PC Builder

The PC Builder lets shoppers put a complete PC together on one page. They pick a part for each slot from your own collections, Kelvin checks every pick against the rest of the build with specs you keep in product metafields, works out how much power the build needs, and adds the whole build to the cart in one step. It runs entirely in your store: no app, no account and no outside service.

A preset build loaded in the PC Builder — The message after loading a preset. 2. The parts, slot by slot. 3. The build summary with the power estimate

What shoppers get

Slots. One row per kind of part: Processor, Motherboard, Memory, Graphics card, Storage, Case, CPU cooler, Power supply, Case fans, Monitor, and Keyboard, mouse and dock. Shoppers fill them in any order.

Processor, Motherboard, Memory, Storage, Case and Power supply are required.
A graphics card is required unless the chosen processor has integrated graphics, and a CPU cooler unless the processor comes with one. Until a processor is chosen, both count as required.
The summary counts them, such as 5 of 8 required parts, and Add build to cart names the parts still missing.

The parts list. Choose or Change opens the slot’s parts from the side.

A search box (name, brand, product type and spec line), Sort (Compatible first; Price, low to high; Price, high to low; Name) and a Compatible only switch.
With Compatible only on, parts that would break the build are hidden behind a Show 2 incompatible parts and why button. With it off, they stay in the list, dimmed, with up to two reasons and a disabled Incompatible button.
Each row shows the price, the difference to the part it would replace, a menu for products with several variants, and Out of stock or Pre-order.

The parts list for the case slot — The parts list with Compatible only off: each case that does not fit says why

Checks at three levels. Every pick is checked in both directions against the parts already chosen. Each message names the parts and the numbers and has an icon and a word, on the slot and in the summary.

Level	What it means	What happens
Error	The parts cannot work together, for example a processor and a motherboard with different sockets.	Add build to cart stays disabled, with Fix the error above to add this build under it.
Check	It works, with a catch worth reading, for example a power supply with little headroom.	The first press of Add build to cart lists the checks under Before you add it, with Add anyway and Review the build (setting Ask once before adding a build that has checks).
Note	Good to know, for example a memory profile to turn on, or a part without specs.	Nothing: the build can be added.

Fix buttons. Under each error and check, Kelvin offers an in-stock part for one of the slots involved: the one with the smallest price change that clears the problem without adding a new error. It reads Use (part) with the price difference, or Add (part) with its price when the slot is empty. Pre-orders are offered last. A fix is never applied without a click.

An error, two checks and a note in the build summary — An error with its fix, two checks and a note: Add build to cart stays disabled until the error is fixed

The rules. These are all the checks. The metafields they read are in the tables further down.

Level	Check
Error	The processor socket differs from the motherboard socket.
Error	The motherboard does not list the processor generation.
Check	The motherboard needs a BIOS update for the processor generation.
Error	The memory type differs from the motherboard, or the processor does not take it.
Error	More memory modules than the motherboard has slots.
Error	More memory than the motherboard or the processor supports (the lower limit counts).
Note	The memory is rated faster than the build officially supports (turn on EXPO or XMP).
Error	More M.2 drives than M.2 slots, or more SATA drives than SATA ports.
Error	The graphics card is longer than the case allows, or takes more slots than the case has.
Check	The graphics card fits with less than 10 mm to spare.
Error	The air cooler is taller than the case allows, or the liquid cooler radiator does not fit the case.
Error	The cooler does not list the processor socket.
Check	The cooler is rated for less heat than the processor can draw at peak.
Check	The memory is taller than the room the air cooler leaves above the slots.
Error	The case does not take the motherboard size, or the power supply size.
Error	A back-connect motherboard in a case without a back-connect layout.
Error	The power supply is below the estimated load.
Check	The power supply is below the recommended size.
Note	The power supply is more than two and a half times the load.
Check	The graphics card needs a 12V-2x6 cable and the power supply has none (a Note when the adapter is in the box).
Check	The graphics card needs more PCIe 8-pin cables than the power supply has.
Check	The case has a front USB-C port and the motherboard has no header for it.
Check	The processor has no cooler in the box and no cooler is chosen.
Check	The processor has no integrated graphics and no graphics card is chosen.
Note	A part has no specs, the shopper uses their own part, a part is a pre-order, or a part has your own compatibility note.

