Files
llmx/codex-rs/mcp-server/src/message_processor.rs
2025-07-22 20:33:49 +00:00

635 lines
24 KiB
Rust

use std::collections::HashMap;
use std::path::PathBuf;
use std::sync::Arc;
use crate::codex_tool_config::CodexToolCallParam;
use crate::codex_tool_config::CodexToolCallReplyParam;
use crate::codex_tool_config::create_tool_for_codex_tool_call_param;
use crate::codex_tool_config::create_tool_for_codex_tool_call_reply_param;
use crate::outgoing_message::OutgoingMessageSender;
use codex_core::Codex;
use codex_core::config::Config as CodexConfig;
use codex_core::protocol::Submission;
use mcp_types::CallToolRequestParams;
use mcp_types::CallToolResult;
use mcp_types::ClientRequest;
use mcp_types::ContentBlock;
use mcp_types::JSONRPCError;
use mcp_types::JSONRPCErrorError;
use mcp_types::JSONRPCNotification;
use mcp_types::JSONRPCRequest;
use mcp_types::JSONRPCResponse;
use mcp_types::ListToolsResult;
use mcp_types::ModelContextProtocolRequest;
use mcp_types::RequestId;
use mcp_types::ServerCapabilitiesTools;
use mcp_types::ServerNotification;
use mcp_types::TextContent;
use serde_json::json;
use tokio::sync::Mutex;
use tokio::task;
use uuid::Uuid;
pub(crate) struct MessageProcessor {
outgoing: Arc<OutgoingMessageSender>,
initialized: bool,
codex_linux_sandbox_exe: Option<PathBuf>,
session_map: Arc<Mutex<HashMap<Uuid, Arc<Codex>>>>,
running_requests_id_to_codex_uuid: Arc<Mutex<HashMap<RequestId, Uuid>>>,
}
impl MessageProcessor {
/// Create a new `MessageProcessor`, retaining a handle to the outgoing
/// `Sender` so handlers can enqueue messages to be written to stdout.
pub(crate) fn new(
outgoing: OutgoingMessageSender,
codex_linux_sandbox_exe: Option<PathBuf>,
) -> Self {
Self {
outgoing: Arc::new(outgoing),
initialized: false,
codex_linux_sandbox_exe,
session_map: Arc::new(Mutex::new(HashMap::new())),
running_requests_id_to_codex_uuid: Arc::new(Mutex::new(HashMap::new())),
}
}
pub(crate) async fn process_request(&mut self, request: JSONRPCRequest) {
// Hold on to the ID so we can respond.
let request_id = request.id.clone();
let client_request = match ClientRequest::try_from(request) {
Ok(client_request) => client_request,
Err(e) => {
tracing::warn!("Failed to convert request: {e}");
return;
}
};
// Dispatch to a dedicated handler for each request type.
match client_request {
ClientRequest::InitializeRequest(params) => {
self.handle_initialize(request_id, params).await;
}
ClientRequest::PingRequest(params) => {
self.handle_ping(request_id, params).await;
}
ClientRequest::ListResourcesRequest(params) => {
self.handle_list_resources(params);
}
ClientRequest::ListResourceTemplatesRequest(params) => {
self.handle_list_resource_templates(params);
}
ClientRequest::ReadResourceRequest(params) => {
self.handle_read_resource(params);
}
ClientRequest::SubscribeRequest(params) => {
self.handle_subscribe(params);
}
ClientRequest::UnsubscribeRequest(params) => {
self.handle_unsubscribe(params);
}
ClientRequest::ListPromptsRequest(params) => {
self.handle_list_prompts(params);
}
ClientRequest::GetPromptRequest(params) => {
self.handle_get_prompt(params);
}
ClientRequest::ListToolsRequest(params) => {
self.handle_list_tools(request_id, params).await;
}
ClientRequest::CallToolRequest(params) => {
self.handle_call_tool(request_id, params).await;
}
ClientRequest::SetLevelRequest(params) => {
self.handle_set_level(params);
}
ClientRequest::CompleteRequest(params) => {
self.handle_complete(params);
}
}
}
/// Handle a standalone JSON-RPC response originating from the peer.
pub(crate) async fn process_response(&mut self, response: JSONRPCResponse) {
tracing::info!("<- response: {:?}", response);
let JSONRPCResponse { id, result, .. } = response;
self.outgoing.notify_client_response(id, result).await
}
/// Handle a fire-and-forget JSON-RPC notification.
pub(crate) async fn process_notification(&mut self, notification: JSONRPCNotification) {
let server_notification = match ServerNotification::try_from(notification) {
Ok(n) => n,
Err(e) => {
tracing::warn!("Failed to convert notification: {e}");
return;
}
};
// Similar to requests, route each notification type to its own stub
// handler so additional logic can be implemented incrementally.
