# `Minga.Extension.CallbackInvoker`
[🔗](https://github.com/jsmestad/minga/blob/main/lib/minga/extension/callback_invoker.ex#L1)

The runtime trust boundary for extension-owned callbacks.

Ordinary invocation admits active source-owned code before entering the
callback. Unload invocation is a distinct token-scoped operation for a source
that is already quiescing. Both entry points normalize exceptions, throws, and
exits without translating failure into a successful decline or no-op.

Domain adapters remain responsible for validating successful return values.
They use `invalid_return/4` so malformed extension values share this boundary's
observable failure type while core callbacks continue to run directly.

# `failure`

```elixir
@type failure() ::
  {:source_unavailable, source(), module(), atom(), term()}
  | {:callback_failed, source(), module(), atom(), :exception | :exit | :throw,
     term()}
  | {:invalid_return, source(), module(), atom(), term()}
```

A contained extension callback failure.

# `result`

```elixir
@type result(value) :: {:ok, value} | {:error, failure()}
```

A successful callback value or an explicit extension failure.

# `semantics`

```elixir
@type semantics() :: atom()
```

The callback operation being performed, used in diagnostics.

# `source`

```elixir
@type source() :: {:extension, atom()}
```

An extension source accepted by the runtime callback boundary.

# `invalid_return`

```elixir
@spec invalid_return(source(), module(), atom(), term()) :: failure()
```

Builds and reports a malformed successful extension return.

# `invoke`

```elixir
@spec invoke(source(), module(), atom(), [term()], semantics(), GenServer.server()) ::
  result(term())
```

Invokes an active extension callback after source-aware admission.

# `invoke_unload`

```elixir
@spec invoke_unload(
  source(),
  Minga.Extension.CodeLease.unload_token(),
  module(),
  atom(),
  [term()],
  semantics(),
  GenServer.server()
) :: result(term())
```

Invokes a callback owned by a quiescing source using unload authority.

---

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