fix(mcp): use standard newline-delimited stdio

examples/mcp_server/funasr_mcp.py

@@ -28,14 +28,14 @@ import base64
 def send_response(id, result):
     msg = {"jsonrpc": "2.0", "id": id, "result": result}
     out = json.dumps(msg)
-    sys.stdout.write(f"Content-Length: {len(out)}\r\n\r\n{out}")
+    sys.stdout.write(f"{out}\n")
     sys.stdout.flush()
 
 
 def send_notification(method, params=None):
     msg = {"jsonrpc": "2.0", "method": method, "params": params or {}}
     out = json.dumps(msg)
-    sys.stdout.write(f"Content-Length: {len(out)}\r\n\r\n{out}")
+    sys.stdout.write(f"{out}\n")
     sys.stdout.flush()
 
 
@@ -154,25 +154,11 @@ def handle_request(request):
 
 def main():
     """Run MCP server over stdio."""
-    import re
-    buffer = ""
-    while True:
-        line = sys.stdin.readline()
+    for line in sys.stdin:
+        line = line.strip()
         if not line:
-            break
-        buffer += line
-        if "\r\n\r\n" in buffer:
-            header, body_start = buffer.split("\r\n\r\n", 1)
-            match = re.search(r"Content-Length: (\d+)", header)
-            if match:
-                length = int(match.group(1))
-                while len(body_start) < length:
-                    body_start += sys.stdin.read(length - len(body_start))
-                request = json.loads(body_start[:length])
-                buffer = body_start[length:]
-                handle_request(request)
-            else:
-                buffer = ""
+            continue
+        handle_request(json.loads(line))
 
 
 if __name__ == "__main__":

examples/mcp_server/test_funasr_mcp.py

@@ -0,0 +1,47 @@
+import json
+import subprocess
+import sys
+import unittest
+from pathlib import Path
+
+
+SERVER = Path(__file__).with_name("funasr_mcp.py")
+
+
+class FunASRMCPTransportTest(unittest.TestCase):
+    def test_stdio_uses_newline_delimited_json_rpc(self):
+        requests = [
+            {
+                "jsonrpc": "2.0",
+                "id": 1,
+                "method": "initialize",
+                "params": {
+                    "protocolVersion": "2024-11-05",
+                    "capabilities": {},
+                    "clientInfo": {"name": "transport-test", "version": "1.0"},
+                },
+            },
+            {"jsonrpc": "2.0", "id": 2, "method": "tools/list", "params": {}},
+        ]
+        stdin = "".join(f"{json.dumps(request)}\n" for request in requests)
+
+        completed = subprocess.run(
+            [sys.executable, str(SERVER)],
+            input=stdin,
+            text=True,
+            capture_output=True,
+            check=False,
+            timeout=5,
+        )
+
+        self.assertEqual(completed.returncode, 0, completed.stderr)
+        responses = [json.loads(line) for line in completed.stdout.splitlines()]
+        self.assertEqual([response["id"] for response in responses], [1, 2])
+        self.assertEqual(responses[0]["result"]["serverInfo"]["name"], "funasr")
+        self.assertEqual(
+            responses[1]["result"]["tools"][0]["name"], "transcribe_audio"
+        )
+
+
+if __name__ == "__main__":
+    unittest.main()