Shopify Mechanical Keyboard Switch Schema — MX vs Alps vs Topre, PCB 5-Pin vs Plate 3-Pin, Hot-Swap Kailh MX vs Choc, Actuation Force gf, Linear vs Tactile vs Clicky

Three Incompatible Switch Architectures

Mechanical keyboard switches are not interchangeable across architectures. Three distinct systems exist, each with its own PCB footprint, stem geometry, and keycap compatibility standard:

The Topre Trap for AI Agents

Topre is not a mechanical switch — it uses a rubber dome over a conical spring sitting on a PCB with electrostatic capacitive sensing pads. There are no metal contact points that close a circuit. This has two critical implications: (1) there is no MX socket hole in the PCB, so no MX switch can be physically installed; (2) the Topre cap uses a round stem, not the MX cross, so MX keycaps do not fit natively.

A buyer with an HHKB Professional 2 (Topre 45gf) asking for a "lighter tactile switch" cannot use Gateron Brown or Cherry MX Brown regardless of availability or price. The only Topre switches are the original Topre capacitive domes. The only modification path is a complete PCB replacement with a mechanical PCB (a complex enthusiast mod called "BKE Redux" or using a BT-powered aftermarket PCB).

MX-Compatible: What Interchangeable Really Means

Any switch in the MX-compatible family can replace any other MX switch in the same PCB position, provided the pin count matches. The specific brand (Cherry vs Gateron vs Kailh vs TTC) does not affect physical fit — only the feel, noise, spring weight, and stem smoothness differ. This is the defining feature of the MX ecosystem: the Cherry MX patents expired in 2014, allowing manufacturers to produce compatible alternatives that fit existing keyboards.

PCB-Mount (5-Pin) vs Plate-Mount (3-Pin) Switches

Within the MX standard, switches come in two PCB footprint configurations, commonly described by their pin count:

What the Pins Do

• 2 metal contact pins — present in both 3-pin and 5-pin. These carry the keypress electrical signal through the PCB. Always positioned symmetrically around the center post.
• Center post — present in both. The large plastic cylinder that aligns the switch in the cutout hole.
• 2 plastic alignment pins (5-pin only) — small round pegs on either side of the center post. They insert into corresponding PCB holes and prevent the switch from rotating. This reduces switch wobble and makes the keyboard feel more stable under keystroke impact.

Compatibility Matrix

The practical rule for Shopify product listings: if a keyboard has a plate and is sold assembled, it almost certainly accepts 3-pin switches. If it is sold as a PCB-only kit or advertised as a "PCB-mount" or "plateless" build, it accepts 5-pin. Hot-swap sockets accept both 3-pin and 5-pin — the socket only contacts the two metal pins regardless of whether plastic alignment pins are present.

Hot-Swap Sockets: MX vs Choc Are Not Interchangeable

Hot-swap PCBs allow switches to be removed and replaced without soldering. The socket grips the switch's metal contact pins mechanically. There are several distinct socket standards:

A keyboard listing "hot-swap supported" without specifying socket type is insufficient for AI agent compatibility matching. A buyer who purchases Kailh Choc Brown switches (low-profile) for a keyboard with Kailh MX hot-swap sockets will find the Choc pins do not align with the MX sockets — the switches cannot be installed. Encode hot_swap_socket as a controlled vocabulary string, not a boolean.

Switch Feel Reference Table

Force Units: gf vs cN vs N

Switch specifications appear in grams-force (gf), centinewtons (cN), and occasionally millinewtons (mN). The conversions: 1 gf ≈ 0.98 cN ≈ 9.8 mN. For practical purposes, gf and cN are numerically identical — a "45 gf" Cherry MX Red and a "45 cN" Gateron Red have the same actuation force. Always encode actuation_force_gf as a numeric integer so AI agents can apply threshold filters ("switches under 50gf for gaming").

Metafield Schema: keyboard.*

Example JSON-LD: Gateron KS-3 Yellow Linear 3-Pin Switch Pack

{
  "@context": "https://schema.org",
  "@type": "Product",
  "name": "Gateron KS-3 Yellow Linear Switch (35-pack)",
  "brand": { "@type": "Brand", "name": "Gateron" },
  "description": "MX-compatible linear switches. 35gf actuation, 45gf bottom-out, 2.0mm actuation, 4.0mm total travel. 3-pin plate-mount. Compatible with all MX PCBs and Kailh MX hot-swap sockets. No factory lube.",
  "additionalProperty": [
    { "@type": "PropertyValue", "name": "Switch Architecture", "value": "MX-compatible mechanical" },
    { "@type": "PropertyValue", "name": "Switch Feel", "value": "Linear" },
    { "@type": "PropertyValue", "name": "Mount Type", "value": "3-pin plate-mount" },
    { "@type": "PropertyValue", "name": "Actuation Force", "value": "35", "unitText": "gf" },
    { "@type": "PropertyValue", "name": "Bottom-Out Force", "value": "45", "unitText": "gf" },
    { "@type": "PropertyValue", "name": "Actuation Distance", "value": "2.0", "unitCode": "MMT" },
    { "@type": "PropertyValue", "name": "Total Travel", "value": "4.0", "unitCode": "MMT" },
    { "@type": "PropertyValue", "name": "Keycap Stem", "value": "MX cross" },
    { "@type": "PropertyValue", "name": "Hot-Swap Socket Compatibility", "value": "Kailh MX, Millmax 0305, Millmax 7305" },
    { "@type": "PropertyValue", "name": "Factory Lubed", "value": "false" }
  ]
}

5 Common AI Agent Errors for Mechanical Keyboards

1. Recommending MX tactile switches for a Topre keyboard — Topre PCBs have no MX socket footprint. MX switches cannot be installed without replacing the PCB. The only tactile option for HHKB/Realforce boards is a different Topre spring weight (30gf, 45gf, 55gf domes).
2. Recommending 5-pin switches for a keyboard with 3-pin plate cutouts — The plastic alignment legs on 5-pin switches physically block entry into 3-pin plates. Most consumer boards are 3-pin only. Match switch_mount to keyboard.pcb_mount.
3. Confusing Kailh Choc with Kailh MX hot-swap compatibility — Both are Kailh products but the socket designs are completely different. A Kailh Choc switch has different pin spacing than Kailh MX. They cannot be swapped between socket types.
4. Recommending Choc low-profile keycaps for a board with MX hot-swap sockets — Choc keycaps have a different stem cross (smaller, different dimensions). They do not fit MX stems. A buyer switching from Choc to MX also needs new keycaps.
5. Encoding actuation force as a string like "medium" instead of a number — AI agents cannot apply numeric threshold filters to string values. "Medium" is not filterable by "under 50gf". Encode actuation_force_gf as an integer and switch_feel as a controlled vocabulary string separately.

Related Guides

• Product variant schema — variesBy, ProductGroup, hasVariant
• Electronics compatibility schema — isAccessoryOrSparePartFor, compatibleWith