The power estimate. The summary shows the Estimated load, the Recommended power supply and the Selected one on a meter, with What this adds up listing every input. See The power estimate below. Presets. Preset builds show as cards above the parts, under Start from a build. Start from this build replaces the current build with the preset’s parts and says Loaded the (name) build. Change any part you like. An Undo button brings the previous build back. Share and print.

Copy link copies the page address with the build in it. Anyone who opens it sees the same parts, the assembly choice and the slots marked I already have one.
Copy as text copies a plain parts list with prices, the total, the power estimate, every check and the link.
Print prints the parts and the summary without the rest of the page.

Autosave and saved builds.

The build in progress is saved on the shopper’s device after every change and comes back on their next visit. The home page’s PC Builder entry links back to it.
Save build keeps a named copy (up to 40 characters) under Saved builds, with Load and Delete. Load replaces the current build, with Undo. Shoppers can keep 10 saved builds; for an eleventh they are asked to delete one.
Start over asks for a second press within four seconds, then offers Undo.

Saved builds on the PC Builder page — Saved builds, kept in the shopper's browser on that device

Add the whole build to the cart. Add build to cart sends every part in one request, as normal cart lines that share a build name, and opens the cart drawer (or the cart page, with Theme settings → Cart → Cart type set to Page).

Pressing it again for the same build in the same visit asks This build is already in your cart, with Add another and Cancel.
If Shopify refuses a part (sold out, or above a quantity limit), none of that build’s lines stay in the cart, and the message names the part when Shopify says which one it was.

On phones. Below 1000 px the summary moves under the parts. A bar pinned to the bottom of the screen shows the total, the status (such as Build ready or 1 error) and Review build, which jumps to the summary. Below 750 px the parts list fills the screen.

The PC Builder on a phone — On a phone, the bottom bar keeps the total and the status in view

Set it up

1. Create the page. In the Shopify admin go to Online Store → Pages → Add page, name it PC Builder (or anything you like), choose pc-builder under Theme template and save. The template holds the PC Builder section with all 11 Slot blocks. 2. Choose it in Theme settings. In the theme editor open Theme settings → PC Builder and pick the page under PC Builder page. Every link to the builder uses this page: the header’s PC Builder link (Header → Show the PC Builder link), the PC Builder entry on the home page, Add to a PC build on product pages, Edit build in the cart and the saved builds on the account page. 3. Put each kind of part in a collection. Create one collection per slot, such as Processors, Motherboards, Memory, Graphics cards, Storage, Cases, Power supplies and Cooling. Automated collections by product type are the easiest to keep up to date. Parts can be in other collections too; the builder only looks at the slot collections. 4. Connect the slots. Choose Pages → pc-builder in the theme editor’s page selector, select the PC Builder section and open each Slot block:

Setting	What it does
Slot	Which row the block is. Each slot is used once; a second block with the same slot is ignored. Links to builds name parts by this slot.
Parts collection	The collection the parts list shows.
Only parts with this tag	Optional. Narrows the collection to products with this tag, for a collection that holds parts for two slots.
Label, Help text	Leave empty for the standard name (such as Processor) and hint.
Required	Standard for this slot (as described above), Always or Never.
Offer I already have this	Adds a checkbox such as I already have one while the slot is empty. Ticked, the slot counts as filled and that part is not checked. On in the template for the graphics card, storage, case, CPU cooler and power supply.
Most parts in this slot	1 to 6. The template allows 2 memory kits, 4 drives, 3 fan packs, 2 monitors and 4 accessories.
Spec columns	Metafield keys from the specs namespace, separated by commas, shown as the spec line under each part, such as cores, socket. Keys from Theme settings → Product cards → Spec rows and the PC Builder keys below both work.

