The Model Context Protocol (MCP) is quickly becoming the standard for connecting AI models to tools and data sources. But as MCP servers move from prototypes to production, a critical question emerges: how do you secure them?
Most MCP server implementations today have no built-in authentication. Anyone who knows the endpoint can call it. This works fine during development but is a non-starter for production deployments where multiple applications and agents need controlled access.
The authentication gap
When you deploy an MCP server, you need to answer several questions:
- Who is allowed to call this server?
- What tools and resources can each caller access?
- Are there rate limits or usage caps?
- What happens when a request violates your content policies?
Traditional API gateways can handle some of these concerns, but they were designed for REST/HTTP traffic patterns. MCP has its own protocol semantics, tool invocation patterns, and streaming responses. Bolting on a generic gateway introduces friction and misses important context.
How Praesidia secures MCP servers
Praesidia provides a native security layer for MCP servers. Here is the workflow:
1. Register your MCP server
Add your MCP server to Praesidia. It receives a set of credentials (client key and secret) that identify it in the platform.
2. Define connections
Specify which applications and agents are allowed to connect to your MCP server. Each connection is explicit - there is no implicit trust.
3. Configure guardrails
Set content-level controls on what can be requested and what can be returned. For example, you might allow a tool to be called but restrict what data it can return based on the caller's trust level.
4. Set policies
Apply operational controls like rate limits per caller, geographic restrictions, and time-based access windows. A development application might get unlimited calls during business hours, while a production agent gets rate-limited to prevent runaway loops.
Content-aware security
What makes this approach different from a standard API gateway is the content awareness. Praesidia does not just check credentials and pass requests through. It inspects the semantic content of interactions.
This matters because MCP servers expose tools that can perform arbitrary actions. A tool that reads from a database is very different from one that writes to it, even though both go through the same MCP endpoint. Content-aware guardrails let you make fine-grained decisions about what each caller can do.
Bidirectional controls
MCP server responses can contain sensitive data. Praesidia applies controls in both directions:
- Inbound: What requests are allowed? Which tools can be invoked? What parameters are permitted?
- Outbound: What data can be returned? Are there content filters on responses? Should certain fields be redacted?
This bidirectional approach ensures that even if a tool produces unexpected output, the response is filtered before reaching the caller.
Getting started
If you are running MCP servers in production (or planning to), adding authentication should be one of your first steps.
Praesidia is free during beta and takes minutes to set up. Register your MCP server, define who can connect, set your guardrails, and you are production-ready.