gateway_join_cluster · API-Central MCP: Risk & Policy

WHAT IT DOES

What gateway_join_cluster does on API-Central

AI agents use gateway_join_cluster to create or update resources in API-Central — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your API-Central environment.

WHY IT NEEDS A POLICY

Why gateway_join_cluster needs a policy

This tool modifies network infrastructure by adding or updating gateway cluster membership. POST and PATCH operations create or update cluster configurations, which are reversible changes but have significant blast radius in production network environments. Clustering decisions affect failover, load balancing, and availability—misuse could disrupt network operations.

From the tool's definition POST to create, PATCH if duplicate — indicates irreversible state modifications to gateway cluster membership configuration

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

gateway_join_cluster Rate-limited

gateway_join_cluster stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "gateway_join_cluster": {
      "limits": [
        {
          "counter": "gateway_join_cluster_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

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

FAQ

Questions about gateway_join_cluster

What does the gateway_join_cluster tool do? +

Add/update gateway cluster membership (POST to create, PATCH if duplicate). It is categorised as a Write tool in the API-Central MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on gateway_join_cluster? +

Register the API-Central MCP server in PolicyLayer and add a rule for gateway_join_cluster: 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 API-Central. Nothing to install.

What risk level is gateway_join_cluster? +

gateway_join_cluster is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit gateway_join_cluster? +

Yes. Add a rate_limit block to the gateway_join_cluster 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 gateway_join_cluster completely? +

Set action: deny in the PolicyLayer policy for gateway_join_cluster. 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 gateway_join_cluster? +

gateway_join_cluster is provided by the API-Central MCP server (secure-ssid/centralmcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.