Use a custom transport

Set a transport at runtime to replace the network send. The client still builds URLs, serializes parameters, resolves authentication, and handles results.

The transport is an AxiosInstance. The default is defaultTransport, an axios.create() instance exported from the generated client, and you can replace it with your own pre-configured instance. Use interceptors for request headers or response logging.

type ClientConfig = {
  // ...
  transport?: AxiosInstance
}

Kubb forwards the resolved URL, query, body, and authentication to the instance.

Pass a pre-configured instance

Give the client an instance with a timeout, default headers, and a logging interceptor:

import axios from 'axios'
import { client } from './gen/.kubb/client'

const instance = axios.create({
  timeout: 10_000,
  headers: { 'X-Client': 'kubb' },
})

instance.interceptors.response.use((response) => {
  console.info(`${response.config.method?.toUpperCase()} ${response.config.url} -> ${response.status}`)
  return response
})

client.setConfig({ transport: instance })

Every generated function now sends through your instance, so its timeout, headers, and interceptors apply to each call. Interceptors registered through client.interceptors move to the new instance and keep their IDs for eject and update.

Kubb sets transformRequest, paramsSerializer, and validateStatus on each request for its own serialization and throwOnError handling, so leave those fields alone. Set timeouts, retries, and interceptors on the instance. For one call, pass options, such as { timeout } or { onUploadProgress }, instead of building a new instance.

Use the default instance

The generated client exports defaultTransport, the instance it sends through when no transport is set. Configure it directly to add tracing or headers without replacing the transport:

import { defaultTransport } from './gen/.kubb/client'

defaultTransport.defaults.timeout = 10_000
defaultTransport.interceptors.request.use((config) => {
  config.headers.set('traceparent', currentTraceparent())
  return config
})

Instances from createClient() get their own axios.create() and do not share these settings.

Where to set it

Use client.setConfig({ transport }) for shared configuration, createClient({ transport }) for an isolated instance, or pass transport on an operation to override it for one call.

Server-sent events

Operations returning text/event-stream produce a typed stream rather than a RequestResult. The client switches to the axios fetch adapter for these calls unless you set adapter yourself, because the default XHR adapter buffers the whole body.