Files
llmx/codex-rs/mcp-server/src/message_processor.rs
jcoens-openai 8a89d3aeda Update cargo to 2024 edition (#842)
Some effects of this change:
- New formatting changes across many files. No functionality changes
should occur from that.
- Calls to `set_env` are considered unsafe, since this only happens in
tests we wrap them in `unsafe` blocks
2025-05-07 08:37:48 -07:00

468 lines
17 KiB
Rust
Raw Blame History

This file contains ambiguous Unicode characters
This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.
use crate::codex_tool_config::CodexToolCallParam;
use crate::codex_tool_config::create_tool_for_codex_tool_call_param;
use codex_core::config::Config as CodexConfig;
use mcp_types::CallToolRequestParams;
use mcp_types::CallToolResult;
use mcp_types::CallToolResultContent;
use mcp_types::ClientRequest;
use mcp_types::JSONRPC_VERSION;
use mcp_types::JSONRPCBatchRequest;
use mcp_types::JSONRPCBatchResponse;
use mcp_types::JSONRPCError;
use mcp_types::JSONRPCErrorError;
use mcp_types::JSONRPCMessage;
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::mpsc;
use tokio::task;
pub(crate) struct MessageProcessor {
outgoing: mpsc::Sender<JSONRPCMessage>,
initialized: bool,
}
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: mpsc::Sender<JSONRPCMessage>) -> Self {
Self {
outgoing,
initialized: false,
}
}
pub(crate) 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);
}
ClientRequest::PingRequest(params) => {
self.handle_ping(request_id, params);
}
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);
}
ClientRequest::CallToolRequest(params) => {
self.handle_call_tool(request_id, params);
}
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) fn process_response(&mut self, response: JSONRPCResponse) {
tracing::info!("<- response: {:?}", response);
}
/// Handle a fire-and-forget JSON-RPC notification.
pub(crate) 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);
}
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 a batch of requests and/or notifications.
pub(crate) fn process_batch_request(&mut self, batch: JSONRPCBatchRequest) {
tracing::info!("<- batch request containing {} item(s)", batch.len());
for item in batch {
match item {
mcp_types::JSONRPCBatchRequestItem::JSONRPCRequest(req) => {
self.process_request(req);
}
mcp_types::JSONRPCBatchRequestItem::JSONRPCNotification(note) => {
self.process_notification(note);
}
}
}
}
/// Handle an error object received from the peer.
pub(crate) fn process_error(&mut self, err: JSONRPCError) {
tracing::error!("<- error: {:?}", err);
}
/// Handle a batch of responses/errors.
pub(crate) fn process_batch_response(&mut self, batch: JSONRPCBatchResponse) {
tracing::info!("<- batch response containing {} item(s)", batch.len());
for item in batch {
match item {
mcp_types::JSONRPCBatchResponseItem::JSONRPCResponse(resp) => {
self.process_response(resp);
}
mcp_types::JSONRPCBatchResponseItem::JSONRPCError(err) => {
self.process_error(err);
}
}
}
}
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_msg = JSONRPCMessage::Error(JSONRPCError {
jsonrpc: JSONRPC_VERSION.into(),
id,
error: JSONRPCErrorError {
code: -32600, // Invalid Request
message: "initialize called more than once".to_string(),
data: None,
},
});
if let Err(e) = self.outgoing.try_send(error_msg) {
tracing::error!("Failed to send initialization error: {e}");
}
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: mcp_types::MCP_SCHEMA_VERSION.to_string(),
},
};
self.send_response::<mcp_types::InitializeRequest>(id, result);
}
fn send_response<T>(&self, id: RequestId, result: T::Result)
where
T: ModelContextProtocolRequest,
{
let response = JSONRPCMessage::Response(JSONRPCResponse {
jsonrpc: JSONRPC_VERSION.into(),
id,
result: serde_json::to_value(result).unwrap(),
});
if let Err(e) = self.outgoing.try_send(response) {
tracing::error!("Failed to send response: {e}");
}
}
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);
}
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);
}
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()],
next_cursor: None,
};
self.send_response::<mcp_types::ListToolsRequest>(id, result);
}
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;
// We only support the "codex" tool for now.
if name != "codex" {
// Tool not found return error result so the LLM can react.
let result = CallToolResult {
content: vec![CallToolResultContent::TextContent(TextContent {
r#type: "text".to_string(),
text: format!("Unknown tool '{name}'"),
annotations: None,
})],
is_error: Some(true),
};
self.send_response::<mcp_types::CallToolRequest>(id, result);
return;
}
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() {
Ok(cfg) => cfg,
Err(e) => {
let result = CallToolResult {
content: vec![CallToolResultContent::TextContent(TextContent {
r#type: "text".to_owned(),
text: format!(
"Failed to load Codex configuration from overrides: {e}"
),
annotations: None,
})],
is_error: Some(true),
};
self.send_response::<mcp_types::CallToolRequest>(id, result);
return;
}
},
Err(e) => {
let result = CallToolResult {
content: vec![CallToolResultContent::TextContent(TextContent {
r#type: "text".to_owned(),
text: format!("Failed to parse configuration for Codex tool: {e}"),
annotations: None,
})],
is_error: Some(true),
};
self.send_response::<mcp_types::CallToolRequest>(id, result);
return;
}
},
None => {
let result = CallToolResult {
content: vec![CallToolResultContent::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),
};
self.send_response::<mcp_types::CallToolRequest>(id, result);
return;
}
};
// Clone outgoing sender to move into async task.
let outgoing = self.outgoing.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)
.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
// ---------------------------------------------------------------------
fn handle_cancelled_notification(
&self,
params: <mcp_types::CancelledNotification as mcp_types::ModelContextProtocolNotification>::Params,
) {
tracing::info!("notifications/cancelled -> params: {:?}", params);
}
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);
}
}