From 01033d683bff1d24f97e9af5b4adcc3d3dd8d05c Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 6 Mar 2026 12:14:51 +0000
Subject: [PATCH 1/2] Initial plan


From 15bb898264b6099e86e10d56a5b93a0fec2e5465 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 6 Mar 2026 12:20:08 +0000
Subject: [PATCH 2/2] Fix isHTTPConnectionError with errors.As and update
 MCPProtocolVersion to 2025-11-25

Co-authored-by: lpcox <15877973+lpcox@users.noreply.github.com>
---
 internal/mcp/connection_test.go | 26 +++++++++++++++++++-------
 internal/mcp/http_transport.go  | 20 +++++++++++---------
 2 files changed, 30 insertions(+), 16 deletions(-)

diff --git a/internal/mcp/connection_test.go b/internal/mcp/connection_test.go
index 04e8624db..c0c4e8b22 100644
--- a/internal/mcp/connection_test.go
+++ b/internal/mcp/connection_test.go
@@ -3,8 +3,10 @@ package mcp
 import (
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
+	"net"
 	"net/http"
 	"net/http/httptest"
 	"strings"
@@ -639,22 +641,32 @@ func TestIsHTTPConnectionError(t *testing.T) {
 			expected: false,
 		},
 		{
-			name:     "connection refused error",
-			err:      fmt.Errorf("dial tcp: connection refused"),
+			name:     "net.OpError dial connection refused",
+			err:      &net.OpError{Op: "dial", Net: "tcp", Err: errors.New("connection refused")},
 			expected: true,
 		},
 		{
-			name:     "no such host error",
-			err:      fmt.Errorf("dial tcp: lookup example.invalid: no such host"),
+			name:     "net.OpError dial no such host",
+			err:      &net.OpError{Op: "dial", Net: "tcp", Err: &net.DNSError{Err: "no such host", IsNotFound: true}},
 			expected: true,
 		},
 		{
-			name:     "network is unreachable error",
-			err:      fmt.Errorf("dial tcp: network is unreachable"),
+			name:     "net.OpError dial network unreachable",
+			err:      &net.OpError{Op: "dial", Net: "tcp", Err: errors.New("network is unreachable")},
 			expected: true,
 		},
 		{
-			name:     "other error",
+			name:     "net.OpError non-dial (read) is not a connection error",
+			err:      &net.OpError{Op: "read", Net: "tcp", Err: errors.New("broken pipe")},
+			expected: false,
+		},
+		{
+			name:     "wrapped net.OpError dial via fmt.Errorf",
+			err:      fmt.Errorf("Post %q: %w", "http://example.com", &net.OpError{Op: "dial", Net: "tcp", Err: errors.New("connection refused")}),
+			expected: true,
+		},
+		{
+			name:     "plain string error",
 			err:      fmt.Errorf("some other error"),
 			expected: false,
 		},
diff --git a/internal/mcp/http_transport.go b/internal/mcp/http_transport.go
index 6c04377d3..933df4dca 100644
--- a/internal/mcp/http_transport.go
+++ b/internal/mcp/http_transport.go
@@ -4,9 +4,11 @@ import (
 	"bytes"
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"log/slog"
+	"net"
 	"net/http"
 	"strings"
 	"sync/atomic"
@@ -31,7 +33,7 @@ const (
 )
 
 // MCPProtocolVersion is the MCP protocol version used in initialization requests.
-const MCPProtocolVersion = "2024-11-05"
+const MCPProtocolVersion = "2025-11-25"
 
 // requestIDCounter is used to generate unique request IDs for HTTP requests
 var requestIDCounter uint64
@@ -46,18 +48,18 @@ type httpRequestResult struct {
 // transportConnector is a function that creates an SDK transport for a given URL and HTTP client
 type transportConnector func(url string, httpClient *http.Client) sdk.Transport
 
-// isHTTPConnectionError checks if an error is a network connection error
-// This helper reduces code duplication for checking common connection error patterns.
-// Note: Uses string matching which is fragile but consistent with existing patterns in the codebase.
-// TODO: Consider using errors.Is() or type assertions (*net.OpError) for more robust error classification.
+// isHTTPConnectionError checks if an error is a network connection error.
+// It uses errors.As to inspect the underlying *net.OpError for dial operations,
+// which covers connection refused, no such host, and network unreachable errors.
 func isHTTPConnectionError(err error) bool {
 	if err == nil {
 		return false
 	}
-	errMsg := err.Error()
-	return strings.Contains(errMsg, "connection refused") ||
-		strings.Contains(errMsg, "no such host") ||
-		strings.Contains(errMsg, "network is unreachable")
+	var opErr *net.OpError
+	if errors.As(err, &opErr) {
+		return opErr.Op == "dial"
+	}
+	return false
 }
 
 // parseSSEResponse extracts JSON data from SSE-formatted response