match server_notification {
ServerNotification::CancelledNotification(params) => {
self.handle_cancelled_notification(params).await;
}
ServerNotification::ProgressNotification(params) => {
self.handle_progress_notification(params);
}
ServerNotification::ResourceListChangedNotification(params) => {
self.handle_resource_list_changed(params);
}
ServerNotification::ResourceUpdatedNotification(params) => {
self.handle_resource_updated(params);
}
ServerNotification::PromptListChangedNotification(params) => {
self.handle_prompt_list_changed(params);
}
ServerNotification::ToolListChangedNotification(params) => {
self.handle_tool_list_changed(params);
}
ServerNotification::LoggingMessageNotification(params) => {
self.handle_logging_message(params);
}
}
}
/// Handle an error object received from the peer.
pub(crate) fn process_error(&mut self, err: JSONRPCError) {
tracing::error!("<- error: {:?}", err);
}
async fn handle_initialize(
&mut self,
id: RequestId,
params: <mcp_types::InitializeRequest as ModelContextProtocolRequest>::Params,
) {
tracing::info!("initialize -> params: {:?}", params);
if self.initialized {
// Already initialised: send JSON-RPC error response.
let error = JSONRPCErrorError {
code: -32600, // Invalid Request
message: "initialize called more than once".to_string(),
data: None,
};
self.outgoing.send_error(id, error).await;
return;
}
self.initialized = true;
// Build a minimal InitializeResult. Fill with placeholders.
let result = mcp_types::InitializeResult {
capabilities: mcp_types::ServerCapabilities {
completions: None,
experimental: None,
logging: None,
prompts: None,
resources: None,
tools: Some(ServerCapabilitiesTools {
list_changed: Some(true),
}),
},
instructions: None,
protocol_version: params.protocol_version.clone(),
server_info: mcp_types::Implementation {
name: "codex-mcp-server".to_string(),
version: env!("CARGO_PKG_VERSION").to_string(),
title: Some("Codex".to_string()),
},
};
self.send_response::<mcp_types::InitializeRequest>(id, result)
.await;
}
async fn send_response<T>(&self, id: RequestId, result: T::Result)
where
T: ModelContextProtocolRequest,
{
// result has `Serialized` instance so should never fail
#[expect(clippy::unwrap_used)]
let result = serde_json::to_value(result).unwrap();
self.outgoing.send_response(id, result).await;
}
async fn handle_ping(
&self,
id: RequestId,
params: <mcp_types::PingRequest as mcp_types::ModelContextProtocolRequest>::Params,
) {
tracing::info!("ping -> params: {:?}", params);
let result = json!({});
self.send_response::<mcp_types::PingRequest>(id, result)
.await;
}
fn handle_list_resources(
&self,
params: <mcp_types::ListResourcesRequest as mcp_types::ModelContextProtocolRequest>::Params,
) {
tracing::info!("resources/list -> params: {:?}", params);
}
fn handle_list_resource_templates(
&self,
params:
<mcp_types::ListResourceTemplatesRequest as mcp_types::ModelContextProtocolRequest>::Params,
) {
tracing::info!("resources/templates/list -> params: {:?}", params);
}
fn handle_read_resource(
&self,
params: <mcp_types::ReadResourceRequest as mcp_types::ModelContextProtocolRequest>::Params,
) {
tracing::info!("resources/read -> params: {:?}", params);
}
fn handle_subscribe(
&self,
params: <mcp_types::SubscribeRequest as mcp_types::ModelContextProtocolRequest>::Params,
) {
tracing::info!("resources/subscribe -> params: {:?}", params);
}
fn handle_unsubscribe(
&self,
params: <mcp_types::UnsubscribeRequest as mcp_types::ModelContextProtocolRequest>::Params,
) {
tracing::info!("resources/unsubscribe -> params: {:?}", params);
}
fn handle_list_prompts(
&self,
params: <mcp_types::ListPromptsRequest as mcp_types::ModelContextProtocolRequest>::Params,
) {
tracing::info!("prompts/list -> params: {:?}", params);
}
fn handle_get_prompt(
&self,
params: <mcp_types::GetPromptRequest as mcp_types::ModelContextProtocolRequest>::Params,
) {
tracing::info!("prompts/get -> params: {:?}", params);
}
async fn handle_list_tools(
&self,
id: RequestId,
params: <mcp_types::ListToolsRequest as mcp_types::ModelContextProtocolRequest>::Params,
) {
tracing::trace!("tools/list -> {params:?}");
let result = ListToolsResult {
tools: vec![
create_tool_for_codex_tool_call_param(),
create_tool_for_codex_tool_call_reply_param(),
],
next_cursor: None,
};
self.send_response::<mcp_types::ListToolsRequest>(id, result)
.await;
}
async fn handle_call_tool(
&self,
id: RequestId,
params: <mcp_types::CallToolRequest as mcp_types::ModelContextProtocolRequest>::Params,
) {
