From 6b716d57d2f5c46a64773e1ad9cce536d2cae54c Mon Sep 17 00:00:00 2001
From: Daniel Chalef <131175+danielchalef@users.noreply.github.com>
Date: Thu, 30 Oct 2025 21:28:34 -0700
Subject: [PATCH] feat: Add helpful error message for database connection
 failures

- Catch Redis/database connection errors during initialization
- Provide clear, formatted error messages with startup instructions
- Include provider-specific guidance (FalkorDB vs Neo4j)
- Improves developer experience when database is not running
---
 mcp_server/src/graphiti_mcp_server.py | 78 ++++++++++++++++++---------
 1 file changed, 53 insertions(+), 25 deletions(-)

diff --git a/mcp_server/src/graphiti_mcp_server.py b/mcp_server/src/graphiti_mcp_server.py
index c062a0da..f0b379d9 100644
--- a/mcp_server/src/graphiti_mcp_server.py
+++ b/mcp_server/src/graphiti_mcp_server.py
@@ -209,33 +209,61 @@ class GraphitiService:
             self.entity_types = custom_types
 
             # Initialize Graphiti client with appropriate driver
-            if self.config.database.provider.lower() == 'falkordb':
-                # For FalkorDB, create a FalkorDriver instance directly
-                from graphiti_core.driver.falkordb_driver import FalkorDriver
+            try:
+                if self.config.database.provider.lower() == 'falkordb':
+                    # For FalkorDB, create a FalkorDriver instance directly
+                    from graphiti_core.driver.falkordb_driver import FalkorDriver
 
-                falkor_driver = FalkorDriver(
-                    host=db_config['host'],
-                    port=db_config['port'],
-                    password=db_config['password'],
-                    database=db_config['database'],
-                )
+                    falkor_driver = FalkorDriver(
+                        host=db_config['host'],
+                        port=db_config['port'],
+                        password=db_config['password'],
+                        database=db_config['database'],
+                    )
 
-                self.client = Graphiti(
-                    graph_driver=falkor_driver,
-                    llm_client=llm_client,
-                    embedder=embedder_client,
-                    max_coroutines=self.semaphore_limit,
-                )
-            else:
-                # For Neo4j (default), use the original approach
-                self.client = Graphiti(
-                    uri=db_config['uri'],
-                    user=db_config['user'],
-                    password=db_config['password'],
-                    llm_client=llm_client,
-                    embedder=embedder_client,
-                    max_coroutines=self.semaphore_limit,
-                )
+                    self.client = Graphiti(
+                        graph_driver=falkor_driver,
+                        llm_client=llm_client,
+                        embedder=embedder_client,
+                        max_coroutines=self.semaphore_limit,
+                    )
+                else:
+                    # For Neo4j (default), use the original approach
+                    self.client = Graphiti(
+                        uri=db_config['uri'],
+                        user=db_config['user'],
+                        password=db_config['password'],
+                        llm_client=llm_client,
+                        embedder=embedder_client,
+                        max_coroutines=self.semaphore_limit,
+                    )
+            except Exception as db_error:
+                # Check for connection errors
+                error_msg = str(db_error).lower()
+                if 'connection refused' in error_msg or 'could not connect' in error_msg:
+                    db_provider = self.config.database.provider
+                    if db_provider.lower() == 'falkordb':
+                        raise RuntimeError(
+                            f"\n{'='*70}\n"
+                            f"Database Connection Error: FalkorDB is not running\n"
+                            f"{'='*70}\n\n"
+                            f"FalkorDB at {db_config['host']}:{db_config['port']} is not accessible.\n\n"
+                            f"To start FalkorDB:\n"
+                            f"  - Using Docker Compose: cd mcp_server && docker compose up\n"
+                            f"  - Or run FalkorDB manually: docker run -p 6379:6379 falkordb/falkordb\n\n"
+                            f"{'='*70}\n"
+                        ) from db_error
+                    else:
+                        raise RuntimeError(
+                            f"\n{'='*70}\n"
+                            f"Database Connection Error: {db_provider} is not running\n"
+                            f"{'='*70}\n\n"
+                            f"{db_provider} at {db_config.get('uri', 'unknown')} is not accessible.\n\n"
+                            f"Please ensure {db_provider} is running and accessible.\n\n"
+                            f"{'='*70}\n"
+                        ) from db_error
+                # Re-raise other errors
+                raise
 
             # Build indices
             await self.client.build_indices_and_constraints()