Use Streamable HTTP transport

stdio is the default MCP transport and is the right choice for most local desktop clients. Streamable HTTP is available for clients that need a local HTTP URL.

Start HTTP on loopback

Run icuvisor with ICUVISOR_TRANSPORT=http:

macOS:

ICUVISOR_TRANSPORT=http /Applications/icuvisor.app/Contents/MacOS/icuvisor

Windows PowerShell:

$env:ICUVISOR_TRANSPORT = "http"
& "$env:LOCALAPPDATA\Programs\icuvisor\icuvisor.exe"

By default, icuvisor listens on loopback only:

http://127.0.0.1:8765/mcp

Equivalent flags:

macOS:

/Applications/icuvisor.app/Contents/MacOS/icuvisor --transport http --http-bind 127.0.0.1:8765

Windows PowerShell:

& "$env:LOCALAPPDATA\Programs\icuvisor\icuvisor.exe" --transport http --http-bind 127.0.0.1:8765

Config files can also set:

{
  "transport": "http",
  "http_bind": "127.0.0.1:8765"
}

See the CLI reference and config file reference for exact field names and defaults.

Configure the client URL

Use this endpoint in MCP clients that require HTTP:

http://127.0.0.1:8765/mcp

If the client runs on the same computer, do not change the bind address.

LAN binding warning

Only set ICUVISOR_HTTP_BIND or --http-bind to a LAN address when you deliberately want another machine to reach the server.

A LAN bind exposes an unauthenticated MCP server: anyone who can connect to that address can call registered tools using the intervals.icu credentials configured for this icuvisor process. Keep 127.0.0.1:8765 unless you understand that risk.

If you do opt in, use an explicit IP address and port:

ICUVISOR_TRANSPORT=http \
ICUVISOR_HTTP_BIND=192.168.1.10:8765 \
/Applications/icuvisor.app/Contents/MacOS/icuvisor

icuvisor logs a warning when HTTP starts on a non-loopback bind. For how the loopback default fits into icuvisor’s local privacy posture, see Privacy posture.

Troubleshooting