Run Cypher queries directly against the GitNexus knowledge graph. Supports MATCH, RETURN, WHERE, ORDER BY for exploring code relationships.\n\nAvailable node properties: name, filePath. Use labels(n) for type.\nExample: MATCH (n) WHERE n.name CONTAINS
AI agents invoke cortex_cypher to trigger actions in Cortex Hub. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.
This tool executes database queries in Cypher language against an underlying knowledge graph. While the description mentions read-like operations (MATCH, RETURN), Cypher is a full query language that can perform traversals, filtering, and transformations. The phrase 'Run...directly' combined with support for complex query construction means an agent can execute arbitrary database operations.
From the tool's definition Tool description states 'Run Cypher queries directly against the GitNexus knowledge graph' and lists supported query operations (MATCH, RETURN, WHERE, ORDER BY).
Documented attack patterns abuse exactly the kind of access cortex_cypher gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Cortex Hub, and nothing reaches the server without passing your rules. This is the rule we recommend for cortex_cypher:
{
"version": "1",
"default": "deny",
"tools": {
"cortex_cypher": {
"limits": [
{
"counter": "cortex_cypher_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}cortex_cypher stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.
Free to start. No card required.
Run Cypher queries directly against the GitNexus knowledge graph. Supports MATCH, RETURN, WHERE, ORDER BY for exploring code relationships.\n\nAvailable node properties: name, filePath. Use labels(n) for type.\nExample: MATCH (n) WHERE n.name CONTAINS. It is categorised as a Execute tool in the Cortex Hub MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Cortex Hub MCP server in PolicyLayer and add a rule for cortex_cypher: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Cortex Hub. Nothing to install.
cortex_cypher is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the cortex_cypher rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for cortex_cypher. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
cortex_cypher is provided by the Cortex Hub MCP server (lktiep/cortex-hub). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Cortex Hub, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
25 Cortex Hub tools catalogued and risk-classified — across an index of 43,000+ MCP servers.