# `Mob.Defect.Sinks.Dev`
[🔗](https://github.com/genericjam/mob/blob/master/lib/mob/defect/sinks/dev.ex#L1)

A defect sink that formats every emitted capsule as a Logger line.

Not started by default — per
`decisions/2026-09-04-defect-reports-are-a-shipped-feature.md`, `mob` is
never the collector, and a sink that runs unbidden would violate that. An
app opts in explicitly:

    Mob.Defect.Sinks.Dev.start_link()

or under its own supervision tree:

    children = [
      # ... app children ...
      Mob.Defect.Sinks.Dev
    ]

It is `Dev` because Logger output is the medium the connected-agent workflow
already uses — `mix mob.connect` streams the device's Logger output into
the agent's IEx session, so a defect logged here reaches the agent for
free. An app that wants a *production* sink (a remote endpoint, a file, a
push channel, or nothing) writes their own subscriber; the API is
`Mob.Defect.Bus.subscribe/0` plus a `handle_info({:mob_defect, capsule}, ...)`.

## What it logs

* `severity: :fatal | :critical` → `Logger.error`
* `severity: :warning` → `Logger.warning`
* anything else → `Logger.info`

The severity mapping is what routes a real bug to the log level a triager
reads first. `Logger.info` for everything would bury a fatal alongside a
perf regression; `Logger.error` for everything would train the reader to
ignore the channel — exactly what the redaction and dedup work goes into
preventing.

# `child_spec`

Returns a specification to start this module under a supervisor.

See `Supervisor`.

# `start_link`

```elixir
@spec start_link(keyword()) :: GenServer.on_start()
```

Start the sink under `name`, defaulting to the module.

---

*Consult [api-reference.md](api-reference.md) for complete listing*