Delete the Slot blocks for parts you do not sell, or leave their collection empty.

How parts find their slot. Slots match products by collection only: a slot lists the products of its Parts collection, narrowed to Only parts with this tag when that is filled. A part that arrives from a preset, a link or a product page goes into the first slot, in block order, whose collection (and tag) holds it. Kelvin does not read slot tags by itself: tags such as slot:cooler on the demo store are only there for Only parts with this tag, and any tag works. Type the tag exactly as it is on the products.

5. Add the build specs. Create the metafield definitions in Build specs below and fill them on your parts. Without them the builder still works as a plain parts picker, and tells shoppers the parts were not checked. 6. Tag the parts. Products with the tag in Theme settings → PC Builder → Parts tag (default pc-part) show the PC compatibility box on their product page, with their build specs and Add to a PC build. The tag does not decide what the builder lists; the slot collections do. 7. Review the section settings.

Setting	What it does
Show compatible parts only by default	Starts the parts list with Compatible only on (default). Shoppers can switch it off to see every part with the reason.
Out of stock parts	Show as unavailable (listed with Out of stock and no Choose button) or Hide.
Block parts without build specs	Off by default. When on, a part without its slot’s main spec cannot be chosen: socket for processors and motherboards, memory_type for memory, gpu_length_mm for graphics cards, storage_kind for storage, form_factors for cases, socket_support for coolers and psu_w for power supplies (marked Main in the tables below). It shows Specs missing, and links, presets and saved builds leave it out.
Show the power estimate	Shows the meter and turns the power supply size checks on or off.
Power supply headroom, Allowance for everything else, Motherboard allowance	The numbers in the power estimate (defaults 30%, 30 W and 40 W).
Assembly product, Select assembly for new builds, Assembly description	Your build service. See Assembly service.
Build discount note	A line of text in the summary. It does not create a discount.
Ask once before adding a build that has checks	On by default: the Before you add it step. Errors always block the add.
Show saved builds, Show how the checks work	The two parts under the builder. How the checks work explains the three levels and, with the power estimate on, the formula with your numbers.

Build specs (metafields)

The checks read product metafields in the namespace specs. Create each definition once in Settings → Custom data → Products (Settings → Metafields and metaobjects → Products in newer admins): Add definition, Namespace and key such as specs.socket, and the type below. Then fill them on each part, one product at a time or in bulk with the bulk editor. How values are read.

Numbers are plain numbers in the unit the key names: _mm millimeters, _w watts, _gb gigabytes, _mhz megatransfers per second (the MT/s on memory kits).
Text is compared without regard to capitals, spaces or punctuation, so AM5 matches am5 and Micro-ATX matches micro ATX. Common short forms are understood: mATX and uATX for Micro-ATX, ITX and mITX for Mini-ITX, Extended ATX for E-ATX, liquid or water for aio, reverse for back_connect.
A list can be a list metafield or one line with values separated by commas.
Use the same spelling on both sides of a rule: if processors say LGA1851, motherboards and coolers must say LGA1851 too.

When a value is missing. A missing value never causes an error: the rule that needs it is skipped. When a part lacks its slot’s main spec (marked Main below), the build shows a note: Specs missing for (part), so its compatibility is not checked. When no part in the build has any build specs, one note says These parts have no build specs, so compatibility is not checked. All parts

Key	Type	What it does
`specs.summary`	Single line text	The spec line under the part in the builder, such as 8 cores / 16 threads · 5.0 GHz boost. Replaces the slot’s Spec columns.
`specs.tdp_w`	Integer	Watts for the power estimate: the processor’s base power (used when it has no peak power) and the graphics card’s rated power. On a motherboard, drive or cooler it replaces the standard allowance.
`specs.compat_note`	Single line text	Your own note, such as Needs BIOS 1.2 for Ryzen 9000. Shown as a Note whenever the part is in a build, and in the product page’s compatibility box.

