Identifier

An identifier literal conforms to snake_case. It always starts with a character from a-z and is followed by one or more characters from a-z and 0-9.

Underscore rules:

• Underscores (_) can be used within the identifier
• Only a single consecutive _ is allowed (no __)
• Underscores cannot be at the start or end of the identifier
• An underscore must always be followed by a character (not at the end)

You will encounter such identifiers when defining targets, environments, extensions, variables, and locals.

There are some syntax extensions for specific usages:

• Target reference identifier can start with ^ (for example ^build) - see target configuration.
• Internal extension identifier starts with @ (for example @dotnet) - see project configuration.

Examples

✅ Valid identifiers

• config - Simple identifier
• project42 - Contains numbers
• this_is_a_var - Single underscore between words
• my_var_123 - Underscore followed by numbers
• a - Single letter
• version_1_0 - Multiple single underscores
• `version` - Backtick-quoted identifier (allows special cases)

❌ Invalid identifiers

• Config - Uppercase letters are not allowed
• _config - Cannot start with underscore
• config_ - Cannot end with underscore
• project__42 - Two consecutive underscores are not allowed
• this_is_a_var_ - Trailing underscore (underscore must be followed by a character)
• _ - Cannot be just an underscore
• var% - Invalid character %
• my-var - Hyphens are not allowed (use underscore instead)
• my.var - Dots are not allowed (use underscore instead)
• 123project - Cannot start with a number