Minibridge

What is Minibridge?

Minibridge is a backend-to-frontend bridge that streamlines and secures communication between Agents and MCP servers. It safely exposes MCP servers to the internet and can integrate with policers for agent authentication, content analysis, and transformation. It also supports SBOM generation and validation to ensure MCP server integrity.

How to use Minibridge?

Minibridge can be used as a single all‑in‑one gateway (minibridge aio), a backend that exposes MCP servers over WebSockets (minibridge backend), a frontend that translates stdio/HTTP+SSE to WebSockets (minibridge frontend), or a scanning tool (minibridge scan). For example, start an all‑in‑one gateway with minibridge aio --listen :8000 -- npx @modelcontextprotocol/server-filesystem /tmp.

Key features of Minibridge

• Acts as a bridge between agents and MCP servers.
• Supports multiple frontend transports: stdio, HTTP+SSE, and WebSocket.
• Integrates with Policers (HTTP or Rego) for authentication and analysis.
• Generates and validates SBOMs for MCP server integrity.
• Supports TLS and mutual TLS for secure connections.
• Enables live SBOM validation of MCP calls.

Use cases of Minibridge

• Exposing a local MCP server securely to agents over the internet.
• Authenticating and monitoring agent requests via a custom HTTP or Rego policer.
• Ensuring an MCP server has not been tampered with using offline or online SBOM checks.
• Connecting legacy HTTP+SSE agents to a WebSocket‑based MCP backend.

FAQ from Minibridge

What transports does Minibridge support?

Minibridge supports stdio, HTTP+SSE, and WebSocket for frontend connections, and stdio for the MCP server backend. The backend also exposes a WebSocket interface for agents.

Can I use Minibridge with any MCP server?

Yes, Minibridge can wrap any MCP server that communicates over stdio. It currently only supports MCP servers over stdio on the backend.

How does authentication work in Minibridge?

Authentication can be handled via Policers (HTTP or Rego) or through TLS client certificates. The Policer receives agent details and can deny or mutate requests.

What is an SBOM and how is it used?

An SBOM (Software Bill of Materials) contains hashes of MCP server tools and prompts. Minibridge can generate it (minibridge scan sbom) and validate it offline or online by checking each MCP call against the SBOM.

What is the difference between the all‑in‑one, backend, and frontend modes?

The all‑in‑one mode combines frontend and backend in a single process. The backend exposes the MCP server over WebSockets. The frontend translates agent‑side transports (stdio, HTTP+SSE) into WebSocket connections to the backend.