Mechanic is a development and ecommerce automation platform for Shopify. :)
Useful for custom orders, this task lets you offer multiple product and variant listings for what is ultimately the same stock. A purchase for a single product leads to the inventory for all other listings, of the same product type, being lowered by the amount ordered.
Runs Occurs when a user manually triggers the task and Occurs every 10 minutes. Configuration includes product types to monitor and only sync active products.
Useful for custom orders, this task lets you offer multiple product and variant listings for what is ultimately the same stock. A purchase for a single product leads to the inventory for all other listings, of the same product type, being lowered by the amount ordered.
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 product_types = options.product_types_to_monitor__array_required %}
{% assign only_sync_active_products = options.only_sync_active_products__boolean %}
{% assign primary_location = shop.locations[shop.primary_location_id] %}
{% if event.topic == "mechanic/user/trigger" %}
{% for product_type in product_types %}
{% assign available_quantites = array %}
{% assign cursor = nil %}
{% capture search_query -%}
location_id:{{ shop.primary_location_id }} product_type:{{ product_type | json }} managed:true
{%- endcapture %}
{% if only_sync_active_products %}
{% assign search_query = search_query | append: " product_status:active" %}
{% endif %}
{% for n in (0..200) %}
{% capture query %}
query {
productVariants(
first: 200
query: {{ search_query | json }}
after: {{ cursor | json }}
) {
pageInfo {
hasNextPage
endCursor
}
nodes {
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",
"inventoryItem": {
"inventoryLevel": {
"quantities": [
{
"name": "available",
"quantity": 30
}
]
}
}
},
{
"id": "gid://shopify/ProductVariant/2345678901",
"inventoryItem": {
"inventoryLevel": {
"quantities": [
{
"name": "available",
"quantity": 30
}
]
}
}
}
]
}
}
}
{% endcapture %}
{% assign result = result_json | parse_json %}
{% endif %}
{% for variant in result.data.productVariants.nodes %}
{% assign available_quantites = available_quantites | push: variant.inventoryItem.inventoryLevel.quantities.first.quantity %}
{% endfor %}
{% if result.data.productVariants.pageInfo.hasNextPage %}
{% assign cursor = result.data.productVariants.pageInfo.endCursor %}
{% else %}
{% break %}
{% endif %}
{% endfor %}
{% assign inventory_total = available_quantites | sum %}
{% assign expected_inventory_total = available_quantites.first | times: available_quantites.size %}
{% if inventory_total != expected_inventory_total %}
{% error
message: "Not all inventory levels are in sync. Manually ensure everything is at the same level, then try again.",
product_type: product_type,
expected_inventory_total: expected_inventory_total,
inventory_total: inventory_total,
available_quantites: available_quantites
%}
{% else %}
{% assign cache_key = "inventory_by_product_type:" | append: product_type | sha256 %}
{% action "cache", "set", cache_key, available_quantites.first %}
{% endif %}
{% endfor %}
{% elsif event.topic contains "mechanic/scheduler/" %}
{% for product_type in product_types %}
{% assign cache_key = "inventory_by_product_type:" | append: product_type | sha256 %}
{% assign inventory_old = cache[cache_key] %}
{% if event.preview %}
{% assign inventory_old = 30 %}
{% endif %}
{% if inventory_old == blank %}
{% error
message: "The inventory for this product type has not yet been cached. Manually synchronize the inventory for this product type and run this task manually per steps 2 and 3 in the task instructions.",
product_type: product_type
%}
{% endif %}
{% assign variants = array %}
{% assign available_quantites = array %}
{% assign cursor = nil %}
{% capture search_query -%}
location_id:{{ shop.primary_location_id }} product_type:{{ product_type | json }} managed:true
{%- endcapture %}
{% if only_sync_active_products %}
{% assign search_query = search_query | append: " product_status:active" %}
{% endif %}
{% for n in (0..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",
"inventoryItem": {
"id": "gid://shopify/InventoryItem/1234567890",
"inventoryLevel": {
"quantities": [
{
"name": "available",
"quantity": 25
}
]
}
}
},
{
"id": "gid://shopify/ProductVariant/2345678901",
"inventoryItem": {
"id": "gid://shopify/InventoryItem/2345678901",
"inventoryLevel": {
"quantities": [
{
"name": "available",
"quantity": 31
}
]
}
}
}
]
}
}
}
{% endcapture %}
{% assign result = result_json | parse_json %}
{% endif %}
{% assign variants = result.data.productVariants.nodes | concat: variants %}
{% if result.data.productVariants.pageInfo.hasNextPage %}
{% assign cursor = result.data.productVariants.pageInfo.endCursor %}
{% else %}
{% break %}
{% endif %}
{% endfor %}
{% for variant in variants %}
{% assign available_quantites = available_quantites | push: variant.inventoryItem.inventoryLevel.quantities.first.quantity %}
{% endfor %}
{% assign inventory_total_old = inventory_old | times: available_quantites.size %}
{% assign inventory_total_new = available_quantites | sum %}
{% assign inventory_total_diff = inventory_total_new | minus: inventory_total_old %}
{% assign inventory_new = inventory_old | plus: inventory_total_diff %}
{% log
inventory_old: inventory_old,
inventory_total_old: inventory_total_old,
inventory_total_new: inventory_total_new,
inventory_total_diff: inventory_total_diff,
inventory_new: inventory_new,
product_type: product_type,
variants_count: variants.size,
variants: variants
%}
{% if inventory_new == inventory_old %}
{% log "No inventory adjustments needed for this product type." %}
{% continue %}
{% endif %}
{% action "cache", "set", cache_key, inventory_new %}
{% assign inventory_adjustments = array %}
{% for variant in variants %}
{% 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"] = inventory_new | minus: variant.inventoryItem.inventoryLevel.quantities.first.quantity %}
{% assign inventory_adjustments = inventory_adjustments | push: inventory_adjustment %}
{% 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 %}
{% endfor %}
{% endif %}
true