Configuration

An optional gridcalc.toml, looked up in $PWD first and then $XDG_CONFIG_HOME/gridcalc/ (default ~/.config/gridcalc/):

sandbox = true             # AST validation of formulas + code blocks
width   = 12               # default column width
format  = "G"              # default cell format

[keys.grid]
next_sheet  = ["Tab", "F4"]
prev_sheet  = ["S-Tab", "F3"]
cursor_left = ["Left", "h"]
cursor_down = ["Down", "j"]
cursor_up   = ["Up", "k"]
cursor_right= ["Right", "l"]

A fuller annotated example ships in the repository as gridcalc.toml.example.

Keybindings

Every TUI context (grid, entry, visual, cmdline, search) is rebindable. User bindings fire before the hardcoded fallback chain, so binding Tab to next_sheet replaces its default cursor-right meaning rather than racing it.

See Keybindings for the keyspec grammar (Tab, S-Tab, C-x, C-Right, F3, and so on), the action registry, and the combinations that are rejected.

Sandboxing

sandbox = true (the default) enables AST validation of formulas and code blocks: dunder access, dangerous attributes and builtins, and blocked imports are rejected before anything executes. Setting sandbox = false, or the environment variable GRIDCALC_SANDBOX=0, turns it off.

The threat model -- what the sandbox is and is not meant to stop -- is in Security plan. The short version: a workbook can carry a Python code block, so opening an untrusted file in PYTHON or HYBRID mode is the main risk, and that is what the load-time trust prompt exists for.