The Bridge to MCP: Scaling AI Tools with Gateways

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Originally published on Towards AI.

If you’ve ever worked with APIs, you already know the idea: a clear way for one system to talk to another. The Model Context Protocol, or MCP, takes that same spirit and brings it into the world of tools and agents. Instead of just passing JSON over HTTP, MCP defines a standard way for an agent (like a coding assistant or automation framework) to discover, call, and interact with tools in a structured manner.

The goal is interoperability. Right now, every new tool or integration often comes with its own custom adapter, its own quirks, and its own security setup. MCP sets the rules so any compliant client can connect to any compliant server without reinventing the wheel. Think of it as a shared language that makes these connections predictable and scalable.

At its core, MCP includes a few key ideas. There’s an initial handshake, where the client and server introduce themselves and agree on capabilities. There’s session management, which makes sure requests and responses aren’t just one-off calls but part of an ongoing conversation. And there’s Streamable HTTP, which allows real-time interaction rather than waiting for a single response at the end. Together, these mechanics let MCP do what plain HTTP APIs can’t: support richer, continuous interactions between tools and agents.

MCP Servers: The New “APIs” for AI

An MCP server is a service that exposes functionality such as running a query, executing a command, or retrieving data, but it does so using the MCP protocol.

The easiest way to think about them is in relation to APIs. An API service gives you endpoints that an application can call. An MCP server, on the other hand, makes tools available for agents to use through a shared protocol. Both are about exposing capabilities in a structured way. The difference is in the consumer: APIs are meant for apps, dashboards, and back-end systems, while MCP servers are designed for intelligent agents, developer tools, and IDEs that need standard, predictable access to tools.

That last row highlights the real shift. APIs are typically transactional: you send a request, you get a response. MCP servers support a richer flow. They begin with an initialization handshake, can maintain sessions for multiple calls, and allow for streaming results in real time. This makes them better suited for scenarios where agents need context and ongoing interaction rather than one-off queries.

In short, an MCP server plays a role similar to an API service, but it is purpose-built for a new kind of consumer and a more interactive style of communication.

How MCP Works Under the Hood

MCP isn’t just REST in disguise. Traditional REST calls tend to be stateless and transactional: you send an HTTP request, get a response, and that’s the end of the conversation. MCP layers in state, structure, and real-time interaction.

MCP encodes its messages using JSON‑RPC 2.0, which means instead of simple GET/POST calls, the client invokes a method by name (like initialize, call, or shutdown), passes parameters, and gets engineered responses back. It supports notifications too—messages that don’t expect any reply—and multiple calls can happen in parallel. This protocol is transport-agnostic, meaning it can ride over standard input/output streams or network protocols without changing its behavior.

MCP’s modern transport mechanism, known as Streamable HTTP, lets a client initialize a session and then continue exchanging messages over HTTP in real time. The server can send partial results or updates back immediately, using techniques like Server‑Sent Events or long-polling, making it feel alive rather than static.

Another powerful feature is session management: after the initial initialize call, the server returns a session ID. The client includes this ID in all further requests, allowing the server to track context across multiple interactions. When that session ends, the client can send a DELETE request to actively terminate it.

In short, MCP goes beyond a one-off API call. It turns communication into a structured, stateful dialogue — complete with continuous streams, contextual sessions, and encoded actions — so agents and tools can coordinate more fluidly, intentionally, and securely.

Why Do We Need MCP Gateways?

One agent talking to one MCP server feels manageable. But in practice, that’s rarely the case. Teams end up with multiple agents and multiple MCP servers, and suddenly every agent has to figure out how to connect to every server. Each connection brings its own authentication flow, logging quirks, and error handling rules. The result is a messy web of connections that grows harder to control as the system scales.

An MCP gateway solves this by acting as the single front door for all MCP traffic. Instead of every agent learning how to talk to every server, the gateway takes care of it. It handles authentication in one place, applies consistent security policies, centralizes logging, and makes monitoring far easier.

The best way to picture it is to think back to how APIs were before gateways became common. Every application managed its own direct calls to every service, and teams had to reinvent authentication and monitoring each time. API gateways simplified that world by giving developers one point of entry, with routing, rate limiting, and observability built in. MCP gateways do the same, but in the world of tools and agents. They don’t just pass traffic along, they understand the protocol, manage sessions, and support richer interactions like streaming.

