Mechanic is a development and ecommerce automation platform for Shopify. :)
This task monitors all variants having a SKU that you configure, and ensures that changes to the available inventory quantity are reflected across all variants sharing that SKU.
Runs Occurs when a user manually triggers the task and Occurs every 10 minutes. Configuration includes product skus to monitor.
This task monitors all variants having a SKU that you configure, and ensures that changes to the available inventory quantity are reflected across all variants sharing that SKU.
First, manually set all available inventory quantities to be equal for each of the SKUs you'd like to monitor. Then manually run this task which will then take a snapshot of the current available inventory quantity for your SKUs. When the task automatically runs, every 10 minutes, it will check for changes to inventory, and ensure that the cumulative change for a SKU is reflected across all product variants sharing that SKU.
Note: This task only considers a store's default location when managing inventory.
Mechanic is designed to benefit everybody: merchants, customers, developers, agencies, Shopifolks, everybody.
That’s why we make it easy to configure automation without code, why we make it easy to tweak the underlying code once tasks are installed, and why we publish it all here for everyone to learn from.
(By the way, have you seen our documentation? Have you joined the Slack community?)
mechanic/user/trigger mechanic/scheduler/10min
{% assign skus_to_monitor = options.product_skus_to_monitor__array_required %}
{% assign primary_location = shop.locations[shop.primary_location_id] %}
{% comment %}
-- clean up SKUs by skipping blanks, stripping outside spaces, and removing duplicates to prevent inventory over-adjustments
{% endcomment %}
{% assign cleaned_skus = array %}
{% for sku in skus_to_monitor %}
{% assign cleaned_sku = sku | strip %}
{% unless cleaned_sku == blank or cleaned_skus contains cleaned_sku %}
{% assign cleaned_skus = cleaned_skus | push: cleaned_sku %}
{% endunless %}
{% endfor %}
{% if cleaned_skus == blank %}
{% error "Please enter one or more shared SKUs to sync." %}
{% break %}
{% elsif cleaned_skus != skus_to_monitor %}
{% comment %}
-- log a warning if there are SKU list issues, but let task keep processing cleaned SKUs
{% endcomment %}
{% action "echo" __error: "There are duplicates, blanks, or extra spaces in the 'Product SKUs to monitor' list, which should be removed." %}
{% endif %}
{% assign skus_to_monitor = cleaned_skus %}
{% log %}
"Processing {{ skus_to_monitor.size }} shared {{ skus_to_monitor.size | pluralize: "SKU", "SKUs" }}."
{% endlog %}
{% assign query_components = array %}
{% for sku in skus_to_monitor %}
{% assign query_components[query_components.size] = sku | json | prepend: "sku:" %}
{% endfor %}
{% capture search_query -%}
location_id:{{ shop.primary_location_id }} AND ({{ query_components | join: " OR " }})
{%- endcapture %}
{% log search_query: search_query %}
{% assign variants_by_sku = hash %}
{% assign cursor = nil %}
{% for n in (1..200) %}
{% capture query %}
query {
productVariants(
first: 200
query: {{ search_query | json }}
after: {{ cursor | json }}
) {
pageInfo {
hasNextPage
endCursor
}
nodes {
id
sku
inventoryItem {
id
inventoryLevel(locationId: {{ primary_location.admin_graphql_api_id | json }}) {
quantities(names: "available") {
name
quantity
}
}
}
}
}
}
{% endcapture %}
{% assign result = query | shopify %}
{% if event.preview %}
{% capture result_json %}
{
"data": {
"productVariants": {
"nodes": [
{
"id": "gid://shopify/ProductVariant/1234567890",
"sku": {{ skus_to_monitor[0] | json }},
"inventoryItem": {
"id": "gid://shopify/InventoryItem/1234567890",
"inventoryLevel": {
"quantities": [
{
"name": "available",
"quantity": {% if event.topic == "mechanic/user/trigger" %}5{% else %}4{% endif %}
}
]
}
}
},
{
"id": "gid://shopify/ProductVariant/2345678901",
"sku": {{ skus_to_monitor[0] | json }},
"inventoryItem": {
"id": "gid://shopify/InventoryItem/2345678901",
"inventoryLevel": {
"quantities": [
{
"name": "available",
"quantity": {% if event.topic == "mechanic/user/trigger" %}5{% else %}4{% endif %}
}
]
}
}
}
]
}
}
}
{% endcapture %}
{% assign result = result_json | parse_json %}
{% endif %}
{% for variant in result.data.productVariants.nodes %}
{% assign variants_by_sku[variant.sku]
= variants_by_sku[variant.sku]
| default: array
| push: variant
