8 posts in this hub //

MCP: Gateways, Shadow Servers, and Discovery

How agents find tools, which MCP servers exist in an environment, and who those tools act for.

MCP is how agents find and call tools. The hard part is not the protocol. It is knowing which servers exist, what they can do, and who they act for.

These posts define the gap and show the controls that hold. Incident write-ups that started as an MCP failure and turned into a control failure are in Agent Security .

Start here

  1. What Is an MCP Gateway? agentgateway Examples An MCP gateway sits between AI agents and MCP servers: one endpoint, sign-in, per-tool CEL rules and audit. How it differs from LLM and API gateways.
  2. What Is Shadow MCP? A Plain Definition Shadow MCP is any MCP server your AI tools can reach that security doesn't know about. Where it comes from, why it's risky, and how to find and stop it.
  3. Find Shadow MCP Servers in Your Environment Find shadow MCP servers on your network, in Kubernetes, on laptops and in vendor accounts, then check them against a registry so unapproved ones stand out.

Every post in this hub

  1. Grok Bot on agentgateway codeSearch: 96% Fewer Tokens on Real GitHub Work
    I put Grok Bot's GitHub MCP connector behind agentgateway Enterprise in codeSearch mode. A real PR review workflow went from 89,038 tokens to 3,809.
  2. What Is an MCP Gateway? agentgateway Examples
    An MCP gateway sits between AI agents and MCP servers: one endpoint, sign-in, per-tool CEL rules and audit. How it differs from LLM and API gateways.
  3. Find Shadow MCP Servers in Your Environment
    Find shadow MCP servers on your network, in Kubernetes, on laptops and in vendor accounts, then check them against a registry so unapproved ones stand out.
  4. MCP Progressive Tool Discovery: Native vs. Hand-Rolled
    A 3-tool MCP entry point cuts tools/list bytes 94% vs a flat 50-tool catalog. agentgateway's Search mode does this, Enterprise-only; here's the OSS version.
  5. What Is Shadow MCP? A Plain Definition
    Shadow MCP is any MCP server your AI tools can reach that security doesn't know about. Where it comes from, why it's risky, and how to find and stop it.
  6. Stateless MCP on Kubernetes: No More Sticky Sessions
    A 3-replica MCP server behind agentgateway, no session affinity, survives a rolling restart mid-session. What the MCP 2026-07-28 spec changed, and the proof.
  7. Conway's Law Is Coming for Your MCP Servers
    Putting every MCP tool behind one federated endpoint rebuilds the ESB and makes agents worse. Why MCP federation should follow business domain boundaries.
  8. Multi-Tenant MCP Servers: Per-Customer Tools
    Run MCP servers multi-tenant: agentgateway gives each customer its own tools, quotas, and chargeback from a JWT claim. The servers hold zero auth code.

Frequently asked questions

What is an MCP gateway?

An MCP gateway is the point on the path that brokers tool calls between agents and Model Context Protocol servers. It is where discovery, identity, and policy can see the same request.

What is shadow MCP?

Shadow MCP is an MCP server that agents are already calling, and that the platform team did not put there. Finding those servers is the first control. Pinning what they can do is the next one.