Without a gateway, scaling MCP is like every airline trying to set up its own private terminals at every airport. Each terminal would have its own check-in process, its own security rules, and its own way of boarding passengers. Travelers would be stuck figuring out a new system at every stop. A gateway is like a central airport terminal: one place where security, gates, and rules are standardized so flights can come and go smoothly.

Emerging MCP projects

Every major shift in tech needs a new kind of connection. When APIs became widespread, API gateways emerged to make sure traffic was secure, reliable, and manageable.

We’re seeing the same pattern with MCP. The protocol has momentum, but to make this ecosystem practical and scalable, we need gateways. These have arrived only in the past few months, signaling that MCP adoption is entering a new phase.

Docker unveiled an open-source MCP Gateway that bundles multiple MCP servers behind a unified, secure endpoint with built-in secrets handling and observability. IBM — or rather their ContextForge project released an MCP Gateway that federates MCP and REST services, offers admin UI, transport flexibility, and rich observability tools. Another project is Unla by AmoyLab, a lightweight Go-based gateway that turns existing servers and APIs into MCP-compatible endpoints, no code changes required.

All of these projects appeared only recently and already show the demand for foundational infrastructure. This moment is exciting because it’s not everyday that we see foundational infrastructure emerging so quickly. It’s an invitation to get involved, contribute something that matters, and shape how agents and tools will connect in the future.

Inside the Bridge MCP Gateway

The Bridge MCP Gateway is my open-source project that takes all of these ideas and puts them into practice. It is designed to be a production-grade entry point for MCP servers, with the kind of features developers expect when moving from experiments to real systems.

The gateway is built on FastAPI and supports async HTTP, making it lightweight and responsive. Out of the box, it integrates with Identity provider for OIDC authentication, handles token exchanges automatically, and enforces rate limits using in memory store (for now). It has structured logging and auditing built in, so every request and response can be tracked. There are health check endpoints, a dashboard in React and TypeScript for service management, and full Docker support for running it anywhere.

Right now, the project already covers the essentials: proxying traffic, validating tokens, and monitoring services. Work is underway to add full MCP compliance, including session management, the initialize handshake, and streamable HTTP support. Looking further ahead, features like RBAC, advanced monitoring with Prometheus and Grafana, and a plugin architecture are planned to make it extensible.

What makes this project exciting is that it is not just a sandbox, it is a real gateway you can run today, experiment with, and extend. And because it is open-source, it’s also a space where contributions from the community can directly shape how gateways evolve in the MCP ecosystem.

For software engineers, it is more than just another infrastructure, it is an opportunity to be part of something new while it is still taking shape. Building or contributing to these projects is hands-on learning at its best. You don’t just read about the protocol, you experience how authentication, session management, and streaming actually work in practice. And because the ecosystem is so young, every pull request or idea can leave a visible mark. It’s a rare chance to grow your skills while also shaping the standards others will rely on.

The Bridge Ahead

One of the best parts about working with MCP right now is how open the field still is. The standards are fresh, the tooling is evolving, and there’s plenty of room to make a visible impact. Contributing to the Bridge MCP Gateway is a chance to be part of that story while learning through hands-on coding.

Getting started is simple. Clone the repository, run the gateway locally, and try pointing it at your own MCP servers. You can explore the service registry, test the health checks, or experiment with the dashboard. Along the way, you’ll get a feel for how sessions, authentication, and monitoring fit together. From there, you can start small — open an issue, fix a bug, write a test, or improve documentation.

The key is that every contribution matters. Because this space is still so young, your code and ideas don’t just disappear into a huge project. They directly shape how gateways will work for others. And in the process, you’ll pick up real experience with MCP, distributed systems, and modern security practices.

This is an exciting time because the ecosystem is still taking form. If you’ve been looking for a project that is both fun and impactful, this is a great place to start. It’s not just about building a gateway, it’s about joining a community of people who are creating the foundations for how agents and tools will connect in the future.

contribute @ https://github.com/codingjam/bridge-mcp

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Published via Towards AI