[](https://gleam.run/)
[](https://www.erlang.org/)
[](https://www.erlang.org/doc/design_principles/des_princ)
[](https://hex.pm/packages/viva_telemetry)
[](https://prometheus.io/)
[](./test)
[](./CHANGELOG.md)
[](./LICENSE)
---
*"Logs whisper. Metrics count. Benchmarks judge. The BEAM observes."*
---
> [!IMPORTANT]
> **viva_telemetry IS NOT A FRAMEWORK.**
> It is **three independent observability surfaces** β structured logging,
> Prometheus-shaped metrics, and statistical benchmarks β that you can pull
> into any Gleam/BEAM app without dragging in a runtime.
>
> Plays well with Erlang `:logger`, Prometheus scrapers, and Grafana.
---
## π― Overview
Observability for Gleam applications on the BEAM. Structured logging,
in-memory metrics, Prometheus export, BEAM memory visibility, and small
statistical benchmarks β without forcing a large framework into your
application.
The three surfaces (`log`, `metrics`, `bench`) are deliberately independent:
import only what you need, configure each per process.
| Property | Value |
| :-------------------- | :--------------------------------------------------- |
| **Language** | Pure Gleam (type-safe functional) |
| **Runtime** | BEAM / OTP 27+ |
| **Logging backend** | Erlang `:logger`, console, JSON file |
| **Metrics backend** | ETS-backed counters, gauges, histograms |
| **Export format** | Prometheus text (`# HELP` / `# TYPE`) |
| **Tests** | 41 passing |
| **Public API** | `viva_telemetry/{log,metrics,bench}` |
---
## β‘ Quick Start
```bash
gleam add viva_telemetry@1
```
### Log, count, time β in one file
```gleam
import viva_telemetry/bench
import viva_telemetry/log
import viva_telemetry/metrics
pub fn main() {
log.configure_erlang(log.info_level)
log.info("Server started", [#("port", "8080")])
let requests = metrics.counter("http_requests_total")
metrics.inc(requests)
bench.run("my_function", fn() { heavy_work() })
|> bench.print()
}
```