Processor

Key	Type	What it does
`specs.socket`	Single line text	Main. Must match the motherboard socket (Error) and be in the cooler’s socket list (Error).
`specs.generation`	Single line text	Such as Ryzen 9000. Must be in the motherboard’s `cpu_generations` (Error). In its `bios_update_generations` it gives a BIOS Check.
`specs.memory_types`	Single line text, list	Memory types it takes, such as DDR5. Memory of another type is an Error.
`specs.max_memory_gb`	Integer	Most memory in GB. More is an Error.
`specs.max_memory_speed_mhz`	Integer	Officially supported memory speed. Faster memory gives a Note.
`specs.peak_power_w`	Integer	Peak draw in watts, for the power estimate and the cooler rating check. Without it, `tdp_w` is used.
`specs.has_igpu`	True or false	True makes the graphics card optional. False with no card chosen gives a Check.
`specs.includes_cooler`	True or false	True makes the CPU cooler optional. False with no cooler chosen gives a Check.

Motherboard

Key	Type	What it does
`specs.socket`	Single line text	Main. Must match the processor socket.
`specs.cpu_generations`	Single line text, list	Processor generations it runs. A processor generation not listed is an Error.
`specs.bios_update_generations`	Single line text, list	Generations that need a BIOS update first: a Check.
`specs.form_factor`	Single line text	Board size, such as ATX. Must be in the case’s `form_factors` (Error).
`specs.memory_type`	Single line text	Such as DDR5. Memory of another type is an Error.
`specs.memory_slots`	Integer	More memory modules than slots is an Error.
`specs.max_memory_gb`	Integer	Most memory in GB. The lower of the motherboard and processor limits counts.
`specs.max_memory_speed_mhz`	Integer	Supported memory speed. The lower of the motherboard and processor speeds counts.
`specs.m2_slots`	Integer	More M.2 drives than slots is an Error.
`specs.sata_ports`	Integer	More SATA SSDs and hard drives than ports is an Error.
`specs.connector_layout`	Single line text	`standard` or `back_connect`. A back-connect board needs a case with `back_connect` or `both` (Error).
`specs.front_usbc_header`	True or false	False, in a case with a front USB-C port, gives a Check.
`specs.chipset`	Single line text	Not checked. Available as a Spec column.

Memory (one kit)

Key	Type	What it does
`specs.memory_type`	Single line text	Main. Such as DDR5. Must match the motherboard and be in the processor’s `memory_types` (Error).
`specs.module_count`	Integer	Modules in the kit. All kits together must fit the motherboard slots (Error; checked when every kit has it). 5 W each in the power estimate, one per kit when empty.
`specs.capacity_gb_total`	Integer	GB in the kit. All kits together must stay within the memory limit (Error; checked when every kit has it).
`specs.speed_mhz`	Integer	Rated speed in MT/s, compared with the supported speed (Note).
`specs.module_height_mm`	Integer	Module height, compared with an air cooler’s memory clearance (Check).

Graphics card

Key	Type	What it does
`specs.gpu_length_mm`	Integer	Main. Card length. Longer than the case allows is an Error; less than 10 mm to spare is a Check.
`specs.gpu_slot_width`	Decimal	Slots the card takes, such as 2.5. More than the case’s expansion slots is an Error.
`specs.tdp_w`	Integer	Rated power in watts, for the power estimate.
`specs.recommended_psu_w`	Integer	The card maker’s minimum power supply. The recommended size is never below it.
`specs.gpu_12v_2x6`	True or false	True when the card uses a 12V-2x6 power cable.
`specs.adapter_included`	True or false	True when an adapter comes with the card. It turns the 12V-2x6 Check into a Note.
`specs.gpu_pcie_8pin_count`	Integer	PCIe 8-pin cables the card needs. More than the power supply has is a Check.

Storage

Key	Type	What it does
`specs.storage_kind`	Single line text	Main. `m2`, `sata_ssd` or `hdd` (M.2 works too). M.2 drives count against the motherboard’s M.2 slots, SATA SSDs and hard drives against its SATA ports. 5 W per drive in the power estimate, 8 W per hard drive.
`specs.capacity_gb`	Integer	Not checked. Available as a Spec column, shown in GB.

