---
status: open
opened: 2026-09-30
located-in:
  - mesh-controller internal/catalogue (requires is a list of hard requirements)
fixed-by:
amended-design:
---

# 166 — A requirement cannot be optional

## What was observed

Making every dependency on ace a provision turned soft dependencies into hard ones. grafana now
requires `influxdb-api` (a data source), ombi requires `sonarr-api`, `radarr-api` and `lidarr-api`,
home-assistant requires the Servarr APIs and `mqtt-topic`. Each is optional to the software — grafana
runs without a data source, ombi without lidarr — but a mesh without influxdb cannot assign grafana at
all, and a mesh without lidarr cannot run ombi.

## What would be right

A requirement a module can run without: resolved and bound when a provider exists, absent (with its
`${bound:…}` placeholders refused or defaulted explicitly, never rendered empty) when none does — so
the module description stays true on every mesh.