All CSS and JS assets missing when deploying to production

[AugustinUpway]

What is the location of your example repository?

No response

Which package or tool is having this issue?

CLI

What version of that package or tool are you using?

4.4.0

What version of React Router 7 are you using?

7.9.2

Steps to Reproduce

Hi Hydrogen team,

We faced a weird issue yesterday where all of our JS & CSS assets went 404 on Shopify Oxygen, fully preventing sales on our Hydrogen stores (we are currently ongoing migration) 😨 :

Expected Behavior

Assets should not 404 😅

Actual Behavior

All CSS & JS assets are missing.

We mitigated the issue by rolling back to the last working version in Shopify Hydrogen Admin first, then
pinned the Shopify CLI version to 4.3.0 (because it wasn't pinned in the first place).
From our test, both 4.4.0 & 4.5.1 are broken.

Our team noticed #3842, but no idea if this really related.

More context:

• Our build & deploy command is pnpx shopify hydrogen deploy --no-lockfile-check --auth-bypass-token
• in our package.json:
  • "@shopify/hydrogen": "2025.7.0" (yeah, we're a little late on updates)
  • "@shopify/cli": "~3.85.4" (not the version used to go to prod tho)

Any idea what's going on ?

[crumeb]

Confirming (Hydrogen 2026.4.4 / CLI 4.4.0)

We hit the same symptom on Oxygen Preview: deployment marked Ready, worker HTML/sitemap.xml/robots.txt OK, every JS/CSS/font/image client asset returned HTTP 404 for the full publication window. Admin runtime logs showed no worker errors.

Environment

• @shopify/cli: 4.4.0 (pinned; upgraded from 3.93.2 on 2026-07-10)
• @shopify/hydrogen: 2026.4.4
• React Router: 7.16.0
• Node in CI: v24
• Deploy: shopify hydrogen deploy --preview --json-output --auth-bypass-token

Controlled Preview experiments (workflow_dispatch only; Production skipped)

Experiment	CLI	Deploy flags	Result
A	4.4.0	--assets-dir dist/client --worker-dir dist/server	Zero HTTP 404s — assets publish
B	4.3.0	none (4.3.0 rejects the new flags)	Zero HTTP 404s — assets publish

So for us this matches the Vite client outDir mis-resolution from #3842: without an explicit assets dir on 4.4.0, the worker goes Ready while the client inventory never lands on the CDN generation. Explicit --assets-dir/--worker-dir on 4.4.0 is a reliable workaround; pinning 4.3.0 alone also works.

Note

After assets started publishing, our exhaustive byte/MIME verifier still fails on image CDN transforms (avif/webp responses rewritten to png/jpeg). That is separate from the all-assets-404 bug.

[AugustinUpway]

@frandiox @fredericoo @graygilmore sorry to ping you all but have you seen this issue ?
Our prod went down because of new NPM version of a CLI tool, loosing sales in the meantime, so I'm a little worried if the report is not even acknowledged by the maintainers 🥲
I'm also curious if we can safely upgrade again or not 🙂

Edit: I'm reaching out directly on Github but let me know if going through Shopify Plus support is better.

[graygilmore]

Hey @AugustinUpway this should be fixed on @shopify/cli 4.5.1 and later. Let me know if you're still having an issue with that version.