Server Functions
Export ERSC.ServerFn.make({ input, handler }) from a module marked 'use server'. input is a
Schema; handler returns an Effect and can use application services. Callers pass the Schema's
encoded type, and the handler receives its decoded type. Let the Schema infer handler parameters.
Forms and mutations
Use Schema.fromFormData(...) for form input and return void to pass a function directly to
<form action>. For feedback with useActionState, declare
input: [StateSchema, FormSchema] and handler: (previousState, form) => ....
Pass the native reference to useActionState to retain submission without JavaScript.
Direct browser calls and form actions refresh the current route after execution. The result can arrive before suspended content in that refresh finishes.
Queries and streams
Import ServerFn from effective-rsc/client to query a Server Function or consume its stream.
ServerFn.query(reference)(...args) retrieves the function's result as an Effect;
ServerFn.queryAtom(reference) exposes it as an atom for @effect/atom-react.
The atom helper cancels its previous request when called again.
Return an Effect Stream from the server handler to send chunks as they become available.
Read it with ServerFn.stream(reference) or display its latest chunk with
ServerFn.streamAtom(reference). Both expose chunks as they arrive, so client code can process or
display an ongoing result.
Outcomes and failures
Return expected outcomes, such as unavailable data or a declined operation, as a tagged success
value. The handler and any returned Stream must have a never error channel.
Framework failures reject direct-call Promises; the client helpers expose ServerFnError in their
Effect or Stream error channel. Use Effect.catchTag or inspect an atom's AsyncResult cause.