%}
{% endfor %}
{% if result.data.productVariants.pageInfo.hasNextPage %}
{% assign cursor = result.data.productVariants.pageInfo.endCursor %}
{% else %}
{% break %}
{% endif %}
{% endfor %}
{% comment %}
-- filter out unmatched SKUs and display an alert, but let task keep processing the matched SKUs
{% endcomment %}
{% assign unmatched_skus = array %}
{% assign skus_to_process = array %}
{% for sku in skus_to_monitor %}
{% if variants_by_sku[sku] == blank %}
{% assign unmatched_skus = unmatched_skus | push: sku %}
{% else %}
{% assign skus_to_process = skus_to_process | push: sku %}
{% endif %}
{% endfor %}
{% if unmatched_skus != blank %}
{% unless event.preview %}
{% action "echo"
__error: "One or more configured SKUs were not matched in this shop. Remove or correct these entries in the task configuration.",
unmatched_skus: unmatched_skus
%}
{% endunless %}
{% endif %}
{% log variants_by_sku: variants_by_sku %}
{% if event.topic == "mechanic/user/trigger" %}
{% comment %}
-- manual runs are used to record leveled inventory in the cache
{% endcomment %}
{% for pair in variants_by_sku %}
{% assign sku = pair[0] %}
{% assign variants = pair[1] %}
{% assign expected_inventory_quantity = variants[0].inventoryItem.inventoryLevel.quantities.first.quantity %}
{% for variant in variants %}
{% if variant.inventoryItem.inventoryLevel.quantities.first.quantity != expected_inventory_quantity %}
{% error %}
{{ "Expected all '" | append: sku | append: "' variants to have an available inventory quantity of " | append: expected_inventory_quantity | append: ", but not every variant is at this level. Ensure every variant is in sync, and try again." | json }}
{% enderror %}
{% endif %}
{% endfor %}
{% endfor %}
{% for pair in variants_by_sku %}
{% assign sku = pair[0] %}
{% assign variants = pair[1] %}
{% assign cache_key = task.id | append: "-" | append: sku | sha256 %}
{% action "cache", "set", cache_key, variants[0].inventoryItem.inventoryLevel.quantities.first.quantity %}
{% endfor %}
{% elsif event.topic contains "mechanic/scheduler/" %}
{% comment %}
-- process SKUs to see if any need adjustments
{% endcomment %}
{% assign inventory_adjustments = array %}
{% for sku in skus_to_process %}
{% assign cache_key = task.id | append: "-" | append: sku | sha256 %}
{% assign cached_inventory_quantity = cache[cache_key] %}
{% if event.preview %}
{% assign cached_inventory_quantity = 5 %}
{% endif %}
{% if cached_inventory_quantity == nil %}
{% error %}{{ "Missing a cached inventory quantity for SKU '" | append: sku | append: "'. Make sure all inventory is in sync across all of this task's monitored SKUs, then use the 'Run task' button to cache current inventory quantities." | json }}{% enderror %}
{% endif %}
{% assign total_delta = 0 %}
{% assign deltas = hash %}
{% for variant in variants_by_sku[sku] %}
{% assign deltas[variant.id] = variant.inventoryItem.inventoryLevel.quantities.first.quantity | minus: cached_inventory_quantity %}
{% assign total_delta = total_delta | plus: deltas[variant.id] %}
{% endfor %}
{% log sku: sku, total_delta: total_delta %}
{% for variant in variants_by_sku[sku] %}
{% assign delta_for_sync = total_delta | minus: deltas[variant.id] %}
{% if delta_for_sync != 0 %}
{% assign inventory_adjustment = hash %}
{% assign inventory_adjustment["inventoryItemId"] = variant.inventoryItem.id %}
{% assign inventory_adjustment["locationId"] = primary_location.admin_graphql_api_id %}
{% assign inventory_adjustment["delta"] = delta_for_sync %}
{% assign inventory_adjustments = inventory_adjustments | push: inventory_adjustment %}
{% endif %}
{% endfor %}
{% if total_delta != 0 %}
{% assign current_inventory_quantity = cached_inventory_quantity | plus: total_delta %}
{% action "cache", "set", cache_key, current_inventory_quantity %}
{% endif %}
{% endfor %}
{% if inventory_adjustments != blank %}
{% assign groups_of_inventory_adjustments = inventory_adjustments | in_groups_of: 250, fill_with: false %}
{% for group_of_inventory_adjustments in groups_of_inventory_adjustments %}
{% action "shopify" %}
mutation {
inventoryAdjustQuantities(
input: {
reason: "correction"
name: "available"
changes: {{ group_of_inventory_adjustments | graphql_arguments }}
}
) {
inventoryAdjustmentGroup {
reason
changes {
name
delta
quantityAfterChange
item {
id
sku
}
location {
name
}
}
}
userErrors {
code
field
message
}
}
}
{% endaction %}
{% endfor %}
{% endif %}
{% endif %}