Just Bash - Sandboxed Execution

Run the user's command or task inside the just-bash sandbox. This provides a read-only filesystem, no network access, and in-memory-only writes.

User's Request

$ARGUMENTS

How to Execute

Translate the user's request into one or more just-bash commands and run them via the Bash tool.

Command Format

# Simple command
just-bash -c 'COMMAND' --root /path/to/project

# Multi-line script
just-bash -c '
COMMAND1
COMMAND2
' --root /path/to/project

# When writes are needed (in-memory only, nothing touches disk)
just-bash --allow-write -c 'COMMAND' --root /path/to/project

# JSON output for structured results
just-bash --json -c 'COMMAND' --root /path/to/project

Key Options

• --root <path> - Mount a specific directory (default: cwd). Always set this to the project root.
• --allow-write - Enable in-memory writes (safe, nothing reaches disk)
• --json - Output as JSON: {"stdout", "stderr", "exitCode"}
• -e, --errexit - Exit on first error
• --python - Enable python3

Available Tools

Reliable (tested, working)

• Text: awk sed grep egrep fgrep rg cut tr sort uniq wc head tail tac rev nl fold column comm join paste split strings
• Data: jq (JSON - older build, no -R/-s flags) xan (CSV)
• Files: ls find cat cp mv rm mkdir rmdir ln touch chmod stat file tree du basename dirname readlink
• Compression: gzip gunzip zcat tar
• Checksums: md5sum sha1sum sha256sum base64
• Utilities: date seq expr env printenv whoami hostname sleep timeout time which xargs tee diff

Broken in v1.0.0 (do NOT use)

• yq - "Dynamic require of process" error
• sqlite3 - "DataView constructor" error

Limitations

• No network (no curl, wget, npm, git, pip)
• No process substitution (<() syntax)
• jq missing -R (raw input) and -s (slurp) flags
• tree missing some flags (e.g. --dirsfirst)
• No interactive commands (no vim, nano, less)

Execution Rules

1. Always use --root to scope to the correct project directory
2. If the user gives a natural language task, translate it to bash commands
3. If a command fails, try an alternative approach using available tools
4. For multi-step tasks, chain commands in a single just-bash -c '...' call
5. Present results clearly to the user
6. Do NOT use yq or sqlite3 - they are broken in v1.0.0