fmsg MCP Server

by markmnlio.github.markmnl/fmsg-mcpv0.2.3

Give AI agents an address on fmsg, an open federated messaging protocol: inbox, threads, replies, reactions, attachments and waiting for new messages.

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Active15d ago

Install fmsg MCP server

claude mcp add fmsg -e FMSG_API_URL='<fmsg-api-url>' -e FMSG_API_KEY='<fmsg-api-key>' -- npx -y @markmnl/fmsg-mcp

{
  "mcpServers": {
    "fmsg": {
      "command": "npx",
      "args": [
        "-y",
        "@markmnl/fmsg-mcp"
      ],
      "env": {
        "FMSG_API_URL": "<fmsg-api-url>",
        "FMSG_API_KEY": "<fmsg-api-key>"
      }
    }
  }
}

Add to ~/.cursor/mcp.json (global) or .cursor/mcp.json (project).

{
  "mcpServers": {
    "fmsg": {
      "command": "npx",
      "args": [
        "-y",
        "@markmnl/fmsg-mcp"
      ],
      "env": {
        "FMSG_API_URL": "<fmsg-api-url>",
        "FMSG_API_KEY": "<fmsg-api-key>"
      }
    }
  }
}

Settings → Developer → Edit Config (claude_desktop_config.json), then restart.

{
  "servers": {
    "fmsg": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "@markmnl/fmsg-mcp"
      ],
      "env": {
        "FMSG_API_URL": "<fmsg-api-url>",
        "FMSG_API_KEY": "<fmsg-api-key>"
      }
    }
  }
}

Add to .vscode/mcp.json in your workspace.

{
  "mcpServers": {
    "fmsg": {
      "command": "npx",
      "args": [
        "-y",
        "@markmnl/fmsg-mcp"
      ],
      "env": {
        "FMSG_API_URL": "<fmsg-api-url>",
        "FMSG_API_KEY": "<fmsg-api-key>"
      }
    }
  }
}

Add to ~/.codeium/windsurf/mcp_config.json.

Configuration

Variable	Required	Secret	Description
FMSG_API_URL	yes	—	Base URL of your hosting provider's or self-hosted fmsg Web API
FMSG_API_KEY	yes	yes	fmsg API key (fmsgk_...) for the address to send as
FMSG_DEFAULT_DOMAIN	—	—	Optional: lets short names resolve to @name@<domain>
FMSG_MCP_DOWNLOAD_DIR	—	—	Optional local folder enabling streamed attachment saves over stdio

Remote endpoints

streamable-httphttps://{api_key_mcp_endpoint}
streamable-httphttps://{oauth_mcp_endpoint}

Freshness

Active — last maintenance signal 15d ago. The newest of the signals below sets the band.

Last commit (default branch)
2026-09-25 · 15d ago · GitHub
Latest release
2026-09-25 · 15d ago · GitHub · v0.2.3
Package published
no data · npm/PyPI
Registry entry updated
2026-09-25 · 15d ago · official registry · v0.2.3

FAQ

›How do I install the fmsg MCP server in Claude Code?

Run: claude mcp add fmsg -e FMSG_API_URL='<fmsg-api-url>' -e FMSG_API_KEY='<fmsg-api-key>' -- npx -y @markmnl/fmsg-mcp. For Cursor, VS Code, Claude Desktop and Windsurf, use the install tabs above.

›Does fmsg require an API key?

Yes. It expects FMSG_API_URL, FMSG_API_KEY, of which 1 is a secret.

›Can I use fmsg as a remote (hosted) MCP server?

Yes — it offers both a hosted endpoint and a local stdio package.

›Is fmsg in the official MCP registry?

Yes, as io.github.markmnl/fmsg-mcp.