# Calculator Local Tool Node

> Secure, sandboxed evaluator that supports a defined set of mathematical operators, functions, and constants.

**URL:** https://caywork.com/learn/docs/node/calculator-local-tool-node

## Content

This node evaluates arithmetic and mathematical expressions safely using a restricted AST interpreter. It accepts a single expression or a list of expressions and returns structured results for each.

### Actions (Mathematical features)

- **Arithmetic operators:** `+`, `-`, `*`, `/`, `%`, `//` (floor division), `**` (power)
- **Unary operators:** `+`, `-`
- **Bitwise operators:** `&`, `|`, `^`, `<<`, `>>`
- **Math functions:** `sin`, `cos`, `tan`, `asin`, `acos`, `atan`, `atan2`, `sinh`, `cosh`, `tanh`, `exp`, `log`, `log10`, `sqrt`, `abs`, `round`, `floor`, `ceil`, `factorial`, `pow`
- **Constants:** `pi`, `e`, `tau`, `inf`, `nan`
- **Tuples:** construction of tuples of supported expressions (e.g., `"(1, 2+3)"`)

### Unsupported / Forbidden Mathematical Constructs

- **Matrix multiplication operator (`@`)** disallowed
- **Function calls other than the listed math functions**
- **Keyword arguments to functions**
- **Variables/identifiers** other than the listed constants
- **Complex numbers** (not supported unless expressed via allowed functions/constants)
- **Results with absolute value > `1e100`** rejected as too large

### Inputs and configuration (brief)

- expr: string or list of strings  expression(s) to evaluate (caret ^ rewrites to \*\*).
- max_nodes: per-expression AST node limit.
- timeout: per-expression timeout in seconds.

### Output (brief)

- results: array of objects per input with fields: input, result (or null), error (or null), meta (includes execution time).