Block a client from accessing the network.
AI agents invoke block_client to trigger actions in UniFi MCP. 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 actively enforces a network access restriction on a client device, triggering an external operation on the UniFi controller that denies network access. It is not a simple data write — it executes a policy enforcement action with real operational impact. It could be reversed (unblock), so it doesn't qualify as Destructive, but misuse could deny network access to legitimate users, making severity high.
From the tool's definition Block a client from accessing the network
Documented attack patterns abuse exactly the kind of access block_client gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and UniFi MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for block_client:
{
"version": "1",
"default": "deny",
"tools": {
"block_client": {
"limits": [
{
"counter": "block_client_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}block_client 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.
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Block a client from accessing the network. It is categorised as a Execute tool in the UniFi MCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the UniFi MCP server in PolicyLayer and add a rule for block_client: 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 UniFi MCP. Nothing to install.
block_client 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 block_client 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 block_client. 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.
block_client is provided by the UniFi MCP server (jmagar/unifi-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from UniFi MCP, 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.
29 UniFi MCP tools catalogued and risk-classified — across an index of 43,000+ MCP servers.