Backends

Rata's public fetch API is backend-neutral. The effect in Rata.Fetch describes the operation:

pub effect Fetch {
  fun fetch : FetchSpec -> Result Response FetchError
}

Backend modules provide handlers for that effect.

Rata.Fetch.Httpc

The first backend wraps Erlang/OTP inets:httpc:

import Rata.Fetch
import Rata.Fetch.Httpc

main () = {
  Fetch.get "https://example.com"
} with Httpc.httpc

The lower-level Httpc.request function is also public for direct backend checks:

pub fun request : FetchSpec -> Result Response FetchError

Most application code should prefer the effectful Fetch.get, Fetch.post, and Fetch.send helpers with Httpc.httpc at the boundary.

TLS

HTTPS requests verify certificates by default through OTP TLS options and the operating system CA store. TLS setup, certificate validation, and hostname verification failures are returned as Fetch.TlsError.

Rata does not currently expose options for disabling verification, custom CA bundles, client certificates, proxies, connection pooling, or a private httpc profile. Those belong to future backend options, not the core FetchSpec.

Future backends

Additional backend modules can implement the same Fetch effect without changing user code:

} with SomeOtherBackend.handler

The core API intentionally returns raw bytes and ordinary Saga records so later backends do not leak their Erlang-specific shapes into application code.