) = handle.push_message(message, http_request_id).await {
tracing::error!(session_id, ?push_err, "push message error");
return Err((
StatusCode::INTERNAL_SERVER_ERROR,
format!("fail to push message: {push_err}"),
)
.into_response());
}
let stream =
ReceiverStream::new(receiver.inner).map(|message| match serde_json::to_string(
&message.message,
) {
Ok(bytes) => Ok(Event::default()
.event("message")
.data(&bytes)
.id(message.event_id.to_string())),
Err(e) => Err(io::Error::new(io::ErrorKind::InvalidData, e)),
});
Ok(Sse::new(stream)
.keep_alive(KeepAlive::new().interval(app.sse_ping_interval))
.into_response())
}
_ => {
let result = handle.push_message(message, None).await;
if result.is_err() {
Err((StatusCode::GONE, "session terminated").into_response())
} else {
Ok(StatusCode::ACCEPTED.into_response())
}
}
}
} else {
// expect initialize message
let session_id = session_id();
let (session, transport) =
super::session::create_session(session_id.clone(), Default::default());
let Ok(_) = app.transport_tx.send(transport) else {
return Err((StatusCode::GONE, "session terminated").into_response());
};
let response = session.handle().initialize(message).await.map_err(|e| {
(
StatusCode::INTERNAL_SERVER_ERROR,
format!("fail to initialize: {e}"),
)
.into_response()
})?;
let mut response = Json(response).into_response();
response.headers_mut().insert(
HEADER_SESSION_ID,
HeaderValue::from_bytes(session_id.as_bytes()).expect("should be valid header value"),
);
app.session_manager
.write()
.await
.insert(session_id, session);
Ok(response)
}
}
async fn get_handler(
State(app): State<App>,
header_map: HeaderMap,
) -> Result<Sse<impl Stream<Item = Result<Event, io::Error>>>, Response> {
let session_id = header_map
.get(HEADER_SESSION_ID)
.and_then(|v| v.to_str().ok());
if let Some(session_id) = session_id {
let last_event_id = header_map
.get(HEADER_LAST_EVENT_ID)
.and_then(|v| v.to_str().ok());
match last_event_id {
Some(last_event_id) => {
let last_event_id = last_event_id.parse::<EventId>().map_err(|e| {
(StatusCode::BAD_REQUEST, format!("invalid event_id {e}")).into_response()
})?;
let sm = app.session_manager.read().await;
let session = sm.get(session_id).ok_or_else(|| {
(
StatusCode::NOT_FOUND,
format!("session {session_id} not found"),
)
.into_response()
})?;
let handle = session.handle();
let receiver = handle.resume(last_event_id).await.map_err(|e| {
(
StatusCode::INTERNAL_SERVER_ERROR,
format!("resume error {e}"),
)
.into_response()
})?;
let stream = receiver_as_stream(receiver);
Ok(Sse::new(stream).keep_alive(KeepAlive::new().interval(app.sse_ping_interval)))
}
None => {
let sm = app.session_manager.read().await;
let session = sm.get(session_id).ok_or_else(|| {
(
StatusCode::NOT_FOUND,
format!("session {session_id} not found"),
)
.into_response()
})?;
let handle = session.handle();
let receiver = handle.establish_common_channel().await.map_err(|e| {
(
StatusCode::INTERNAL_SERVER_ERROR,
format!("establish common channel error {e}"),
)
.into_response()
})?;
let stream = receiver_as_stream(receiver);
Ok(Sse::new(stream).keep_alive(KeepAlive::new().interval(app.sse_ping_interval)))
}
}
} else {
Err((StatusCode::BAD_REQUEST, "missing session id").into_response())
}
}
async fn delete_handler(
State(app): State<App>,
header_map: HeaderMap,
) -> Result<StatusCode, Response> {
if let Some(session_id) = header_map.get(HEADER_SESSION_ID) {
let session_id = session_id
.to_str()
.map_err(|e| (StatusCode::BAD_REQUEST, e.to_string()).into_response())?;
let mut sm = app.session_manager.write().await;
let session = sm
.remove(session_id)
.ok_or((StatusCode::NOT_FOUND, "session not found").into_response())?;
let cancel_result = session.cancel().await.map_err(|e| {
(
StatusCode::INTERNAL_SERVER_ERROR,
