genspark-custom-mcp

genspark-custom-mcp is a local MCP bridge for Genspark.

It runs as a STDIO server, which is the format Genspark expects, and proxies requests to an upstream MCP server exposed over HTTP/SSE. The first practical preset is Meta Ads, but the code is intentionally generic so the same bridge can be pointed at other MCP servers in the future.

What it does

• Genspark talks to this repo over STDIO.

• This process connects to the upstream MCP server over streamable-http or sse.

• tools/list and tools/call are forwarded to the upstream server.

Related MCP server: MCP Stdio to SSE Proxy

Configuration

Set these environment variables before starting the bridge:

• UPSTREAM_MCP_URL or META_MCP_URL: upstream MCP endpoint

• UPSTREAM_MCP_NAME or META_MCP_NAME: display name for logs

• UPSTREAM_TRANSPORT: auto, streamable-http, or sse

• UPSTREAM_BEARER_TOKEN, UPSTREAM_AUTH_TOKEN, META_ADS_ACCESS_TOKEN, or META_ACCESS_TOKEN: bearer token

• UPSTREAM_API_KEY: API key forwarded as X-Api-Key

• UPSTREAM_AUTH_HEADER_NAME and UPSTREAM_AUTH_HEADER_VALUE: custom auth header pair

• UPSTREAM_HEADERS_JSON: extra headers as JSON

Example:

export UPSTREAM_MCP_URL="https://example.com/mcp"
export UPSTREAM_TRANSPORT="auto"
export UPSTREAM_BEARER_TOKEN="your-token"
npm start

Genspark setup

• Build command: npm install

• Start command: npm start

Meta Ads preset

If you are using the Meta Ads MCP from the guide, set the upstream URL and the Meta token in the environment, then start the bridge locally or inside the Genspark sandbox.