Shopify Webhook → OpenAI HTTP Request causing 429 rate limit errors (multiple executions per single update)

Questions
1

Hi everyone,

I’m building an n8n workflow where a Shopify product update webhook triggers an OpenAI API call to auto-categorize products.

Current Architecture

Workflow A (single workflow):
Shopify Webhook (products/update)
→ Code node (clean product data)
→ HTTP Request (OpenAI Chat Completions API)
The OpenAI call works correctly in isolation.
However, in production, I’m consistently hitting:

AxiosError: Request failed with status code 429

OpenAI returns:

Try spacing your requests out using the batching settings under ‘Options’

What I’ve Observed

Even when I update a single product once, Shopify appears to fire multiple webhooks.

This results in:

  • Multiple parallel executions of the workflow

  • Multiple HTTP calls to OpenAI

  • Burst traffic → 429 rate limit

Batching inside the HTTP node does not help because:

  • Each webhook creates a separate execution

  • Batching only applies within one execution

Adding a Wait node (time delay) also does not prevent parallel executions.

What I’ve Already Tried

Inside the HTTP Request node:

  • Items per batch: 1

  • Batch interval: 1500–3000 ms

  • Retry on fail: OFF

  • Always output data: ON

  • On error: Continue

Despite this, I still get 429 errors.

How do I avoid getting the 429 errors?

2

Hey @chaitanya_maheshwari , welcome to the community.

So yeah, this is a super common issue with Shopify webhooks — you’re not doing anything wrong. Here’s what’s actually happening:

When you update a single product, Shopify doesn’t just fire one webhook. It fires like 3-5 of them because internally it saves the product, then the inventory, then variants, etc. Each save triggers another products/update event. Annoying, I know.

And since each webhook creates its own execution in n8n, your OpenAI calls all hit at the same time and boom — 429 rate limit.

Here’s the easy fix — three small changes:

1. Add a Code node right after your webhook to kill the duplicates

Just paste this in:

JavaScript

const productId = $input.first().json.body.id;
const updatedAt = $input.first().json.body.updated_at;
const key = `${productId}_${updatedAt}`;

const staticData = $getWorkflowStaticData('global');
if (!staticData.seen) staticData.seen = {};

const now = Date.now();
for (const k in staticData.seen) {
  if (now - staticData.seen[k] > 60000) delete staticData.seen[k];
}

if (staticData.seen[key]) return [];

staticData.seen[key] = now;
return $input.all();

What this does is — if Shopify sends the same update 5 times, only the first one actually goes through. The rest just stop right there. Simple.

2. Add a Wait node (3 seconds) before your OpenAI call

Just gives it a little breathing room. Nothing fancy.

3. Set your workflow concurrency to 1

Click the gear icon in your workflow → set concurrency to 1. This makes sure even if multiple webhooks come in, they line up and run one at a time instead of all at once.

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