cypher_query

THE RISK

High Risk

Why cypher_query needs a policy

Cypher is the query language for graph databases (e.g., Neo4j). A 'cypher_query' tool likely executes arbitrary Cypher statements, which can include both read (MATCH) and write/destructive operations (CREATE, MERGE, DELETE, DROP).

From the tool's definition Tool name 'cypher_query' on a graph database server; description is empty and uninformative.

Documented attack patterns abuse exactly the kind of access cypher_query gives an agent:

POLICY

How to control cypher_query

PolicyLayer is an MCP gateway — it sits between your AI agents and Mcp Graph Engine, and nothing reaches the server without passing your rules. This is the rule we recommend for cypher_query:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "cypher_query": {
      "limits": [
        {
          "counter": "cypher_query_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

cypher_query 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.

Create a free account and register Mcp Graph Engine — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

RATE-LIMIT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More Mcp Graph Engine tools

Destructive delete_graph Delete a graph session Destructive forget Remove a node and its connected edges Destructive forget_relationship Remove an edge from the graph Destructive transitive_reduction Remove redundant transitive edges (if A->B->C and A->C exist, remove A->C) Execute stop_visualization Stop the visualization server. Execute visualize_graph Open browser visualization at localhost URL. Updates in real-time. Write add_facts Add facts (relationships) to the graph. Nodes are auto-created if they don Write add_knowledge Add knowledge using text DSL. Format:

All 24 Mcp Graph Engine tools →

Execute tools on other servers

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Go deeper

High-risk tools in Mcp Graph Engine → Every high-risk tool this server exposes, in one view.
All high-risk MCP tools → Every high-risk tool across the catalogue, and the policy pattern that contains them.
The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Agent sandbox → Bounding what an agent can execute and where the boundary should sit.
Least privilege for MCP → Granting agents the minimum tool surface the task needs.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about cypher_query

What does the cypher_query tool do? +

cypher_query. It is categorised as a Execute tool in the Mcp Graph Engine MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on cypher_query? +

Register the Mcp Graph Engine MCP server in PolicyLayer and add a rule for cypher_query: 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 Mcp Graph Engine. Nothing to install.

What risk level is cypher_query? +

cypher_query is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit cypher_query? +

Yes. Add a rate_limit block to the cypher_query 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.

How do I block cypher_query completely? +

Set action: deny in the PolicyLayer policy for cypher_query. 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.

What MCP server provides cypher_query? +

cypher_query is provided by the Mcp Graph Engine MCP server (utilitydelta/mcp-graph-engine). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Mcp Graph Engine tool call.

Start from Mcp Graph Engine, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →