# mini-coi > A minimalistic version of coi-serviceworker Latest version **0.4.3** (published 2025-12-10) · MIT license · 0 weekly downloads ## Install ```sh npm install mini-coi pnpm add mini-coi yarn add mini-coi bun add mini-coi ``` Provides the command `mini-coi`. ## Health **Score 45/100 (D)** — status: stable. Positive: no vulnerabilities. Warnings: low downloads; no types; no esm support; pre 1.0. ## Facts | | | |---|---| | Version | 0.4.3 | | Published | 2025-12-10 | | First published | 2023-07-26 | | Weekly downloads | 0 | | License | MIT | | TypeScript types | none | | Module format | CommonJS | | Dependencies | 1 | | Unpacked size | 10.2 KB | | Known vulnerabilities | 0 | | Install scripts | no | | GitHub stars | 33 | | Author | Andrea Giammarchi | | Maintainers | webreflection | | Keywords | mini, coi, coi-serviceworker | ## Links - npm: https://www.npmjs.com/package/mini-coi - Repository: https://github.com/WebReflection/mini-coi - Homepage: https://github.com/WebReflection/mini-coi#readme - Issues: https://github.com/WebReflection/mini-coi/issues - npm.io page: https://npm.io/package/mini-coi ## Dependencies (1) - [static-handler](https://npm.io/package/static-handler.md) ^0.5.3 ## Alternatives - [cron](https://npm.io/package/cron.md) — 4.9M weekly downloads - [@vercel/queue](https://npm.io/package/@vercel/queue.md) — 731.6K weekly downloads - [create-sonicjs](https://npm.io/package/create-sonicjs.md) — 1.6K weekly downloads - [@exellix/jobs-api](https://npm.io/package/@exellix/jobs-api.md) — 941 weekly downloads - [@forwardimpact/libskill](https://npm.io/package/@forwardimpact/libskill.md) — 575 weekly downloads ## Recent versions - 0.4.3 (latest) — 2025-12-10 - 0.4.2 — 2024-09-12 - 0.4.1 — 2024-09-11 - 0.4.0 — 2024-09-10 - 0.3.3 — 2024-02-07 - 0.3.2 — 2024-02-06 - 0.3.1 — 2024-02-06 - 0.3.0 — 2024-02-06 - 0.2.1 — 2023-09-27 - 0.2.0 — 2023-07-27 - 0.1.1 — 2023-07-26 - 0.1.0 — 2023-07-26 - 0.0.0 — 2023-07-26 ## README # mini-coi This project ensures your browser's [complicated Cross Origin Isolation (COI) settings](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/SharedArrayBuffer#security_requirements) "just work"™ for web workers. This is especially useful when you have no control over the HTTP headers returned by the server. The simplest way to use mini-coi is to **place the `mini-coi.js` file in the root of your website (i.e. `/`), and reference it as the first child tag in the `` of your HTML documents**: ```html ``` For more complete technical details, read on... ## What is mini-coi? A minimalistic *CLI* utility or a simplified version of [coi-serviceworker](https://github.com/gzuidhof/coi-serviceworker), with an optional `scope` attribute to define where Cross Origin Isolation should happen. ## CLI Bootstrap a local server with all headers enforced: ```sh npx mini-coi . # the third argument is a path so ... # npx mini-coi ./public/ # npx mini-coi ./test/ # ... ``` The *CLI* brings in what's possible already to do with [static-handler](https://github.com/WebReflection/static-handler/tree/main) by passing `--coi` by default. ## Service Worker Allow headers in places like GitHub pages or any other server where you cannot change current headers: ```html ``` #### What's different from coi-serviceworker? * no options at all: "*it just works*" ™ * always *require-corp* to have this working on Safari as well as Chrome or Firefox * errors are just thrown in devtools - - - ### How to use mini-coi as Service Worker * the file **must be a local file**, you can't use any CDN or raw GitHub URL, you need to copy the file content locally [^1] * the script *must not be a module*, it has to be exactly a `` at the top of your `` tag in your page (or in general before any other `script` or `link` or `style` is used, it can be after `meta` and `title` though) [^1]: You can either use the *CLI* utility: ```sh npx mini-coi -sw public/mini-coi.js // or ... npx mini-coi --service-worker public/mini-coi.js ``` Or you can grab the file from a CDN and save it locally: ```sh # grab mini-coi.js and save it locally as mini-coi.js curl -LO https://raw.githubusercontent.com/WebReflection/mini-coi/main/mini-coi.js ``` --- _Source: https://npm.io/package/mini-coi · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._