Power supply

Key	Type	What it does
`specs.psu_w`	Integer	Main. Wattage, checked against the power estimate and shown as Selected on the meter.
`specs.psu_form_factor`	Single line text	Such as ATX or SFX. Must be in the case’s `psu_form_factors` (Error).
`specs.psu_12v_2x6_count`	Integer	Native 12V-2x6 connectors. 0 triggers the 12V-2x6 message for cards that need one; leave it empty if you do not know.
`specs.psu_pcie_8pin_count`	Integer	PCIe 8-pin cables, compared with what the card needs (Check).

Case

Key	Type	What it does
`specs.form_factors`	Single line text, list	Main. Motherboard sizes it takes, such as ATX, Micro-ATX, Mini-ITX.
`specs.max_gpu_length_mm`	Integer	Longest graphics card it fits.
`specs.expansion_slots`	Integer	Expansion slots, compared with the card’s slot width.
`specs.max_cooler_height_mm`	Integer	Tallest air cooler it fits.
`specs.radiator_sizes_mm`	Integer, list	Radiator sizes it mounts, such as 240, 280, 360. A liquid cooler with another size is an Error. Used instead of `max_radiator_mm` when filled.
`specs.max_radiator_mm`	Integer	Largest radiator, used when there is no size list.
`specs.psu_form_factors`	Single line text, list	Power supply sizes it takes, such as ATX.
`specs.connector_layout`	Single line text	`standard`, `back_connect` or `both`.
`specs.front_usbc`	True or false	True when the case has a front USB-C port.
`specs.fans_included`	Integer	Fans that come with the case, 3 W each in the power estimate.

CPU cooler

Key	Type	What it does
`specs.cooler_type`	Single line text	`air` or `aio` (liquid). Decides which fit checks apply, and counts 5 W or 15 W in the power estimate.
`specs.socket_support`	Single line text, list	Main. Sockets it fits, such as AM5, LGA1851. A processor socket not listed is an Error.
`specs.cooler_height_mm`	Integer	Air coolers: height, compared with the case (Error).
`specs.radiator_size_mm`	Integer	Liquid coolers: radiator size, compared with the case (Error).
`specs.max_tdp_w`	Integer	Heat it is rated for in watts. Below the processor’s peak draw is a Check.
`specs.ram_clearance_mm`	Integer	Air coolers: room above the memory slots. Taller memory is a Check.

Case fans

Key	Type	What it does
`specs.fan_count`	Integer	Fans in the pack, 3 W each in the power estimate. Without it a pack counts as one fan.

Monitors and keyboards, mice and docks have no checks and are not counted in the power estimate. Their Spec columns can use any key from Spec rows.

On products with the Parts tag, the same specs show in the product page’s PC compatibility box, so shoppers see a part’s socket, memory and power figures before they open the builder.

The power estimate

Kelvin adds up an estimated load from the parts in the build:

processor: peak_power_w, or tdp_w without it;
graphics card: tdp_w;
motherboard: its tdp_w, or Motherboard allowance (default 40 W);
memory: 5 W per module;
drives: 5 W each, 8 W per hard drive, or the drive’s tdp_w;
CPU cooler: 5 W for air, 15 W for liquid, or the cooler’s tdp_w;
fans: 3 W per fan, counting the case’s fans_included and each pack’s fan_count;
Allowance for everything else (default 30 W).

Monitors and accessories are not counted. The two allowances are added once the build has any part besides monitors and accessories. The recommended size is the load plus Power supply headroom (default 30%), rounded up to the next 50 W, and never below the graphics card’s recommended_psu_w. For example, a processor that peaks at 162 W, a 220 W graphics card, the 40 W motherboard allowance, two memory modules (10 W), one drive (5 W), an air cooler (5 W), three case fans (9 W) and 30 W for everything else make 481 W. Plus 30% is 625 W, rounded up to 650 W. The selected power supply is then checked: below the load is an Error, below the recommended size a Check that names the headroom and the size to choose, and more than two and a half times the load a Note that a smaller unit would do.