format!("fail to cancel session {session_id}: tokio join error: {e}"),
)
.into_response()
})?;
tracing::info!(session_id, ?cancel_result, "session deleted");
Ok(StatusCode::ACCEPTED)
} else {
Err((StatusCode::BAD_REQUEST, "missing session id").into_response())
}
}
#[derive(Debug, Clone)]
pub struct StreamableHttpServerConfig {
pub bind: SocketAddr,
pub path: String,
pub ct: CancellationToken,
pub sse_keep_alive: Option<Duration>,
}
#[derive(Debug)]
pub struct StreamableHttpServer {
transport_rx: tokio::sync::mpsc::UnboundedReceiver<SessionTransport>,
pub config: StreamableHttpServerConfig,
}
impl StreamableHttpServer {
pub async fn serve(bind: SocketAddr) -> io::Result<Self> {
Self::serve_with_config(StreamableHttpServerConfig {
bind,
path: "/".to_string(),
ct: CancellationToken::new(),
sse_keep_alive: None,
})
.await
}
pub async fn serve_with_config(config: StreamableHttpServerConfig) -> io::Result<Self> {
let (streamable_http_server, service) = Self::new(config);
let listener = tokio::net::TcpListener::bind(streamable_http_server.config.bind).await?;
let ct = streamable_http_server.config.ct.child_token();
let server = axum::serve(listener, service).with_graceful_shutdown(async move {
ct.cancelled().await;
tracing::info!("streamable http server cancelled");
});
tokio::spawn(
async move {
if let Err(e) = server.await {
tracing::error!(error = %e, "streamable http server shutdown with error");
}
}
.instrument(tracing::info_span!("streamable-http-server", bind_address = %streamable_http_server.config.bind)),
);
Ok(streamable_http_server)
}
/// Warning: This function creates a new StreamableHttpServer instance with the provided configuration.
/// `App.post_path` may be incorrect if using `Router` as an embedded router.
pub fn new(config: StreamableHttpServerConfig) -> (StreamableHttpServer, Router) {
let (app, transport_rx) =
App::new(config.sse_keep_alive.unwrap_or(DEFAULT_AUTO_PING_INTERVAL));
let router = Router::new()
.route(
&config.path,
get(get_handler).post(post_handler).delete(delete_handler),
)
.with_state(app);
let server = StreamableHttpServer {
transport_rx,
config,
};
(server, router)
}
pub fn with_service<S, F>(mut self, service_provider: F) -> CancellationToken
where
S: Service<RoleServer>,
F: Fn() -> S + Send + 'static,
{
use crate::service::ServiceExt;
let ct = self.config.ct.clone();
tokio::spawn(async move {
while let Some(transport) = self.next_transport().await {
let service = service_provider();
let ct = self.config.ct.child_token();
tokio::spawn(async move {
let server = service.serve_with_ct(transport, ct).await?;
server.waiting().await?;
tokio::io::Result::Ok(())
});
}
});
ct
}
pub fn cancel(&self) {
self.config.ct.cancel();
}
pub async fn next_transport(&mut self) -> Option<SessionTransport> {
self.transport_rx.recv().await
}
}

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@ -0,0 +1,767 @@
use std::{
borrow::Cow,
collections::{HashMap, HashSet, VecDeque},
num::ParseIntError,
sync::Arc,
};
use futures::{Sink, SinkExt, Stream};
use thiserror::Error;
use tokio::sync::{
mpsc::{Receiver, Sender},
oneshot,
};
use tokio_stream::wrappers::ReceiverStream;
use tokio_util::sync::{CancellationToken, DropGuard, PollSender};
use tracing::instrument;
use crate::{
RoleServer,
model::{
CancelledNotificationParam, ClientJsonRpcMessage, ClientNotification, ClientRequest,
JsonRpcNotification, JsonRpcRequest, Notification, ProgressNotificationParam,
ProgressToken, RequestId, ServerJsonRpcMessage, ServerNotification,
},
transport::IntoTransport,
};
pub const HEADER_SESSION_ID: &str = "Mcp-Session-Id";
pub const HEADER_LAST_EVENT_ID: &str = "Last-Event-Id";
#[derive(Debug, Clone)]
pub struct ServerSessionMessage {
pub event_id: EventId,
pub message: Arc<ServerJsonRpcMessage>,
}
/// <index>-<request_id>
