BoundaryML/baml · warning

Unknown command: . Type :help for available commands.

Error message

Unknown command: {}. Type :help for available commands.

What it means

REPL dispatcher fallback: the typed colon-command entered is not one of the known commands (load, reset, vars, thir, help, quit, etc.). The match on parts[0] exhausted every arm, so the input is echoed back with a pointer to :help rather than being evaluated as an expression.

Solutions

1. Run :help to list supported commands
2. Check spelling of the command (e.g. :load not :loade, :q to quit)
3. Use the documented aliases: l/r/t/q for load/reset/type/quit

Example fix

// before
:loade ./baml_src
// after
:load ./baml_src

// Pre-validate against the known command set before dispatch
const COMMANDS: &[&str] = &["load","l","reset","r","type","t","thir","help","quit","exit","q"];
let name = input[1..].split_whitespace().next().unwrap_or("");
let ok = COMMANDS.contains(&name);

match result { Err(e) if e.to_string().starts_with("Unknown command:") => println!("{e}; try :help"), other => { let _ = other; } }

When it happens

Trigger: Typing an unrecognized command like :foo, :functions (if unsupported), or misspelling a known command such as :loade in handle_command.

Common situations: Typos in command names, using commands from other REPLs (e.g. :r for run instead of reset), assuming commands that this REPL version does not implement.

Understand the failure class

Background: "Unknown argument", "Invalid value", and "must be one of": invalid CLI argument errors explained — this error's family across 35 libraries.

Related errors

• Empty command
• unknown toolchain command
• Usage: :load (or :l )
• Usage: :type (or :t )
• active BAML toolchain does not include…

AI-assisted analysis of BoundaryML/baml@bd85ce9dee (2026-09-12). Data as JSON: /api/errors/0c43fd4cdc306ee0. Report an issue: GitHub.

Appendix: source

Thrown at engine/baml-runtime/src/cli/repl.rs:1697

  :quit (:q)         - Exit the REPL

Expression syntax:
  x = expr       - Assign expression result to variable x
  variable_name  - Show value of variable

Supported literals:
  Numbers: 42, 3.14
  Strings: "hello world"
  Booleans: true, false
  Null: null
  Arrays: [1, 2, 3]"#
                    .to_string(),
            )),
            "quit" | "exit" | "q" => {
                println!("Goodbye!");
                Ok(None)
            }
            _ => Err(anyhow!(
                "Unknown command: {}. Type :help for available commands.",
                parts[0]
            )),
        }
    }
}

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