CLI Reference

The keel unified command-line tool provides all Keel development utilities in a single binary.

Installation

See Installation for setup instructions.

Commands

keel run

Execute a Keel file.

keel run script.kl

keel -f

Shorthand for keel run:

keel -f script.kl

keel repl

Start the interactive REPL.

keel repl

See Using the REPL for details.

keel fmt

Format source code.

keel fmt file.kl             # Format in-place
keel fmt --check file.kl     # Check without modifying
keel fmt --stdout file.kl    # Print to stdout
keel fmt --width 80 file.kl  # Custom line width
echo 'let   x  =  42' | keel fmt  # Format from stdin

See the Formatter page for full documentation.

keel lsp

Start the Language Server Protocol server.

keel lsp

The server communicates over stdio. See Language Server & Editor Setup for editor configuration.

IO Security

File system IO is disabled by default for security.

Variable	Values	Effect
`KEEL_IO_DISABLED`	`0` or `false`	Enable file/directory IO
`KEEL_IO_READ_ONLY`	`1` or `true`	Allow only read operations
`KEEL_IO_SANDBOX`	`/path/to/dir`	Restrict to directory

Examples

KEEL_IO_DISABLED=0 keel run script.kl                    # Enable IO
KEEL_IO_DISABLED=0 KEEL_IO_READ_ONLY=1 keel run script.kl # Read-only
KEEL_IO_DISABLED=0 KEEL_IO_SANDBOX=/tmp/sandbox keel run script.kl

Console operations (print, println, readLine) are always allowed.

HTTP Security

HTTP requests via the Http module are disabled by default.

Variable	Values	Effect
`KEEL_HTTP_DISABLED`	`0` or `false`	Enable HTTP requests
`KEEL_HTTP_ALLOWED_HOSTS`	`host1,host2`	Restrict to listed hosts

Examples

KEEL_HTTP_DISABLED=0 keel run api-client.kl                    # Enable HTTP
KEEL_HTTP_DISABLED=0 KEEL_HTTP_ALLOWED_HOSTS=api.example.com keel run client.kl  # Restrict hosts

Request construction (Http.get, Http.withHeader, etc.) is always allowed — only Http.send requires HTTP to be enabled.

DataFrame Security

DataFrame file operations (readCsv, readJson, readParquet, writeCsv, writeJson) are enabled by default but can be restricted.

Variable	Values	Effect
`KEEL_DATAFRAME_DISABLED`	`1` or `true`	Disable DataFrame file operations
`KEEL_DATAFRAME_SANDBOX`	`/path/to/dir`	Restrict file I/O to directory
`KEEL_DATAFRAME_MAX_ROWS`	`10000`	Limit rows loaded from files

Examples

KEEL_DATAFRAME_SANDBOX=/data keel run analysis.kl          # Restrict to /data
KEEL_DATAFRAME_MAX_ROWS=10000 keel run analysis.kl         # Limit row count
KEEL_DATAFRAME_DISABLED=1 keel run untrusted.kl            # Disable entirely

In-memory operations (select, filter, groupBy, etc.) are always allowed — only file I/O functions are affected by these controls.

For detailed information, see the IO Security Guide.

DateTime Security

DateTime operations can be disabled for untrusted code.

Variable	Values	Effect
`KEEL_DATETIME_DISABLED`	`1` or `true`	Disable DateTime operations

Environment Variables

Variable	Description
`NO_COLOR`	Disable colored output
`KEEL_IO_DISABLED`	`0` or `false` to enable file IO
`KEEL_IO_READ_ONLY`	`1` or `true` for read-only IO
`KEEL_IO_SANDBOX`	Restrict IO to a directory
`KEEL_HTTP_DISABLED`	`0` or `false` to enable HTTP requests
`KEEL_HTTP_ALLOWED_HOSTS`	Comma-separated list of allowed HTTP hosts
`KEEL_DATAFRAME_DISABLED`	`1` or `true` to disable DataFrame operations
`KEEL_DATAFRAME_SANDBOX`	Restrict DataFrame file I/O to a directory
`KEEL_DATAFRAME_MAX_ROWS`	Limit rows loaded from files (e.g. `10000`)
`KEEL_DATETIME_DISABLED`	`1` or `true` to disable DateTime operations

Exit Codes

Code	Meaning
0	Success
1	Compilation error
2	Runtime error