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct EventId {
http_request_id: Option<HttpRequestId>,
index: usize,
}
impl std::fmt::Display for EventId {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
write!(f, "{}", self.index)?;
match &self.http_request_id {
Some(http_request_id) => write!(f, "/{http_request_id}"),
None => write!(f, ""),
}
}
}
#[derive(Debug, Clone, Error)]
pub enum EventIdParseError {
#[error("Invalid index: {0}")]
InvalidIndex(ParseIntError),
#[error("Invalid numeric request id: {0}")]
InvalidNumericRequestId(ParseIntError),
#[error("Missing request id type")]
InvalidRequestIdType,
#[error("Missing request id")]
MissingRequestId,
}
impl std::str::FromStr for EventId {
type Err = EventIdParseError;
fn from_str(s: &str) -> Result<Self, Self::Err> {
if let Some((index, request_id)) = s.split_once("/") {
let index = usize::from_str(index).map_err(EventIdParseError::InvalidIndex)?;
let request_id = u64::from_str(request_id).map_err(EventIdParseError::InvalidIndex)?;
Ok(EventId {
http_request_id: Some(request_id),
index,
})
} else {
let index = usize::from_str(s).map_err(EventIdParseError::InvalidIndex)?;
Ok(EventId {
http_request_id: None,
index,
})
}
}
}
pub use crate::transport::common::axum::SessionId;
struct CachedTx {
tx: Sender<ServerSessionMessage>,
cache: VecDeque<ServerSessionMessage>,
http_request_id: Option<HttpRequestId>,
capacity: usize,
}
impl CachedTx {
fn new(tx: Sender<ServerSessionMessage>, http_request_id: Option<HttpRequestId>) -> Self {
Self {
cache: VecDeque::with_capacity(tx.capacity()),
capacity: tx.capacity(),
tx,
http_request_id,
}
}
fn new_common(tx: Sender<ServerSessionMessage>) -> Self {
Self::new(tx, None)
}
async fn send(&mut self, message: ServerJsonRpcMessage) {
let index = self.cache.back().map_or(0, |m| m.event_id.index + 1);
let event_id = EventId {
http_request_id: self.http_request_id,
index,
};
let message = ServerSessionMessage {
event_id: event_id.clone(),
message: Arc::new(message),
};
if self.cache.len() >= self.capacity {
self.cache.pop_front();
self.cache.push_back(message.clone());
} else {
self.cache.push_back(message.clone());
}
let _ = self.tx.send(message).await.inspect_err(|e| {
let event_id = &e.0.event_id;
tracing::trace!(%event_id, "trying to send message in a closed session")
});
}
async fn sync(&mut self, index: usize) -> Result<(), SessionError> {
let Some(front) = self.cache.front() else {
return Ok(());
};
let sync_index = index.saturating_sub(front.event_id.index);
if sync_index > self.cache.len() {
// invalid index
return Err(SessionError::InvalidEventId);
}
for message in self.cache.iter().skip(sync_index) {
let send_result = self.tx.send(message.clone()).await;
if send_result.is_err() {
return Err(SessionError::ChannelClosed(
message.event_id.http_request_id,
));
}
}
Ok(())
}
}
struct HttpRequestWise {
resources: HashSet<ResourceKey>,
tx: CachedTx,
}
type HttpRequestId = u64;
#[derive(Debug, Clone, Hash, PartialEq, Eq)]
enum ResourceKey {
McpRequestId(RequestId),
ProgressToken(ProgressToken),
}
struct SessionContext {
id: SessionId,
next_http_request_id: HttpRequestId,
tx_router: HashMap<HttpRequestId, HttpRequestWise>,
resource_router: HashMap<ResourceKey, HttpRequestId>,
common: CachedTx,
to_service_tx: Sender<ClientJsonRpcMessage>,
event_rx: Receiver<SessionEvent>,
session_config: SessionConfig,
}
#[derive(Debug, Error)]
pub enum SessionError {
#[error("Invalid request id: {0}")]
DuplicatedRequestId(HttpRequestId),
#[error("Channel closed: {0:?}")]
ChannelClosed(Option<HttpRequestId>),
#[error("Cannot parse event id: {0}")]
EventIdParseError(Cow<'static, str>),
#[error("Session service terminated")]
SessionServiceTerminated,
#[error("Invalid event id")]
InvalidEventId,
#[error("Transport closed")]
TransportClosed,
#[error("IO error: {0}")]
