diff --git a/internal/client/client.go b/internal/client/client.go
index 7db76fbb..9dc465d9 100644
--- a/internal/client/client.go
+++ b/internal/client/client.go
@@ -48,14 +48,12 @@ func New() (*Client, error) {
 func (c *Client) Do(method, path string, body interface{}, query url.Values) (*output.Envelope, error) {
 	// Append .json suffix if not already present (GitLink API convention)
 	// Handle paths that may already contain query strings (e.g., /path?key=val)
-	if !c.SkipJSONSuffix {
+	if c.shouldAppendJSONSuffix(path) {
 		if idx := strings.Index(path, "?"); idx != -1 {
 			basePath := path[:idx]
 			queryStr := path[idx:]
-			if !strings.HasSuffix(basePath, ".json") {
-				path = basePath + ".json" + queryStr
-			}
-		} else if !strings.HasSuffix(path, ".json") {
+			path = basePath + ".json" + queryStr
+		} else {
 			path += ".json"
 		}
 	}
@@ -225,3 +223,24 @@ func lookupStatusInfo(code int) statusInfo {
 		message: fmt.Sprintf("API 返回错误码 %d", code),
 	}
 }
+
+// shouldAppendJSONSuffix reports whether the .json suffix should be appended to path.
+// Returns false (skip append) when:
+//   - c.SkipJSONSuffix is set (explicit opt-out for non-JSON endpoints such as gateway)
+//   - path already ends with .json
+//   - path matches the raw content pattern (e.g., /api/:owner/:repo/raw/...)
+func (c *Client) shouldAppendJSONSuffix(path string) bool {
+	if c.SkipJSONSuffix {
+		return false
+	}
+	if strings.HasSuffix(path, ".json") {
+		return false
+	}
+	parts := strings.Split(strings.Trim(path, "/"), "/")
+	for i, part := range parts {
+		if part == "raw" && i >= 2 && i+2 < len(parts) {
+			return false
+		}
+	}
+	return true
+}