The power estimate in the build summary — Estimated load, recommended and selected power supply, with What this adds up open

Untick Show the power estimate to hide the meter and drop the power supply size checks. The figure is always called an estimate, and How the checks work, under the builder, explains the formula with your own numbers.

Presets

Add Preset build blocks to the PC Builder section: Name, Note, Image (empty uses the first part’s photo) and up to 12 Parts. Each part goes into the first slot whose collection holds it. The card shows the sum of the parts’ current prices, the number of parts and a line naming the processor, graphics card and memory. When a shopper loads a preset, parts that are sold out, in no slot’s collection, or more than a slot allows are left out and named after Left out, not in any parts list. Link to a preset. Add ?preset= and the Preset build block’s ID to the PC Builder page address, for example /pages/pc-builder?preset=preset-sweet. It loads the preset as its Start from this build button does, with Undo to the shopper’s previous build. A block ID that starts with preset- also works without that prefix, so ?preset=sweet loads preset-sweet. The link is ignored when it also carries a build (?b=, ?add= or ?parts=). Find the block ID. The theme editor does not show it. Go to Online Store → Themes, open the theme’s … menu, choose Edit code and open templates/page.pc-builder.json: each preset is a block of type preset, and the name in front of it is its ID, next to the title you gave it. The ID stays the same while the block exists; if you delete a block and add a new one, update your links.

A ?preset= link follows the block, so changing the preset’s parts in the theme editor changes what the link loads. A Copy link address (?b=) keeps the exact parts it was made with. The home page’s PC Builder entry has its own Preset build blocks and links them for you.

Links into the builder

Every build lives in the page address, so any link can open the builder with parts in it. Parts are named by their variant ID: in the admin, open the product, then the variant; the ID is the number at the end of the address.

Link	What it does
`?b=cpu.41234567890,memory.41234567891x2`	A whole build: the slot key, a dot and the variant ID, with `x` and a count for more than one. Slot keys: `cpu`, `board`, `memory`, `gpu`, `storage`, `case`, `cooler`, `psu`, `fans`, `monitor`, `accessory`. Copy link and Edit build in the cart make these.
`&own=gpu,case`	Slots marked I already have one (only slots that offer it).
`&asm=1`	Assembly ticked (needs an Assembly product).
`?add=41234567890`	Adds one part to the shopper’s build in progress, in the first slot whose collection holds it. If that slot is full, it replaces the slot’s first part. Add to a PC build on product pages uses it.
`?parts=41234567890,41234567891`	Starts a new build from these parts (up to 24), each in its slot, with Undo to get the previous build back. The home page presets use it.
`?preset=preset-sweet`	Loads the Preset build block with that ID (see Presets). Ignored when the link has `?b=`, `?add=` or `?parts=`.

A link with a build in it replaces the shopper’s build in progress; their saved builds are kept. Parts that are sold out or no longer in their slot’s collection are left out with a message, and a part in no parts list is not added (That part is not in any of the builder’s parts lists, so it was not added.).

Builds in the cart

Each part is a normal cart line, and every line of one build carries three line item properties:

Property	Who sees it	Value
`Build`	Shoppers in the cart and at checkout; you on the order	The build name, such as PC build K7Q2MX. The same on every line of the build.
`_Build`	Hidden from shoppers; you on the order	The build ID, such as k7q2mx.
`_Slot`	Hidden from shoppers; you on the order	The slot, such as cpu or psu, or service for the assembly line.

The cart drawer and the cart page group a build’s lines under PC build and its name, with the number of lines and the build total, after the other lines.

A line under the group says Assembled and stress-tested before it ships. when the build has the assembly line, or Shipped as parts. Add assembly in the PC Builder. when it does not. Change these words in Edit default theme content if your service differs.
Edit build opens the builder with the build’s parts (and assembly). Remove build takes all its lines out of the cart.
Each line keeps its own quantity buttons and Remove.