Io(std::io::Error),
}
impl From<SessionError> for std::io::Error {
fn from(value: SessionError) -> Self {
match value {
SessionError::Io(io) => io,
_ => std::io::Error::new(std::io::ErrorKind::Other, format!("Session error: {value}")),
}
}
}
impl From<std::io::Error> for SessionError {
fn from(value: std::io::Error) -> Self {
SessionError::Io(value)
}
}
enum OutboundChannel {
RequestWise { id: HttpRequestId, close: bool },
Common,
}
pub struct StreamableHttpMessageReceiver {
pub http_request_id: Option<HttpRequestId>,
pub inner: Receiver<ServerSessionMessage>,
}
impl SessionContext {
fn unregister_resource(&mut self, resource: &ResourceKey) {
if let Some(http_request_id) = self.resource_router.remove(resource) {
tracing::trace!(?resource, http_request_id, "unregister resource");
if let Some(channel) = self.tx_router.get_mut(&http_request_id) {
channel.resources.remove(resource);
if channel.resources.is_empty() {
tracing::debug!(http_request_id, "close http request wise channel");
self.tx_router.remove(&http_request_id);
}
}
}
}
fn register_resource(&mut self, resource: ResourceKey, http_request_id: HttpRequestId) {
tracing::trace!(?resource, http_request_id, "register resource");
if let Some(channel) = self.tx_router.get_mut(&http_request_id) {
channel.resources.insert(resource.clone());
self.resource_router.insert(resource, http_request_id);
}
}
fn register_request(
&mut self,
request: &JsonRpcRequest<ClientRequest>,
http_request_id: HttpRequestId,
) {
use crate::model::GetMeta;
self.register_resource(
ResourceKey::McpRequestId(request.id.clone()),
http_request_id,
);
if let Some(progress_token) = request.request.get_meta().get_progress_token() {
self.register_resource(
ResourceKey::ProgressToken(progress_token.clone()),
http_request_id,
);
}
}
fn catch_cancellation_notification(
&mut self,
notification: &JsonRpcNotification<ClientNotification>,
) {
if let ClientNotification::CancelledNotification(n) = &notification.notification {
let request_id = n.params.request_id.clone();
let resource = ResourceKey::McpRequestId(request_id);
self.unregister_resource(&resource);
}
}
fn next_http_request_id(&mut self) -> HttpRequestId {
let id = self.next_http_request_id;
self.next_http_request_id = self.next_http_request_id.wrapping_add(1);
id
}
async fn send_to_service(&self, message: ClientJsonRpcMessage) -> Result<(), SessionError> {
if self.to_service_tx.send(message).await.is_err() {
return Err(SessionError::TransportClosed);
}
Ok(())
}
async fn establish_request_wise_channel(
&mut self,
) -> Result<StreamableHttpMessageReceiver, SessionError> {
let http_request_id = self.next_http_request_id();
let (tx, rx) = tokio::sync::mpsc::channel(self.session_config.channel_capacity);
self.tx_router.insert(
http_request_id,
HttpRequestWise {
resources: Default::default(),
tx: CachedTx::new(tx, Some(http_request_id)),
},
);
tracing::debug!(http_request_id, "establish new request wise channel");
Ok(StreamableHttpMessageReceiver {
http_request_id: Some(http_request_id),
inner: rx,
})
}
fn resolve_outbound_channel(&self, message: &ServerJsonRpcMessage) -> OutboundChannel {
match &message {
ServerJsonRpcMessage::Request(_) => OutboundChannel::Common,
ServerJsonRpcMessage::Notification(JsonRpcNotification {
notification:
ServerNotification::ProgressNotification(Notification {
params: ProgressNotificationParam { progress_token, .. },
..
}),
..
}) => {
let id = self
.resource_router
.get(&ResourceKey::ProgressToken(progress_token.clone()));
if let Some(id) = id {
OutboundChannel::RequestWise {
id: *id,
close: false,
}
} else {
OutboundChannel::Common
}
}
ServerJsonRpcMessage::Notification(JsonRpcNotification {
notification:
ServerNotification::CancelledNotification(Notification {
params: CancelledNotificationParam { request_id, .. },
..
}),
..
