---
status: open
opened: 2026-09-30
located-in:
  - mesh-controller internal/catalogue/settings.go (settle: every key but `ports` merges into every mergeable file and every contribution)
  - mesh-controller internal/catalogue/declaration.go (a provider's settings are laid over what it serves)
fixed-by:
amended-design:
---

# 168 — A setting reaches every file and every contribution

## What was observed

Settings merge key by key into **every** `"merge": "json"` file of a module **and** every contribution
it makes; a provider's settings are also laid over what it serves. Seen on ace:

- searxng's `endpoints` and a route `label` land in searxng's own `settings.yml`; nodered's
  `timeZone` and `mqtt` keys land in mosquitto's grants file; keycloak's `issuer` lands in its
  `postgres-database` and `route` contributions.
- every consumer's `plex-api` binding carries plex's `endpoints` and `expose` settings — and a provider
  setting named `port` would silently redirect every consumer.
- a module cannot have two configurable files: searxng's sidecar config had to stop being mergeable
  so searxng's keys would not reach it.

Harmless today only because every receiver happens to ignore unknown keys.

## What would be right

A setting is aimed: at a file (by resource id), at a contribution (by requirement), or at what the
module serves — declared settable by the module (ADR 0046 already says settings drive "the fields the
manifest marks") — and an unaimed key is refused like any unknown setting.