A PC build grouped in the cart — The build name, its lines and total. 2. Edit build and Remove build

Editing a build and adding it again adds a second build. Shoppers remove the first one with Remove build. On the order, the Build name on each line tells your team which parts go together.

Assembly service

Create a product for your build fee, such as PC assembly, priced at what you charge, and choose it in the PC Builder section’s Assembly product. The summary then offers a checkbox, Add (product) for (price), with your Assembly description under it, for example: We build it, update the BIOS and test it for 24 hours.

Select assembly for new builds ticks it in advance.
When ticked, the assembly is one more line of the build, with _Slot set to service.
If the product is sold out, the checkbox is hidden, so set it not to track inventory.
Leave Assembly product empty to sell parts only.

Build discount note adds a line of text to the summary. It does not create a discount: first create an automatic discount in Discounts, for example 5% off orders with 5 or more items, then describe it here. The summary’s Sale savings included line only counts compare-at prices.

Elsewhere in Kelvin

Home page: the PC Builder entry section has a start button, its own presets, and a Continue your build: 7 parts, (total) link to the shopper’s build in progress.
Product pages: on products with the Parts tag, the PC compatibility block of Product information lists the build specs the product has, its specs.compat_note, and Add to a PC build (block setting Show Add to a PC build). The button opens the builder with the selected variant, when it is in stock and the PC Builder page is chosen.
Header: Show the PC Builder link and PC Builder link label in the Header section.
Account page: the saved builds from this device, each with Open in PC Builder.
Cart: grouped builds with Edit build and Remove build.

The PC compatibility box on a product page — The PC compatibility box with Add to a PC build

Limits

Everything happens in the shopper’s browser and your store. Parts, prices and stock come from your own collections; no request goes to an outside service and no app is needed.
Builds are not stored in Shopify or in a customer account. The build in progress and up to 10 saved builds stay in the browser on that device: another device, another browser or cleared browsing data starts empty. Shoppers share a build with Copy link.
The checks cover only the rules above, and only with the specs you fill in. They cannot know about anything that is not in your metafields, and the power figure is an estimate, not a measurement.
A build is a set of normal cart lines, not one product: stock, prices, taxes and discounts work per part, and Shopify charges the current price at checkout. Nothing is reserved while a shopper builds.
Each slot lists up to 500 products and up to 25 variants per product. Parts lists are kept in the browser tab for 10 minutes, so a new price or stock level can take that long to appear in the list.
The builder never swaps a part on its own and never adds anything to the cart without Add build to cart.

Troubleshooting

A slot says No parts in this category yet. Its Slot block has no Parts collection, the collection is empty, or Only parts with this tag matches no product.
A preset or a link leaves a part out. The part is sold out, in no slot’s collection, or missing the slot’s tag.
Every part says Specs missing. Check that the namespace is specs and that the key is spelled exactly, such as specs.socket.
Two parts that fit are marked incompatible. Compare the values on both sides: socket, memory type and size names must match (capitals and spaces do not matter).
A shopper lost a build. Builds live in the browser where they were made. Ask for the Copy link address, or look at the Build name on their order.

In the theme editor

PC Builder settings — The PC Builder page and the parts tag: 1 Theme settings · 2 PC Builder

Getting started

Theme settings

Header and footer

Home page

PC Builder and compare

Product page

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What shoppers get

Set it up

Build specs (metafields)

The power estimate

Presets

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Builds in the cart

Assembly service

Elsewhere in Kelvin

Limits

Troubleshooting

In the theme editor

​What shoppers get

​Set it up

​Build specs (metafields)

​The power estimate

​Presets

​Links into the builder

​Builds in the cart

​Assembly service

​Elsewhere in Kelvin

​Limits

​Troubleshooting

​In the theme editor

What shoppers get

Set it up

Build specs (metafields)

The power estimate

Presets

Links into the builder

Builds in the cart

Assembly service

Elsewhere in Kelvin

Limits

Troubleshooting

In the theme editor