MCPFlo supports two transports for connecting to an MCP server. Which one you pick depends on where the server runs.

stdio

Use stdio when the server is a local process that MCPFlo should spawn and manage — most command-line MCP servers work this way (e.g. anything you’d normally run with npx, python, node, etc.).

To add one:

1. Click + Add Server, choose the stdio transport.
2. Enter the command (e.g. npx) and its args (e.g. -y, @modelcontextprotocol/server-memory).
3. Add any environment variables the server needs, using the key/value row editor.
4. Click Add Server — MCPFlo spawns the process and connects over its stdin/stdout.

MCPFlo manages the process lifecycle: it’s started when you expand the server, and cleaned up automatically when you remove the server or quit the app.

{
  "mcpServers": {
    "memory": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-memory"]
    }
  }
}

Streamable HTTP

Use Streamable HTTP when the server is already running remotely (or locally as its own long-lived process) and exposes an HTTP endpoint.

To add one:

1. Click + Add Server, choose the Streamable HTTP transport.
2. Enter the server’s URL.
3. Add any request headers it needs — most commonly an Authorization: Bearer <token> header for token-authed servers.
4. Click Add Server — MCPFlo connects directly to the URL.

If the server requires OAuth 2.1 instead of a static token, see Authentication & OAuth 2.1 — MCPFlo handles the sign-in flow automatically and doesn’t need a header in that case.

{
  "mcpServers": {
    "remote-api": {
      "url": "https://example.com/mcp",
      "headers": {
        "Authorization": "Bearer <token>"
      }
    }
  }
}

Which one should I use?

	stdio	Streamable HTTP
Server location	Local process, spawned by MCPFlo	Remote or already-running
Auth	Environment variables	Headers, or OAuth 2.1
Typical use case	CLI-style servers, local dev	Hosted/production servers

Not supported

MCPFlo intentionally does not support the deprecated HTTP+SSE transport — only stdio and Streamable HTTP are implemented.

Advanced options

Both transports expose an Advanced section when adding a server:

• Connection timeout — override the default timeout for slow-starting servers.
• Protocol version override — pin the connection to a specific MCP protocol version, useful for testing how a server negotiates against an older or newer version.

JSON import

Instead of filling out the form, switch to JSON import and paste an mcpServers block — single or multiple entries — matching the examples above. See Importing Servers via JSON for details.