add get_relationship_properties_keys

Author: brs96

CHANGELOG.md

@@ -1,7 +1,7 @@
 # Changelog - [0.3.0] - yyyy-mm-dd
 
 ### New Features
-
+1. Add a new get_relationship_properties_keys tool.
 
 ### Bug Fixes
 

mcp_server/src/mcp_server_neo4j_gds/gds.py

@@ -197,3 +197,15 @@ def get_node_properties_keys(gds: GraphDataScience):
         if df.empty:
             return []
         return df["properties_keys"].iloc[0]
+
+
+def get_relationship_properties_keys(gds: GraphDataScience):
+    with projected_graph(gds):
+        query = """
+        MATCH (n)-[r]->(m)
+        RETURN DISTINCT keys(properties(r)) AS properties_keys
+        """
+        df = gds.run_cypher(query)
+        if df.empty:
+            return []
+        return df["properties_keys"].iloc[0]

mcp_server/src/mcp_server_neo4j_gds/server.py

@@ -12,7 +12,7 @@
 from .community_algorithm_specs import community_tool_definitions
 from .path_algorithm_specs import path_tool_definitions
 from .registry import AlgorithmRegistry
-from .gds import count_nodes, get_node_properties_keys
+from .gds import count_nodes, get_node_properties_keys, get_relationship_properties_keys
 
 logger = logging.getLogger("mcp_server_neo4j_gds")
 
@@ -80,6 +80,13 @@ async def handle_list_tools() -> list[types.Tool]:
                             "type": "object",
                         },
                     ),
+                    types.Tool(
+                        name="get_relationship_properties_keys",
+                        description="""Get all relationship properties keys in the database""",
+                        inputSchema={
+                            "type": "object",
+                        },
+                    ),
                 ]
                 + centrality_tool_definitions
                 + community_tool_definitions
@@ -105,6 +112,10 @@ async def handle_call_tool(
                 result = get_node_properties_keys(gds)
                 return [types.TextContent(type="text", text=serialize_result(result))]
 
+            elif name == "get_relationship_properties_keys":
+                result = get_relationship_properties_keys(gds)
+                return [types.TextContent(type="text", text=serialize_result(result))]
+
             else:
                 handler = AlgorithmRegistry.get_handler(name, gds)
                 result = handler.execute(arguments or {})

mcp_server/tests/test_basic_tools.py

@@ -25,6 +25,7 @@ async def test_list_tools(mcp_client):
         # Basic tools
         "count_nodes",
         "get_node_properties_keys",
+        "get_relationship_properties_keys",
         # Centrality algorithms
         "article_rank",
         "articulation_points",
@@ -97,3 +98,14 @@ async def test_get_node_properties_keys(mcp_client):
         "display_name",
         "longitude",
     ]
+
+
+@pytest.mark.asyncio
+async def test_get_relationship_properties_keys(mcp_client):
+    result = await mcp_client.call_tool("get_relationship_properties_keys")
+
+    assert len(result) == 1
+    result_text = result[0]["text"]
+    properties_keys = json.loads(result_text)
+
+    assert properties_keys == ["distance", "line", "time"]