joi
Object schema validation
About
Object schema validation
What detecting joi tells you about a site
Joi turning up in browser-shipped JavaScript is notable because it is fundamentally a server-side validation library, born in the Hapi ecosystem. When it ends up in a client bundle it usually means shared validation schemas between back-end and front-end, or a build that pulled in server code that wasn't fully tree-shaken out. Either way it points to a JavaScript-everywhere team reusing the same validation contracts across the stack. It is heavier than browser-first validators, so its presence in the client often reveals a code-sharing strategy rather than a deliberate front-end choice.
Why the exact joi version matters
Joi has a tangled lineage: it moved out of the @hapi namespace and back to standalone joi, and major versions reshaped the API around how schemas are defined and how validation results are returned. The exact version tells you which era of that history the project is anchored to, and whether it is the maintained line or an abandoned namespaced fork.
joi in a real-world stack
When you find joi in a bundle, it rarely travels alone. Server frameworks like Hapi or Express, and shared-schema setups in full-stack TypeScript monorepos.
Quick facts
npm install joiWhat joi pulls in
joi declares 7 direct dependencies — each one also rides into any bundle that ships joi, so they are detection targets too. Reading them is a quick way to understand the package's real footprint .
How Sourcemap Explorer detects joi
joi ships as v18.2.3, published 2026-06-17 and carries 7 direct dependencies, 249 versions on the registry. Those exact numbers are the footprint Sourcemap Explorer matches when joi rides inside a deployed bundle — here is how the detection works.
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 — that map is where the `joi` paths live.
- 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.
Major releases of joi
When each major version first landed. Major bumps are where breaking changes live, so this timeline is the fastest way to date the joi version a site actually ships against the ecosystem.
Recent security advisories for joi
The 1 most recent advisories affecting some versions of joi, aggregated from OSV.dev (GitHub Advisory + CVE data). A listing here doesn't mean the version a given site ships is affected — each advisory applies to a specific version range. Sourcemap Explorer reads the exact bundled version so you can check it against these ranges.
joi has an uncaught RangeError on deeply nested input through recursive `link()` schemas
Recent versions
joi README
Live mirror of the GitHub README, for reference. 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
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.
How do I find out which version of joi a website is running?
Read it straight from the site's JavaScript sourcemap. When a build ships source maps, the bundled `joi/package.json` carries the exact `version` string — Sourcemap Explorer extracts it in one click on the Stack tab, and you can do it by hand in DevTools by opening the `.map` file and searching for `node_modules/joi/package.json`. That is far more reliable than inferring the version from an asset-hash or a `?ver=` query string, which is all surface-level detectors have to go on. The current npm release is 18.2.3, but real deployments frequently run an older pinned version — which is exactly why reading the bundled number matters.
What is the latest version of joi?
18.2.3, 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.
Is joi actively maintained?
Very actively maintained — the last release shipped within the past three months. The last published release was 2026-06-17. Source code: https://github.com/hapijs/joi.
Does joi have known security vulnerabilities?
1 recent advisory affecting some versions of joi is listed in the "Recent security advisories" section above, aggregated from OSV.dev (GitHub Advisory + CVE data). Whether a particular site is exposed depends entirely on the exact version it ships — each advisory applies to a specific version range, not to the package as a whole. That is why the precise bundled version matters: Sourcemap Explorer reads the version a site actually runs, so you can check it against the affected ranges instead of assuming the latest release is what's deployed.
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 (the registry's latest is v18.2.3, published 2026-06-17; the bundled copy is often older). Without sourcemaps, an import / require in the page's scripts is enough to flag it.