Teams usually control MCP use in one of three ways: a static allowlist of approved servers, a central proxy that inspects traffic, or client side approval prompts for each action. Each catches different problems. The right choice depends on team size, how fast servers change, and how much evidence you need to keep.
Allowlist of approved servers
You publish a short list of servers people may connect and review each one once. It is cheap, easy to explain and works well for a small team. Its weakness is drift. A server you approved can change its tools or code later, and an allowlist alone does not notice. It also does nothing for a server someone adds on a personal machine unless you can see client configuration.
Central proxy or gateway
All MCP traffic passes through a component you control. That gives you one place to apply policy, log calls and rotate credentials. The costs are real: another system to run, latency, a single point of failure, and the need to route every client through it. A proxy also cannot easily see local stdio servers that never touch the network, so coverage depends on how your team works.
Client side approval prompts
The agent asks a person before using a tool. This is low effort and keeps a human in the loop. The weakness is human. Prompt fatigue sets in quickly, people click approve, and a prompt shows a tool name more often than the full meaning of the arguments. Prompts are best for rare, high impact actions, not as the main control.
Combining them
Most teams end up layering. Start with an allowlist, add prompts for destructive actions, and add central policy and logging once the number of servers or users grows. Ask of each layer: what does it catch that the others miss? If the answer is nothing, skip it. Also decide who reviews logs. A control that nobody reads is theater.
Whatever you choose, write down the decision and the reasoning. Teams often adopt a control during a scare and forget why. When someone later asks why prompts are required for file deletion or why a server was rejected, a short record saves a long argument. Review the choice when your server count doubles, when a serious incident hits a similar team, or when a new client changes how connections are made. Controls should track how you work.
Try it yourself
Click through the demo and watch how the results change as you move through each step.
Click through it at your own pace, or open it full screen.
Where Safeguard fits
Safeguard provides an MCP Guardrail with policies and logging, plus asset discovery that can find MCP servers and agents already in use, so teams can start from what is actually there.
Quick check
Is a proxy always better than an allowlist?
No. For a small team with few servers, an allowlist plus prompts can be enough, and it is much simpler to run.
Last reviewed: 19 October 2026.
