fix: validate transport, add lint+coverage to MCP CI job

- server.py: unknown transport now prints error and exits non-zero
  instead of silently falling back to stdio
- .flake8: new config matching backend (bugs-only, 120 char lines)
- ci.yml: MCP job now runs flake8 lint + pytest with --cov

Author: DevanshuNEU

.github/workflows/ci.yml

@@ -126,15 +126,21 @@ jobs:
       working-directory: ./mcp-server
       run: |
         python -m pip install --upgrade pip
+        pip install pytest-cov flake8
         pip install -r requirements.txt
 
+    - name: Lint (flake8)
+      working-directory: ./mcp-server
+      run: |
+        flake8 .
+
     - name: Run tests
       working-directory: ./mcp-server
       env:
         API_KEY: "test-key"
         BACKEND_API_URL: "http://localhost:8000"
       run: |
-        pytest tests/ -v
+        pytest tests/ -v --cov=. --cov-report=term-missing
 
   security-scan:
     name: Security Scan

mcp-server/.flake8

@@ -0,0 +1,17 @@
+[flake8]
+max-line-length = 120
+
+# Match backend config: only check for real bugs, not style.
+select = E9,F,W6
+
+exclude =
+    .git,
+    __pycache__,
+    venv,
+    .venv
+
+per-file-ignores =
+    # handlers.py imports formatters after logger (intentional grouping)
+    handlers.py:E402
+    # Test files may import pytest for fixtures/marks even if not directly referenced
+    tests/*.py:F401

mcp-server/server.py

@@ -69,6 +69,9 @@ def _get_http_app():
     return app
 
 
+_VALID_TRANSPORTS = {"stdio", "streamable-http", "http"}
+
+
 def main():
     """Run with configured transport."""
     transport = TRANSPORT
@@ -77,8 +80,15 @@ def main():
     if "--transport" in sys.argv:
         idx = sys.argv.index("--transport")
         if idx + 1 < len(sys.argv):
-            arg = sys.argv[idx + 1]
-            transport = "streamable-http" if arg in ("http", "streamable-http") else arg
+            transport = sys.argv[idx + 1]
+
+    # Normalize alias
+    if transport == "http":
+        transport = "streamable-http"
+
+    if transport not in ("stdio", "streamable-http"):
+        print(f"Error: unknown transport '{transport}'. Use 'stdio' or 'http'.")
+        sys.exit(1)
 
     if transport == "streamable-http":
         import uvicorn