# 31-haskell-writer-audit

This example shows intermediate Haskell rollout simulation with `Writer`.

It includes:

- a release job with rollout modes and replica counts,
- a `Writer [String]` audit trail that records ordered rollout events,
- a final rollout report computed alongside the log, and
- a test suite run by `nix flake check`.

Useful commands:

```bash
nix develop
cabal run
cabal run -- api:production:canary:20:3 worker:staging:rolling:0:2
cabal test

nix build
./result/bin/mini-audit api:production:canary:20:3 worker:staging:rolling:0:2

nix run . -- api:production:canary:20:3 worker:staging:rolling:0:2
nix flake check
```