Shopify Checkout Extension Concurrency Issue - Cart Line Attribute Updates

Extensions
1

I’m experiencing a synchronization challenge with UI extensions in a highly customized checkout process, specifically related to concurrent cart line attribute modifications.

Scenario Details:

  • Checkout Extension 1 (init, in header): Adds 5 attributes to each cart line
  • Checkout Extension 2 (shipping options): Adds 1 attribute to each cart line

Specific Problem:

  • In “three-step layout”, the process works smoothly because initialization happens sequentially
  • In “onepage layout”, extensions are instantiated simultaneously, causing concurrency conflicts

Key Questions:

  1. Is there a reliable method to detect ongoing cart modification processes?
  2. Our current retry mechanism based on “negotiation was stale” error is inconsistent. Are there more robust approaches?

Has anyone encountered similar synchronization challenges in Shopify checkout extensions? What strategies or best practices have you found effective for managing concurrent cart updates?

Appreciate any insights or guidance.

2

Hi rndgf,

Just to confirm, are you looking to activate individual checkout ui extensions in a specific sequence?

3

Hi Liam

It could be a solution yes because for now, the execution order is not consistent.
I need to have my initialization to be fully completed and then, run other extensions.
Our implementation run well on the third-page layout because the init done in the header does not conflict with the other one which is done at “shipping” step.

Is that clearer with this explanation ?