run_opencypher_query · Awslabs Valkey MCP: Risk & Policy

WHAT IT DOES

What run_opencypher_query does on Awslabs Valkey

AI agents invoke run_opencypher_query to trigger actions in Awslabs Valkey. 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.

WHY IT NEEDS A POLICY

Why run_opencypher_query needs a policy

This tool allows execution of openCypher queries against a graph database. While read-only queries are possible, openCypher supports data modification operations (CREATE, SET, DELETE, MERGE) and the tool description does not restrict query types. An AI agent could misuse this to modify or delete graph data without authorization.

From the tool's definition Tool description states 'Executes the provided openCypher against the graph' - the verb 'Executes' combined with 'query' indicates arbitrary code execution against a database.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

run_opencypher_query Rate-limited

run_opencypher_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.

View as policy code

policy.json

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

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Awslabs Valkey, so you can run agents against it safely.

FAQ

Questions about run_opencypher_query

What does the run_opencypher_query tool do? +

Executes the provided openCypher against the graph. It is categorised as a Execute tool in the Awslabs Valkey MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on run_opencypher_query? +

Register the Awslabs Valkey MCP server in PolicyLayer and add a rule for run_opencypher_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 Awslabs Valkey. Nothing to install.

What risk level is run_opencypher_query? +

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

Can I rate-limit run_opencypher_query? +

Yes. Add a rate_limit block to the run_opencypher_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 run_opencypher_query completely? +

Set action: deny in the PolicyLayer policy for run_opencypher_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 run_opencypher_query? +

run_opencypher_query is provided by the Awslabs Valkey MCP server (awslabs.valkey-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.