openFetch — HTTP client for the fetch era

Fetch-only transport

One code path on top of standard fetch — Node, Bun, Deno, Workers, and modern browsers without mandatory polyfills.

Interceptors & middleware

Request/response interceptors plus composable middleware for auth, logging, retries, and caching in a predictable order.

Retry & in-memory cache

Optional retry with backoff and GET/HEAD memory cache with TTL / SWR-style patterns when you opt in.

Structured errors & safety hooks

OpenFetchError with stable codes, optional URL guard for untrusted URLs, and helpers for safe logging.

Tree-shakable entrypoints

Import the core client or add plugins and the fluent sugar API from dedicated subpaths.

Server components friendly

No window assumption — suitable for SSR, APIs, and React Server Components patterns.

At a glance

Capability	openFetchThis library	Axios	ky
Transport	fetch	XHR (default in browsers)	fetch
Runtime deps	Zero	Own stack	Zero
Instance & defaults	createClient	axios.create	ky.create
Request / response interceptors	Both	Both	Hooks only
Composable middleware	use()	—	—
Retry & memory cache (opt-in)	Plugins	Separate	Retry only
Uniform client response	OpenFetchResponse	AxiosResponse	Response / parsed
Edge & RSC friendly	Uses fetch	Adapters	fetch

Bundle size depends on your toolchain and imports. The core idea: openFetch layers ergonomics on native fetch without switching transports.

Same request — three HTTP clients

The EscuelaJS categories API returns a JSON array. Below: openFetch, Axios, and ky.

openFetch — shared defaults, structured response, and room for interceptors/middleware:

import openFetch from "@hamdymohamedak/openfetch";

const res = await openFetch.get(
  "https://api.escuelajs.co/api/v1/categories"
);
// res.data, res.status, res.headers, res.config

Axios — familiar API; different transport defaults in the browser:

import axios from "axios";

const res = await axios.get(
  "https://api.escuelajs.co/api/v1/categories"
);
// res.data, res.status, res.headers, res.config

ky — minimal API on top of fetch:

import ky from "ky";

const data = await ky
  .get("https://api.escuelajs.co/api/v1/categories")
  .json();

Why developers reach for a client layer

Shared configuration — baseURL, headers, timeouts, and unwrapResponse once per createClient instance.

Cross-cutting behavior — attach auth, tracing, feature flags, and error normalization via interceptors and middleware.

Resilience — retry policies and caching strategies without rewriting every call site.

Predictable errors — map HTTP and network failures to typed errors instead of ad-hoc try/catch parsing.

openFetch targets teams that want those benefits while staying on fetch everywhere the platform already provides it.

Documentation

Getting started — install, default export, createClient, first requests

HTTP methods — GET, POST, PUT, PATCH, DELETE, request(), bodies and query params

React & Vue — hooks, composables, shared clients, RSC notes

Configuration — full request config, rawResponse, merge rules, helper exports

Plugins & fluent API — @hamdymohamedak/openfetch/plugins, @hamdymohamedak/openfetch/sugar

Interceptors & middleware — execution order, dispatch internals, use(), custom middleware

Retry & cache — retry budgets, idempotency, createCacheMiddleware, TTL / SWR

Errors & security — OpenFetchError, codes, safe logging, assertSafeHttpUrl

Public API (summary)

Export	Role
default	Pre-built `createClient()` instance
`createClient` / `create`	New client with optional `initialDefaults`
`createFluentClient`	Callable fluent URL chains (from `/sugar`)
`retry`, `timeout`, `hooks`, `debug`, `strictFetch`	Middleware plugins (from `/plugins`)
`OpenFetchError`, `isOpenFetchError`	Typed errors + type guard
`InterceptorManager`	Low-level interceptor stack
`createRetryMiddleware`	Retry middleware factory
`MemoryCacheStore`, `createCacheMiddleware`, `appendCacheKeyVaryHeaders`	In-memory cache
`maskHeaderValues`, `cloneResponse`, idempotency helpers	Logging and retry ergonomics
Types	`OpenFetchConfig`, `OpenFetchResponse`, `Middleware`, `OpenFetchClient`, etc.
`assertSafeHttpUrl`	Optional SSRF-style guard for literal IP/localhost in URLs

Export

Role

default

Pre-built createClient() instance

createClient / create

New client with optional initialDefaults

createFluentClient

Callable fluent URL chains (from /sugar)

retry, timeout, hooks, debug, strictFetch

Middleware plugins (from /plugins)

OpenFetchError, isOpenFetchError

Typed errors + type guard

InterceptorManager

Low-level interceptor stack

createRetryMiddleware

Retry middleware factory

MemoryCacheStore, createCacheMiddleware, appendCacheKeyVaryHeaders

In-memory cache

maskHeaderValues, cloneResponse, idempotency helpers

Logging and retry ergonomics

Types

OpenFetchConfig, OpenFetchResponse, Middleware, OpenFetchClient, etc.

assertSafeHttpUrl

Optional SSRF-style guard for literal IP/localhost in URLs

openFetchHTTP client for the fetch era

Fetch-only transport

Interceptors & middleware

Retry & in-memory cache

Structured errors & safety hooks

Tree-shakable entrypoints

Server components friendly

At a glance

Same request — three HTTP clients

Why developers reach for a client layer

Documentation

Public API (summary)

Requirements

Source & package

Other languages

openFetchHTTP client for the fetch era

Fetch-only transport

Interceptors & middleware

Retry & in-memory cache

Structured errors & safety hooks

Tree-shakable entrypoints

Server components friendly

At a glance ​

Same request — three HTTP clients ​

Why developers reach for a client layer ​

Documentation ​

Public API (summary) ​

Requirements ​

Source & package ​

Other languages ​

At a glance

Same request — three HTTP clients

Why developers reach for a client layer

Documentation

Public API (summary)

Requirements

Source & package

Other languages