}) => {
if let Some(id) = self
.resource_router
.get(&ResourceKey::McpRequestId(request_id.clone()))
{
OutboundChannel::RequestWise {
id: *id,
close: false,
}
} else {
OutboundChannel::Common
}
}
ServerJsonRpcMessage::Notification(_) => OutboundChannel::Common,
ServerJsonRpcMessage::Response(json_rpc_response) => {
if let Some(id) = self
.resource_router
.get(&ResourceKey::McpRequestId(json_rpc_response.id.clone()))
{
OutboundChannel::RequestWise {
id: *id,
close: false,
}
} else {
OutboundChannel::Common
}
}
ServerJsonRpcMessage::Error(json_rpc_error) => {
if let Some(id) = self
.resource_router
.get(&ResourceKey::McpRequestId(json_rpc_error.id.clone()))
{
OutboundChannel::RequestWise {
id: *id,
close: false,
}
} else {
OutboundChannel::Common
}
}
ServerJsonRpcMessage::BatchRequest(_) | ServerJsonRpcMessage::BatchResponse(_) => {
// the server side should never yield a batch request or response now
unreachable!("server side won't yield batch request or response")
}
}
}
async fn handle_server_message(
&mut self,
message: ServerJsonRpcMessage,
) -> Result<(), SessionError> {
let outbound_channel = self.resolve_outbound_channel(&message);
match outbound_channel {
OutboundChannel::RequestWise { id, close } => {
if let Some(request_wise) = self.tx_router.get_mut(&id) {
request_wise.tx.send(message).await;
if close {
self.tx_router.remove(&id);
}
} else {
return Err(SessionError::ChannelClosed(Some(id)));
}
}
OutboundChannel::Common => self.common.send(message).await,
}
Ok(())
}
async fn resume(
&mut self,
last_event_id: EventId,
) -> Result<StreamableHttpMessageReceiver, SessionError> {
match last_event_id.http_request_id {
Some(http_request_id) => {
let request_wise = self
.tx_router
.get_mut(&http_request_id)
.ok_or(SessionError::ChannelClosed(Some(http_request_id)))?;
let channel = tokio::sync::mpsc::channel(self.session_config.channel_capacity);
let (tx, rx) = channel;
request_wise.tx.tx = tx;
let index = last_event_id.index;
// sync messages after index
request_wise.tx.sync(index).await?;
Ok(StreamableHttpMessageReceiver {
http_request_id: Some(http_request_id),
inner: rx,
})
}
None => {
let channel = tokio::sync::mpsc::channel(self.session_config.channel_capacity);
let (tx, rx) = channel;
self.common.tx = tx;
let index = last_event_id.index;
// sync messages after index
self.common.sync(index).await?;
Ok(StreamableHttpMessageReceiver {
http_request_id: None,
inner: rx,
})
}
}
}
}
enum SessionEvent {
ServiceMessage(ServerJsonRpcMessage),
ClientMessage {
message: ClientJsonRpcMessage,
http_request_id: Option<HttpRequestId>,
},
EstablishRequestWiseChannel {
responder: oneshot::Sender<Result<StreamableHttpMessageReceiver, SessionError>>,
},
CloseRequestWiseChannel {
id: HttpRequestId,
responder: oneshot::Sender<Result<(), SessionError>>,
},
Resume {
last_event_id: EventId,
responder: oneshot::Sender<Result<StreamableHttpMessageReceiver, SessionError>>,
},
InitializeRequest {
request: ClientJsonRpcMessage,
responder: oneshot::Sender<Result<ServerJsonRpcMessage, SessionError>>,
},
}
#[derive(Debug, Clone)]
pub enum SessionQuitReason {
ServiceTerminated,
ClientTerminated,
ExpectInitializeRequest,
ExpectInitializeResponse,
Cancelled,
}
impl SessionContext {
#[instrument(name = "streamable_http_session", skip_all, fields(id = self.id.as_ref()))]
pub async fn run(mut self, ct: CancellationToken) -> SessionQuitReason {
// waiting for initialize request
let Some(evt) = self.event_rx.recv().await else {
return SessionQuitReason::ServiceTerminated;
};
let SessionEvent::InitializeRequest { request, responder } = evt else {
return SessionQuitReason::ExpectInitializeRequest;
};
let send_result = self.send_to_service(request).await;
if let Err(e) = send_result {
let _ = responder.send(Err(e));
return SessionQuitReason::ServiceTerminated;
}
let Some(evt) = self.event_rx.recv().await else {
return SessionQuitReason::ServiceTerminated;
};
let SessionEvent::ServiceMessage(response) = evt else {
return SessionQuitReason::ExpectInitializeResponse;
};
let response_result = responder.send(Ok(response));
if response_result.is_err() {
return SessionQuitReason::ClientTerminated;
}
let quit_reason = loop {
