How to Connect Multiple MCP Servers Through One Gateway

A team running ten MCP servers across filesystems, databases, GitHub, Slack, and internal APIs maintains ten separate connections, ten sets of credentials, and ten tool catalogs that every AI client loads on every request. As that count grows, the per-server configuration, the missing access control, and the token cost of stuffing hundreds of tool definitions into context stop being minor annoyances and become the primary obstacle to shipping. The fix is to connect multiple MCP servers through a single gateway: Bifrost, the open-source MCP gateway built in Go by Maxim AI, aggregates every connected server behind one endpoint and applies discovery, routing, authentication, and governance in one layer. This guide explains how an MCP gateway works and how to set one up.

What Is an MCP Gateway?

An MCP gateway is a single service that sits between AI clients and multiple Model Context Protocol servers. It connects to each upstream server, aggregates their tools into one catalog, and exposes that catalog through a single endpoint, adding authentication, access control, and observability in one place. The mental model is the same as an API gateway, applied to tool traffic instead of REST calls.

Model Context Protocol is the open standard that lets AI models discover and call external tools at runtime. Anthropic, which created MCP, describes the pre-MCP status quo as an N×M integration problem, where every AI application needs a bespoke connector for every data source. MCP solves the connector problem for a single server. It does nothing to help a team manage fifty of them. That is the gap a gateway fills.

Bifrost operates as both an MCP client and an MCP server. As a client, it connects out to any number of upstream tool servers. As a server, it presents every discovered tool through one interface that your applications and agents connect to. Full setup patterns are covered on the MCP gateway resource page.

Why Connecting Multiple MCP Servers Directly Becomes a Problem

Connecting each MCP server directly to each client works for one or two servers. It degrades predictably as the number of servers and clients grows, because every server adds its own connection, credentials, and failure mode to every client that uses it. The specific problems that appear at scale:

• Configuration sprawl: Every client (Claude Desktop, Cursor, a custom app) needs the same server list maintained by hand, so adding or rotating a server means editing every consumer.
• Tool-name collisions: Two servers that both expose a search tool leave the model unable to tell them apart.
• Context window bloat: Connecting 8 to 10 servers can put 150 or more tool definitions into the context of every request, so the model spends its budget reading tool catalogs instead of doing work.
• Credential exposure: API keys, bearer tokens, and OAuth secrets end up scattered across developer configs and environment files.
• No central control: There is no single place to enforce access policy, rate limits, or an audit trail across all tool calls.

Routing every tool through a single MCP gateway collapses these problems into one control point. Clients hold one credential to the gateway, and the gateway manages every upstream connection, policy, and log.

How to Connect Multiple MCP Servers Through One Gateway with Bifrost

Bifrost turns a set of scattered MCP servers into one governed endpoint in three steps. It runs as an HTTP gateway with a built-in web UI, so the whole configuration lives in one place rather than in each client. The gateway overhead on the request path is 11 microseconds at 5,000 requests per second in sustained benchmarks, so the aggregation layer does not become the bottleneck.

Step 1: Run the gateway

Start Bifrost with a single command using NPX or Docker, then open the dashboard at http://localhost:8080.

npx -y @maximhq/bifrost
# or
docker run -p 8080:8080 maximhq/bifrost

The same image deploys to Kubernetes, Docker Swarm, or bare metal without platform-specific changes.

Step 2: Connect your upstream MCP servers

Bifrost can connect to any MCP-compatible server over three transports: STDIO for local tools and scripts, HTTP for remote APIs and cloud services, and SSE for streaming servers. Each connection is registered as an MCP client with a name, a transport, and the endpoint or command. For HTTP and SSE servers, you attach the headers, keys, or tokens the upstream server requires.

{
  "name": "filesystem",
  "connection_type": "stdio",
  "stdio_config": {
    "command": "npx",
    "args": ["-y", "@anthropic/mcp-filesystem"]
  },
  "auth_type": "none",
  "tools_to_execute": ["*"]
}

Once a server is saved, Bifrost connects to it, discovers its tools, and syncs them on a configured interval. Tool names are prefixed with the client name (for example, filesystem_list_directory), which keeps tools unique across servers and removes the collision problem that direct connections create.