tracing::info!("tools/call -> params: {:?}", params);
let CallToolRequestParams { name, arguments } = params;
match name.as_str() {
"codex" => self.handle_tool_call_codex(id, arguments).await,
"codex-reply" => {
self.handle_tool_call_codex_session_reply(id, arguments)
.await
}
_ => {
let result = CallToolResult {
content: vec![ContentBlock::TextContent(TextContent {
r#type: "text".to_string(),
text: format!("Unknown tool '{name}'"),
annotations: None,
})],
is_error: Some(true),
structured_content: None,
};
self.send_response::<mcp_types::CallToolRequest>(id, result)
.await;
}
}
}
async fn handle_tool_call_codex(&self, id: RequestId, arguments: Option<serde_json::Value>) {
let (initial_prompt, config): (String, CodexConfig) = match arguments {
Some(json_val) => match serde_json::from_value::<CodexToolCallParam>(json_val) {
Ok(tool_cfg) => match tool_cfg.into_config(self.codex_linux_sandbox_exe.clone()) {
Ok(cfg) => cfg,
Err(e) => {
let result = CallToolResult {
content: vec![ContentBlock::TextContent(TextContent {
r#type: "text".to_owned(),
text: format!(
"Failed to load Codex configuration from overrides: {e}"
),
annotations: None,
})],
is_error: Some(true),
structured_content: None,
};
self.send_response::<mcp_types::CallToolRequest>(id, result)
.await;
return;
}
},
Err(e) => {
let result = CallToolResult {
content: vec![ContentBlock::TextContent(TextContent {
r#type: "text".to_owned(),
text: format!("Failed to parse configuration for Codex tool: {e}"),
annotations: None,
})],
is_error: Some(true),
structured_content: None,
};
self.send_response::<mcp_types::CallToolRequest>(id, result)
.await;
return;
}
},
None => {
let result = CallToolResult {
content: vec![ContentBlock::TextContent(TextContent {
r#type: "text".to_string(),
text:
"Missing arguments for codex tool-call; the `prompt` field is required."
.to_string(),
annotations: None,
})],
is_error: Some(true),
structured_content: None,
};
self.send_response::<mcp_types::CallToolRequest>(id, result)
.await;
return;
}
};
// Clone outgoing and session map to move into async task.
let outgoing = self.outgoing.clone();
let session_map = self.session_map.clone();
let running_requests_id_to_codex_uuid = self.running_requests_id_to_codex_uuid.clone();
// Spawn an async task to handle the Codex session so that we do not
// block the synchronous message-processing loop.
task::spawn(async move {
// Run the Codex session and stream events back to the client.
crate::codex_tool_runner::run_codex_tool_session(
id,
initial_prompt,
config,
outgoing,
session_map,
running_requests_id_to_codex_uuid,
)
.await;
});
}
async fn handle_tool_call_codex_session_reply(
&self,
request_id: RequestId,
arguments: Option<serde_json::Value>,
) {
tracing::info!("tools/call -> params: {:?}", arguments);
// parse arguments
let CodexToolCallReplyParam { session_id, prompt } = match arguments {
Some(json_val) => match serde_json::from_value::<CodexToolCallReplyParam>(json_val) {
Ok(params) => params,
Err(e) => {
tracing::error!("Failed to parse Codex tool call reply parameters: {e}");
let result = CallToolResult {
content: vec![ContentBlock::TextContent(TextContent {
r#type: "text".to_owned(),
text: format!("Failed to parse configuration for Codex tool: {e}"),
annotations: None,
})],
is_error: Some(true),
structured_content: None,
};
self.send_response::<mcp_types::CallToolRequest>(request_id, result)
.await;
return;
}
},
None => {
tracing::error!(
"Missing arguments for codex-reply tool-call; the `session_id` and `prompt` fields are required."
);
let result = CallToolResult {
content: vec![ContentBlock::TextContent(TextContent {
r#type: "text".to_owned(),
text: "Missing arguments for codex-reply tool-call; the `session_id` and `prompt` fields are required.".to_owned(),
annotations: None,
})],
is_error: Some(true),
structured_content: None,
};
self.send_response::<mcp_types::CallToolRequest>(request_id, result)
.await;
return;
}
};
let session_id = match Uuid::parse_str(&session_id) {
Ok(id) => id,
Err(e) => {
tracing::error!("Failed to parse session_id: {e}");
let result = CallToolResult {
content: vec![ContentBlock::TextContent(TextContent {
r#type: "text".to_owned(),
text: format!("Failed to parse session_id: {e}"),
annotations: None,
})],
is_error: Some(true),
structured_content: None,
};
self.send_response::<mcp_types::CallToolRequest>(request_id, result)
.await;
return;
}
};
// load codex from session map
let session_map_mutex = Arc::clone(&self.session_map);
// Clone outgoing and session map to move into async task.