let event = tokio::select! {
event = self.event_rx.recv() => {
if let Some(event) = event {
event
} else {
break SessionQuitReason::ServiceTerminated;
}
},
_ = ct.cancelled() => {
break SessionQuitReason::Cancelled;
}
};
match event {
SessionEvent::ServiceMessage(json_rpc_message) => {
// catch response
match &json_rpc_message {
crate::model::JsonRpcMessage::Response(json_rpc_response) => {
let request_id = json_rpc_response.id.clone();
self.unregister_resource(&ResourceKey::McpRequestId(request_id));
}
crate::model::JsonRpcMessage::Error(json_rpc_error) => {
let request_id = json_rpc_error.id.clone();
self.unregister_resource(&ResourceKey::McpRequestId(request_id));
}
// unlikely happen
crate::model::JsonRpcMessage::BatchResponse(
json_rpc_batch_response_items,
) => {
for item in json_rpc_batch_response_items {
let request_id = match item {
crate::model::JsonRpcBatchResponseItem::Response(
json_rpc_response,
) => json_rpc_response.id.clone(),
crate::model::JsonRpcBatchResponseItem::Error(
json_rpc_error,
) => json_rpc_error.id.clone(),
};
self.unregister_resource(&ResourceKey::McpRequestId(request_id));
}
}
_ => {
// no need to unregister resource
}
}
let _handle_result = self.handle_server_message(json_rpc_message).await;
}
SessionEvent::ClientMessage {
message: json_rpc_message,
http_request_id,
} => {
match &json_rpc_message {
crate::model::JsonRpcMessage::Request(request) => {
if let Some(http_request_id) = http_request_id {
self.register_request(request, http_request_id)
}
}
crate::model::JsonRpcMessage::Notification(notification) => {
self.catch_cancellation_notification(notification)
}
crate::model::JsonRpcMessage::BatchRequest(items) => {
for r in items {
match r {
crate::model::JsonRpcBatchRequestItem::Request(request) => {
if let Some(http_request_id) = http_request_id {
self.register_request(request, http_request_id)
}
}
crate::model::JsonRpcBatchRequestItem::Notification(
notification,
) => self.catch_cancellation_notification(notification),
}
}
}
_ => {}
}
let _handle_result = self.send_to_service(json_rpc_message).await;
}
SessionEvent::EstablishRequestWiseChannel { responder } => {
let handle_result = self.establish_request_wise_channel().await;
let _ = responder.send(handle_result);
}
SessionEvent::CloseRequestWiseChannel { id, responder } => {
let _handle_result = self.tx_router.remove(&id);
let _ = responder.send(Ok(()));
}
SessionEvent::Resume {
last_event_id,
responder,
} => {
let handle_result = self.resume(last_event_id).await;
let _ = responder.send(handle_result);
}
_ => {
// ignore
}
}
};
tracing::debug!("session terminated: {:?}", quit_reason);
quit_reason
}
}
pub struct Session {
handle: SessionHandle,
guard: DropGuard,
task_handle: tokio::task::JoinHandle<SessionQuitReason>,
}
impl Session {
pub fn handle(&self) -> &SessionHandle {
&self.handle
}
pub async fn cancel(self) -> Result<SessionQuitReason, tokio::task::JoinError> {
self.guard.disarm().cancel();
self.task_handle.await
}
}
#[derive(Debug, Clone)]
pub struct SessionHandle {
// after all event_tx drop, inner task will be terminated
event_tx: Sender<SessionEvent>,
}
impl SessionHandle {
pub async fn push_message(
&self,
message: ClientJsonRpcMessage,
http_request_id: Option<HttpRequestId>,
) -> Result<(), SessionError> {
self.event_tx
.send(SessionEvent::ClientMessage {
message,
http_request_id,
})
.await
.map_err(|_| SessionError::SessionServiceTerminated)?;
Ok(())
}
pub async fn establish_request_wise_channel(
&self,
) -> Result<StreamableHttpMessageReceiver, SessionError> {
let (tx, rx) = tokio::sync::oneshot::channel();
self.event_tx
.send(SessionEvent::EstablishRequestWiseChannel { responder: tx })
.await
.map_err(|_| SessionError::SessionServiceTerminated)?;
rx.await
.map_err(|_| SessionError::SessionServiceTerminated)?
}
pub async fn close_request_wise_channel(
&self,
request_id: HttpRequestId,
) -> Result<(), SessionError> {
let (tx, rx) = tokio::sync::oneshot::channel();
self.event_tx
.send(SessionEvent::CloseRequestWiseChannel {
id: request_id,
responder: tx,
})
.await
.map_err(|_| SessionError::SessionServiceTerminated)?;
rx.await
.map_err(|_| SessionError::SessionServiceTerminated)?