Step 3: Expose everything through one endpoint

With the upstream servers connected, Bifrost as an MCP gateway exposes every aggregated tool through a single /mcp endpoint. External MCP clients like Claude Desktop, Cursor, and coding agents connect to that one URL and see the full, filtered tool catalog. Adding, removing, or rotating an upstream server becomes a gateway config change that requires no client-side update.

claude mcp add gateway --transport sse <http://localhost:8080/mcp>

The endpoint speaks standard MCP: a POST to /mcp handles JSON-RPC tool discovery and execution, and a GET opens an SSE stream for persistent connections. Bifrost also integrates directly with coding agents and editors including Claude Code, Codex CLI, Gemini CLI, and Cursor.

Governing Tools Across Every Connected Server

Aggregating tools is only half the value of an MCP gateway; the other half is controlling who can use which tool. Bifrost does not execute tool calls automatically by default, so tool execution stays an explicit, auditable step unless you opt into autonomous execution with Agent Mode. On top of that baseline, the gateway applies tool filtering at three levels that stack, so a tool must pass every applicable filter to reach the model:

• Client level: the tools_to_execute list on each server sets the baseline of available tools, with deny-by-default when the list is empty.
• Request level: headers narrow the tool set for a single request.
• Virtual key level: each virtual key carries its own allow-list of servers and tools.

Virtual keys are the primary governance entity in Bifrost. A key defined for one team can be restricted to a specific set of MCP servers and tools through per-key MCP tool filtering, which is deny-by-default: a key with no MCP configuration gets no tools. The same layer centralizes MCP authentication, supporting shared admin credentials (static headers or OAuth 2.0) and per-user credentials that Bifrost stores against each caller's identity and reuses on later calls. Credentials stay in the gateway instead of on developer machines, and every tool call flows through one system with an immutable audit trail. Bifrost applies the same governance layer to budgets, rate limits, and access profiles, so access policy for tools and models is defined in one place.

Reducing Token Costs Across Multiple MCP Servers

The more MCP servers you connect, the more tool definitions land in every request, and input token cost rises with them. Code Mode addresses this directly. Instead of exposing every connected tool to the model, the gateway exposes four generic tools, and the model writes Python in a sandbox to orchestrate the rest, loading tool signatures only when needed.

In controlled benchmarks across 16 connected MCP servers exposing more than 500 tools, Code Mode reduced input token usage by up to 92.8% and cut estimated cost by a comparable margin, while raising execution speed by roughly 40%. That token reduction is what keeps a multi-server agent workflow affordable at scale, and it is documented in detail in the MCP gateway benchmark writeup. The savings compound with every server you add, which inverts the usual tradeoff where connecting more tools means paying more per request.

Key Considerations When You Connect Multiple MCP Servers

A gateway adds one network hop and one control point, so a few design choices determine whether it stays fast and safe as usage grows:

• Keep the aggregated catalog manageable. Merging ten servers can hand a model well over a hundred tools. Use virtual-key filtering to give each consumer only the tools it needs, and enable Code Mode when the catalog is large.
• Scope credentials per identity. Prefer per-user authentication for services like GitHub or Notion so access follows the person, not a shared key.
• Plan for scale early. Regulated and large-team deployments benefit from clustering, RBAC, and in-VPC options; the Bifrost Enterprise tier extends the open-source gateway with these controls. Enterprise deployments can also group curated tool collections into virtual MCP servers with MCP tool groups.

Frequently Asked Questions

How does an MCP gateway handle tool-name conflicts between servers?
Bifrost prefixes every tool with its source client name, so two servers that each expose a search tool become distinct entries the model can call unambiguously.

Do I need to change client code to add a new MCP server?
No. Clients point at the single gateway endpoint. Adding or rotating an upstream server is a gateway configuration change, and connected clients see the updated tool catalog without any local update.

Can one endpoint serve different tools to different teams?
Yes. Virtual keys carry per-key allow-lists, so the same gateway endpoint returns a different filtered catalog depending on which key made the request.

Getting Started with Bifrost

Connecting multiple MCP servers through one gateway replaces per-server configuration, scattered credentials, and unbounded token cost with a single endpoint, unified authentication, per-key tool governance, and one audit trail. As the open-source Bifrost gateway runs from a single command and scales to clustered, in-VPC enterprise deployments, the same setup that works for a first pair of servers holds as the count grows into the dozens.

To see how Bifrost can serve as the MCP gateway for your team, with clustering, federated authentication, and dedicated support, book a demo with the Bifrost team.