hulla.dev

Client connections

Same-process calls

Call your API directly when the client and server run in the same process.

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Use inProcessTransport() to call an implementation from the same JavaScript process. It runs validation, middleware, and the handler without making an HTTP request.

The example calls the server from Build a task API. Keep this client in server code: it imports the implementation directly.

src/api/local-client.ts
import { createClient } from '@hulla/api/client'
import { inProcessTransport } from '@hulla/api/in-process'
import { contract } from './contract'
import { implementation } from './implementation'

const api = createClient(contract, {
  transport: inProcessTransport(implementation),
})

const result = await api.createTask({
  body: { title: 'Write the quick start' },
})

console.log(result.body.title) // Write the quick start

This is a zero-network call, not an HTTP simulation. Native JSON values pass directly instead of being stringified and parsed, so keep type-only JSON declarations JSON-compatible if the same contract also uses HTTP. Codecs still encode and decode their application values.

Because the local client imports the implementation, place it behind a server-only module boundary. Browser code should build a separate client from the same contract with fetchTransport() or another remote transport. Server and browser calls explains how to choose and place each client across full-stack frameworks.

Use ordinary functions when no contract lifecycle is needed. In-process transport is useful when a local caller should observe the same validation, middleware, declared statuses, errors, and cancellation behavior as a remote caller.