How the catalogue works

The catalogue is the shared data a design references. You do not author it and nothing is copied into your file — you name entries from it, and the compiler resolves them.

catalogs:
  materials: std/lumber@1
  fixtures:  std/fixtures@1
  standards: std/standards@1

All three default to the bundled std/…@1, so this section is normally omitted.

Three families

Family	Ids look like	What an entry is
Materials	lumber.hardwood.s4s, sheet.plywood.birch	A stock family and the sizes it is actually milled in
Fixtures	fixtures.wood_screw.4x50	A solid, plus a machining recipe, plus design rules
Standards	standards.bed.slat_gap_max	A published number, with its citation

Species sit alongside materials: walnut, pine, white_oak and the rest carry the physical properties that solid-lumber families inherit.

Where each one is referenced from

materials:
  - id: rail_stock
    from: lumber.hardwood.s4s        # ← a material family
    species: walnut                  # ← a species
    thickness: 38
    width: 190

parameters:
  - id: mattress
    type: catalog_ref
    catalog: standards.mattress      # ← a standard, as a parameter
    value: us-queen

  - id: max_slat_gap
    type: length
    derived: standards.bed.slat_gap_max   # ← a standard, in an expression

joints:
  - id: cleat_to_rail_left
    fixture: fixtures.wood_screw.4x50     # ← a fixture

An id that does not exist is RES-005 or RES-009, and the finding lists what does — near misses first. Invented ids are the single most common way an LLM-authored design fails, so the failure is fast, specific and repairable rather than mysterious.

A material family is not a board

lumber.hardwood.s4s carries nine species, seven thicknesses and eleven widths. A design narrows it to one real board:

- id: post_stock
  from: lumber.hardwood.s4s
  species: walnut
  thickness: 75
  width: 75

A combination that is not milled is rejected, and the finding names the nearest two that are. The sizes are actual, never nominal — see Solid lumber.

A fixture is a machining recipe

This is the part that has no equivalent in any open woodworking library, and it is the reason hardware in a kaicad design is structural rather than decorative.

A fixture entry is:

1. A solid — a mesh or a couple of primitives, for the 3D view. Threads are never modelled; a smooth shank with a head is all a preview needs and a fraction of the triangles.
2. A machining recipe for its neighbours — what to cut in the part the fastener passes through, and what to cut in the part it goes into. Every hole in a compiled design comes from one of these.
3. The design rules it imposes — minimum edge distance, end distance, engagement, spacing, and whether it may go into end grain.
4. The dimensions it determines — a counterbore diameter, a cross-dowel depth.

machining:
  through_from: opposite
  through_part:
    - { kind: hole, diameter: 9, through: true }
    - { kind: counterbore, diameter: 18, depth: 8 }
  receiving_part:
    - { kind: hole, diameter: 9, depth: 100, axis: from_mating_face }
    - { kind: cross_hole, diameter: 12.5, at_depth: 80, depth: through_width }

The joint supplies the position; the fixture supplies the operations. You never write a pilot hole.

through_from is the field that catches people

Value	Means
mating	The fastener enters on the face that touches the other part — a screw through a cleat into a rail.
opposite	It enters on the far face — a bed bolt through a post from the outside, counterbore and head away from the rail.

Getting this wrong puts an 18 mm counterbore in the wrong surface and runs the clearance hole down the length of the board instead of across it. That design compiles and exports cleanly and cannot be built, which is why the fixture declares the direction rather than the joint guessing it. Your side of it is the joint’s through: part.

N * d rules

Some rules are written against the fixture’s nominal diameter:

rules:
  min_edge_distance: "3 * d"
  min_end_distance: "6 * d"
  min_spacing: "8 * d"

d is nominalDiameter. For a 4 mm screw that is 12 mm from an edge, 24 mm from an end and 32 mm between screws — the usual shop rules, applied by something that does not forget them.

A standard carries its source

- id: standards.bed.slat_gap_max
  kind: limit
  source: >
    Consensus of mattress-maker warranty conditions (Tempur, Sealy, IKEA and
    others all specify 75–80 mm); 76 mm is the most commonly stated figure.
  limit: { value: 76, direction: max, unit: mm }

source is required. An uncited number is an opinion, and the whole value of this validator is that it is not giving you opinions — when a report says a slat gap is too wide, it can say who says so.

Four kinds:

Kind	Shape	Example
dimension_set	Named sizes	standards.mattress.us-queen
limit	One bound, max or min	standards.bed.slat_gap_max
range	min, max, typical	standards.table.dining_height
rule	A requirement in prose, with a condition	standards.bed.centre_rail_required

A dimension_set used as a catalog_ref parameter behaves like the entry it names, so mattress.width reads naturally. A limit or a range field can be referenced directly in an expression.

What is in it

Page
Species	Fourteen timbers, with density, stiffness, movement and screw holding
Solid lumber	Three families, and every milled thickness and width
Sheet goods	Plywood, MDF and veneered MDF, with sheet sizes
Wood screws	Six sizes, with pilot, clearance and countersink
Bed bolts	Four sizes, and the five holes each one cuts
Knock-down hardware	Threaded inserts, cam locks, dowels, shelf pins
Cable management	Grommets and tie mounts
Standards	Mattress sizes, slat gaps, ergonomic ranges — each cited

Coming in v2: concealed hinges, side-mount and undermount slides, pulls and knobs, levelling feet, and figure-8s, Z-clips and buttons.

Licence

The catalogue is CC0-1.0 — public domain, and meant to be adopted elsewhere. It encodes published standard dimensions and cites vendor part numbers; it never redistributes vendor CAD files. See Licences.

If you build something else that needs to know that an M8 bed bolt wants a 12.5 mm cross bore at 80 mm, take the data. That is what it is for.