gmxhr-fetch

library0.1.2jsnpmunverified

A fetch-like polyfill for userscript managers (Tampermonkey, Greasemonkey, Violentmonkey). Version 0.1.2 provides a familiar `fetch` interface over `GM_xmlhttpRequest`, allowing userscript authors to use Promise-based HTTP requests without managing raw GM API calls. Lightweight, no external dependencies, supports typical fetch options (method, headers, body). Key differentiator: simplifies migrating from standard fetch to userscript context by mimicking the Fetch API.

testing

npm install gmxhr-fetch

package ↗

INSTALL

IMPORT

SIG · GMXHR-FETCH

gmxhr-fetch

testingjavascriptv0.1.2

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

gmfetch

✓ import { gmfetch } from 'gmxhr-fetch'

✗ const gmfetch = require('gmxhr-fetch')

ESM-only; CommonJS require not supported. In userscripts, add @require directive in metablock.

default

✓ import gmfetch from 'gmxhr-fetch'

✗ import { gmfetch } from 'gmxhr-fetch'

When imported as default, the symbol is named `gmfetch`; but the library's default export is also named `gmfetch`. Both work.

GM_xmlhttpRequest

✓ // @grant GM_xmlhttpRequest

✗ // @grant GM.xmlHttpRequest

Must grant both `GM_xmlhttpRequest` and `GM.xmlHttpRequest` in metablock for cross-platform compatibility.

Demonstrates basic usage in a userscript: making a POST request with headers and body, handling response and errors.

// ==UserScript== // @name my script // @require https://unpkg.com/gmxhr-fetch // @grant GM_xmlhttpRequest // @grant GM.xmlHttpRequest // ==/UserScript== async function main() { try { const response = await gmfetch('https://api.example.com/data', { method: 'POST', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify({ key: 'value' }) }); const data = await response.json(); console.log('Success:', data); } catch (error) { console.error('Request failed:', error); } } main();

Debug

Known issues

gotcha`gmfetch` does not support streaming (e.g., response.body) or abort signals (AbortController).

fix

Do not rely on Streams or AbortController; use alternative methods if needed.

affects: <=0.1.2

gotchaThe response object's `.json()`, `.text()`, etc. may not fully mimic the Fetch API response (e.g., statusText, redirected).

fix

Test response properties before using non-standard ones.

affects: <=0.1.2

breakingRequires both `GM_xmlhttpRequest` and `GM.xmlHttpRequest` grants; missing one may cause silent failures.

fix

Add both @grant directives to userscript metablock.

affects: >=0.1.0

deprecatedPackage version 0.1.2 is early alpha; API may change without notice.

fix

Pin version in @require URL or monitor repository for updates.

affects: =0.1.2

Errors

Common errors & fixes

TypeError: gmfetch is not a function

Missing @require directive or incorrect import statement (e.g., using require instead of @require).

fix

Add `// @require https://unpkg.com/gmxhr-fetch` to metablock and ensure script runs in userscript context.

gmfetch is not defined

Incorrect @grant directives or using gmfetch outside userscript scope.

fix

Grant both `GM_xmlhttpRequest` and `GM.xmlHttpRequest` in metablock.

ReferenceError: GM_xmlhttpRequest is not defined

Missing @grant for GM_xmlhttpRequest.

fix

Add `// @grant GM_xmlhttpRequest` to metablock.

Upgrade

Version history

0.1.2latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

6 hits · last 30 days

node

Resources

packagegmxhr-fetch ↗