MCP Registry vs. MCP Gateway: What's the Difference?

Coding agents like Claude Code, Cursor, GitHub Copilot, and Windsurf, as well as Claude for business users, are all getting a boost from MCP integrations with external capabilities. But as organizations move to operationalize MCP in real-world settings, this shift has created a need for new infrastructure layers.

Most notably, MCP registries and MCP gateways stand out as two areas undergoing much current development. While registries specialize in cataloging MCP servers for discovery, gateways specialize in routing, securing, and governing MCP traffic. They’re similar in that they’re largely a response to ad hoc MCP configurations and the need to govern MCP use and avoid the insecurities of overpermissioned AI agents.

As we’ll see, both are complementary, but MCP gateways are becoming especially important for enterprise-scale MCP adoption.

What Is An MCP Registry?

An MCP registry is like an app store or integration catalog for agents. It catalogs MCP servers and the metadata needed to discover, evaluate, install, or connect to them. In enterprise contexts, a private MCP registry can behave as an approved inventory of MCP servers sanctioned for internal use.

MCP registry features

An MCP registry catalogs metadata about MCP servers, including their names, locations, installation methods, configuration details, and advertised capabilities.

Some MCP directories implement lightweight moderation controls for viewing, approving, and adding servers into the catalog. Other MCP registries implement more advanced features, such as supply chain security vetting and lifecycle management controls.

While the MCP project itself does define a specification for a standard MCP registry API, the concept of an MCP registry is still in flux. As such, there are still nuances in how MCP directories are implemented across open-source projects, vendor marketplaces, and private enterprise registries.

Examples of MCP registries

• The official MCP registry
• Docker MCP Registry
• Vendor-specific catalogs, such as Microsoft MCP
• Most MCP gateways, like Composio MCP Gateway or Lunar.dev’s MCPX, have an integrated MCP directory or catalog

Benefits of MCP registries

MCP registries benefit agentic workflows in a few ways. First, they help compatible MCP clients discover available MCP servers, narrowing the set of tools that can be configured for agent use. By pointing agents at an approved directory of servers to choose from, you bring more determinism to AI behaviors, and reduce the chance of shadow MCP servers living outside corporate IT governance.

Maintaining a proper inventory of MCP servers avoids the side effects of scattered MCP configuration files living in AI agent platforms across engineering teams. This arguably improves software supply chain security, since it requires some discipline to vet the provenance of servers and add them to a registry.

Limitations of MCP registries

Although MCP registries are a positive step toward governing MCP use, they do present some limitations. For the most part, MCP registries are typically a static catalog — they help agents discover servers, but are not actively authenticating with upstream servers, or enforcing specific tool permissions per user, department, or role. This functionality requires an orchestration layer or gateway to fully enforce.

Since registries are primarily catalog and metadata layers, they typically do not produce runtime monitoring and logs for auditing purposes. Given these limitations, an MCP registry is not a complete governance solution to fully safeguard and control organization-wide MCP usage.

What Is An MCP Gateway?

An MCP gateway is a unified control plane for governing MCP use. Similar to how an API gateway acts as a coordination layer around APIs, an MCP gateway is an abstraction layer between agents and MCP servers. It provides a way to universally apply security, governance, and observability for MCP interactions.

MCP gateway features

An MCP gateway brings a number of features to govern internal MCP adoption. For instance, an MCP gateway provides a dynamic way to enforce role-based access across various servers. Some MCP gateways offer universal authentication, helping secure various MCP types, regardless of whether the downstream MCP servers use OAuth or API keys.

MCP gateways also provide governance features. A gateway typically has some sort of registry function, whether it’s an inventory or catalog of approved MCP servers and tools. Some gateways take this a step further. For instance, using Zuplo MCP Gateway, each virtual MCP server exposes a curated subset of a single upstream’s tools, prompts, and resources at its own URL, so different agents or teams can get different views of the same server.

Lastly, observability is a common feature. MCP gateways typically provide ongoing visibility into MCP tool calls and usage patterns. Gateways typically produce exportable logs and audit trails. Some gateways, like Operant MCP Gateway, conduct ongoing threat monitoring to detect MCP risks like tool poisoning or sensitive data exposures.

Examples of MCP gateways

• Zuplo MCP Gateway provides a central way to manage, govern, and control access to MCP servers.
• Other MCP gateways include Portkey MCP Gateway, Lasso MCP Gateway, and TrueFoundry MCP Gateway.
• Some API management platforms and API gateways, such as Tyk and Gravitee, also support MCP.

Benefits of MCP gateways

An enterprise can benefit from an MCP gateway in a number of ways. For one, gateways make discovering MCP tools highly curated, not only increasing the utility of your agents but also providing a means to orchestrate access in a flexible manner to various consumer types throughout an organization.

Funneling MCP use through a gateway also helps govern an increasingly large MCP portfolio at scale, providing a way to clearly delimit usage controls and prevent rogue MCP use. A gateway goes beyond static registries by providing more granular controls to prevent privilege drift, along with runtime observability to support auditing and debugging.

A gateway acts as an abstraction layer between an organization and potentially hazardous third-party MCP servers, but, given the cross-over functionality, it can also behave as a means to externalize MCP servers for others to consume and even monetize them and their underlying API-based methods.

Limitations of MCP gateways

Although MCP gateways are an important aspect of securing agentic use of MCP, they do have some possible downsides. For instance, while most gateways ship with default settings to increase onboarding, some require administrative effort to scope tooling permissions to your organization’s requirements.

In terms of identity, MCP gateways only go so far — most require integration with a third-party identity provider (IdP). Lastly, a fully-fledged MCP gateway is likely overkill if you are a solo developer or working in a small team and only using a few MCP servers. In this case, keeping a simple MCP inventory is probably sufficient.

MCP Gateways and MCP Registries: Different But Complementary

Both MCP gateways and MCP registries are helpful components that grant AI agents more autonomy to interact with tools in a safe and compliant manner.

The key difference is that an MCP registry is a static inventory for capability tracking and discovery, whereas an MCP gateway actively handles the ingress and egress traffic routing and scoping for MCP tool access. MCP registries or catalogs are also commonly built into MCP gateway platforms.

The distinction between the two concepts matters, because these are frontier, evolving areas. Incorrectly conflating terms this early on could negatively impact the technology procurement process, especially for AI engineers or security leadership requiring quick solutions to avoid MCP security flaws.

As such, it’s important to grasp what MCP registries and gateways are, and how they could be applied in practice. Because together, these components combine to fill an important and widening gap around governing MCP tool use.