URL: https://gofastmcp.com/cli/overview
Title: CLI - FastMCP

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Commands at a Glance
Server Targets
Name-Based Resolution
Authentication
Transport Override
CLI
CLI
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The fastmcp command-line interface
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The
fastmcp
CLI is installed automatically with FastMCP. It’s the primary way to run, test, install, and interact with MCP servers from your terminal.
fastmcp
--help
​
Commands at a Glance
Command
What it does
run
Run a server (local file, factory function, remote URL, or config file)
dev apps
Launch a browser-based preview UI for Prefab App tools
dev inspector
Launch a server inside the MCP Inspector for interactive testing
install
Install a server into Claude Code, Claude Desktop, Cursor, Gemini CLI, or Goose
inspect
Print a server’s tools, resources, and prompts as a summary or JSON report
list
List a server’s tools (and optionally resources and prompts)
call
Call a single tool with arguments
discover
Find MCP servers configured in your editors and tools
generate-cli
Scaffold a standalone typed CLI from a server’s tool schemas
project prepare
Pre-install dependencies into a reusable uv project
auth cimd
Create and validate CIMD documents for OAuth
version
Print version info (
--copy
to copy to clipboard)
​
Server Targets
Most commands need to know
which server
to talk to. You pass a “server spec” as the first argument, and FastMCP resolves the right transport automatically.
URLs
connect to a running HTTP server:
fastmcp
list
http://localhost:8000/mcp
fastmcp
call
http://localhost:8000/mcp
get_forecast
city=London
Python files
are loaded directly — no
mcp.run()
boilerplate needed. FastMCP finds a server instance named
mcp
,
server
, or
app
in the file, or you can specify one explicitly:
fastmcp
list
server.py
fastmcp
run
server.py:my_custom_server
Config files
work too — both FastMCP’s own
fastmcp.json
format and standard MCP config files with an
mcpServers
key:
fastmcp
run
fastmcp.json
fastmcp
list
mcp-config.json
Stdio commands
connect to any MCP server that speaks over standard I/O. Use
--command
instead of a positional argument:
fastmcp
list
--command
'
npx -y @modelcontextprotocol/server-github
'
​
Name-Based Resolution
If your servers are already configured in an editor or tool, you can refer to them by name. FastMCP scans configs from Claude Desktop, Claude Code, Cursor, Gemini CLI, and Goose:
fastmcp
list
weather
fastmcp
call
weather
get_forecast
city=London
When the same name appears in multiple configs, use the
source:name
form to be specific:
fastmcp
list
claude-code:my-server
fastmcp
call
cursor:weather
get_forecast
city=London
Run
fastmcp discover
to see what’s available on your machine.
​
Authentication
When targeting an HTTP URL, the CLI enables OAuth authentication by default. If the server requires it, you’ll be guided through the flow (typically opening a browser). If it doesn’t, the setup is a silent no-op.
To skip authentication entirely — useful for local development servers — pass
--auth none
:
fastmcp
call
http://localhost:8000/mcp
my_tool
--auth
none
You can also pass a bearer token directly:
fastmcp
list
http://localhost:8000/mcp
--auth
"
Bearer sk-...
"
​
Transport Override
FastMCP defaults to Streamable HTTP for URL targets. If the server only supports Server-Sent Events (SSE), force the older transport:
fastmcp
list
http://localhost:8000
--transport
sse
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