Robustness and Efficiency

DESCRIPTION

@@ -26,12 +26,13 @@ Imports:
     ellmer,
     jsonlite,
     later,
-    nanonext,
+    nanonext (>= 1.5.2.9009),
     promises,
     rlang
 Depends: R (>= 4.1.0)
 URL: https://github.com/simonpcouch/acquaint, https://simonpcouch.github.io/acquaint/
 BugReports: https://github.com/simonpcouch/acquaint/issues
 Config/Needs/website: tidyverse/tidytemplate
 Remotes:
-    posit-dev/btw
+    posit-dev/btw,
+    r-lib/nanonext

R/proxy.R

@@ -11,8 +11,7 @@ mcp_proxy <- function() {
 
   # Note that we're using file("stdin") instead of stdin(), which are not the
   # same.
-  the$f <- file("stdin")
-  open(the$f, blocking = FALSE)
+  the$f <- file("stdin", open = "r")
 
   schedule_handle_message_from_client()
   schedule_handle_message_from_server()
@@ -108,19 +107,19 @@ handle_message_from_server <- function(data) {
 
   logcat("FROM SERVER: ", data)
 
-  # The response_text is alredy JSON, so we'll use cat() instead of cat_json()
-  cat(data, "\n", sep = "")
+  # The response_text is already JSON, so we'll use cat() instead of cat_json()
+  nanonext::write_stdout(data)
 }
 
 schedule_handle_message_from_server <- function() {
-  r <- nanonext::recv_aio(the$proxy_socket)
+  r <- nanonext::recv_aio(the$proxy_socket, mode = "string")
   promises::as.promise(r)$then(handle_message_from_server)
 }
 
 forward_request <- function(data) {
   logcat("TO SERVER: ", data)
 
-  nanonext::send_aio(the$proxy_socket, data)
+  the$saio <- nanonext::send_aio(the$proxy_socket, data, mode = "raw")
 }
 
 # This process will be launched by the MCP client, so stdout/stderr aren't
@@ -132,7 +131,7 @@ logcat <- function(x, ..., append = TRUE) {
 }
 
 cat_json <- function(x) {
-  cat(to_json(x), "\n", sep = "")
+  nanonext::write_stdout(to_json(x))
 }
 
 capabilities <- function() {

R/server.R

@@ -1,16 +1,16 @@
 #' Model context protocol for your R session
-#' 
+#'
 #' @description
 #' Together, these functions implement a model context protocol server for your
 #' R session.
-#' 
-#' @section Configuration: 
-#' 
+#'
+#' @section Configuration:
+#'
 #' [mcp_proxy()] should be configured with the MCP clients via the `Rscript`
 #' command. For example, to use with Claude Desktop, paste the following in your
-#' Claude Desktop configuration (on macOS, at 
+#' Claude Desktop configuration (on macOS, at
 #' `file.edit("~/Library/Application Support/Claude/claude_desktop_config.json")`):
-#' 
+#'
 #' ```json
 #' {
 #'   "mcpServers": {
@@ -21,31 +21,31 @@
 #'   }
 #' }
 #' ```
-#' 
+#'
 #' Or, to use with Claude Code, you might type in a terminal:
-#' 
+#'
 #' ```bash
 #' claude mcp add -s "user" r-acquaint Rscript -e "acquaint::mcp_proxy()"
 #' ```
-#' 
+#'
 #' **mcp_proxy() is not intended for interactive use.**
-#' 
+#'
 #' The proxy interfaces with the MCP client on behalf of the server hosted in
 #' your R session. **Use [mcp_serve()] to start the MCP server in your R session.**
 #' Place a call to `acquaint::mcp_serve()` in your `.Rprofile`, perhaps with
 #' `usethis::edit_r_profile()`, to start a server for your R session every time
 #' you start R.
-#' 
+#'
 #' @examples
 #' if (interactive()) {
 #' mcp_serve()
 #' }
-#' 
+#'
 #' @name mcp
 #' @export
 mcp_serve <- function() {
-  # HACK: If a server is already running in one session via `.Rprofile`, 
-  # `mcp_serve()` will be called again when the client runs the command 
+  # HACK: If a server is already running in one session via `.Rprofile`,
+  # `mcp_serve()` will be called again when the client runs the command
   # Rscript -e "acquaint::mcp_serve()" and the existing server will be wiped.
   # Returning early in this case allows for the desired R session server to be
   # running already before the client initiates the proxy.
@@ -99,11 +99,12 @@ handle_message_from_proxy <- function(msg) {
   }
   # cat("SEND:", to_json(body), "\n", sep = "", file = stderr())
 
-  nanonext::send_aio(the$server_socket, to_json(body))
+  # TODO: consider if better / more robust using synchronous sends
+  the$saio <- nanonext::send_aio(the$server_socket, to_json(body), mode = "raw")
 }
 
 schedule_handle_message_from_proxy <- function() {
-  r <- nanonext::recv_aio(the$server_socket)
+  r <- nanonext::recv_aio(the$server_socket, mode = "string")
   promises::as.promise(r)$then(handle_message_from_proxy)$catch(function(e) {
     print(e)
   })