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fastmcp.cli.install.shared

Shared utilities for install commands.

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Functions

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validate_server_name

Validate that a server name is safe for use as a subprocess argument. Raises SystemExit if the name contains shell metacharacters.

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quote_windows_batch_argument

Quote one argument for a command line that runs a .cmd or .bat file. The result reaches the program that the batch file launches as the original literal string. This follows the batch file argument quoting in Rust’s standard library: arguments are wrapped in double quotes so cmd.exe treats &, |, <, >, ^, parentheses and similar characters as text, including when the batch file expands them again through %*. Embedded quotes are doubled, which both cmd.exe and the Microsoft C runtime read as a literal quote. Each % is rewritten so cmd.exe does not expand environment variables. Delayed ! expansion is disabled by the command processor options in windows_batch_command_line. Raises:
  • ValueError: If the argument contains a line break. cmd.exe ends the command at a line break, so it cannot be passed literally.

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windows_batch_command_line

Build a cmd.exe command line that runs a batch file with literal arguments. command[0] is the batch file path and the remaining items are its arguments. The returned string is passed verbatim to CreateProcess with cmd.exe as the executable. Command extensions are enabled for the % handling, delayed expansion and AutoRun commands are disabled, and /s makes cmd.exe remove exactly the outer pair of quotes. Raises:
  • ValueError: If the batch file path or an argument cannot be passed.

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run_cli_command

Run a client CLI so that it receives each argument literally. On Windows, a .cmd or .bat file always runs through cmd.exe, which would otherwise interpret operators and % expansions in the arguments. For those files the command line is built with windows_batch_command_line. Other executables, and every executable on other platforms, receive the argument list directly. Raises:
  • subprocess.CalledProcessError: If the command exits with an error.
  • ValueError: If an argument cannot be passed to a batch file.

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parse_env_var

Parse environment variable string in format KEY=VALUE.

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process_common_args

Process common arguments shared by all install commands. Handles both fastmcp.json config files and traditional file.py:object syntax.
Attempt to open a deeplink URL using the system’s default handler. Args:
  • url: The deeplink URL to open.
  • expected_scheme: The URL scheme to validate (e.g. “cursor”, “goose”).
Returns:
  • True if the command succeeded, False otherwise.