}
pub async fn establish_common_channel(
&self,
) -> Result<StreamableHttpMessageReceiver, SessionError> {
let (tx, rx) = tokio::sync::oneshot::channel();
self.event_tx
.send(SessionEvent::Resume {
last_event_id: EventId {
http_request_id: None,
index: 0,
},
responder: tx,
})
.await
.map_err(|_| SessionError::SessionServiceTerminated)?;
rx.await
.map_err(|_| SessionError::SessionServiceTerminated)?
}
pub async fn resume(
&self,
last_event_id: EventId,
) -> Result<StreamableHttpMessageReceiver, SessionError> {
let (tx, rx) = tokio::sync::oneshot::channel();
self.event_tx
.send(SessionEvent::Resume {
last_event_id,
responder: tx,
})
.await
.map_err(|_| SessionError::SessionServiceTerminated)?;
rx.await
.map_err(|_| SessionError::SessionServiceTerminated)?
}
pub async fn initialize(
&self,
request: ClientJsonRpcMessage,
) -> Result<ServerJsonRpcMessage, SessionError> {
let (tx, rx) = tokio::sync::oneshot::channel();
self.event_tx
.send(SessionEvent::InitializeRequest {
request,
responder: tx,
})
.await
.map_err(|_| SessionError::SessionServiceTerminated)?;
rx.await
.map_err(|_| SessionError::SessionServiceTerminated)?
}
}
pub struct SessionTransport {
session_handle: SessionHandle,
to_service_rx: Receiver<ClientJsonRpcMessage>,
}
impl IntoTransport<RoleServer, SessionError, ()> for SessionTransport {
fn into_transport(
self,
) -> (
impl Sink<ServerJsonRpcMessage, Error = SessionError> + Send + 'static,
impl Stream<Item = ClientJsonRpcMessage> + Send + 'static,
) {
let stream = ReceiverStream::new(self.to_service_rx);
let sink = PollSender::new(self.session_handle.event_tx.clone())
.sink_map_err(|_| SessionError::SessionServiceTerminated)
.with(async |m| Ok(SessionEvent::ServiceMessage(m)));
(sink, stream)
}
}
#[derive(Debug, Clone)]
pub struct SessionConfig {
channel_capacity: usize,
}
impl SessionConfig {
pub const DEFAULT_CHANNEL_CAPACITY: usize = 16;
}
impl Default for SessionConfig {
fn default() -> Self {
Self {
channel_capacity: Self::DEFAULT_CHANNEL_CAPACITY,
}
}
}
pub fn create_session(id: SessionId, config: SessionConfig) -> (Session, SessionTransport) {
let (to_service_tx, to_service_rx) = tokio::sync::mpsc::channel(config.channel_capacity);
let (event_tx, event_rx) = tokio::sync::mpsc::channel(config.channel_capacity);
let (common_tx, _) = tokio::sync::mpsc::channel(config.channel_capacity);
let common = CachedTx::new_common(common_tx);
tracing::info!(session_id = ?id, "create new session");
let session_context = SessionContext {
next_http_request_id: 0,
id,
tx_router: HashMap::new(),
resource_router: HashMap::new(),
common,
to_service_tx,
event_rx,
session_config: config.clone(),
};
let ct = CancellationToken::new();
let handle = SessionHandle { event_tx };
let task_handle = tokio::spawn(session_context.run(ct.child_token()));
let session = Session {
handle: handle.clone(),
task_handle,
guard: ct.drop_guard(),
};
let session_transport = SessionTransport {
to_service_rx,
session_handle: handle,
};
(session, session_transport)
}

View file

@ -1,12 +1,13 @@
use rmcp::{
ServiceExt,
transport::{SseServer, TokioChildProcess},
transport::{SseServer, TokioChildProcess, streamable_http_server::axum::StreamableHttpServer},
};
use tracing_subscriber::{layer::SubscriberExt, util::SubscriberInitExt};
mod common;
use common::calculator::Calculator;
const BIND_ADDRESS: &str = "127.0.0.1:8000";
const SSE_BIND_ADDRESS: &str = "127.0.0.1:8000";
const STREAMABLE_HTTP_BIND_ADDRESS: &str = "127.0.0.1:8001";
#[tokio::test]
async fn test_with_js_client() -> anyhow::Result<()> {
@ -24,7 +25,7 @@ async fn test_with_js_client() -> anyhow::Result<()> {
.wait()
.await?;
let ct = SseServer::serve(BIND_ADDRESS.parse()?)
let ct = SseServer::serve(SSE_BIND_ADDRESS.parse()?)
