mcp-bridge (mcpb)

A local stdio MCP Server that bridges any remote Streamable HTTP MCP server to your MCP client (Claude Desktop, Cursor, VS Code, WorkBuddy, …) with zero changes to the remote side.

• Transport normalization — clients only need stdio support.

• Network traversal — optional outbound HTTP proxy for restricted/corporate networks.

• Zero-change bridging — the remote server needs no modification.

CLI command: mcpb. Repo: github.com/Slothtron/mcp-bridge.

Install

From GitHub (npm installs directly from the repo; the prebuilt binary is fetched from GitHub Releases at install time — no npm publish needed):

# MUST pin a tag that matches a GitHub Release (vX.Y.Z)
npm install github:Slothtron/mcp-bridge#v0.1.0
# or run without installing:
npx github:Slothtron/mcp-bridge#v0.1.0 --remote https://example.com/mcp

Note: the installer downloads mcpb-<os>-<arch> from the GitHub Release matching this package's version. When installing from git, pin a tag (e.g. #v0.1.0); installing the default branch only works if its package.json version has a matching Release.

Via Go (no npm needed):

go install github.com/Slothtron/mcp-bridge@latest

Related MCP server: @qelos/better-mcp

Usage

mcpb --remote https://example.com/mcp
mcpb --remote https://example.com/mcp --proxy http://corp-proxy:8080
mcpb --remote https://example.com/mcp --header "Authorization: Bearer <TOKEN>"
# Opt in to server-initiated list_changed via GET SSE (off by default):
mcpb --remote https://example.com/mcp --standalone-sse

MCP Client config

{
  "command": "mcpb",
  "args": [
    "--remote", "https://example.com/mcp",
    "--proxy", "http://corp-proxy:8080",
    "--header", "Authorization: Bearer <TOKEN>"
  ]
}

For npx, set "command": "npx" and "args": ["github:Slothtron/mcp-bridge#v0.1.0", "--remote", "https://example.com/mcp"].

If secrets / proxy live in mise [env], Cursor does not load them automatically for MCP child processes. Prefer wrapping with mise x:

{
  "command": "mise",
  "args": [
    "x", "--",
    "mcpb",
    "--remote", "https://example.com/mcp",
    "--header", "Authorization: Bearer ${TOKEN}",
    "--proxy", "${HTTPS_PROXY}"
  ],
  "env": {},
  "type": "stdio"
}

Or keep "command": "mcpb" and put the variables in the MCP entry's "env" block, and ensure mcpb is on Cursor's PATH.

Flags

Header values support ${VAR} placeholders resolved from the environment at runtime (fail-fast if unset).

Outbound HTTP uses a 15s response-header timeout (not a total request timeout), so hanging peers fail faster without cutting off long tool-call response bodies.

Standalone GET SSE is off by default. Some gateways accept initialize but never return headers for the follow-up GET; leaving SSE on would block mcpb startup and surface as a client MCP error -32001: Request timed out. Enable --standalone-sse only when the remote correctly supports GET SSE and you need live list_changed pushes (startup still syncs tools/prompts/resources once).

Troubleshooting

See TECHNICAL_DESIGN.md for the full design.