fix: #216 - adds sarch for classes as a resource

Author: KenSuenobu

.github/workflows/ci.yml

@@ -22,7 +22,7 @@ jobs:
       TAG_SERVICES: 0.0.9
       TAG_EXTERNAL: 0.0.1
       TAG_UI: 0.0.31
-      TAG_MCP: 0.0.1
+      TAG_MCP: 0.0.2
 
     steps:
       - name: Checkout code

objectified-mcp/Dockerfile

@@ -4,6 +4,6 @@ RUN mkdir objectified-mcp
 COPY server.py objectified-mcp
 COPY run.sh objectified-mcp
 WORKDIR /objectified-mcp
-RUN pip install mcp
+RUN pip install mcp psycopg2-binary
 ENTRYPOINT ./run.sh
 

objectified-mcp/server.py

@@ -1,17 +1,78 @@
+import psycopg2
+import os
 from mcp.server.fastmcp import FastMCP
 from datetime import datetime, timezone
-import os
+from psycopg2.extras import RealDictCursor
+from typing import List, Dict, Any, Optional
 
+DATABASE_URL = os.environ.get("DATABASE_URL")
 SSE_PATH = os.environ.get("SSE_PATH", "/mcp/sse")
 MESSAGE_PATH = os.environ.get("MESSAGE_PATH", "/mcp/messages/")
 
 mcp = FastMCP("Objectified", sse_path=SSE_PATH, message_path=MESSAGE_PATH)
 
+def connect_to_postgres(database_url: str) -> psycopg2.extensions.connection:
+    """
+    Establishes a connection to a PostgreSQL database using a DATABASE_URL.
+
+    Args:
+        database_url (str): The PostgreSQL connection string in URL format
+                           (e.g., 'postgresql://username:password@hostname:port/database')
+
+    Returns:
+        psycopg2.extensions.connection: A connection object to the PostgreSQL database
+
+    Raises:
+        Exception: If connection fails
+    """
+    try:
+        conn = psycopg2.connect(database_url)
+        return conn
+    except Exception as e:
+        raise Exception(f"Error connecting to PostgreSQL database: {str(e)}")
+
+def run_query(conn: psycopg2.extensions.connection, query: str,
+              params: Optional[tuple] = None) -> List[Dict[str, Any]]:
+    """
+    Executes a SQL query and returns all results.
+
+    Args:
+        conn (psycopg2.extensions.connection): PostgreSQL connection object
+        query (str): SQL query to execute
+        params (tuple, optional): Parameters to be used with the query for safe parameterization
+
+    Returns:
+        List[Dict[str, Any]]: List of dictionaries, where each dictionary
+                             represents a row with column names as keys
+
+    Raises:
+        Exception: If query execution fails
+    """
+    try:
+        with conn.cursor(cursor_factory=RealDictCursor) as cursor:
+            cursor.execute(query, params)
+            results = cursor.fetchall()
+            return [dict(row) for row in results]
+    except Exception as e:
+        conn.rollback()
+        raise Exception(f"Error executing query: {str(e)}")
+    finally:
+        # We don't close the connection here to allow for multiple queries
+        # with the same connection. The caller should close it when done.
+        pass
+
 @mcp.tool()
 def hello() -> str:
     """Greets the user."""
     return f"Hello world!"
 
+@mcp.resource("classes://{name}/by_name")
+def get_classes_by_name(name: str) -> list[str]:
+    conn = connect_to_postgres(DATABASE_URL)
+    results = run_query(conn, "SELECT id FROM obj.class WHERE name LIKE %s", (f"%{name}%",))
+    result_list = [row["id"] for row in results] if len(results) > 0 else []
+    return result_list
+
 if __name__ == "__main__":
     print("""
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