FxSocket MCP Server

FxSocket MCP

Lets Claude, Cursor, VS Code and other MCP clients read your MetaTrader 4 and 5 accounts on FxSocket: balances, open positions, closed trades with win rate and P/L, quotes, symbol specifications and price history. It is read-only. It cannot place, modify or close orders.

This image runs FxSocket's MCP server as a local stdio server, for clients that start their servers themselves (Claude Desktop, Docker's MCP Toolkit, or anything configured with a command). It relays each message to https://mcp.fxsocket.com/mcp with your API key. The tools run on FxSocket, next to the terminals your accounts are connected to, so the image stays tiny and never needs updating when tools change.

If your client takes a remote server URL plus a header, you can skip the image: point it at https://mcp.fxsocket.com/mcp with your key in an X-API-Key header.

1. Get an API key

Create a read-only key (fxs_ro_...) at app.fxsocket.com/dashboard/api-key. A named key scoped to some of your accounts limits the agent to exactly those. A full fxs_live_... key works too, but an agent has no use for one.

2. Add it to your client

Claude Desktop (Settings, Developer, Edit Config, then restart):

{
  "mcpServers": {
    "fxsocket": {
      "command": "docker",
      "args": ["run", "-i", "--rm", "-e", "FXSOCKET_API_KEY", "fxsocket/mcp"],
      "env": { "FXSOCKET_API_KEY": "fxs_ro_..." }
    }
  }
}

Claude Code:

claude mcp add fxsocket -e FXSOCKET_API_KEY=fxs_ro_... -- docker run -i --rm -e FXSOCKET_API_KEY fxsocket/mcp

Cursor (~/.cursor/mcp.json):

{
  "mcpServers": {
    "fxsocket": {
      "command": "docker",
      "args": ["run", "-i", "--rm", "-e", "FXSOCKET_API_KEY", "fxsocket/mcp"],
      "env": { "FXSOCKET_API_KEY": "fxs_ro_..." }
    }
  }
}

VS Code (.vscode/mcp.json, prompts for the key once):

{
  "inputs": [
    { "type": "promptString", "id": "fxsocket-key", "description": "FxSocket API key", "password": true }
  ],
  "servers": {
    "fxsocket": {
      "type": "stdio",
      "command": "docker",
      "args": ["run", "-i", "--rm", "-e", "FXSOCKET_API_KEY", "fxsocket/mcp"],
      "env": { "FXSOCKET_API_KEY": "${input:fxsocket-key}" }
    }
  }
}

-e FXSOCKET_API_KEY without a value passes the variable through from the client's env, so the key never appears in the process list.

Without Docker: the relay is one file with no dependencies. Download fxsocket_mcp.py and use python3 (3.10 or newer) as the command with the file's path as the argument, keeping the same env.

Tools

Amounts are in each account's deposit currency and are never summed across currencies. Times are broker server time.

Configuration

FxSocket allows 60 MCP requests a minute per user.

How it works

The client writes newline-delimited JSON-RPC to the container's stdin. The relay POSTs each message to the MCP endpoint over a kept-alive HTTPS connection, adds the API key and the headers the protocol requires, and writes the replies to stdout. It handles both protocol eras:

• 2026-07-28: the protocol version travels in each request's _meta, and the relay mirrors it into the MCP-Protocol-Version, Mcp-Method and Mcp-Name headers (plus any x-mcp-header tool parameters).
• 2025-03-26 to 2025-11-25: the client opens with initialize, and the relay sends the negotiated version as MCP-Protocol-Version from then on.

If FxSocket rejects the key, the relay still answers initialize and tools/list from the server's public card (https://mcp.fxsocket.com/.well-known/mcp/server-card.json), so directories and inspectors that start it with a placeholder key can see the tools. Every tool call still needs a valid key and otherwise returns the rejection.

Requests run concurrently. A notifications/cancelled from the client closes that request's connection, which is how Streamable HTTP cancels. HTTP failures (bad key, rate limit, network) come back as JSON-RPC errors with a sentence saying what to fix, rather than a hung client.

Development

python3 -m unittest discover -s tests
docker build -t fxsocket/mcp:dev .

The tests start the relay as a subprocess against a local stub server, so they cover the real stdio and HTTP paths.

To release, bump __version__ in fxsocket_mcp.py, then push a matching tag (git tag v1.0.1 && git push --tags). The publish workflow builds linux/amd64 and linux/arm64 and pushes fxsocket/mcp:<version>, :<major>.<minor> and :latest, and the dockerhub-overview workflow copies this README to the Docker Hub page.

License

MIT