let outgoing = self.outgoing.clone();
let running_requests_id_to_codex_uuid = self.running_requests_id_to_codex_uuid.clone();
let codex = {
let session_map = session_map_mutex.lock().await;
match session_map.get(&session_id).cloned() {
Some(c) => c,
None => {
tracing::warn!("Session not found for session_id: {session_id}");
let result = CallToolResult {
content: vec![ContentBlock::TextContent(TextContent {
r#type: "text".to_owned(),
text: format!("Session not found for session_id: {session_id}"),
annotations: None,
})],
is_error: Some(true),
structured_content: None,
};
outgoing
.send_response(request_id, serde_json::to_value(result).unwrap_or_default())
.await;
return;
}
}
};
// Spawn the long-running reply handler.
tokio::spawn({
let codex = codex.clone();
let outgoing = outgoing.clone();
let prompt = prompt.clone();
let running_requests_id_to_codex_uuid = running_requests_id_to_codex_uuid.clone();
async move {
crate::codex_tool_runner::run_codex_tool_session_reply(
codex,
outgoing,
request_id,
prompt,
running_requests_id_to_codex_uuid,
session_id,
)
.await;
}
});
}
fn handle_set_level(
&self,
params: <mcp_types::SetLevelRequest as mcp_types::ModelContextProtocolRequest>::Params,
) {
tracing::info!("logging/setLevel -> params: {:?}", params);
}
fn handle_complete(
&self,
params: <mcp_types::CompleteRequest as mcp_types::ModelContextProtocolRequest>::Params,
) {
tracing::info!("completion/complete -> params: {:?}", params);
}
// ---------------------------------------------------------------------
// Notification handlers
// ---------------------------------------------------------------------
async fn handle_cancelled_notification(
&self,
params: <mcp_types::CancelledNotification as mcp_types::ModelContextProtocolNotification>::Params,
) {
let request_id = params.request_id;
// Create a stable string form early for logging and submission id.
let request_id_string = match &request_id {
RequestId::String(s) => s.clone(),
RequestId::Integer(i) => i.to_string(),
};
// Obtain the session_id while holding the first lock, then release.
let session_id = {
let map_guard = self.running_requests_id_to_codex_uuid.lock().await;
match map_guard.get(&request_id) {
Some(id) => *id, // Uuid is Copy
None => {
tracing::warn!("Session not found for request_id: {}", request_id_string);
return;
}
}
};
tracing::info!("session_id: {session_id}");
// Obtain the Codex Arc while holding the session_map lock, then release.
let codex_arc = {
let sessions_guard = self.session_map.lock().await;
match sessions_guard.get(&session_id) {
Some(codex) => Arc::clone(codex),
None => {
tracing::warn!("Session not found for session_id: {session_id}");
return;
}
}
};
// Submit interrupt to Codex.
let err = codex_arc
.submit_with_id(Submission {
id: request_id_string,
op: codex_core::protocol::Op::Interrupt,
})
.await;
if let Err(e) = err {
tracing::error!("Failed to submit interrupt to Codex: {e}");
return;
}
// unregister the id so we don't keep it in the map
self.running_requests_id_to_codex_uuid
.lock()
.await
.remove(&request_id);
}
fn handle_progress_notification(
&self,
params: <mcp_types::ProgressNotification as mcp_types::ModelContextProtocolNotification>::Params,
) {
tracing::info!("notifications/progress -> params: {:?}", params);
}
fn handle_resource_list_changed(
&self,
params: <mcp_types::ResourceListChangedNotification as mcp_types::ModelContextProtocolNotification>::Params,
) {
tracing::info!(
"notifications/resources/list_changed -> params: {:?}",
params
);
}
fn handle_resource_updated(
&self,
params: <mcp_types::ResourceUpdatedNotification as mcp_types::ModelContextProtocolNotification>::Params,
) {
tracing::info!("notifications/resources/updated -> params: {:?}", params);
}
fn handle_prompt_list_changed(
&self,
params: <mcp_types::PromptListChangedNotification as mcp_types::ModelContextProtocolNotification>::Params,
) {
tracing::info!("notifications/prompts/list_changed -> params: {:?}", params);
}
fn handle_tool_list_changed(
&self,
params: <mcp_types::ToolListChangedNotification as mcp_types::ModelContextProtocolNotification>::Params,
) {
tracing::info!("notifications/tools/list_changed -> params: {:?}", params);
}
fn handle_logging_message(
&self,
params: <mcp_types::LoggingMessageNotification as mcp_types::ModelContextProtocolNotification>::Params,
) {
tracing::info!("notifications/message -> params: {:?}", params);
}
}