From 31f230af217927548248f06548ddbcde5b3b5918 Mon Sep 17 00:00:00 2001
From: hugocasa <hugo@casademont.ch>
Date: Mon, 12 Oct 2026 10:19:42 +0200
Subject: [PATCH] fix: run rmcp's reqwest client without a log subscriber

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 backend/windmill-mcp/src/client/redacting.rs | 83 ++++++++++----------
 1 file changed, 42 insertions(+), 41 deletions(-)

diff --git a/backend/windmill-mcp/src/client/redacting.rs b/backend/windmill-mcp/src/client/redacting.rs
index 1beffefaf3..9f7b366110 100644
--- a/backend/windmill-mcp/src/client/redacting.rs
+++ b/backend/windmill-mcp/src/client/redacting.rs
@@ -1,4 +1,4 @@
-use std::{collections::HashMap, sync::Arc};
+use std::{collections::HashMap, future::Future, sync::Arc};
 
 use futures::stream::BoxStream;
 use reqwest::header::{HeaderName, HeaderValue};
@@ -9,19 +9,21 @@ use rmcp::{
     },
 };
 use sse_stream::Sse;
+use tracing::{instrument::WithSubscriber, subscriber::NoSubscriber};
 
 type Error = StreamableHttpError<reqwest::Error>;
 
 /// reqwest names the URL it failed on in its errors, and an MCP server URL can
-/// carry the server's key. rmcp logs those errors itself as well as returning
-/// them, so the URL is dropped here, before either can happen.
+/// carry the server's key. rmcp logs those errors as well as returning them, so
+/// the URL is dropped before the transport sees one, and rmcp's reqwest client,
+/// which logs the errors it swallows, runs without a subscriber.
 #[derive(Clone)]
 pub(super) struct UrlRedactingClient(pub(super) reqwest::Client);
 
-fn without_url(e: Error) -> Error {
-    match e {
-        StreamableHttpError::Client(e) => StreamableHttpError::Client(e.without_url()),
-        e => e,
+async fn redacted<T>(request: impl Future<Output = Result<T, Error>>) -> Result<T, Error> {
+    match request.with_subscriber(NoSubscriber::default()).await {
+        Err(StreamableHttpError::Client(e)) => Err(StreamableHttpError::Client(e.without_url())),
+        r => r,
     }
 }
 
@@ -36,10 +38,11 @@ impl StreamableHttpClient for UrlRedactingClient {
         auth_header: Option<String>,
         custom_headers: HashMap<HeaderName, HeaderValue>,
     ) -> Result<StreamableHttpPostResponse, Error> {
-        self.0
-            .post_message(uri, message, session_id, auth_header, custom_headers)
-            .await
-            .map_err(without_url)
+        redacted(
+            self.0
+                .post_message(uri, message, session_id, auth_header, custom_headers),
+        )
+        .await
     }
 
     async fn post_message_with_max_sse_event_size(
@@ -51,17 +54,15 @@ impl StreamableHttpClient for UrlRedactingClient {
         custom_headers: HashMap<HeaderName, HeaderValue>,
         max_sse_event_size: usize,
     ) -> Result<StreamableHttpPostResponse, Error> {
-        self.0
-            .post_message_with_max_sse_event_size(
-                uri,
-                message,
-                session_id,
-                auth_header,
-                custom_headers,
-                max_sse_event_size,
-            )
-            .await
-            .map_err(without_url)
+        redacted(self.0.post_message_with_max_sse_event_size(
+            uri,
+            message,
+            session_id,
+            auth_header,
+            custom_headers,
+            max_sse_event_size,
+        ))
+        .await
     }
 
     async fn delete_session(
@@ -71,10 +72,11 @@ impl StreamableHttpClient for UrlRedactingClient {
         auth_header: Option<String>,
         custom_headers: HashMap<HeaderName, HeaderValue>,
     ) -> Result<(), Error> {
-        self.0
-            .delete_session(uri, session_id, auth_header, custom_headers)
-            .await
-            .map_err(without_url)
+        redacted(
+            self.0
+                .delete_session(uri, session_id, auth_header, custom_headers),
+        )
+        .await
     }
 
     async fn get_stream(
@@ -85,10 +87,11 @@ impl StreamableHttpClient for UrlRedactingClient {
         auth_header: Option<String>,
         custom_headers: HashMap<HeaderName, HeaderValue>,
     ) -> Result<BoxStream<'static, Result<Sse, SseError>>, Error> {
-        self.0
-            .get_stream(uri, session_id, last_event_id, auth_header, custom_headers)
-            .await
-            .map_err(without_url)
+        redacted(
+            self.0
+                .get_stream(uri, session_id, last_event_id, auth_header, custom_headers),
+        )
+        .await
     }
 
     async fn get_stream_with_max_sse_event_size(
@@ -100,16 +103,14 @@ impl StreamableHttpClient for UrlRedactingClient {
         custom_headers: HashMap<HeaderName, HeaderValue>,
         max_sse_event_size: usize,
     ) -> Result<BoxStream<'static, Result<Sse, SseError>>, Error> {
-        self.0
-            .get_stream_with_max_sse_event_size(
-                uri,
-                session_id,
-                last_event_id,
-                auth_header,
-                custom_headers,
-                max_sse_event_size,
-            )
-            .await
-            .map_err(without_url)
+        redacted(self.0.get_stream_with_max_sse_event_size(
+            uri,
+            session_id,
+            last_event_id,
+            auth_header,
+            custom_headers,
+            max_sse_event_size,
+        ))
+        .await
     }
 }