instrument

# Changelog

All notable changes to this project will be documented in this file.

## [0.2.0] - 2026-03-31

### Added
- Vec API for labeled metrics (prometheus-cpp style): `new_counter_vec/3`, `new_gauge_vec/3`, `new_histogram_vec/3`
- Direct vec operations: `inc_counter_vec/2,3`, `get_counter_vec/2`, `inc_gauge_vec/2,3`, `dec_gauge_vec/2,3`, `set_gauge_vec/3`, `get_gauge_vec/2`, `observe_histogram_vec/3`, `get_histogram_vec/2`
- `labels/2` function to get labeled metric instances
- Prometheus text format export via `instrument_prometheus:format/0`
- GitHub Actions CI for OTP 26/27 on Linux and macOS
- ex_doc documentation support
- Type specs for prometheus, vector, and registry modules

### Changed
- Modernized NIF code from C++ to C11 with CMake build system
- Updated README with examples and API documentation
- Updated copyright to 2017-2026

## [0.1.0] - 2017-04-28

### Added
- Initial release
- Counter metrics with `new_counter/2`, `inc_counter/1,2`, `get_counter/1`
- Gauge metrics with `new_gauge/2`, `inc_gauge/1,2`, `dec_gauge/1,2`, `set_gauge/2`, `get_gauge/1`
- Histogram metrics with `new_histogram/2,3`, `observe_histogram/2`, `get_histogram/1`
- Vector support for labeled metrics
- NIF-based implementation for high performance