index.md

layout	home
title	openFetch — fetch-native HTTP client
titleTemplate	false
description	Fetch-native HTTP client with interceptors, middleware, Standard Schema JSON, retry lifecycle hooks, memory cache, and Ky-style ergonomics — Node 18+, edge, browsers. No XHR.
head	meta property content og:type website meta property content og:url https://openfetch-js.github.io/openfetch-docs/ meta property content og:locale en_US meta property content og:title openFetch — fetch-native HTTP client meta property content og:description Interceptors, middleware, Standard Schema JSON, retry hooks, memory cache on fetch — Node 18+, edge, browsers. No XHR. meta name content twitter:title openFetch — fetch-native HTTP client meta name content twitter:description Standard Schema JSON, retry lifecycle hooks, interceptors, middleware, cache on fetch. Node 18+, edge — no XHR.
hero	name text tagline actions openFetch HTTP that feels native to fetch Interceptors, middleware, Standard Schema JSON, retry lifecycle hooks, and memory cache — fetch-only for Node 18+, the edge, and modern browsers. theme text link brand Get started /getting-started theme text link alt npm https://www.npmjs.com/package/@hamdymohamedak/openfetch theme text link alt GitHub https://github.com/openfetch-js/OpenFetch
features	title details Fetch-only transport One code path on top of standard fetch — Node, Bun, Deno, Workers, and modern browsers without mandatory polyfills. title details Interceptors & middleware Request/response interceptors plus composable middleware for auth, logging, retries, and caching in a predictable order. title details Retry & in-memory cache Optional retry with backoff and GET/HEAD memory cache with TTL / SWR-style patterns when you opt in. title details Structured errors & safety hooks OpenFetchError with stable codes, optional URL guard for untrusted URLs, and helpers for safe logging. title details Tree-shakable entrypoints Import the core client or add plugins and the fluent sugar API from dedicated subpaths. title details Server components friendly No window assumption — suitable for SSR, APIs, and React Server Components patterns. title details Schema validation & Ky-style ergonomics Optional Standard Schema on JSON, throwHttpErrors, native Request input, sync init hooks, retry onAfterResponse / OpenFetchForceRetry — see Features & pipeline.

At a glance

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

1. Getting started — install, default export, createClient, first requests
2. HTTP methods — GET, POST, PUT, PATCH, DELETE, request(), bodies and query params
3. React & Vue — hooks, composables, shared clients, RSC notes
4. Configuration — full request config, rawResponse, merge rules, helper exports
5. Features & request pipeline — full feature list, merge → dispatch diagrams, retry hooks
6. Plugins & fluent API — @hamdymohamedak/openfetch/plugins, @hamdymohamedak/openfetch/sugar
7. Interceptors & middleware — execution order, dispatch internals, use(), custom middleware
8. Retry & cache — retry budgets, idempotency, createCacheMiddleware, TTL / SWR
9. Errors & security — OpenFetchError, codes, guards, safe logging, assertSafeHttpUrl
10. AI assistants & skills — concise API guidance for models; SKILL.md skill bundle and skills.sh / Agent Skills format

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, isHTTPError, isTimeoutError	Typed errors + guards
SchemaValidationError, isSchemaValidationError	Standard Schema failures on JSON
OpenFetchForceRetry, isOpenFetchForceRetry	Force another retry attempt from onAfterResponse
Standard Schema types	StandardSchemaV1, StandardSchemaV1InferOutput, …
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

Requirements

Node.js 18+ or any runtime with fetch and AbortController.

Source & package

• GitHub: openfetch-js/OpenFetch
• npm: @hamdymohamedak/openfetch

Other languages

Browse all translations.