joi
Object schema validation
About
Object schema validation
Live mirror of the GitHub README. Updated whenever the repo's default branch changes.
joi
The most powerful schema description language and data validator for JavaScript.
Installation
npm install joi
Visit the joi.dev Developer Portal for tutorials, documentation, and support
Useful resources
Quick facts
npm install joiHow Sourcemap Explorer detects joi
We catch joi from two complementary signals: bundled source paths and the embedded package.json. Modern bundlers (webpack, Vite, esbuild, Rollup, Turbopack) preserve the original node_modules/joi/ paths inside the JavaScript sourcemap's sources[] array — that's the canonical signal. When the matching package.json is also captured in sourcesContent[], we read the exact version field — patch number included. No regex guessing, no version inference.
- 1
Confirm the site exposes sourcemaps
In DevTools Network, check the response headers of any application script for `SourceMap` or `X-SourceMap`. Failing that, fetch the script's last 4 KB and look for a `//# sourceMappingURL=` comment.
- 2
Find the package in the bundle
Open DevTools → Network → reload. Click any application script and look at its sourcemap. Inside, search `sources[]` for entries matching `node_modules/joi/` — every match confirms the package is bundled. The matching `sourcesContent[i]` for `node_modules/joi/package.json` gives you the exact installed version.
- 3
Read the version directly from package.json
Run `jq -r '. as $m | $m.sources | to_entries[] | select(.value | endswith("node_modules/joi/package.json")) | $m.sourcesContent[.key] | fromjson | .version' bundle.js.map`. Sourcemap Explorer automates the same query in the popup.
Recent versions
FAQ
What is joi used for?
Object schema validation
How can I tell if a website is using joi?
Open the page in Chrome with the Sourcemap Explorer extension installed and read the Stack tab. We catch `joi` from two complementary signals: `node_modules/joi/` paths inside the JavaScript sourcemap, and the embedded `package.json` we read for exact-version detection. Without the extension you can do the same lookup manually in DevTools — the steps are listed in the "How Sourcemap Explorer detects" section above.
What is the latest version of joi?
18.2.1, as published on the npm registry. The "Recent versions" table on this page lists the most recent 8 releases with their release dates. Sourcemap Explorer reports the version actually bundled into a site, which can lag the latest release by months on real-world deployments.
Where can I read more?
Project homepage: https://github.com/hapijs/joi#readme. Source code: https://github.com/hapijs/joi. Published on npm: https://www.npmjs.com/package/joi. Licensed as BSD-3-Clause.
Keep reading on Sourcemap Explorer
Practical guides
Detection deep dives
Detected by Sourcemap Explorer
When a bundle ships sourcemaps, we read the embedded package.json for joi and report the precise version. Without sourcemaps, an import / require in the page's scripts is enough to flag it.