# `ExternalService.Gateway`
[🔗](https://github.com/jvoegele/external_service/blob/main/lib/external_service/gateway.ex#L1)

Deprecated. Use `use ExternalService` instead.

`ExternalService.Gateway` was the original module-based gateway. In 2.0 the
module-based front door moved to `ExternalService` itself, with a unified,
validated configuration (`:circuit_breaker`/`:rate_limit`/`:retry`) and shorter
generated function names (`call/1` instead of `external_call/1`).

`use ExternalService.Gateway` still works but emits a deprecation warning. It
delegates to `use ExternalService` and additionally generates the old
`external_call/*` (and `reset_fuse/0`) function names as deprecated aliases.
Note that the option shape is the same as `use ExternalService`: the old
`fuse: [strategy:, refresh:]` options are no longer supported — see the
migration guide.

## Migration

    # Before
    use ExternalService.Gateway,
      fuse: [name: MyService, strategy: {:standard, 5, 1_000}, refresh: 5_000],
      rate_limit: {100, 1_000},
      retry: [backoff: {:linear, 100, 1}, expiry: 5_000]

    def call_service(p), do: external_call(fn -> ... end)

    # After
    use ExternalService,
      name: MyService,
      circuit_breaker: [tolerate: 5, within: 1_000, reset: 5_000],
      rate_limit: [limit: 100, per: 1_000],
      retry: [backoff: :linear, base: 100, expiry: 5_000]

    def call_service(p), do: call(fn -> ... end)

---

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