.await?
.with_service(Calculator::default);
@ -66,3 +67,33 @@ async fn test_with_js_server() -> anyhow::Result<()> {
client.cancel().await?;
Ok(())
}
#[tokio::test]
async fn test_with_js_streamable_http_client() -> anyhow::Result<()> {
let _ = tracing_subscriber::registry()
.with(
tracing_subscriber::EnvFilter::try_from_default_env()
.unwrap_or_else(|_| "debug".to_string().into()),
)
.with(tracing_subscriber::fmt::layer())
.try_init();
tokio::process::Command::new("npm")
.arg("install")
.current_dir("tests/test_with_js")
.spawn()?
.wait()
.await?;
let ct = StreamableHttpServer::serve(STREAMABLE_HTTP_BIND_ADDRESS.parse()?)
.await?
.with_service(Calculator::default);
let exit_status = tokio::process::Command::new("node")
.arg("tests/test_with_js/streamable_client.js")
.spawn()?
.wait()
.await?;
assert!(exit_status.success());
ct.cancel();
Ok(())
}

View file

@ -1,6 +1,7 @@
{
"dependencies": {
"@modelcontextprotocol/sdk": "^1.7.0"
"@modelcontextprotocol/sdk": "^1.10",
"eventsource-parser": "^3.0.1"
},
"type": "module",
"name": "test_with_ts",

View file

@ -0,0 +1,28 @@
import { Client } from "@modelcontextprotocol/sdk/client/index.js";
import { StreamableHTTPClientTransport } from "@modelcontextprotocol/sdk/client/streamableHttp.js";
const transport = new StreamableHTTPClientTransport(new URL(`http://127.0.0.1:8001/`));
const client = new Client(
{
name: "example-client",
version: "1.0.0"
},
{
capabilities: {
prompts: {},
resources: {},
tools: {}
}
}
);
await client.connect(transport);
const tools = await client.listTools();
console.log(tools);
const resources = await client.listResources();
console.log(resources);
const templates = await client.listResourceTemplates();
console.log(templates);
const prompts = await client.listPrompts();
console.log(prompts);
await client.close();

View file

@ -1,3 +1,5 @@
[package]
name = "mcp-server-examples"
version = "0.1.5"
@ -5,7 +7,7 @@ edition = "2024"
publish = false
[dependencies]
rmcp= { path = "../../crates/rmcp", features = ["server", "transport-sse-server", "transport-io", "auth"] }
rmcp= { path = "../../crates/rmcp", features = ["server", "transport-sse-server", "transport-io", "transport-streamable-http-server", "auth"] }
tokio = { version = "1", features = ["macros", "rt", "rt-multi-thread", "io-std", "signal"] }
serde = { version = "1.0", features = ["derive"] }
serde_json = "1.0"
@ -49,6 +51,10 @@ path = "src/axum_router.rs"
name = "servers_generic_server"
path = "src/generic_service.rs"
[[example]]
name = "servers_axum_streamable_http"
path = "src/axum_streamable_http.rs"
[[example]]
name = "servers_auth_sse"
path = "src/auth_sse.rs"

View file

@ -0,0 +1,29 @@
use rmcp::transport::streamable_http_server::axum::StreamableHttpServer;
use tracing_subscriber::{
layer::SubscriberExt,
util::SubscriberInitExt,
{self},
};
mod common;
use common::counter::Counter;
const BIND_ADDRESS: &str = "127.0.0.1:8000";
#[tokio::main]
async fn main() -> anyhow::Result<()> {
tracing_subscriber::registry()
.with(
tracing_subscriber::EnvFilter::try_from_default_env()
.unwrap_or_else(|_| "debug".to_string().into()),
)
.with(tracing_subscriber::fmt::layer())
.init();
let ct = StreamableHttpServer::serve(BIND_ADDRESS.parse()?)
.await?
.with_service(Counter::new);
tokio::signal::ctrl_c().await?;
ct.cancel();
Ok(())
}

View file

@ -13,6 +13,6 @@ async fn main() -> Result<(), Box<dyn Error>> {
let io = (tokio::io::stdin(), tokio::io::stdout());
serve_server(generic_service, io).await?.waiting().await?;
serve_server(generic_service, io).await?;
Ok(())
}