---
name: Integer
kind: type
since: 0.1
stability: stable
---

64-bit signed integer.

Range is `[-2^63, 2^63)` — the host platform's native `i64`. Wrap or
overflow throws a runtime error rather than wrapping silently;
arithmetic that may exceed the range should explicitly route through
`refine` or a refinement type.

Used for counts, IDs, durations expressed in milliseconds, and any
discrete numeric quantity that doesn't need a fractional component
(use `Float` for that).
