[Bug]: `/cart/add` 404ing in local development

[fergus-haywood]

Please confirm that you have:

• [x] Searched existing issues to see if your issue is a duplicate. (If you’ve found a duplicate issue, feel free to add additional information in a comment on it.)
• [x] Reproduced the issue in the latest CLI version.

In which of these areas are you experiencing a problem?

Other

Expected behavior

When adding a variant to the cart, the cart should be updated to include the new item

Actual behavior

When adding an variant to the cart, the CLI is showing a 404 error for the /cart/add endpoint.

Verbose output

Verbose output

• 09:19:58 Request »    GET 404 /cart/add/41431326228614 554ms

Reproduction steps

1. Launch the CLI with shopify theme dev
2. Try to add a variant to the cart manually by entering http://127.0.0.1:9292/cart/add/{{ variant_id}}

Operating System

Mac OS Sequoia 15.3.2

Shopify CLI version (shopify --version)

3.79.0

Shell

zsh

Node version (run node -v if you're not sure)

v23.11.0

What language and version are you using in your application?

Shopify Liquid

[pietervandendungen]

Encountering the same issue on our local env with Shopify CLI

[vfcoding]

Same error for me with Shopify CLI v3.79.0

[MaxDesignFR]

I confirm, I have this issue too.

[Teunel]

Same here. cart/update.js isn't working either.

[ceri-waterscreative]

Same here CLI version 3.79.1

[stijns96]

Same here on v3.78.1.

Nothing showing with --verbose as well.

[msev]

Same problem with version 3.79.0.

The only temporary fix I've found is to delete all cookies on 127.0.0.1. 🤷‍♂️

[jahlbom]

Same problem with version 3.79.0.

The only temporary fix I've found is to delete all cookies on 127.0.0.1. 🤷‍♂️

Smashing, thanks. Worked fine here on CLI version 3.79.0

[procarrera]

Following this topic - also happening here.

[NerdieIrina]

Same here!

[jo-elbdev]

Same here

[tr-elbdev]

Same here

[veno-02]

Same issue here — just following this thread.

I’m not using Shopify CLI for local development, I run a regular Shopify store in production. We’re experiencing the same /cart/add.js and cart/update.js ,404 error, even for new visitors.

[djordje-st]

Just tried out with CLI v3.38.0, issue is still there

[vfcoding]

It seems to work on v3.80.4 🎊

[graygilmore]

I just tested on v3.81.2 and this appears to be fixed. If it's still an issue let us know!